from flask import Flask, render_template_string, request, redirect, url_for, jsonify, flash, abort, Response, session, g
import json
import os
import logging
import threading
import time
from datetime import datetime, timedelta
import pytz
from huggingface_hub import HfApi, hf_hub_download
from huggingface_hub.utils import RepositoryNotFoundError, HfHubHTTPError
import uuid
from decimal import Decimal, InvalidOperation, ROUND_HALF_UP
import functools
from functools import wraps
from collections import defaultdict
from urllib.parse import quote

app = Flask(__name__)
app.secret_key = os.urandom(24)
app.permanent_session_lifetime = timedelta(days=7)

ADMIN_PASS = os.getenv("ADMIN_PASS", "admin123")

DATA_DIR = 'pos_data'
os.makedirs(DATA_DIR, exist_ok=True)
os.makedirs(os.path.join(app.static_folder, 'product_images'), exist_ok=True)

INVENTORY_FILE = os.path.join(DATA_DIR, 'inventory.json')
TRANSACTIONS_FILE = os.path.join(DATA_DIR, 'transactions.json')
USERS_FILE = os.path.join(DATA_DIR, 'users.json')
KASSAS_FILE = os.path.join(DATA_DIR, 'kassas.json')
EXPENSES_FILE = os.path.join(DATA_DIR, 'expenses.json')
PERSONAL_EXPENSES_FILE = os.path.join(DATA_DIR, 'personal_expenses.json')
SHIFTS_FILE = os.path.join(DATA_DIR, 'shifts.json')
HELD_BILLS_FILE = os.path.join(DATA_DIR, 'held_bills.json')
CUSTOMERS_FILE = os.path.join(DATA_DIR, 'customers.json')
STOCK_HISTORY_FILE = os.path.join(DATA_DIR, 'stock_history.json')
LINKS_FILE = os.path.join(DATA_DIR, 'links.json')

DATA_FILES = {
    'inventory': (INVENTORY_FILE, threading.Lock()),
    'transactions': (TRANSACTIONS_FILE, threading.Lock()),
    'users': (USERS_FILE, threading.Lock()),
    'kassas': (KASSAS_FILE, threading.Lock()),
    'expenses': (EXPENSES_FILE, threading.Lock()),
    'personal_expenses': (PERSONAL_EXPENSES_FILE, threading.Lock()),
    'shifts': (SHIFTS_FILE, threading.Lock()),
    'held_bills': (HELD_BILLS_FILE, threading.Lock()),
    'customers': (CUSTOMERS_FILE, threading.Lock()),
    'stock_history': (STOCK_HISTORY_FILE, threading.Lock()),
    'links': (LINKS_FILE, threading.Lock()),
}

HF_TOKEN_WRITE = os.getenv("HF_TOKEN_WRITE", "YOUR_WRITE_TOKEN_HERE")
HF_TOKEN_READ = os.getenv("HF_TOKEN_READ", "YOUR_READ_TOKEN_HERE")
REPO_ID = "Kgshop/techbase"

ALMATY_TZ = pytz.timezone('Asia/Almaty')

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')

def get_current_time():
    return datetime.now(ALMATY_TZ)

class DecimalEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, Decimal):
            return str(obj)
        return json.JSONEncoder.default(self, obj)

def to_decimal(value_str, default='0'):
    if value_str is None or str(value_str).strip() == '':
        return Decimal(default)
    try:
        return Decimal(str(value_str).replace(',', '.').replace(' ', ''))
    except InvalidOperation:
        logging.warning(f"Could not convert '{value_str}' to Decimal. Returned {default}.")
        return Decimal(default)
        
def load_json_data(file_key):
    filepath, lock = DATA_FILES[file_key]
    filename = os.path.basename(filepath)
    with lock:
        try:
            hf_hub_download(
                repo_id=REPO_ID, filename=filename, repo_type="dataset", token=HF_TOKEN_READ,
                local_dir=DATA_DIR, local_dir_use_symlinks=False
            )
        except HfHubHTTPError as e:
            if e.response.status_code != 404:
                logging.error(f"HTTP error downloading {filename}: {e}")
        except Exception as e:
            logging.error(f"Unknown error downloading {filename}: {e}")

        try:
            with open(filepath, 'r', encoding='utf-8') as f:
                return json.load(f)
        except (FileNotFoundError, json.JSONDecodeError):
            return []

def save_json_data(file_key, data):
    filepath, lock = DATA_FILES[file_key]
    with lock:
        try:
            temp_file = filepath + ".tmp"
            with open(temp_file, 'w', encoding='utf-8') as f:
                json.dump(data, f, ensure_ascii=False, indent=4, cls=DecimalEncoder)
            os.replace(temp_file, filepath)
        except Exception as e:
            logging.error(f"Critical error saving {filepath}: {e}", exc_info=True)

@functools.lru_cache(maxsize=1)
def get_hf_api():
    if not HF_TOKEN_WRITE or HF_TOKEN_WRITE == "YOUR_WRITE_TOKEN_HERE":
        return None
    try:
        return HfApi()
    except Exception as e:
        logging.error(f"Error initializing HfApi: {e}")
        return None

def upload_db_to_hf(file_key):
    api = get_hf_api()
    if not api:
        return
    filepath, _ = DATA_FILES[file_key]
    if not os.path.exists(filepath):
        return
    try:
        filename = os.path.basename(filepath)
        commit_time = get_current_time().strftime('%Y-%m-%d %H:%M:%S %Z%z')
        api.upload_file(
            path_or_fileobj=filepath, path_in_repo=filename, repo_id=REPO_ID, repo_type="dataset",
            token=HF_TOKEN_WRITE, commit_message=f"Automated backup {filename} {commit_time}",
            run_as_future=True
        )
    except Exception as e:
        logging.error(f"Error initiating upload of {filepath}: {e}")

def periodic_backup():
    while True:
        time.sleep(1800)
        try:
            for key in DATA_FILES.keys():
                upload_db_to_hf(key)
        except Exception as e:
            logging.error(f"Error during scheduled backup: {e}", exc_info=True)
            
def find_item_by_field(data, field, value):
    for item in data:
        if isinstance(item, dict) and str(item.get(field)) == str(value):
            return item
    return None

def find_user_by_pin(pin):
    users = load_json_data('users')
    return find_item_by_field(users, 'pin', pin)

def format_currency_py(value):
    try:
        number = to_decimal(value)
        return f"{number:,.0f}".replace(",", " ")
    except (InvalidOperation, TypeError, ValueError):
        return "0"

def generate_receipt_html(transaction):
    has_discounts = any(to_decimal(item.get('discount_per_item', '0')) > 0 for item in transaction.get('items', []))
    delivery_cost = to_decimal(transaction.get('delivery_cost', '0'))
    note = transaction.get('note', '')

    if has_discounts:
        table_headers = """
        <th style="text-align: center; width: 5%;">№</th>
        <th style="text-align: left;">Наименование</th>
        <th style="text-align: right;">Кол-во</th>
        <th style="text-align: right;">Цена</th>
        <th style="text-align: right;">Скидка</th>
        <th style="text-align: right;">Сумма</th>
        """
        total_colspan = 5
    else:
        table_headers = """
        <th style="text-align: center; width: 5%;">№</th>
        <th style="text-align: left;">Наименование</th>
        <th style="text-align: right;">Кол-во</th>
        <th style="text-align: right;">Цена</th>
        <th style="text-align: right;">Сумма</th>
        """
        total_colspan = 4

    items_html = ""
    for i, item in enumerate(transaction['items']):
        discount_cell = f"""<td style="text-align: right;">{format_currency_py(item.get('discount_per_item', '0'))}</td>""" if has_discounts else ""
        items_html += f"""
        <tr>
            <td style="text-align: center;">{i + 1}</td>
            <td>{item['name']}</td>
            <td style="text-align: right;">{item['quantity']}</td>
            <td style="text-align: right;">{format_currency_py(item['price_at_sale'])}</td>
            {discount_cell}
            <td style="text-align: right;">{format_currency_py(item['total'])}</td>
        </tr>
        """
        
    total_amount_from_db = to_decimal(transaction['total_amount'])
    
    totals_html = ""
    if delivery_cost > 0:
        subtotal = total_amount_from_db - delivery_cost
        totals_html += f"""
        <tr>
            <td colspan="{total_colspan}" style="text-align: right;">Подытог:</td>
            <td style="text-align: right;">{format_currency_py(subtotal)} ₸</td>
        </tr>
        <tr>
            <td colspan="{total_colspan}" style="text-align: right;">Доставка:</td>
            <td style="text-align: right;">{format_currency_py(delivery_cost)} ₸</td>
        </tr>
        """

    totals_html += f"""
    <tr class="total">
        <td colspan="{total_colspan}" style="text-align: right;">Итого к оплате:</td>
        <td style="text-align: right;">{format_currency_py(total_amount_from_db)} ₸</td>
    </tr>
    """

    note_html = ""
    if note:
        safe_note = note.replace('<', '&lt;').replace('>', '&gt;')
        note_html = f"""
        <div style="margin-top: 20px; padding: 10px; border: 2px solid #333; background-color: #fdfdea; border-radius: 5px;">
            <h4 style="margin: 0 0 5px 0; font-size: 16px;">Примечание к заказу:</h4>
            <p style="margin: 0; white-space: pre-wrap; font-size: 14px;">{safe_note}</p>
        </div>
        """
        
    links = load_json_data('links')
    links_html = ""
    if links:
        links_html = '<div class="print-hide" style="margin-top: 20px; text-align: center; border-top: 1px solid #ddd; padding-top: 15px;">'
        for link in links:
            links_html += f'<a href="{link["url"]}" target="_blank" style="display: inline-block; margin: 5px; padding: 10px 15px; background: #0d6efd; color: white; text-decoration: none; border-radius: 5px; font-weight: bold; font-size: 14px; box-shadow: 0 2px 4px rgba(0,0,0,0.1);">{link["name"]}</a>'
        links_html += '</div>'
    
    return f"""
    <!DOCTYPE html>
    <html lang="ru">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Накладная {transaction['id'][:8]}</title>
        <style>
            body {{ font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; margin: 0; padding: 10px; background-color: #f4f4f4; color: #333; }}
            .invoice-box {{ max-width: 800px; margin: auto; padding: 20px; border: 1px solid #eee; background: white; box-shadow: 0 0 10px rgba(0,0,0,0.15); }}
            .header {{ text-align: center; margin-bottom: 20px; }}
            .header h1 {{ margin: 0; font-size: 22px; font-weight: 600; }}
            .header p {{ margin: 2px 0; font-size: 14px; }}
            .details-grid {{ display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; font-size: 14px; }}
            table {{ width: 100%; line-height: inherit; text-align: left; border-collapse: collapse; }}
            table th {{ background: #f2f2f2; font-weight: bold; padding: 8px; border-bottom: 2px solid #ddd; }}
            table td {{ padding: 8px; border-bottom: 1px solid #eee; }}
            table tr.total td {{ font-weight: bold; font-size: 1.1em; border-top: 2px solid #ddd; }}
            .footer-info {{ font-size: 14px; margin-top: 20px; }}
            .print-hide {{ display: block; }}
            @media print {{
                body {{ margin: 0; padding: 0; background-color: #fff; }}
                .invoice-box {{ box-shadow: none; border: none; margin: 0; padding: 0; }}
                .print-hide {{ display: none; }}
            }}
            @media screen and (max-width: 600px) {{
                body {{ padding: 0; }}
                .invoice-box {{ padding: 15px; box-shadow: none; border: none; }}
                .details-grid {{ grid-template-columns: 1fr; gap: 10px; }}
                table th, table td {{ font-size: 12px; padding: 5px; }}
                .header h1 {{ font-size: 18px; }}
                .header p {{ font-size: 12px; }}
                table tr.total td {{ font-size: 1em; }}
            }}
        </style>
    </head>
    <body>
        <div class="invoice-box">
            <div class="print-hide" style="text-align: right; margin-bottom: 20px;">
                <button onclick="window.print()" style="padding: 8px 12px; font-size: 14px; cursor: pointer; background: #6c757d; color: white; border: none; border-radius: 4px;">Печать</button>
                <button onclick="editReceipt()" style="padding: 8px 12px; font-size: 14px; cursor: pointer; background: #ffc107; color: #000; border: none; border-radius: 4px; margin-left: 10px;">Изменить накладную</button>
            </div>
            <div class="header">
                <h1>Товарная накладная № {transaction['id'][:8]}</h1>
                <p>от {datetime.fromisoformat(transaction['timestamp']).strftime('%d.%m.%Y %H:%M')}</p>
            </div>
            <table>
                <thead>
                    <tr>{table_headers}</tr>
                </thead>
                <tbody>{items_html}</tbody>
            </table>
            <table style="margin-top: 20px;">
                {totals_html}
            </table>
            {note_html}
            <div class="footer-info">
                <p>Способ оплаты: {'Наличные' if transaction['payment_method'] == 'cash' else 'Карта'}</p>
                <p>Кассир: {transaction['user_name']}</p>
            </div>
            {links_html}
        </div>
        <script>
        function editReceipt() {{
            let code = prompt("Введите ПИН-код кассира или пароль администратора для изменения накладной:");
            if (!code) return;
            fetch('/api/auth/universal', {{
                method: 'POST',
                headers: {{'Content-Type': 'application/json'}},
                body: JSON.stringify({{code: code}})
            }})
            .then(r => r.json())
            .then(d => {{
                if (d.success) {{
                    window.location.href = '/?edit_tx={transaction["id"]}';
                }} else {{
                    alert("Неверный пароль или ПИН-код");
                }}
            }});
        }}
        </script>
    </body>
    </html>
    """

def admin_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if 'admin_logged_in' not in session:
            flash("Для доступа к этой странице требуется аутентификация.", "warning")
            return redirect(url_for('admin_login', next=request.url))
        return f(*args, **kwargs)
    return decorated_function

@app.context_processor
def inject_utils():
    return {'format_currency_py': format_currency_py, 'get_current_time': get_current_time, 'quote': quote}

@app.route('/api/auth/universal', methods=['POST'])
def auth_universal():
    code = request.json.get('code')
    if code == ADMIN_PASS:
        return jsonify({'success': True})
    user = find_user_by_pin(code)
    if user:
        return jsonify({'success': True})
    return jsonify({'success': False})

@app.route('/')
def sales_screen():
    inventory = load_json_data('inventory')
    kassas = load_json_data('kassas')
    
    edit_tx_id = request.args.get('edit_tx')
    edit_tx = None
    if edit_tx_id:
        transactions = load_json_data('transactions')
        edit_tx = find_item_by_field(transactions, 'id', edit_tx_id)
    
    active_inventory = []
    for p in inventory:
        if isinstance(p, dict) and any(v.get('stock', 0) > 0 for v in p.get('variants', [])):
            active_inventory.append(p)

    active_inventory.sort(key=lambda x: x.get('name', '').lower())

    grouped_inventory = defaultdict(list)
    for p in active_inventory:
        first_letter = p.get('name', '#')[0].upper()
        grouped_inventory[first_letter].append(p)

    sorted_grouped_inventory = sorted(grouped_inventory.items())

    html = BASE_TEMPLATE.replace('__TITLE__', "Касса").replace('__CONTENT__', SALES_SCREEN_CONTENT).replace('__SCRIPTS__', SALES_SCREEN_SCRIPTS)
    return render_template_string(html, inventory=active_inventory, kassas=kassas, grouped_inventory=sorted_grouped_inventory, edit_tx=edit_tx)

@app.route('/inventory', methods=['GET', 'POST'])
def inventory_management():
    is_admin = session.get('admin_logged_in', False)
    
    if request.method == 'POST':
        try:
            name = request.form.get('name', '').strip()
            barcode = request.form.get('barcode', '').strip()
            
            if not name or not barcode:
                flash("Название и штрих-код - обязательные поля.", "danger")
                return redirect(url_for('inventory_management'))

            inventory = load_json_data('inventory')
            if find_item_by_field(inventory, 'barcode', barcode):
                flash(f"Товар со штрих-кодом {barcode} уже существует.", "warning")
                return redirect(url_for('inventory_management'))

            variants = []
            variant_names = request.form.getlist('variant_name[]')
            variant_prices_regular = request.form.getlist('variant_price_regular[]')
            variant_prices_min = request.form.getlist('variant_price_min[]')
            variant_prices_wholesale = request.form.getlist('variant_price_wholesale[]')
            variant_cost_prices = request.form.getlist('variant_cost_price[]')
            variant_stocks = request.form.getlist('variant_stock[]')
            variant_image_urls = request.form.getlist('variant_image_url[]')

            for i in range(len(variant_names)):
                v_name = variant_names[i].strip()
                if not v_name: continue
                
                if is_admin:
                    v_price_regular = str(to_decimal(variant_prices_regular[i])) if i < len(variant_prices_regular) else '0'
                    v_price_min = str(to_decimal(variant_prices_min[i])) if i < len(variant_prices_min) else '0'
                    v_price_wholesale = str(to_decimal(variant_prices_wholesale[i])) if i < len(variant_prices_wholesale) else '0'
                    v_cost = str(to_decimal(variant_cost_prices[i])) if i < len(variant_cost_prices) else '0'
                else:
                    v_price_regular = '0'
                    v_price_min = '0'
                    v_price_wholesale = '0'
                    v_cost = '0'
                    
                variants.append({
                    'id': uuid.uuid4().hex,
                    'option_name': "Вариант",
                    'option_value': v_name,
                    'price_regular': v_price_regular,
                    'price_min': v_price_min,
                    'price_wholesale': v_price_wholesale,
                    'cost_price': v_cost,
                    'stock': int(to_decimal(variant_stocks[i], '0')),
                    'image_url': variant_image_urls[i] if i < len(variant_image_urls) else '',
                })
            
            if not variants:
                flash("Нужно добавить хотя бы один вариант товара.", "danger")
                return redirect(url_for('inventory_management'))

            new_product = {
                'id': uuid.uuid4().hex,
                'name': name,
                'barcode': barcode,
                'variants': variants,
                'timestamp_added': get_current_time().isoformat(),
                'timestamp_updated': get_current_time().isoformat()
            }
            inventory.append(new_product)
            save_json_data('inventory', inventory)
            upload_db_to_hf('inventory')
            flash(f"Товар '{name}' успешно добавлен.", "success")
        except Exception as e:
            logging.error(f"Error adding product: {e}", exc_info=True)
            flash(f"Ошибка при добавлении товара: {e}", "danger")
        return redirect(url_for('inventory_management'))
    
    inventory_list = load_json_data('inventory')
    inventory_list.sort(key=lambda x: x.get('name', '').lower())
    
    total_units = 0
    total_cost_value = Decimal('0')
    total_retail_value = Decimal('0')

    for product in inventory_list:
        if isinstance(product, dict) and 'variants' in product:
            for variant in product.get('variants', []):
                stock = variant.get('stock', 0)
                cost_price = to_decimal(variant.get('cost_price', '0'))
                price = to_decimal(variant.get('price_regular', variant.get('price', '0')))
                
                total_units += stock
                total_cost_value += Decimal(stock) * cost_price
                total_retail_value += Decimal(stock) * price
    
    potential_profit = total_retail_value - total_cost_value

    inventory_summary = {
        'total_names': len(inventory_list),
        'total_units': total_units,
        'total_cost_value': total_cost_value,
        'potential_profit': potential_profit
    }

    html = BASE_TEMPLATE.replace('__TITLE__', "Склад").replace('__CONTENT__', INVENTORY_CONTENT).replace('__SCRIPTS__', INVENTORY_SCRIPTS)
    return render_template_string(html, inventory=inventory_list, inventory_summary=inventory_summary)

@app.route('/inventory/update_prices', methods=['POST'])
@admin_required
def update_prices():
    inventory = load_json_data('inventory')
    variant_ids = request.form.getlist('variant_id[]')
    prices_regular = request.form.getlist('price_regular[]')
    prices_min = request.form.getlist('price_min[]')
    prices_wholesale = request.form.getlist('price_wholesale[]')
    cost_prices = request.form.getlist('cost_price[]')
    
    updates = {}
    for i, vid in enumerate(variant_ids):
        updates[vid] = (
            prices_regular[i],
            prices_min[i],
            prices_wholesale[i],
            cost_prices[i]
        )
    
    for p in inventory:
        updated = False
        for v in p.get('variants', []):
            if v.get('id') in updates:
                v['price_regular'] = str(to_decimal(updates[v['id']][0]))
                v['price_min'] = str(to_decimal(updates[v['id']][1]))
                v['price_wholesale'] = str(to_decimal(updates[v['id']][2]))
                v['cost_price'] = str(to_decimal(updates[v['id']][3]))
                updated = True
        if updated:
            p['timestamp_updated'] = get_current_time().isoformat()
            
    save_json_data('inventory', inventory)
    upload_db_to_hf('inventory')
    flash("Цены успешно обновлены.", "success")
    return redirect(url_for('inventory_management'))

@app.route('/inventory/edit/<product_id>', methods=['POST'])
@admin_required
def edit_product(product_id):
    inventory = load_json_data('inventory')
    product_found = False
    for i, product in enumerate(inventory):
        if isinstance(product, dict) and product.get('id') == product_id:
            try:
                name = request.form.get('name', '').strip()
                barcode = request.form.get('barcode', '').strip()

                if not name or not barcode:
                    flash("Название и штрих-код обязательны.", "danger")
                    return redirect(url_for('inventory_management'))

                existing_barcode = find_item_by_field(inventory, 'barcode', barcode)
                if existing_barcode and existing_barcode.get('id') != product_id:
                    flash(f"Штрих-код {barcode} уже используется другим товаром.", "warning")
                    return redirect(url_for('inventory_management'))

                inventory[i]['name'] = name
                inventory[i]['barcode'] = barcode
                
                new_variants = []
                variant_ids = request.form.getlist('variant_id[]')
                variant_names = request.form.getlist('variant_name[]')
                variant_prices_regular = request.form.getlist('variant_price_regular[]')
                variant_prices_min = request.form.getlist('variant_price_min[]')
                variant_prices_wholesale = request.form.getlist('variant_price_wholesale[]')
                variant_cost_prices = request.form.getlist('variant_cost_price[]')
                variant_stocks = request.form.getlist('variant_stock[]')
                variant_image_urls = request.form.getlist('variant_image_url[]')

                for j in range(len(variant_ids)):
                    v_name = variant_names[j].strip()
                    if not v_name: continue
                    new_variants.append({
                        'id': variant_ids[j] or uuid.uuid4().hex,
                        'option_name': "Вариант",
                        'option_value': v_name,
                        'price_regular': str(to_decimal(variant_prices_regular[j])),
                        'price_min': str(to_decimal(variant_prices_min[j])),
                        'price_wholesale': str(to_decimal(variant_prices_wholesale[j])),
                        'cost_price': str(to_decimal(variant_cost_prices[j])),
                        'stock': int(to_decimal(variant_stocks[j], '0')),
                        'image_url': variant_image_urls[j] if j < len(variant_image_urls) else '',
                    })
                
                inventory[i]['variants'] = new_variants
                inventory[i]['timestamp_updated'] = get_current_time().isoformat()
                product_found = True
                break
            except Exception as e:
                logging.error(f"Error updating product: {e}", exc_info=True)
                flash(f"Ошибка при обновлении товара: {e}", "danger")
                return redirect(url_for('inventory_management'))
    
    if product_found:
        save_json_data('inventory', inventory)
        upload_db_to_hf('inventory')
        flash("Товар успешно обновлен.", "success")
    else:
        flash("Товар не найден.", "danger")
    return redirect(url_for('inventory_management'))

@app.route('/inventory/delete/<product_id>', methods=['POST'])
@admin_required
def delete_product(product_id):
    inventory = load_json_data('inventory')
    initial_len = len(inventory)
    inventory = [p for p in inventory if not (isinstance(p, dict) and p.get('id') == product_id)]
    if len(inventory) < initial_len:
        save_json_data('inventory', inventory)
        upload_db_to_hf('inventory')
        flash("Товар удален.", "success")
    else:
        flash("Товар не найден.", "warning")
    return redirect(url_for('inventory_management'))

@app.route('/inventory/stock_in', methods=['POST'])
def stock_in():
    is_admin = session.get('admin_logged_in', False)
    try:
        product_id = request.form.get('product_id')
        variant_id = request.form.get('variant_id')
        quantity = int(request.form.get('quantity', 0))
        
        cost_price_str = request.form.get('cost_price') if is_admin else None
        delivery_cost = to_decimal(request.form.get('delivery_cost', '0')) if is_admin else Decimal('0')

        if not product_id or not variant_id or quantity <= 0:
            flash("Неверные данные для оприходования.", "danger")
            return redirect(url_for('inventory_management'))

        inventory = load_json_data('inventory')
        product = find_item_by_field(inventory, 'id', product_id)
        if not product:
            flash("Товар не найден.", "danger")
            return redirect(url_for('inventory_management'))

        variant_found = False
        variant_name_for_log = ""
        for i, variant in enumerate(product.get('variants', [])):
            if variant.get('id') == variant_id:
                variant_name_for_log = variant.get('option_value', '')
                
                old_stock = variant.get('stock', 0)
                variant['stock'] = old_stock + quantity
                
                old_cost = to_decimal(variant.get('cost_price', '0'))
                new_cost = to_decimal(cost_price_str) if cost_price_str else old_cost

                if old_stock + quantity > 0:
                    avg_cost = ((old_cost * old_stock) + (new_cost * quantity) + delivery_cost) / (old_stock + quantity)
                    variant['cost_price'] = str(avg_cost.quantize(Decimal('1'), rounding=ROUND_HALF_UP))
                
                variant_found = True
                break

        if not variant_found:
            flash("Вариант товара не найден.", "danger")
            return redirect(url_for('inventory_management'))

        if delivery_cost > 0:
            expenses = load_json_data('expenses')
            new_expense = {
                'id': uuid.uuid4().hex,
                'timestamp': get_current_time().isoformat(),
                'amount': str(delivery_cost),
                'description': f"Дорога: {product['name']} ({variant_name_for_log})"
            }
            expenses.append(new_expense)
            save_json_data('expenses', expenses)
            upload_db_to_hf('expenses')

        stock_history = load_json_data('stock_history')
        stock_history.append({
            'id': uuid.uuid4().hex,
            'timestamp': get_current_time().isoformat(),
            'product_id': product_id,
            'variant_id': variant_id,
            'product_name': product['name'],
            'variant_name': variant_name_for_log,
            'quantity': quantity,
            'cost_price': cost_price_str or str(old_cost),
            'type': 'stock_in'
        })
        save_json_data('stock_history', stock_history)
        upload_db_to_hf('stock_history')

        product['timestamp_updated'] = get_current_time().isoformat()
        save_json_data('inventory', inventory)
        upload_db_to_hf('inventory')
        flash(f"Остаток товара '{product['name']} ({variant_name_for_log})' увеличен на {quantity}.", "success")

    except Exception as e:
        logging.error(f"Error stocking in: {e}", exc_info=True)
        flash(f"Ошибка при оприходовании: {e}", "danger")

    return redirect(url_for('inventory_management'))

@app.route('/upload_image', methods=['POST'])
@admin_required
def upload_image():
    if 'image' not in request.files:
        return jsonify({'success': False, 'message': 'No file part'}), 400
    file = request.files['image']
    if file.filename == '':
        return jsonify({'success': False, 'message': 'No selected file'}), 400
    if file:
        try:
            filename = str(uuid.uuid4()) + os.path.splitext(file.filename)[1]
            save_path = os.path.join(app.static_folder, 'product_images', filename)
            file.save(save_path)
            url = url_for('static', filename=f'product_images/{filename}')
            return jsonify({'success': True, 'url': url})
        except Exception as e:
            logging.error(f"Image upload failed: {e}", exc_info=True)
            return jsonify({'success': False, 'message': f'Server error: {e}'}), 500
    return jsonify({'success': False, 'message': 'Unknown error'}), 500

@app.route('/api/product_by_barcode/<barcode>')
def get_product_by_barcode(barcode):
    inventory = load_json_data('inventory')
    product = find_item_by_field(inventory, 'barcode', barcode)
    if product:
        active_variants = [v for v in product.get('variants', []) if v.get('stock', 0) > 0]
        if active_variants:
            product_copy = product.copy()
            product_copy['variants'] = active_variants
            return jsonify({'success': True, 'product': product_copy})
        else:
            return jsonify({'success': False, 'message': 'Товар закончился на складе'}), 404
    return jsonify({'success': False, 'message': 'Товар не найден'}), 404

@app.route('/api/complete_sale', methods=['POST'])
def complete_sale():
    try:
        data = request.get_json()
        cart = data.get('cart', {})
        payment_method = data.get('paymentMethod', 'cash')
        delivery_cost_str = data.get('deliveryCost', '0')
        note = data.get('note', '')
        edit_tx_id = data.get('edit_tx_id')

        inventory = load_json_data('inventory')
        users = load_json_data('users')
        kassas = load_json_data('kassas')
        transactions = load_json_data('transactions')

        original_tx = None
        if edit_tx_id:
            original_tx = find_item_by_field(transactions, 'id', edit_tx_id)
            if not original_tx:
                return jsonify({'success': False, 'message': 'Оригинальная накладная не найдена.'}), 404
            
            for item in original_tx.get('items', []):
                if not item.get('is_custom'):
                    for p in inventory:
                        if p.get('id') == item.get('product_id'):
                            for v in p.get('variants', []):
                                if v.get('id') == item.get('variant_id'):
                                    v['stock'] = v.get('stock', 0) + item.get('quantity', 0)
                                    break
                            break
                            
            if original_tx.get('payment_method') == 'cash':
                for k in kassas:
                    if k.get('id') == original_tx.get('kassa_id'):
                        current_balance = to_decimal(k.get('balance', '0'))
                        amount = to_decimal(original_tx.get('total_amount', '0'))
                        k['balance'] = str(current_balance - amount)
                        k.setdefault('history', []).append({
                            'type': 'correction_revert',
                            'amount': str(-amount),
                            'timestamp': get_current_time().isoformat(),
                            'description': f"Отмена до изменения {edit_tx_id[:8]}"
                        })
                        break
        else:
            if not data.get('userId') or not data.get('kassaId') or not data.get('shiftId'):
                return jsonify({'success': False, 'message': 'Неполные данные для продажи. Начните смену.'}), 400

        user_id = data.get('userId') if data.get('userId') else original_tx.get('user_id')
        kassa_id = data.get('kassaId') if data.get('kassaId') else original_tx.get('kassa_id')
        shift_id = data.get('shiftId') if data.get('shiftId') else original_tx.get('shift_id')

        if not cart:
            return jsonify({'success': False, 'message': 'Корзина пуста.'}), 400

        user = find_item_by_field(users, 'id', user_id)
        kassa = find_item_by_field(kassas, 'id', kassa_id)

        if not user or not kassa:
            return jsonify({'success': False, 'message': 'Кассир или касса были удалены. Требуется повторный вход.', 'logout_required': True}), 401

        sale_items = []
        items_total = Decimal('0')
        inventory_updates = {}

        for item_id, cart_item in cart.items():
            if cart_item.get('isCustom'):
                price_at_sale = to_decimal(cart_item.get('price', '0'))
                quantity_sold = cart_item.get('quantity', 1)
                item_total = price_at_sale * Decimal(quantity_sold)
                items_total += item_total
                sale_items.append({
                    'product_id': None,
                    'variant_id': item_id,
                    'name': cart_item.get('productName', 'Товар без штрихкода'),
                    'barcode': 'CUSTOM',
                    'quantity': quantity_sold,
                    'price_at_sale': str(price_at_sale),
                    'cost_price_at_sale': '0',
                    'discount_per_item': '0',
                    'total': str(item_total),
                    'is_custom': True
                })
                continue
            
            variant_id = item_id
            product = find_item_by_field(inventory, 'id', cart_item['productId'])
            if not product:
                return jsonify({'success': False, 'message': f"Товар с ID {cart_item['productId']} не найден."}), 404
            
            variant = find_item_by_field(product.get('variants', []), 'id', variant_id)
            if not variant:
                 return jsonify({'success': False, 'message': f"Вариант товара с ID {variant_id} не найден."}), 404
            
            quantity_sold = cart_item['quantity']
            current_stock = variant.get('stock', 0)

            if quantity_sold > current_stock:
                return jsonify({'success': False, 'message': f"Недостаточно товара '{product['name']} ({variant['option_value']})'. В наличии: {current_stock}"}), 400

            price_at_sale = to_decimal(cart_item.get('price', '0'))
            cost_price_at_sale = to_decimal(variant.get('cost_price', '0'))
            discount_per_item = to_decimal(cart_item.get('discount', '0'))

            if discount_per_item > price_at_sale:
                return jsonify({'success': False, 'message': f"Скидка на '{product['name']}' не может быть больше цены."}), 400

            final_price = price_at_sale - discount_per_item
            item_total = final_price * Decimal(quantity_sold)
            items_total += item_total

            name_to_use = f"{product['name']} ({variant['option_value']})" if not edit_tx_id else cart_item.get('productName') or f"{product['name']} ({variant['option_value']})"

            sale_items.append({
                'product_id': product['id'],
                'variant_id': variant_id,
                'name': name_to_use,
                'barcode': product.get('barcode'),
                'quantity': quantity_sold,
                'price_at_sale': str(price_at_sale),
                'cost_price_at_sale': str(cost_price_at_sale),
                'discount_per_item': str(discount_per_item),
                'total': str(item_total)
            })
            inventory_updates[variant_id] = {'product_id': product['id'], 'new_stock': current_stock - quantity_sold}

        delivery_cost = to_decimal(delivery_cost_str)
        total_amount = items_total + delivery_cost
        now_iso = get_current_time().isoformat()
        
        new_transaction = {
            'id': edit_tx_id if edit_tx_id else uuid.uuid4().hex,
            'timestamp': original_tx['timestamp'] if original_tx else now_iso,
            'type': 'sale',
            'status': 'completed',
            'original_transaction_id': None,
            'user_id': user_id,
            'user_name': user.get('name', 'N/A'),
            'kassa_id': kassa_id,
            'kassa_name': kassa.get('name', 'N/A'),
            'shift_id': shift_id,
            'items': sale_items,
            'total_amount': str(total_amount),
            'delivery_cost': str(delivery_cost),
            'note': note,
            'payment_method': payment_method
        }
        
        if edit_tx_id:
            new_transaction['edits'] = original_tx.get('edits', []) + [{'timestamp': now_iso, 'type': 'full_edit'}]
            
        new_transaction['invoice_html'] = generate_receipt_html(new_transaction)
        
        if edit_tx_id:
            for i, t in enumerate(transactions):
                if t.get('id') == edit_tx_id:
                    transactions[i] = new_transaction
                    break
        else:
            transactions.append(new_transaction)

        for variant_id, update_info in inventory_updates.items():
            for p in inventory:
                if p.get('id') == update_info['product_id']:
                    for v in p.get('variants', []):
                        if v.get('id') == variant_id:
                            v['stock'] = update_info['new_stock']
                            p['timestamp_updated'] = now_iso
                            break
                    break

        if payment_method == 'cash':
            for i, k in enumerate(kassas):
                if k.get('id') == kassa_id:
                    current_balance = to_decimal(k.get('balance', '0'))
                    kassas[i]['balance'] = str(current_balance + total_amount)
                    if 'history' not in kassas[i] or not isinstance(kassas[i]['history'], list):
                        kassas[i]['history'] = []
                    kassas[i]['history'].append({
                        'type': 'sale' if not edit_tx_id else 'correction_apply',
                        'amount': str(total_amount),
                        'timestamp': now_iso,
                        'transaction_id': new_transaction['id'],
                        'description': 'Продажа' if not edit_tx_id else f'Измененная накладная {edit_tx_id[:8]}'
                    })
                    break

        save_json_data('transactions', transactions)
        save_json_data('inventory', inventory)
        save_json_data('kassas', kassas)
        
        upload_db_to_hf('transactions')
        upload_db_to_hf('inventory')
        upload_db_to_hf('kassas')

        receipt_url = url_for('view_receipt', transaction_id=new_transaction['id'], _external=True)
        return jsonify({
            'success': True, 
            'message': 'Накладная успешно сохранена.' if edit_tx_id else 'Продажа успешно зарегистрирована.', 
            'transactionId': new_transaction['id'],
            'receiptUrl': receipt_url
        })

    except Exception as e:
        logging.error(f"Error completing sale: {e}", exc_info=True)
        return jsonify({'success': False, 'message': f'Внутренняя ошибка сервера: {e}'}), 500

@app.route('/receipt/<transaction_id>')
def view_receipt(transaction_id):
    transactions = load_json_data('transactions')
    transaction = find_item_by_field(transactions, 'id', transaction_id)
    if transaction and 'invoice_html' in transaction:
        return Response(transaction['invoice_html'], mimetype='text/html')
    if transaction and 'receipt_html' in transaction:
        return Response(transaction['receipt_html'], mimetype='text/html')
    abort(404, description="Накладная не найдена")

@app.route('/transactions')
@admin_required
def transaction_history():
    selected_date_str = request.args.get('date', get_current_time().strftime('%Y-%m-%d'))
    selected_kassa_id = request.args.get('kassa', '')
    try:
        selected_date = datetime.strptime(selected_date_str, '%Y-%m-%d').date()
    except ValueError:
        selected_date = get_current_time().date()
        selected_date_str = selected_date.strftime('%Y-%m-%d')
    
    transactions = load_json_data('transactions')
    kassas = load_json_data('kassas')
    
    filtered_transactions = [
        t for t in transactions 
        if datetime.fromisoformat(t['timestamp']).date() == selected_date
    ]
    
    if selected_kassa_id:
        filtered_transactions = [
            t for t in filtered_transactions
            if t.get('kassa_id') == selected_kassa_id
        ]
    
    total_sales = sum(to_decimal(t['total_amount']) for t in filtered_transactions if t.get('type') == 'sale')
    
    total_quantity_sold = 0
    for t in filtered_transactions:
        if t.get('type') == 'sale':
            for item in t.get('items', []):
                total_quantity_sold += int(item.get('quantity', 0))
    
    filtered_transactions.sort(key=lambda x: x.get('timestamp', ''), reverse=True)
    
    html = BASE_TEMPLATE.replace('__TITLE__', "История транзакций").replace('__CONTENT__', TRANSACTIONS_CONTENT).replace('__SCRIPTS__', TRANSACTIONS_SCRIPTS)
    return render_template_string(html, transactions=filtered_transactions, total_sales=total_sales, total_quantity_sold=total_quantity_sold, selected_date=selected_date_str, kassas=kassas, selected_kassa_id=selected_kassa_id)

@app.route('/admin/transaction/edit/<transaction_id>', methods=['POST'])
@admin_required
def edit_transaction(transaction_id):
    try:
        data = request.get_json()
        items_update = data.get('items', [])
        
        transactions = load_json_data('transactions')
        kassas = load_json_data('kassas')
        
        transaction_index = -1
        for i, t in enumerate(transactions):
            if t.get('id') == transaction_id:
                transaction_index = i
                break
        
        if transaction_index == -1:
            return jsonify({'success': False, 'message': 'Транзакция не найдена'}), 404
        
        original_transaction = transactions[transaction_index]
        old_total_amount = to_decimal(original_transaction['total_amount'])
        
        new_items_total = Decimal('0')
        updated_items = []
        
        for item in original_transaction['items']:
            item_id = item.get('variant_id') or item.get('product_id') 
            update_data = find_item_by_field(items_update, 'id', item_id)
            
            if update_data:
                new_price = to_decimal(update_data.get('price', item['price_at_sale']))
                new_discount = to_decimal(update_data.get('discount', item.get('discount_per_item', '0')))
                
                item['price_at_sale'] = str(new_price)
                item['discount_per_item'] = str(new_discount)
                item_total = (new_price - new_discount) * Decimal(item['quantity'])
                item['total'] = str(item_total)
            
            new_items_total += to_decimal(item['total'])
        
        delivery_cost = to_decimal(original_transaction.get('delivery_cost', '0'))
        new_total_amount = new_items_total + delivery_cost
        transactions[transaction_index]['total_amount'] = str(new_total_amount)
        
        if 'edits' not in transactions[transaction_index]:
            transactions[transaction_index]['edits'] = []
            
        transactions[transaction_index]['edits'].append({
            'timestamp': get_current_time().isoformat(),
            'admin_user': session.get('admin_username', 'admin'),
            'old_total': str(old_total_amount),
            'new_total': str(new_total_amount)
        })

        transactions[transaction_index]['invoice_html'] = generate_receipt_html(transactions[transaction_index])

        amount_diff = new_total_amount - old_total_amount
        if amount_diff != Decimal(0) and original_transaction['payment_method'] == 'cash':
            kassa_id = original_transaction.get('kassa_id')
            for i, k in enumerate(kassas):
                if k.get('id') == kassa_id:
                    k['balance'] = str(to_decimal(k.get('balance', '0')) + amount_diff)
                    k.setdefault('history', []).append({
                        'type': 'correction',
                        'amount': str(amount_diff),
                        'timestamp': get_current_time().isoformat(),
                        'description': f"Корректировка транзакции {transaction_id[:8]}"
                    })
                    break
            save_json_data('kassas', kassas)
            upload_db_to_hf('kassas')

        save_json_data('transactions', transactions)
        upload_db_to_hf('transactions')
        
        flash("Транзакция успешно обновлена.", "success")
        return jsonify({'success': True, 'message': 'Транзакция обновлена'})
    except Exception as e:
        logging.error(f"Error editing transaction: {e}", exc_info=True)
        return jsonify({'success': False, 'message': f'Внутренняя ошибка: {e}'}), 500

@app.route('/admin/transaction/delete/<transaction_id>', methods=['POST'])
@admin_required
def delete_transaction(transaction_id):
    transactions = load_json_data('transactions')
    inventory = load_json_data('inventory')
    kassas = load_json_data('kassas')

    transaction_to_delete = find_item_by_field(transactions, 'id', transaction_id)
    if not transaction_to_delete:
        flash("Транзакция не найдена.", "danger")
        return redirect(url_for('transaction_history'))

    for item in transaction_to_delete.get('items', []):
        if item.get('is_custom'):
            continue
        
        product = find_item_by_field(inventory, 'id', item.get('product_id'))
        if not product: continue
        
        variant = find_item_by_field(product.get('variants', []), 'id', item.get('variant_id'))
        if not variant: continue

        quantity_change = item.get('quantity', 0)
        
        if transaction_to_delete.get('type') == 'sale':
            variant['stock'] = variant.get('stock', 0) + quantity_change
        elif transaction_to_delete.get('type') == 'return':
             variant['stock'] = variant.get('stock', 0) - quantity_change

    if transaction_to_delete.get('payment_method') == 'cash':
        kassa = find_item_by_field(kassas, 'id', transaction_to_delete.get('kassa_id'))
        if kassa:
            current_balance = to_decimal(kassa.get('balance', '0'))
            amount_change = to_decimal(transaction_to_delete.get('total_amount'))
            
            kassa['balance'] = str(current_balance - amount_change)
            
            kassa.setdefault('history', []).append({
                'type': 'deletion',
                'amount': str(-amount_change),
                'timestamp': get_current_time().isoformat(),
                'description': f"Удаление транзакции {transaction_id[:8]}"
            })

    transactions = [t for t in transactions if t.get('id') != transaction_id]
    
    if transaction_to_delete.get('type') == 'return':
        original_id = transaction_to_delete.get('original_transaction_id')
        if original_id:
            for i, t in enumerate(transactions):
                if t.get('id') == original_id:
                    transactions[i]['status'] = 'completed'
                    break

    save_json_data('inventory', inventory)
    save_json_data('kassas', kassas)
    save_json_data('transactions', transactions)
    
    upload_db_to_hf('inventory')
    upload_db_to_hf('kassas')
    upload_db_to_hf('transactions')
    
    flash("Транзакция успешно удалена.", "success")
    return redirect(url_for('transaction_history'))

@app.route('/reports')
@admin_required
def reports():
    today = get_current_time().date()
    start_date_str = request.args.get('start_date', (today.replace(day=1)).strftime('%Y-%m-%d'))
    end_date_str = request.args.get('end_date', (today).strftime('%Y-%m-%d'))

    start_date = datetime.strptime(start_date_str, '%Y-%m-%d').replace(tzinfo=ALMATY_TZ)
    end_date = (datetime.strptime(end_date_str, '%Y-%m-%d') + timedelta(days=1)).replace(tzinfo=ALMATY_TZ)
    num_days = (end_date - start_date).days

    transactions = load_json_data('transactions')
    expenses = load_json_data('expenses')
    personal_expenses = load_json_data('personal_expenses')
    users = load_json_data('users')

    filtered_transactions = [
        t for t in transactions 
        if start_date <= datetime.fromisoformat(t['timestamp']) < end_date
    ]
    filtered_expenses = [
        e for e in expenses 
        if start_date <= datetime.fromisoformat(e['timestamp']) < end_date
    ]
    filtered_personal_expenses = [
        e for e in personal_expenses 
        if start_date <= datetime.fromisoformat(e['timestamp']) < end_date
    ]
    
    return_transactions = [t for t in filtered_transactions if t.get('type') == 'return']
    total_returns_amount = sum(to_decimal(t['total_amount']) for t in return_transactions)
    total_returns_count = len(return_transactions)

    total_revenue = sum(to_decimal(t['total_amount']) for t in filtered_transactions)
    total_cogs = sum(
        to_decimal(item.get('cost_price_at_sale', '0')) * to_decimal(str(item['quantity']))
        for t in filtered_transactions for item in t['items']
    )
    gross_profit = total_revenue - total_cogs
    total_expenses = sum(to_decimal(e['amount']) for e in filtered_expenses)
    total_personal_expenses = sum(to_decimal(e['amount']) for e in filtered_personal_expenses)
    
    sales_by_cashier = defaultdict(lambda: {'count': 0, 'total': Decimal(0)})
    for t in filtered_transactions:
        if t.get('type') == 'sale':
            cashier_name = t.get('user_name', 'Неизвестный')
            sales_by_cashier[cashier_name]['count'] += 1
            sales_by_cashier[cashier_name]['total'] += to_decimal(t['total_amount'])
        elif t.get('type') == 'return':
            cashier_name = t.get('user_name', 'Неизвестный')
            sales_by_cashier[cashier_name]['count'] -= 1
            sales_by_cashier[cashier_name]['total'] += to_decimal(t['total_amount'])

    cashier_payouts = defaultdict(Decimal)
    for t in filtered_transactions:
        if t.get('type') != 'sale': continue
        user = find_item_by_field(users, 'id', t.get('user_id'))
        if user:
            payment_type = user.get('payment_type')
            payment_value = to_decimal(user.get('payment_value', '0'))
            if payment_type == 'percentage' and payment_value > 0:
                payout = to_decimal(t['total_amount']) * (payment_value / Decimal(100))
                cashier_payouts[user['name']] += payout

    for user in users:
        if user.get('payment_type') == 'salary':
            monthly_salary = to_decimal(user.get('payment_value', '0'))
            if monthly_salary > 0:
                daily_salary = monthly_salary / Decimal(30) 
                period_salary = daily_salary * Decimal(num_days)
                cashier_payouts[user['name']] += period_salary

    total_salary_expenses = sum(cashier_payouts.values())
    net_profit = gross_profit - total_expenses - total_personal_expenses - total_salary_expenses
    
    stats = {
        'total_revenue': total_revenue,
        'total_returns_amount': abs(total_returns_amount),
        'total_returns_count': total_returns_count,
        'total_cogs': total_cogs,
        'gross_profit': gross_profit,
        'total_expenses': total_expenses,
        'total_personal_expenses': total_personal_expenses,
        'total_salary_expenses': total_salary_expenses,
        'net_profit': net_profit,
        'sales_by_cashier': sorted(sales_by_cashier.items(), key=lambda item: item[1]['total'], reverse=True),
        'cashier_payouts': sorted(cashier_payouts.items(), key=lambda item: item[1], reverse=True)
    }

    filtered_expenses.sort(key=lambda x: x['timestamp'], reverse=True)
    filtered_personal_expenses.sort(key=lambda x: x['timestamp'], reverse=True)

    html = BASE_TEMPLATE.replace('__TITLE__', "Отчеты").replace('__CONTENT__', REPORTS_CONTENT).replace('__SCRIPTS__', REPORTS_SCRIPTS)
    return render_template_string(html, stats=stats, start_date=start_date_str, end_date=end_date_str, expenses=filtered_expenses, personal_expenses=filtered_personal_expenses)

@app.route('/reports/employee')
@admin_required
def employee_report():
    users = load_json_data('users')
    today = get_current_time().date()
    start_date_str = request.args.get('start_date', (today.replace(day=1)).strftime('%Y-%m-%d'))
    end_date_str = request.args.get('end_date', today.strftime('%Y-%m-%d'))
    user_id = request.args.get('user_id', '')

    start_date = datetime.strptime(start_date_str, '%Y-%m-%d').replace(tzinfo=ALMATY_TZ)
    end_date = (datetime.strptime(end_date_str, '%Y-%m-%d') + timedelta(days=1)).replace(tzinfo=ALMATY_TZ)

    transactions = load_json_data('transactions')
    employee_transactions = []
    totals = {'sales': Decimal(0), 'returns': Decimal(0), 'net': Decimal(0)}

    if user_id:
        for t in transactions:
            if t.get('user_id') == user_id:
                t_date = datetime.fromisoformat(t['timestamp'])
                if start_date <= t_date < end_date:
                    employee_transactions.append(t)
                    amt = to_decimal(t['total_amount'])
                    if t['type'] == 'sale':
                        totals['sales'] += amt
                        totals['net'] += amt
                    elif t['type'] == 'return':
                        totals['returns'] += abs(amt)
                        totals['net'] -= abs(amt)

    employee_transactions.sort(key=lambda x: x['timestamp'], reverse=True)

    html = BASE_TEMPLATE.replace('__TITLE__', "Отчет по сотрудникам").replace('__CONTENT__', EMPLOYEE_REPORT_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html, users=users, transactions=employee_transactions, start_date=start_date_str, end_date=end_date_str, selected_user=user_id, totals=totals)

@app.route('/reports/item_movement')
@admin_required
def item_movement_report():
    inventory = load_json_data('inventory')
    transactions = load_json_data('transactions')
    stock_history = load_json_data('stock_history')

    product_id = request.args.get('product_id', '')
    variant_id = request.args.get('variant_id', '')

    movements = []
    selected_product = None
    selected_variant = None

    if product_id:
        selected_product = find_item_by_field(inventory, 'id', product_id)
        if selected_product and variant_id:
            selected_variant = find_item_by_field(selected_product.get('variants', []), 'id', variant_id)

        for t in transactions:
            for item in t.get('items', []):
                if item.get('product_id') == product_id and (not variant_id or item.get('variant_id') == variant_id):
                    movements.append({
                        'timestamp': t['timestamp'],
                        'type': t['type'],
                        'qty': -item['quantity'] if t['type'] == 'sale' else item['quantity'],
                        'price': item['price_at_sale'],
                        'doc_id': t['id'][:8],
                        'user': t.get('user_name', 'Система'),
                        'variant_name': item.get('name', '')
                    })

        for sh in stock_history:
            if sh.get('product_id') == product_id and (not variant_id or sh.get('variant_id') == variant_id):
                movements.append({
                    'timestamp': sh['timestamp'],
                    'type': 'stock_in',
                    'qty': sh['quantity'],
                    'price': sh.get('cost_price', '0'),
                    'doc_id': 'Приход',
                    'user': 'Админ',
                    'variant_name': f"{sh.get('product_name')} ({sh.get('variant_name')})"
                })

    movements.sort(key=lambda x: x['timestamp'], reverse=True)

    html = BASE_TEMPLATE.replace('__TITLE__', "Движение товаров").replace('__CONTENT__', ITEM_MOVEMENT_CONTENT).replace('__SCRIPTS__', ITEM_MOVEMENT_SCRIPTS)
    return render_template_string(html, inventory=inventory, movements=movements, product_id=product_id, variant_id=variant_id, selected_product=selected_product, selected_variant=selected_variant)

@app.route('/reports/product_roi')
@admin_required
def product_roi_report():
    inventory = load_json_data('inventory')
    transactions = load_json_data('transactions')

    product_stats = []

    for product in inventory:
        for variant in product.get('variants', []):
            total_revenue = Decimal('0')
            total_cogs = Decimal('0')
            total_qty_sold = 0

            for t in transactions:
                if t['type'] in ['sale', 'return']:
                    for item in t['items']:
                        if item.get('variant_id') == variant['id']:
                            total_revenue += to_decimal(item['total'])
                            total_cogs += to_decimal(item.get('cost_price_at_sale', '0')) * to_decimal(str(item['quantity']))
                            if t['type'] == 'sale':
                                total_qty_sold += item['quantity']
                            elif t['type'] == 'return':
                                total_qty_sold -= item['quantity']

            current_stock = to_decimal(str(variant.get('stock', 0)))
            cost_price = to_decimal(variant.get('cost_price', '0'))
            
            inventory_value = current_stock * cost_price
            
            total_investment = total_cogs + inventory_value 
            payback = total_revenue - total_investment

            product_stats.append({
                'name': product['name'],
                'variant_name': variant['option_value'],
                'total_qty_sold': total_qty_sold,
                'total_revenue': total_revenue,
                'total_investment': total_investment,
                'inventory_value': inventory_value,
                'payback': payback
            })

    product_stats.sort(key=lambda x: x['payback'], reverse=True)
    html = BASE_TEMPLATE.replace('__TITLE__', "Отчет по окупаемости товаров").replace('__CONTENT__', PRODUCT_ROI_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html, stats=product_stats)

@app.route('/admin', methods=['GET'])
@admin_required
def admin_panel():
    users = load_json_data('users')
    kassas = load_json_data('kassas')
    expenses = load_json_data('expenses')
    personal_expenses = load_json_data('personal_expenses')
    links = load_json_data('links')
    expenses.sort(key=lambda x: x.get('timestamp', ''), reverse=True)
    personal_expenses.sort(key=lambda x: x.get('timestamp', ''), reverse=True)
    html = BASE_TEMPLATE.replace('__TITLE__', "Админ-панель").replace('__CONTENT__', ADMIN_CONTENT).replace('__SCRIPTS__', ADMIN_SCRIPTS)
    return render_template_string(html, users=users, kassas=kassas, expenses=expenses, personal_expenses=personal_expenses, links=links)

@app.route('/admin/shifts')
@admin_required
def admin_shifts():
    shifts = load_json_data('shifts')
    shifts.sort(key=lambda x: x.get('start_time', ''), reverse=True)
    html = BASE_TEMPLATE.replace('__TITLE__', "История смен").replace('__CONTENT__', SHIFTS_CONTENT)
    return render_template_string(html, shifts=shifts)

@app.route('/admin/user', methods=['POST'])
@admin_required
def manage_user():
    action = request.form.get('action')
    users = load_json_data('users')
    
    if action == 'add':
        name = request.form.get('name', '').strip()
        pin = request.form.get('pin', '').strip()
        payment_type = request.form.get('payment_type')
        payment_value = to_decimal(request.form.get('payment_value', '0'))
        if name and pin and pin.isdigit() and payment_type:
            new_user = {
                'id': uuid.uuid4().hex, 'name': name, 'pin': pin,
                'payment_type': payment_type, 'payment_value': str(payment_value)
            }
            users.append(new_user)
            flash(f"Кассир '{name}' добавлен.", "success")
        else:
            flash("Все поля обязательны.", "danger")
    
    elif action == 'edit':
        user_id = request.form.get('id')
        user = find_item_by_field(users, 'id', user_id)
        if user:
            user['name'] = request.form.get('name', '').strip()
            user['pin'] = request.form.get('pin', '').strip()
            user['payment_type'] = request.form.get('payment_type')
            user['payment_value'] = str(to_decimal(request.form.get('payment_value', '0')))
            flash(f"Данные кассира '{user['name']}' обновлены.", "success")
        else:
            flash("Кассир не найден.", "warning")

    elif action == 'delete':
        user_id = request.form.get('id')
        initial_len = len(users)
        users = [u for u in users if u.get('id') != user_id]
        if len(users) < initial_len:
            flash("Кассир удален.", "success")
        else:
            flash("Кассир не найден.", "warning")

    save_json_data('users', users)
    upload_db_to_hf('users')
    return redirect(url_for('admin_panel'))

@app.route('/admin/kassa', methods=['POST'])
@admin_required
def manage_kassa():
    action = request.form.get('action')
    kassas = load_json_data('kassas')
    
    if action == 'add':
        name = request.form.get('name', '').strip()
        balance = to_decimal(request.form.get('balance', '0'))
        if name:
            new_kassa = {
                'id': uuid.uuid4().hex,
                'name': name,
                'balance': str(balance),
                'history': []
            }
            if balance > 0:
                new_kassa['history'].append({
                    'type': 'deposit',
                    'amount': str(balance),
                    'timestamp': get_current_time().isoformat(),
                    'description': 'Начальный баланс'
                })
            kassas.append(new_kassa)
            flash(f"Касса '{name}' добавлена.", "success")
        else:
            flash("Название кассы обязательно.", "danger")

    elif action == 'delete':
        kassa_id = request.form.get('id')
        initial_len = len(kassas)
        kassas = [k for k in kassas if k.get('id') != kassa_id]
        if len(kassas) < initial_len:
            flash("Касса удалена.", "success")
        else:
            flash("Касса не найдена.", "warning")
            
    save_json_data('kassas', kassas)
    upload_db_to_hf('kassas')
    return redirect(url_for('admin_panel'))

@app.route('/admin/kassa_op', methods=['POST'])
@admin_required
def kassa_operation():
    kassa_id = request.form.get('kassa_id')
    op_type = request.form.get('op_type')
    amount = to_decimal(request.form.get('amount', '0'))
    description = request.form.get('description', '').strip()
    
    if not kassa_id or not op_type or amount <= 0:
        flash("Выберите кассу, тип операции и укажите положительную сумму.", "danger")
        return redirect(url_for('admin_panel'))
    
    kassas = load_json_data('kassas')
    kassa_found = False
    for i, kassa in enumerate(kassas):
        if kassa.get('id') == kassa_id:
            current_balance = to_decimal(kassa.get('balance', '0'))
            new_balance = current_balance
            
            if op_type == 'deposit':
                new_balance += amount
            elif op_type == 'withdrawal':
                if amount > current_balance:
                    flash("Сумма изъятия превышает баланс кассы.", "danger")
                    return redirect(url_for('admin_panel'))
                new_balance -= amount
            
            kassas[i]['balance'] = str(new_balance)
            if 'history' not in kassas[i]: kassas[i]['history'] = []
            kassas[i]['history'].append({
                'type': op_type,
                'amount': str(amount),
                'timestamp': get_current_time().isoformat(),
                'description': description or f"{'Внесение' if op_type == 'deposit' else 'Изъятие'} средств"
            })
            kassa_found = True
            break
            
    if kassa_found:
        save_json_data('kassas', kassas)
        upload_db_to_hf('kassas')
        flash("Операция по кассе успешно проведена.", "success")
    else:
        flash("Касса не найдена.", "danger")
        
    return redirect(url_for('admin_panel'))
    
@app.route('/admin/expense', methods=['POST'])
@admin_required
def manage_expense():
    amount = to_decimal(request.form.get('amount', '0'))
    description = request.form.get('description', '').strip()

    if amount <= 0 or not description:
        flash("Укажите положительную сумму и описание расхода.", "danger")
        return redirect(url_for('admin_panel'))

    new_expense = {
        'id': uuid.uuid4().hex,
        'timestamp': get_current_time().isoformat(),
        'amount': str(amount),
        'description': description
    }
    expenses = load_json_data('expenses')
    expenses.append(new_expense)
    save_json_data('expenses', expenses)
    upload_db_to_hf('expenses')
    flash("Расход успешно добавлен.", "success")
    return redirect(url_for('admin_panel'))

@app.route('/admin/expense/delete/<expense_id>', methods=['POST'])
@admin_required
def delete_expense(expense_id):
    expenses = load_json_data('expenses')
    initial_len = len(expenses)
    expenses = [e for e in expenses if e.get('id') != expense_id]
    if len(expenses) < initial_len:
        save_json_data('expenses', expenses)
        upload_db_to_hf('expenses')
        flash("Расход удален.", "success")
    else:
        flash("Расход не найден.", "warning")
    return redirect(url_for('admin_panel'))

@app.route('/admin/personal_expense', methods=['POST'])
@admin_required
def manage_personal_expense():
    amount = to_decimal(request.form.get('amount', '0'))
    description = request.form.get('description', '').strip()

    if amount <= 0 or not description:
        flash("Укажите положительную сумму и описание личного расхода.", "danger")
        return redirect(url_for('admin_panel'))

    new_expense = {
        'id': uuid.uuid4().hex,
        'timestamp': get_current_time().isoformat(),
        'amount': str(amount),
        'description': description
    }
    expenses = load_json_data('personal_expenses')
    expenses.append(new_expense)
    save_json_data('personal_expenses', expenses)
    upload_db_to_hf('personal_expenses')
    flash("Личный расход успешно добавлен.", "success")
    return redirect(url_for('admin_panel'))

@app.route('/admin/personal_expense/delete/<expense_id>', methods=['POST'])
@admin_required
def delete_personal_expense(expense_id):
    expenses = load_json_data('personal_expenses')
    initial_len = len(expenses)
    expenses = [e for e in expenses if e.get('id') != expense_id]
    if len(expenses) < initial_len:
        save_json_data('personal_expenses', expenses)
        upload_db_to_hf('personal_expenses')
        flash("Личный расход удален.", "success")
    else:
        flash("Личный расход не найден.", "warning")
    return redirect(url_for('admin_panel'))

@app.route('/admin/link', methods=['POST'])
@admin_required
def manage_link():
    action = request.form.get('action')
    links = load_json_data('links')
    if action == 'add':
        name = request.form.get('name', '').strip()
        url = request.form.get('url', '').strip()
        if name and url:
            links.append({'id': uuid.uuid4().hex, 'name': name, 'url': url})
            flash("Ссылка добавлена.", "success")
    elif action == 'delete':
        link_id = request.form.get('id')
        links = [l for l in links if l.get('id') != link_id]
        flash("Ссылка удалена.", "success")
    save_json_data('links', links)
    upload_db_to_hf('links')
    return redirect(url_for('admin_panel'))

@app.route('/cashier_login', methods=['GET', 'POST'])
def cashier_login():
    if request.method == 'POST':
        pin = request.form.get('pin')
        user = find_user_by_pin(pin)
        if user:
            return redirect(url_for('cashier_dashboard', user_id=user['id']))
        else:
            flash("Неверный ПИН-код.", "danger")
    html = BASE_TEMPLATE.replace('__TITLE__', "Вход для кассира").replace('__CONTENT__', CASHIER_LOGIN_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html)

@app.route('/api/verify_pin', methods=['POST'])
def verify_pin():
    pin = request.json.get('pin')
    user = find_user_by_pin(pin)
    if user:
        return jsonify({'success': True, 'user': {'id': user['id'], 'name': user['name']}})
    else:
        return jsonify({'success': False, 'message': 'Неверный ПИН-код'}), 401

@app.route('/api/shift/start', methods=['POST'])
def start_shift():
    data = request.json
    user_id = data.get('userId')
    kassa_id = data.get('kassaId')
    
    if not user_id:
        return jsonify({'success': False, 'message': 'Missing user ID'}), 400
        
    shifts = load_json_data('shifts')
    open_shift = next((s for s in shifts if s.get('user_id') == user_id and s.get('end_time') is None), None)
    if open_shift:
        return jsonify({'success': True, 'shift': open_shift})

    if not kassa_id:
        return jsonify({'success': False, 'message': 'Выберите кассу для начала новой смены'}), 400

    users = load_json_data('users')
    kassas = load_json_data('kassas')
    user = find_item_by_field(users, 'id', user_id)

    if not user:
        return jsonify({'success': False, 'message': 'Ваш пользователь был удален. Требуется повторный вход.', 'logout_required': True}), 401

    kassa = find_item_by_field(kassas, 'id', kassa_id)
    if not kassa:
        return jsonify({'success': False, 'message': 'Выбранная касса не найдена. Возможно, она была удалена.'}), 404

    new_shift = {
        'id': uuid.uuid4().hex,
        'user_id': user_id,
        'user_name': user['name'],
        'kassa_id': kassa_id,
        'kassa_name': kassa['name'],
        'start_time': get_current_time().isoformat(),
        'start_balance': kassa.get('balance', '0'),
        'end_time': None
    }
    shifts.append(new_shift)
    save_json_data('shifts', shifts)
    upload_db_to_hf('shifts')
    return jsonify({'success': True, 'shift': new_shift})

@app.route('/api/shift/end', methods=['POST'])
def end_shift():
    data = request.json
    shift_id = data.get('shiftId')
    if not shift_id:
        return jsonify({'success': False, 'message': 'Missing shift ID'}), 400

    shifts = load_json_data('shifts')
    kassas = load_json_data('kassas')
    transactions = load_json_data('transactions')
    users = load_json_data('users')
    
    shift_found = False
    for i, shift in enumerate(shifts):
        if shift.get('id') == shift_id:
            if shift.get('end_time'):
                return jsonify({'success': False, 'message': 'Смена уже закрыта'}), 400
            
            user = find_item_by_field(users, 'id', shift.get('user_id'))
            kassa = find_item_by_field(kassas, 'id', shift.get('kassa_id'))
            if not user or not kassa:
                return jsonify({'success': False, 'message': 'Кассир или касса были удалены. Невозможно завершить смену. Требуется повторный вход.', 'logout_required': True}), 401

            shift['end_time'] = get_current_time().isoformat()
            
            shift['end_balance'] = kassa.get('balance', '0') if kassa else '0'

            shift_transactions = [
                t for t in transactions 
                if t.get('shift_id') == shift_id and datetime.fromisoformat(t['timestamp']) >= datetime.fromisoformat(shift['start_time'])
            ]
            
            cash_sales = sum(to_decimal(t['total_amount']) for t in shift_transactions if t['type'] == 'sale' and t['payment_method'] == 'cash')
            card_sales = sum(to_decimal(t['total_amount']) for t in shift_transactions if t['type'] == 'sale' and t['payment_method'] == 'card')
            
            shift['cash_sales'] = str(cash_sales)
            shift['card_sales'] = str(card_sales)
            shift['total_sales'] = str(cash_sales + card_sales)
            
            shifts[i] = shift
            shift_found = True
            break
    
    if not shift_found:
        return jsonify({'success': False, 'message': 'Смена не найдена'}), 404
        
    save_json_data('shifts', shifts)
    upload_db_to_hf('shifts')
    return jsonify({'success': True, 'message': 'Смена успешно закрыта'})

@app.route('/cashier_dashboard/<user_id>')
def cashier_dashboard(user_id):
    users = load_json_data('users')
    user = find_item_by_field(users, 'id', user_id)
    if not user:
        abort(404, "Кассир не найден")
    
    transactions = load_json_data('transactions')
    user_transactions = [t for t in transactions if t.get('user_id') == user_id]
    user_transactions.sort(key=lambda x: x['timestamp'], reverse=True)
    
    html = BASE_TEMPLATE.replace('__TITLE__', f"Продажи кассира: {user['name']}").replace('__CONTENT__', CASHIER_DASHBOARD_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html, user=user, transactions=user_transactions)

@app.route('/return_transaction/<transaction_id>', methods=['GET', 'POST'])
def return_transaction(transaction_id):
    transactions = load_json_data('transactions')
    inventory = load_json_data('inventory')
    kassas = load_json_data('kassas')

    original_transaction_index = -1
    for i, t in enumerate(transactions):
        if t.get('id') == transaction_id:
            original_transaction_index = i
            break
    
    if original_transaction_index == -1:
        flash("Оригинальная транзакция не найдена.", "danger")
        return redirect(url_for('cashier_login'))

    original_transaction = transactions[original_transaction_index]

    if request.method == 'GET':
        cashier_id = request.args.get('cashier_id')
        if not cashier_id:
            flash("Не указан ID кассира.", "danger")
            return redirect(url_for('cashier_login'))
            
        returnable_items = []
        already_returned = original_transaction.get('return_info', {}).get('returned_items', {})
        
        for item in original_transaction['items']:
            variant_id = item.get('variant_id')
            returned_qty = already_returned.get(variant_id, 0)
            max_returnable = item['quantity'] - returned_qty
            if max_returnable > 0:
                item_copy = item.copy()
                item_copy['max_returnable'] = max_returnable
                returnable_items.append(item_copy)

        html = BASE_TEMPLATE.replace('__TITLE__', f"Возврат по накладной {transaction_id[:8]}").replace('__CONTENT__', RETURN_PAGE_CONTENT).replace('__SCRIPTS__', '')
        return render_template_string(html, transaction=original_transaction, items=returnable_items, cashier_id=cashier_id)

    if request.method == 'POST':
        cashier_id = request.form.get('cashier_id')
        if not cashier_id:
            flash("Не удалось определить кассира.", "danger")
            return redirect(url_for('cashier_login'))

        return_items = []
        total_return_amount = Decimal('0')
        inventory_updates = {}
        items_to_process = defaultdict(int)

        for key, value in request.form.items():
            if key.startswith('return_qty_'):
                variant_id = key.replace('return_qty_', '')
                try:
                    qty = int(value)
                    if qty > 0:
                        items_to_process[variant_id] = qty
                except (ValueError, TypeError):
                    continue
        
        if not items_to_process:
            flash("Не выбрано ни одного товара для возврата.", "warning")
            return redirect(url_for('return_transaction', transaction_id=transaction_id, cashier_id=cashier_id))

        already_returned = original_transaction.get('return_info', {}).get('returned_items', {})
        total_items_in_sale = 0
        total_items_returned_before = sum(already_returned.values())

        for item in original_transaction['items']:
            variant_id = item.get('variant_id')
            total_items_in_sale += item['quantity']

            if variant_id in items_to_process:
                qty_to_return = items_to_process[variant_id]
                
                returned_so_far = already_returned.get(variant_id, 0)
                if qty_to_return > (item['quantity'] - returned_so_far):
                    flash(f"Нельзя вернуть {qty_to_return} шт. товара '{item['name']}', т.к. доступно к возврату {item['quantity'] - returned_so_far}.", "danger")
                    return redirect(url_for('return_transaction', transaction_id=transaction_id, cashier_id=cashier_id))
                
                price = to_decimal(item['price_at_sale'])
                discount = to_decimal(item.get('discount_per_item', '0'))
                item_total = (price - discount) * qty_to_return
                total_return_amount += item_total
                
                return_items.append({**item, 'quantity': qty_to_return, 'total': str(item_total)})

                if not item.get('is_custom'):
                    product = find_item_by_field(inventory, 'id', item['product_id'])
                    if product:
                        variant = find_item_by_field(product.get('variants', []), 'id', variant_id)
                        if variant:
                            inventory_updates[variant_id] = {'product_id': item['product_id'], 'stock_change': qty_to_return}

        now_iso = get_current_time().isoformat()
        return_transaction_id = uuid.uuid4().hex
        return_transaction = {
            'id': return_transaction_id, 'timestamp': now_iso, 'type': 'return', 'status': 'completed',
            'original_transaction_id': transaction_id,
            'user_id': original_transaction['user_id'], 'user_name': original_transaction['user_name'],
            'kassa_id': original_transaction['kassa_id'], 'kassa_name': original_transaction['kassa_name'],
            'shift_id': original_transaction.get('shift_id'),
            'items': return_items,
            'total_amount': str(-total_return_amount),
            'payment_method': original_transaction['payment_method']
        }
        transactions.append(return_transaction)
        
        return_info = original_transaction.setdefault('return_info', {'returned_items': {}, 'return_transaction_ids': []})
        return_info['return_transaction_ids'].append(return_transaction_id)
        total_items_returned_now = 0
        for variant_id, qty in items_to_process.items():
            return_info['returned_items'][variant_id] = return_info['returned_items'].get(variant_id, 0) + qty
            total_items_returned_now += qty

        if (total_items_returned_before + total_items_returned_now) >= total_items_in_sale:
            original_transaction['status'] = 'returned'
        else:
            original_transaction['status'] = 'partially_returned'
        
        transactions[original_transaction_index] = original_transaction

        for variant_id, update_info in inventory_updates.items():
            for p_idx, p in enumerate(inventory):
                if p.get('id') == update_info['product_id']:
                    for v_idx, v in enumerate(p.get('variants', [])):
                        if v.get('id') == variant_id:
                            inventory[p_idx]['variants'][v_idx]['stock'] += update_info['stock_change']
                            inventory[p_idx]['timestamp_updated'] = now_iso
                            break
                    break

        if original_transaction['payment_method'] == 'cash' and total_return_amount > 0:
            for k_idx, k in enumerate(kassas):
                if k.get('id') == original_transaction['kassa_id']:
                    current_balance = to_decimal(k.get('balance', '0'))
                    kassas[k_idx]['balance'] = str(current_balance - total_return_amount)
                    kassas[k_idx].setdefault('history', []).append({
                        'type': 'return', 'amount': str(-total_return_amount), 'timestamp': now_iso,
                        'transaction_id': return_transaction_id
                    })
                    break

        save_json_data('transactions', transactions)
        save_json_data('inventory', inventory)
        save_json_data('kassas', kassas)
        upload_db_to_hf('transactions')
        upload_db_to_hf('inventory')
        upload_db_to_hf('kassas')

        flash("Возврат успешно оформлен.", "success")
        return redirect(url_for('cashier_dashboard', user_id=cashier_id))

@app.route('/backup', methods=['POST'])
@admin_required
def backup_hf():
    try:
        for key in DATA_FILES.keys():
            upload_db_to_hf(key)
        flash(f"Резервное копирование {len(DATA_FILES)} файлов инициировано.", "success")
    except Exception as e:
        flash(f"Ошибка при резервном копировании: {e}", "danger")
    return redirect(url_for('admin_panel'))

@app.route('/download', methods=['GET'])
@admin_required
def download_hf():
    errors = []
    success_count = 0
    for key in DATA_FILES.keys():
        filepath, _ = DATA_FILES[key]
        filename = os.path.basename(filepath)
        try:
            hf_hub_download(
                repo_id=REPO_ID, filename=filename, repo_type="dataset", token=HF_TOKEN_READ,
                local_dir=DATA_DIR, local_dir_use_symlinks=False, force_download=True,
            )
            success_count += 1
        except Exception as e:
            errors.append(f"Ошибка загрузки {filename}: {e}")
    if success_count > 0:
        flash(f"Успешно загружено {success_count} файлов. Данные перезаписаны.", "success")
    if errors:
        flash("Произошли ошибки: " + "; ".join(errors), "danger")
    return redirect(url_for('admin_panel'))

@app.route('/admin_login', methods=['GET', 'POST'])
def admin_login():
    if request.method == 'POST':
        password = request.form.get('password')
        if password == ADMIN_PASS:
            session['admin_logged_in'] = True
            session.permanent = True
            next_url = request.args.get('next')
            flash("Вы успешно вошли в систему.", "success")
            return redirect(next_url or url_for('admin_panel'))
        else:
            flash("Неверный пароль.", "danger")
    html = BASE_TEMPLATE.replace('__TITLE__', "Вход для администратора").replace('__CONTENT__', ADMIN_LOGIN_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html)

@app.route('/admin_logout')
def admin_logout():
    session.pop('admin_logged_in', None)
    flash("Вы вышли из системы.", "info")
    return redirect(url_for('sales_screen'))

@app.route('/api/held_bills', methods=['GET'])
def get_held_bills():
    bills = load_json_data('held_bills')
    bills.sort(key=lambda x: x.get('timestamp', ''), reverse=True)
    return jsonify(bills)

@app.route('/api/hold_bill', methods=['POST'])
def hold_bill():
    data = request.json
    if not data or 'name' not in data or 'cart' not in data:
        return jsonify({'success': False, 'message': 'Invalid data'}), 400
    
    bills = load_json_data('held_bills')
    new_bill = {
        'id': uuid.uuid4().hex,
        'name': data['name'],
        'cart': data['cart'],
        'timestamp': get_current_time().isoformat()
    }
    bills.append(new_bill)
    save_json_data('held_bills', bills)
    upload_db_to_hf('held_bills')
    return jsonify({'success': True, 'bill': new_bill})

@app.route('/api/restore_bill/<bill_id>', methods=['POST'])
def restore_bill(bill_id):
    bills = load_json_data('held_bills')
    bill_to_restore = find_item_by_field(bills, 'id', bill_id)
    if not bill_to_restore:
        return jsonify({'success': False, 'message': 'Bill not found'}), 404
        
    remaining_bills = [b for b in bills if b.get('id') != bill_id]
    save_json_data('held_bills', remaining_bills)
    upload_db_to_hf('held_bills')
    return jsonify({'success': True, 'bill': bill_to_restore})

@app.route('/api/hold_bill/<bill_id>', methods=['DELETE'])
def delete_held_bill(bill_id):
    bills = load_json_data('held_bills')
    initial_len = len(bills)
    bills = [b for b in bills if b.get('id') != bill_id]
    if len(bills) < initial_len:
        save_json_data('held_bills', bills)
        upload_db_to_hf('held_bills')
        return jsonify({'success': True})
    else:
        return jsonify({'success': False, 'message': 'Bill not found'}), 404

@app.route('/customers')
@admin_required
def customer_management():
    customers = load_json_data('customers')
    customers.sort(key=lambda x: x.get('name', '').lower())
    html = BASE_TEMPLATE.replace('__TITLE__', "Клиенты").replace('__CONTENT__', CUSTOMERS_CONTENT).replace('__SCRIPTS__', '')
    return render_template_string(html, customers=customers)

@app.route('/admin/customer', methods=['POST'])
@admin_required
def manage_customer():
    action = request.form.get('action')
    customers = load_json_data('customers')
    
    if action == 'add':
        name = request.form.get('name', '').strip()
        phone = request.form.get('phone', '').strip().replace('+', '').replace(' ', '')
        if name and phone:
            if not find_item_by_field(customers, 'phone', phone):
                new_customer = {'id': uuid.uuid4().hex, 'name': name, 'phone': phone}
                customers.append(new_customer)
                flash(f"Клиент '{name}' добавлен.", "success")
            else:
                flash(f"Клиент с номером {phone} уже существует.", "warning")
        else:
            flash("Имя и телефон обязательны.", "danger")
    
    elif action == 'delete':
        customer_id = request.form.get('id')
        initial_len = len(customers)
        customers = [c for c in customers if c.get('id') != customer_id]
        if len(customers) < initial_len:
            flash("Клиент удален.", "success")
        else:
            flash("Клиент не найден.", "warning")

    save_json_data('customers', customers)
    upload_db_to_hf('customers')
    return redirect(url_for('customer_management'))

@app.route('/api/customers/search')
def search_customers():
    query = request.args.get('q', '').lower()
    if not query:
        return jsonify([])
    customers = load_json_data('customers')
    matches = [
        c for c in customers 
        if query in c.get('name', '').lower() or query in c.get('phone', '')
    ]
    return jsonify(matches[:10])

@app.route('/api/customers/save', methods=['POST'])
def save_customer():
    data = request.json
    name = data.get('name', '').strip()
    phone = data.get('phone', '').strip()
    if not name or not phone:
        return jsonify({'success': False, 'message': 'Name and phone required'}), 400

    customers = load_json_data('customers')
    existing_customer = find_item_by_field(customers, 'phone', phone)
    if existing_customer:
        existing_customer['name'] = name
    else:
        new_customer = {'id': uuid.uuid4().hex, 'name': name, 'phone': phone}
        customers.append(new_customer)
    
    save_json_data('customers', customers)
    upload_db_to_hf('customers')
    return jsonify({'success': True})
    
BASE_TEMPLATE = """
<!DOCTYPE html>
<html lang="ru" data-bs-theme="light">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>__TITLE__ - POS</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
    <style>
        :root { --sidebar-width: 250px; }
        body { background-color: #f8f9fa; }
        .sidebar { position: fixed; top: 0; left: 0; width: var(--sidebar-width); height: 100vh; background-color: #343a40; padding-top: 1rem; }
        .sidebar .nav-link { color: rgba(255,255,255,.75); }
        .sidebar .nav-link:hover, .sidebar .nav-link.active { color: #fff; }
        .main-content { margin-left: var(--sidebar-width); padding: 1.5rem; }
        @media (max-width: 992px) {
            .sidebar { transform: translateX(calc(-1 * var(--sidebar-width))); transition: transform 0.3s ease-in-out; z-index: 1040; }
            .sidebar.active { transform: translateX(0); }
            .main-content { margin-left: 0; }
        }
        [data-bs-theme="dark"] body { background-color: #212529; color: #dee2e6; }
        [data-bs-theme="dark"] .card, [data-bs-theme="dark"] .modal-content, [data-bs-theme="dark"] .list-group-item, [data-bs-theme="dark"] .table, [data-bs-theme="dark"] .accordion-item { background-color: #343a40; }
        [data-bs-theme="dark"] .accordion-button { background-color: #3e444a; color: #fff; }
        [data-bs-theme="dark"] .accordion-button:not(.collapsed) { background-color: #495057;}
        [data-bs-theme="dark"] .accordion-button::after { filter: invert(1) grayscale(100) brightness(200%); }
        [data-bs-theme="dark"] .table-hover>tbody>tr:hover>* { color: var(--bs-table-hover-color); background-color: rgba(255, 255, 255, 0.075); }
        [data-bs-theme="dark"] .text-dark { color: #dee2e6 !important; }
        .product-card { cursor: pointer; }
        .product-card:hover { border-color: var(--bs-primary); }
        .payback-positive { color: var(--bs-success); }
        .payback-negative { color: var(--bs-danger); }
        .payback-zero { color: var(--bs-secondary); }
    </style>
</head>
<body>
<nav class="sidebar">
    <div class="p-3 text-white">
        <a href="/" class="text-white text-decoration-none"><h4 class="fw-bold"><i class="fas fa-cash-register me-2"></i>POS System</h4></a>
    </div>
    <ul class="nav flex-column">
        <li class="nav-item"><a class="nav-link {% if request.endpoint == 'sales_screen' %}active{% endif %}" href="{{ url_for('sales_screen') }}"><i class="fas fa-fw fa-dollar-sign me-2"></i>Касса</a></li>
        <li class="nav-item"><a class="nav-link {% if request.endpoint == 'inventory_management' %}active{% endif %}" href="{{ url_for('inventory_management') }}"><i class="fas fa-fw fa-boxes me-2"></i>Склад</a></li>
        <li class="nav-item"><a class="nav-link {% if request.endpoint == 'transaction_history' %}active{% endif %}" href="{{ url_for('transaction_history') }}"><i class="fas fa-fw fa-history me-2"></i>Транзакции</a></li>
        <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle {% if request.endpoint in ['reports', 'product_roi_report', 'employee_report', 'item_movement_report'] %}active{% endif %}" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false">
                <i class="fas fa-fw fa-chart-line me-2"></i>Отчеты
            </a>
            <ul class="dropdown-menu dropdown-menu-dark">
                <li><a class="dropdown-item" href="{{ url_for('reports') }}">Сводный отчет</a></li>
                <li><a class="dropdown-item" href="{{ url_for('employee_report') }}">Отчет по сотрудникам</a></li>
                <li><a class="dropdown-item" href="{{ url_for('item_movement_report') }}">Движение товаров</a></li>
                <li><a class="dropdown-item" href="{{ url_for('product_roi_report') }}">Окупаемость товаров</a></li>
            </ul>
        </li>
        <li class="nav-item"><a class="nav-link {% if request.endpoint == 'customer_management' %}active{% endif %}" href="{{ url_for('customer_management') }}"><i class="fas fa-fw fa-users me-2"></i>Клиенты</a></li>
        <li class="nav-item"><a class="nav-link {% if request.endpoint in ['cashier_login', 'cashier_dashboard'] %}active{% endif %}" href="{{ url_for('cashier_login') }}"><i class="fas fa-fw fa-user-circle me-2"></i>Кабинет кассира</a></li>
        <li class="nav-item"><a class="nav-link {% if request.endpoint in ['admin_panel', 'admin_shifts'] %}active{% endif %}" href="{{ url_for('admin_panel') }}"><i class="fas fa-fw fa-cogs me-2"></i>Админка</a></li>
        
        {% if not session.admin_logged_in %}
        <li class="nav-item mt-3"><a class="nav-link text-warning" href="{{ url_for('admin_login') }}"><i class="fas fa-fw fa-user-shield me-2"></i>Войти как админ</a></li>
        {% else %}
        <li class="nav-item mt-3"><a class="nav-link text-warning" href="{{ url_for('admin_logout') }}"><i class="fas fa-fw fa-sign-out-alt me-2"></i>Выйти (Админ)</a></li>
        {% endif %}
    </ul>
    <div class="mt-auto p-3 text-secondary small">
        &copy; {{ get_current_time().year }}<br>{{ get_current_time().strftime('%Y-%m-%d %H:%M') }}
    </div>
</nav>

<div class="main-content">
    <header class="d-flex justify-content-between align-items-center mb-4">
        <button class="btn btn-dark d-lg-none" id="sidebar-toggle"><i class="fas fa-bars"></i></button>
        <h2 class="h3 mb-0">__TITLE__</h2>
        <div class="d-flex align-items-center">
            {% if not session.admin_logged_in %}
            <a href="{{ url_for('admin_login') }}" class="btn btn-outline-primary btn-sm me-3"><i class="fas fa-user-shield me-1"></i>Войти как админ</a>
            {% endif %}
            <div id="theme-toggle" style="cursor: pointer;"><i class="fas fa-sun fa-lg"></i></div>
        </div>
    </header>
    <main>
        {% with messages = get_flashed_messages(with_categories=true) %}
          {% if messages %}
            {% for category, message in messages %}
              <div class="alert alert-{{ category }} alert-dismissible fade show" role="alert">
                {{ message }}
                <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
              </div>
            {% endfor %}
          {% endif %}
        {% endwith %}
        __CONTENT__
    </main>
</div>

<div class="modal fade" id="receiptModal" tabindex="-1" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title">Готово</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        <p>Накладная успешно сохранена.</p>
        <div class="mb-3">
            <label for="whatsapp-phone" class="form-label">Отправить накладную на WhatsApp</label>
            <div class="input-group">
                <span class="input-group-text">+7</span>
                <input type="tel" class="form-control" id="whatsapp-phone" placeholder="7071234567">
            </div>
            <div class="form-text">Введите номер без +7.</div>
        </div>
        <div class="mb-3">
            <label for="customer-search" class="form-label">Поиск клиента</label>
            <input type="text" id="customer-search" class="form-control" placeholder="Начните вводить имя...">
            <div id="customer-search-results" class="list-group mt-1" style="max-height: 150px; overflow-y: auto;"></div>
        </div>
        <div class="form-check">
            <input class="form-check-input" type="checkbox" id="save-customer-checkbox">
            <label class="form-check-label" for="save-customer-checkbox">Сохранить/обновить клиента</label>
        </div>
        <div class="mb-3 mt-2" id="customer-name-container" style="display:none;">
            <label for="customer-name-input" class="form-label">Имя клиента</label>
            <input type="text" class="form-control" id="customer-name-input">
        </div>
        <input type="hidden" id="receipt-url">
      </div>
      <div class="modal-footer">
        <a id="view-receipt-btn" href="#" target="_blank" class="btn btn-secondary">Посмотреть накладную</a>
        <button type="button" id="send-whatsapp-btn" class="btn btn-success"><i class="fab fa-whatsapp"></i> Отправить</button>
      </div>
    </div>
  </div>
</div>

<div class="modal fade" id="variantSelectModal" tabindex="-1" aria-hidden="true">
  <div class="modal-dialog modal-lg">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="variantSelectModalTitle">Выберите вариант</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        <div id="variant-list" class="list-group"></div>
      </div>
    </div>
  </div>
</div>

<div class="modal fade" id="priceSelectModal" tabindex="-1" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="priceSelectModalTitle">Выберите цену</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        <div class="d-grid gap-3" id="price-options-container">
        </div>
      </div>
    </div>
  </div>
</div>

<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"></script>
<script src="https://unpkg.com/html5-qrcode@2.3.8/html5-qrcode.min.js"></script>
<script>
    let receiptModal;
    document.addEventListener('DOMContentLoaded', () => {
        receiptModal = new bootstrap.Modal(document.getElementById('receiptModal'));
        document.getElementById('sidebar-toggle')?.addEventListener('click', () => document.querySelector('.sidebar').classList.toggle('active'));
        const themeToggle = document.getElementById('theme-toggle');
        const getStoredTheme = () => localStorage.getItem('theme');
        const setStoredTheme = theme => localStorage.setItem('theme', theme);
        const getPreferredTheme = () => getStoredTheme() || (window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light');
        const setTheme = theme => {
            document.documentElement.setAttribute('data-bs-theme', theme);
            themeToggle.innerHTML = theme === 'dark' ? '<i class="fas fa-moon fa-lg"></i>' : '<i class="fas fa-sun fa-lg"></i>';
        };
        setTheme(getPreferredTheme());
        themeToggle.addEventListener('click', () => {
            const newTheme = getPreferredTheme() === 'light' ? 'dark' : 'light';
            setStoredTheme(newTheme);
            setTheme(newTheme);
        });

        const receiptModalEl = document.getElementById('receiptModal');
        if (receiptModalEl) {
            const saveCustomerCheckbox = document.getElementById('save-customer-checkbox');
            const customerNameContainer = document.getElementById('customer-name-container');
            const customerSearchInput = document.getElementById('customer-search');
            const customerSearchResults = document.getElementById('customer-search-results');
            const whatsappPhoneInput = document.getElementById('whatsapp-phone');
            const customerNameInput = document.getElementById('customer-name-input');
            const sendWhatsappBtn = document.getElementById('send-whatsapp-btn');

            saveCustomerCheckbox.addEventListener('change', () => {
                customerNameContainer.style.display = saveCustomerCheckbox.checked ? 'block' : 'none';
            });

            let searchTimeout;
            customerSearchInput.addEventListener('input', () => {
                clearTimeout(searchTimeout);
                const query = customerSearchInput.value.trim();
                if (query.length < 2) {
                    customerSearchResults.innerHTML = '';
                    return;
                }
                searchTimeout = setTimeout(() => {
                    fetch(`/api/customers/search?q=${encodeURIComponent(query)}`)
                        .then(res => res.json())
                        .then(customers => {
                            customerSearchResults.innerHTML = '';
                            if (customers.length > 0) {
                                customers.forEach(customer => {
                                    const item = document.createElement('a');
                                    item.href = '#';
                                    item.className = 'list-group-item list-group-item-action';
                                    item.textContent = `${customer.name} - ${customer.phone}`;
                                    item.addEventListener('click', (e) => {
                                        e.preventDefault();
                                        whatsappPhoneInput.value = customer.phone;
                                        customerNameInput.value = customer.name;
                                        customerSearchInput.value = customer.name;
                                        customerSearchResults.innerHTML = '';
                                    });
                                    customerSearchResults.appendChild(item);
                                });
                            } else {
                                customerSearchResults.innerHTML = '<div class="list-group-item">Клиенты не найдены.</div>';
                            }
                        });
                }, 300);
            });

            sendWhatsappBtn.addEventListener('click', () => {
                const phone = whatsappPhoneInput.value.replace(/\\D/g, '');
                const receiptUrl = document.getElementById('receipt-url').value;
                if (!phone || !receiptUrl) {
                    alert('Введите номер телефона.');
                    return;
                }
                const fullPhone = '7' + phone;
                const message = encodeURIComponent(`Ваша накладная: ${receiptUrl}`);
                window.open(`https://wa.me/${fullPhone}?text=${message}`, '_blank');
                
                if (saveCustomerCheckbox.checked) {
                    const name = customerNameInput.value.trim();
                    if (name && phone) {
                        fetch('/api/customers/save', {
                            method: 'POST',
                            headers: {'Content-Type': 'application/json'},
                            body: JSON.stringify({name: name, phone: phone})
                        })
                        .then(res => res.json())
                        .then(data => {
                            if (!data.success) console.error('Failed to save customer:', data.message);
                        });
                    }
                }
            });

            receiptModalEl.addEventListener('show.bs.modal', () => {
                whatsappPhoneInput.value = '';
                customerSearchInput.value = '';
                customerNameInput.value = '';
                customerSearchResults.innerHTML = '';
                saveCustomerCheckbox.checked = false;
                customerNameContainer.style.display = 'none';
            });
        }
    });
</script>
__SCRIPTS__
</body>
</html>
"""

SALES_SCREEN_CONTENT = """
<div class="row">
    <div class="col-lg-7 mb-4">
        <div class="card">
            <div class="card-header d-flex justify-content-between align-items-center">
                <h5 class="mb-0">Товары</h5>
                <div>
                    <button id="custom-item-btn" class="btn btn-info btn-sm"><i class="fas fa-plus me-2"></i>Свой товар</button>
                    <button id="scan-btn" class="btn btn-primary btn-sm"><i class="fas fa-barcode me-2"></i>Сканировать</button>
                </div>
            </div>
            <div class="card-body">
                <div id="scanner-container" class="mb-3" style="display: none; position: relative;">
                    <div id="reader" style="width: 100%;"></div>
                    <div id="scanner-status" style="position: absolute; top: 10px; left: 10px; background: rgba(0,0,0,0.5); color: white; padding: 5px; border-radius: 5px; display: none;"></div>
                    <button id="stop-scan-btn" class="btn btn-danger btn-sm mt-2">Остановить</button>
                </div>
                <input type="text" id="product-search" class="form-control mb-3" placeholder="Поиск по названию или штрих-коду...">
                <div id="product-search-results" class="d-grid gap-2" style="display: none; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));"></div>
                
                <div id="product-accordion" class="accordion">
                    {% for letter, products in grouped_inventory %}
                    <div class="accordion-item">
                        <h2 class="accordion-header" id="heading-{{ letter }}">
                            <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapse-{{ letter }}" aria-expanded="false" aria-controls="collapse-{{ letter }}">
                                {{ letter }}
                            </button>
                        </h2>
                        <div id="collapse-{{ letter }}" class="accordion-collapse collapse" aria-labelledby="heading-{{ letter }}" data-bs-parent="#product-accordion">
                            <div class="accordion-body d-grid gap-2" style="grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));">
                                {% for p in products %}
                                <div class="card text-center product-card" data-barcode="{{ p.barcode }}">
                                    <div class="card-body p-2">
                                        <h6 class="card-title small mb-1">{{ p.name }}</h6>
                                        <p class="card-text fw-bold mb-0">
                                            {% if p.variants|length > 1 %}
                                                от {{ format_currency_py(p.variants|map(attribute='price_regular')|min) }} ₸ 
                                            {% elif p.variants|length == 1 %}
                                                {{ format_currency_py(p.variants[0].get('price_regular', p.variants[0].get('price'))) }} ₸
                                            {% else %}
                                                Нет в наличии
                                            {% endif %}
                                        </p>
                                    </div>
                                </div>
                                {% endfor %}
                            </div>
                        </div>
                    </div>
                    {% endfor %}
                </div>
            </div>
        </div>
    </div>
    <div class="col-lg-5">
        <div class="card">
            <div class="card-header">
                <div class="d-flex justify-content-between align-items-center">
                    <h5 class="mb-0">Накладная</h5>
                    <div id="shift-controls"></div>
                </div>
                <div id="session-info" class="small text-muted mt-1"></div>
            </div>
            <div class="card-body">
                <div id="edit-mode-banner" class="alert alert-warning mb-2 p-2" style="display:none;">
                    <strong>Режим редактирования:</strong> Накладная <span id="edit-tx-id-display"></span>
                    <button class="btn btn-sm btn-danger float-end py-0" onclick="window.location.href='/'">Отмена</button>
                </div>
                <div id="cart-items" class="list-group mb-3" style="max-height: 400px; overflow-y: auto;"></div>
                <div class="mb-3">
                    <div class="d-flex justify-content-between"><span>Подытог:</span><span id="cart-subtotal">0 ₸</span></div>
                    <div class="d-flex justify-content-between"><span>Доставка:</span><span id="cart-delivery">0 ₸</span></div>
                    <hr class="my-1">
                    <div class="d-flex justify-content-between align-items-center h4"><span>Итого:</span><span id="cart-total">0 ₸</span></div>
                </div>
                <div class="btn-group w-100 mb-2">
                    <button class="btn btn-outline-secondary btn-sm" id="add-delivery-btn"><i class="fas fa-truck"></i> Доставка</button>
                    <button class="btn btn-outline-secondary btn-sm" id="add-note-btn"><i class="fas fa-sticky-note"></i> Заметка</button>
                </div>
                <div class="d-grid gap-2" id="payment-buttons-container">
                    <div class="btn-group"><button class="btn btn-success flex-grow-1" id="pay-cash-btn"><i class="fas fa-money-bill-wave me-2"></i>Наличные</button><button class="btn btn-info flex-grow-1" id="pay-card-btn"><i class="far fa-credit-card me-2"></i>Карта</button></div>
                    <div class="btn-group">
                        <button class="btn btn-secondary" id="hold-bill-btn"><i class="fas fa-pause me-2"></i>Отложить накладную</button>
                        <button class="btn btn-secondary" id="list-held-bills-btn"><i class="fas fa-list me-2"></i>Отложенные <span id="held-bills-count" class="badge bg-primary ms-1" style="display:none;"></span></button>
                    </div>
                    <button class="btn btn-danger" id="clear-cart-btn">Очистить</button>
                </div>
            </div>
        </div>
    </div>
</div>

<div class="modal fade" id="cashierLoginModal" data-bs-backdrop="static" data-bs-keyboard="false" tabindex="-1">
  <div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Вход для кассира</h5></div>
      <div class="modal-body">
        <label for="cashier-pin-input" class="form-label">Введите ПИН-код</label>
        <input type="password" id="cashier-pin-input" class="form-control form-control-lg text-center" inputmode="numeric" autofocus>
        <div id="pin-error" class="text-danger mt-2"></div>
      </div>
       <div class="modal-footer"><button type="button" id="pin-submit-btn" class="btn btn-primary">Войти</button></div>
    </div>
  </div>
</div>

<div class="modal fade" id="startShiftModal" data-bs-backdrop="static" data-bs-keyboard="false" tabindex="-1">
  <div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Начать смену</h5></div>
      <div class="modal-body">
        <p>Кассир: <strong id="start-shift-cashier-name"></strong></p>
        <label for="kassa-select-modal" class="form-label">Выберите кассу</label>
        <select id="kassa-select-modal" class="form-select">
            <option value="">-- Выберите кассу --</option>
            {% for k in kassas %}<option value="{{ k.id }}" data-name="{{ k.name }}">{{ k.name }}</option>{% endfor %}
        </select>
      </div>
      <div class="modal-footer">
        <button type="button" id="logout-btn" class="btn btn-secondary me-auto">Сменить кассира</button>
        <button type="button" id="start-shift-confirm-btn" class="btn btn-primary">Начать</button>
      </div>
    </div>
  </div>
</div>

<div class="modal fade" id="customItemModal" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Товар без штрихкода</h5></div>
      <form id="custom-item-form">
        <div class="modal-body">
          <div class="mb-3"><label class="form-label">Название (необязательно)</label><input type="text" id="custom-item-name" class="form-control" placeholder="Напр. 'Пакет'"></div>
          <div class="mb-3"><label class="form-label">Цена за 1 шт.</label><input type="text" id="custom-item-price" class="form-control" inputmode="decimal" placeholder="0" required></div>
          <div class="mb-3"><label class="form-label">Количество</label><input type="number" id="custom-item-qty" class="form-control" value="" placeholder="1" min="1" required></div>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Добавить в накладную</button></div>
      </form>
    </div>
  </div>
</div>

<div class="modal fade" id="holdBillModal" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Отложить накладную</h5></div>
      <form id="hold-bill-form">
        <div class="modal-body">
          <label for="hold-bill-name" class="form-label">Название для этой накладной</label>
          <input type="text" id="hold-bill-name" class="form-control" placeholder="Напр. 'Стол 5', 'Мария'" required>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Отложить</button></div>
      </form>
    </div>
  </div>
</div>

<div class="modal fade" id="heldBillsListModal" tabindex="-1">
  <div class="modal-dialog modal-lg">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Отложенные накладные</h5></div>
      <div class="modal-body">
        <div id="held-bills-list" class="list-group">
        </div>
      </div>
    </div>
  </div>
</div>
"""

SALES_SCREEN_SCRIPTS = """
<script>
document.addEventListener('DOMContentLoaded', () => {
    const cart = {};
    let deliveryCost = 0;
    let transactionNote = '';
    
    const cartItemsEl = document.getElementById('cart-items');
    const cartSubtotalEl = document.getElementById('cart-subtotal');
    const cartDeliveryEl = document.getElementById('cart-delivery');
    const cartTotalEl = document.getElementById('cart-total');
    
    let audioCtx;
    let isScannerPaused = false;
    
    const variantSelectModal = new bootstrap.Modal(document.getElementById('variantSelectModal'));
    const priceSelectModal = new bootstrap.Modal(document.getElementById('priceSelectModal'));
    const cashierLoginModal = new bootstrap.Modal(document.getElementById('cashierLoginModal'));
    const startShiftModal = new bootstrap.Modal(document.getElementById('startShiftModal'));
    const customItemModal = new bootstrap.Modal(document.getElementById('customItemModal'));
    const holdBillModal = new bootstrap.Modal(document.getElementById('holdBillModal'));
    const heldBillsListModal = new bootstrap.Modal(document.getElementById('heldBillsListModal'));
    const allProducts = {{ inventory|tojson|safe }};

    const session = {
        cashier: null,
        kassa: null,
        shift: null
    };

    const editTx = {{ edit_tx|tojson|safe if edit_tx else 'null' }};
    if (editTx) {
        document.getElementById('edit-mode-banner').style.display = 'block';
        document.getElementById('edit-tx-id-display').textContent = editTx.id.substring(0,8);
        editTx.items.forEach(item => {
            let variantName = '';
            if (item.name.includes('(')) {
                variantName = item.name.substring(item.name.indexOf('(')+1, item.name.lastIndexOf(')'));
            }
            cart[item.variant_id] = {
                productId: item.product_id,
                productName: item.name,
                variantName: variantName,
                price: String(item.price_at_sale).replace('.', ','),
                quantity: item.quantity,
                discount: String(item.discount_per_item || '0').replace('.', ','),
                isCustom: item.is_custom || false
            };
        });
        deliveryCost = parseFloat(editTx.delivery_cost || 0);
        transactionNote = editTx.note || '';
        
        const paymentContainer = document.getElementById('payment-buttons-container');
        paymentContainer.innerHTML = `<button class="btn btn-warning w-100 btn-lg mb-2" id="save-edit-btn"><i class="fas fa-save me-2"></i>Сохранить изменения</button>`;
        document.getElementById('save-edit-btn').addEventListener('click', () => {
            completeSale(editTx.payment_method, editTx.id);
        });
    }

    function playBeep() {
        if (!audioCtx) {
            try { audioCtx = new (window.AudioContext || window.webkitAudioContext)(); } 
            catch (e) { console.error("Web Audio API is not supported"); return; }
        }
        const oscillator = audioCtx.createOscillator();
        const gainNode = audioCtx.createGain();
        oscillator.connect(gainNode);
        gainNode.connect(audioCtx.destination);
        oscillator.type = 'sine';
        oscillator.frequency.setValueAtTime(880, audioCtx.currentTime);
        gainNode.gain.setValueAtTime(0.5, audioCtx.currentTime);
        gainNode.gain.exponentialRampToValueAtTime(0.0001, audioCtx.currentTime + 0.15);
        oscillator.start(audioCtx.currentTime);
        oscillator.stop(audioCtx.currentTime + 0.15);
    }
    
    function parseLocaleNumber(stringNumber) {
        return parseFloat(String(stringNumber).replace(/\\s/g, '').replace(',', '.')) || 0;
    }

    const formatCurrencyJS = (value) => {
        try {
            const number = parseFloat(String(value).replace(/\\s/g, '').replace(',', '.'));
            if (isNaN(number)) return '0';
            return number.toLocaleString('ru-RU', {minimumFractionDigits: 0, maximumFractionDigits: 0});
        } catch (e) {
            return '0';
        }
    };

    const updateCartView = () => {
        cartItemsEl.innerHTML = '';
        let subtotal = 0;
        if (Object.keys(cart).length === 0) {
            cartItemsEl.innerHTML = '<p class="text-center text-muted">Корзина пуста</p>';
        }
        for (const id in cart) {
            const item = cart[id];
            subtotal += (parseLocaleNumber(item.price) - parseLocaleNumber(item.discount)) * item.quantity;
            cartItemsEl.innerHTML += `
                <div class="list-group-item">
                    <div class="d-flex justify-content-between align-items-start">
                        <div>
                            <h6 class="mb-0 small">${item.productName} ${item.variantName && !item.isCustom && !item.productName.includes(item.variantName) ? '('+item.variantName+')' : ''}</h6>
                            <small>${formatCurrencyJS(item.price)} ₸</small>
                        </div>
                        <div class="d-flex align-items-center">
                            <button class="btn btn-sm btn-outline-secondary cart-qty-btn" data-id="${id}" data-op="-1">-</button>
                            <input type="number" class="form-control form-control-sm text-center mx-1 cart-qty-input" data-id="${id}" value="${item.quantity}" style="width: 60px;" min="1">
                            <button class="btn btn-sm btn-outline-secondary cart-qty-btn" data-id="${id}" data-op="1">+</button>
                        </div>
                    </div>
                     <div class="input-group input-group-sm mt-2">
                      <span class="input-group-text">Скидка</span>
                      <input type="text" class="form-control cart-discount-input" data-id="${id}" value="${item.discount}" inputmode="decimal" placeholder="0">
                    </div>
                </div>`;
        }
        const total = subtotal + deliveryCost;
        cartSubtotalEl.textContent = formatCurrencyJS(subtotal) + ' ₸';
        cartDeliveryEl.textContent = formatCurrencyJS(deliveryCost) + ' ₸';
        cartTotalEl.textContent = formatCurrencyJS(total) + ' ₸';
    };

    const addToCart = (product, variant, price, priceType) => {
        if (cart[variant.id]) {
            cart[variant.id].quantity += 1;
        } else {
            cart[variant.id] = {
                productId: product.id,
                productName: product.name,
                variantName: variant.option_value,
                price: String(price).replace('.',','),
                priceType: priceType,
                quantity: 1,
                discount: '0',
            };
        }
        playBeep();
        updateCartView();
    };

    const showPriceSelector = (product, variant) => {
        document.getElementById('priceSelectModalTitle').textContent = `${product.name} (${variant.option_value})`;
        const container = document.getElementById('price-options-container');
        container.innerHTML = '';
        
        const prices = [
            { type: 'Общая', value: variant.price_regular || variant.price },
            { type: 'Минимальная', value: variant.price_min },
            { type: 'Оптовая', value: variant.price_wholesale }
        ];

        prices.forEach(p => {
            if (p.value !== undefined && p.value !== '0' && p.value !== '0.00' && p.value !== '') {
                const btn = document.createElement('button');
                btn.type = 'button';
                btn.className = 'btn btn-primary btn-lg';
                btn.innerHTML = `${p.type} <br><strong>${formatCurrencyJS(p.value)} ₸</strong>`;
                btn.onclick = () => {
                    addToCart(product, variant, p.value, p.type);
                    priceSelectModal.hide();
                };
                container.appendChild(btn);
            }
        });
        
        if (container.innerHTML === '') {
            addToCart(product, variant, variant.price_regular || variant.price || '0', 'Общая');
        } else {
            priceSelectModal.show();
        }
    };
    
    const handleProductSelection = (product) => {
        let activeVariants = product.variants;
        if (!editTx) {
            activeVariants = product.variants.filter(v => v.stock > 0);
        }
        if (activeVariants.length === 0) {
            alert("У этого товара нет доступных вариантов.");
            return;
        }
        if (activeVariants.length === 1) {
            showPriceSelector(product, activeVariants[0]);
        } else {
            document.getElementById('variantSelectModalTitle').textContent = `Выберите вариант для "${product.name}"`;
            const variantList = document.getElementById('variant-list');
            variantList.innerHTML = '';
            activeVariants.forEach(variant => {
                const btn = document.createElement('button');
                btn.type = 'button';
                btn.className = 'list-group-item list-group-item-action d-flex justify-content-between align-items-center';
                const imageUrl = variant.image_url ? `<img src="${variant.image_url}" class="img-thumbnail me-3" style="width: 50px; height: 50px; object-fit: cover;">` : '<div style="width: 50px; height: 50px;" class="me-3"></div>';
                btn.innerHTML = `
                    <div class="d-flex align-items-center">
                        ${imageUrl}
                        <div>${variant.option_value} - <strong>${formatCurrencyJS(variant.price_regular || variant.price)} ₸</strong></div>
                    </div>
                    <span class="badge bg-secondary">Остаток: ${variant.stock}</span>`;
                btn.addEventListener('click', () => {
                    variantSelectModal.hide();
                    showPriceSelector(product, variant);
                });
                variantList.appendChild(btn);
            });
            variantSelectModal.show();
        }
    };
    
    const fetchAndHandleProduct = (barcode) => {
        fetch(`/api/product_by_barcode/${barcode}`)
            .then(res => res.json())
            .then(data => {
                if (data.success) handleProductSelection(data.product);
                else alert(data.message);
            });
    }

    const productsContainer = document.querySelector('.col-lg-7 .card .card-body');
    productsContainer.addEventListener('click', e => {
        const card = e.target.closest('.product-card');
        if (card) {
            fetchAndHandleProduct(card.dataset.barcode);
        }
    });

    const updateCartItemQuantity = (id, newQuantity) => {
        if (cart[id]) {
            const qty = parseInt(newQuantity, 10);
            if (!isNaN(qty) && qty > 0) {
                cart[id].quantity = qty;
            } else {
                delete cart[id];
            }
            updateCartView();
        }
    };

    cartItemsEl.addEventListener('click', e => {
        if (e.target.classList.contains('cart-qty-btn')) {
            const id = e.target.dataset.id;
            const op = parseInt(e.target.dataset.op, 10);
            if (cart[id]) {
                let newQuantity = cart[id].quantity + op;
                updateCartItemQuantity(id, newQuantity);
            }
        }
    });

    cartItemsEl.addEventListener('change', e => {
        if (e.target.classList.contains('cart-qty-input')) {
            const id = e.target.dataset.id;
            updateCartItemQuantity(id, e.target.value);
        }
        if (e.target.classList.contains('cart-discount-input')) {
            const id = e.target.dataset.id;
            if (cart[id]) {
                cart[id].discount = e.target.value;
                updateCartView();
            }
        }
    });
    
    if (document.getElementById('clear-cart-btn')) {
        document.getElementById('clear-cart-btn').addEventListener('click', () => {
            for(const id in cart) delete cart[id];
            deliveryCost = 0;
            transactionNote = '';
            updateCartView();
        });
    }

    const productSearchInput = document.getElementById('product-search');
    const productAccordionEl = document.getElementById('product-accordion');
    const productSearchResultsEl = document.getElementById('product-search-results');

    productSearchInput.addEventListener('input', e => {
        const term = e.target.value.toLowerCase().trim();

        if (term === '') {
            productAccordionEl.style.display = '';
            productSearchResultsEl.style.display = 'none';
            productSearchResultsEl.innerHTML = '';
            document.querySelectorAll('#product-accordion .accordion-collapse.show').forEach(el => {
                bootstrap.Collapse.getOrCreateInstance(el).hide();
            });
            return;
        }

        productAccordionEl.style.display = 'none';
        productSearchResultsEl.style.display = 'grid';

        const filtered = allProducts.filter(p => p.name.toLowerCase().includes(term) || p.barcode.toLowerCase().includes(term));

        filtered.sort((a, b) => {
            const aName = a.name.toLowerCase();
            const bName = b.name.toLowerCase();
            const aStarts = aName.startsWith(term);
            const bStarts = bName.startsWith(term);
            const aBarcode = a.barcode.toLowerCase() === term;
            const bBarcode = b.barcode.toLowerCase() === term;
            
            if (aBarcode && !bBarcode) return -1;
            if (!aBarcode && bBarcode) return 1;
            if (aStarts && !bStarts) return -1;
            if (!aStarts && bStarts) return 1;
            
            return aName.localeCompare(bName);
        });

        productSearchResultsEl.innerHTML = filtered.length > 0 ? filtered.map(p => {
            let priceText = 'Нет в наличии';
            if (p.variants && p.variants.length > 0) {
                const activeVariants = p.variants.filter(v => v.stock > 0);
                if (activeVariants.length > 0 || editTx) {
                    let variantsToUse = editTx ? p.variants : activeVariants;
                    if (variantsToUse.length === 1) {
                        priceText = `${formatCurrencyJS(variantsToUse[0].price_regular || variantsToUse[0].price)} ₸`;
                    } else {
                        const prices = variantsToUse.map(v => parseFloat(v.price_regular || v.price));
                        priceText = `от ${formatCurrencyJS(Math.min(...prices))} ₸`;
                    }
                }
            }
            return `
                <div class="card text-center product-card" data-barcode="${p.barcode}">
                    <div class="card-body p-2">
                        <h6 class="card-title small mb-1">${p.name}</h6>
                        <p class="card-text fw-bold mb-0">${priceText}</p>
                    </div>
                </div>`;
        }).join('') : '<p class="text-muted text-center col-12">Товары не найдены.</p>';
    });

    const completeSale = (paymentMethod, editTxId = null) => {
        if (!editTxId && (!session.shift || !session.cashier || !session.kassa)) {
            alert('Смена не активна. Начните смену, чтобы проводить продажи.');
            return;
        }
        if (Object.keys(cart).length === 0) {
            alert('Корзина пуста!');
            return;
        }
        fetch('/api/complete_sale', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({ 
                cart: cart, 
                userId: session.cashier ? session.cashier.id : (editTx ? editTx.user_id : ''), 
                kassaId: session.kassa ? session.kassa.id : (editTx ? editTx.kassa_id : ''),
                shiftId: session.shift ? session.shift.id : (editTx ? editTx.shift_id : ''),
                paymentMethod: paymentMethod,
                deliveryCost: deliveryCost,
                note: transactionNote,
                edit_tx_id: editTxId
            })
        })
        .then(res => {
            if (res.status === 401) {
                return res.json().then(data => {
                    alert(data.message || 'Сессия недействительна. Пожалуйста, войдите снова.');
                    handleLogout();
                    return Promise.reject(new Error('Logout required'));
                });
            }
            return res.json();
        })
        .then(data => {
            if (data.success) {
                if (editTxId) {
                    window.location.href = data.receiptUrl;
                    return;
                }
                for(const id in cart) delete cart[id];
                deliveryCost = 0;
                transactionNote = '';
                updateCartView();
                document.getElementById('receipt-url').value = data.receiptUrl;
                document.getElementById('view-receipt-btn').href = data.receiptUrl;
                receiptModal.show();
            } else {
                alert(`Ошибка: ${data.message}`);
            }
        })
        .catch(err => {
            if (err.message !== 'Logout required') {
                alert(`Сетевая ошибка: ${err}`);
            }
        });
    };
    
    if (document.getElementById('pay-cash-btn')) {
        document.getElementById('pay-cash-btn').addEventListener('click', () => completeSale('cash'));
        document.getElementById('pay-card-btn').addEventListener('click', () => completeSale('card'));
    }

    const html5QrCode = new Html5Qrcode("reader");
    const scannerStatusEl = document.getElementById('scanner-status');
    
    const onScanSuccess = (decodedText, decodedResult) => {
        if (isScannerPaused) return;
        isScannerPaused = true;
        scannerStatusEl.textContent = 'Пауза...';
        scannerStatusEl.style.display = 'block';
        if (html5QrCode.getState() === 2) html5QrCode.pause();
        fetchAndHandleProduct(decodedText);
        setTimeout(() => {
            isScannerPaused = false;
            scannerStatusEl.style.display = 'none';
            if (html5QrCode.getState() === 2) html5QrCode.resume();
        }, 1000);
    };

    const startScanner = () => {
        document.getElementById('scanner-container').style.display = 'block';
        const config = { fps: 15, qrbox: { width: 300, height: 150 } };
        html5QrCode.start({ facingMode: "environment" }, config, onScanSuccess)
            .catch(err => console.error("Scanner start error:", err));
    };
    
    const stopScanner = () => {
        if (html5QrCode.isScanning) {
            html5QrCode.stop().then(() => {
                document.getElementById('scanner-container').style.display = 'none';
            }).catch(err => console.error("Failed to stop scanner", err));
        } else {
            document.getElementById('scanner-container').style.display = 'none';
        }
    };

    document.getElementById('scan-btn').addEventListener('click', startScanner);
    document.getElementById('stop-scan-btn').addEventListener('click', stopScanner);

    const updateSessionUI = () => {
        const sessionInfoEl = document.getElementById('session-info');
        const shiftControlsEl = document.getElementById('shift-controls');
        
        if (session.shift) {
            sessionInfoEl.innerHTML = `Кассир: <strong>${session.cashier.name}</strong> | Касса: <strong>${session.kassa.name}</strong>`;
            shiftControlsEl.innerHTML = '<button id="end-shift-btn" class="btn btn-danger btn-sm">Закончить смену</button>';
            document.getElementById('end-shift-btn').addEventListener('click', handleEndShift);
        } else if (session.cashier) {
            sessionInfoEl.innerHTML = `Кассир: <strong>${session.cashier.name}</strong>. Смена не начата.`;
            shiftControlsEl.innerHTML = '<button id="start-shift-btn" class="btn btn-success btn-sm">Начать смену</button>';
            document.getElementById('start-shift-btn').addEventListener('click', () => {
                 document.getElementById('start-shift-cashier-name').textContent = session.cashier.name;
                 startShiftModal.show();
            });
        } else {
            sessionInfoEl.innerHTML = 'Нет активного кассира';
            shiftControlsEl.innerHTML = '';
        }
    };
    
    const handleLogin = (pin) => {
        fetch('/api/verify_pin', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({pin: pin})
        })
        .then(res => res.json())
        .then(data => {
            if (data.success) {
                session.cashier = data.user;
                localStorage.setItem('current_cashier', JSON.stringify(data.user));
                cashierLoginModal.hide();
                updateSessionUI();
                document.getElementById('start-shift-cashier-name').textContent = session.cashier.name;
                startShiftModal.show();
            } else {
                document.getElementById('pin-error').textContent = data.message;
            }
        });
    };

    const handleLogout = () => {
        session.cashier = null;
        session.kassa = null;
        session.shift = null;
        localStorage.removeItem('current_cashier');
        localStorage.removeItem('current_kassa');
        localStorage.removeItem('current_shift');
        startShiftModal.hide();
        updateSessionUI();
        if (!editTx) cashierLoginModal.show();
    };

    const handleStartShift = () => {
        const kassaSelect = document.getElementById('kassa-select-modal');
        const kassaId = kassaSelect.value;
        const kassaName = kassaSelect.options[kassaSelect.selectedIndex].dataset.name;
        if (!kassaId) { alert('Выберите кассу'); return; }

        fetch('/api/shift/start', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({userId: session.cashier.id, kassaId: kassaId})
        })
        .then(res => {
            if (res.status === 401) {
                return res.json().then(data => {
                    alert(data.message || 'Сессия недействительна. Пожалуйста, войдите снова.');
                    handleLogout();
                    return Promise.reject(new Error('Logout required'));
                });
            }
            return res.json();
        })
        .then(data => {
            if (data.success) {
                session.kassa = {id: data.shift.kassa_id, name: data.shift.kassa_name};
                session.shift = data.shift;
                localStorage.setItem('current_kassa', JSON.stringify(session.kassa));
                localStorage.setItem('current_shift', JSON.stringify(session.shift));
                startShiftModal.hide();
                updateSessionUI();
            } else {
                alert(`Ошибка: ${data.message}`);
            }
        })
        .catch(err => {
            if (err.message !== 'Logout required') {
                alert(`Сетевая ошибка: ${err}`);
            }
        });
    };
    
    const handleEndShift = () => {
        if (!confirm('Вы уверены, что хотите закончить смену?')) return;
        fetch('/api/shift/end', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({shiftId: session.shift.id})
        })
        .then(res => {
            if (res.status === 401) {
                return res.json().then(data => {
                    alert(data.message || 'Сессия недействительна. Пожалуйста, войдите снова.');
                    handleLogout();
                    return Promise.reject(new Error('Logout required'));
                });
            }
            return res.json();
        })
        .then(data => {
            if (data.success) {
                session.kassa = null;
                session.shift = null;
                localStorage.removeItem('current_kassa');
                localStorage.removeItem('current_shift');
                updateSessionUI();
                alert(data.message);
            } else {
                alert(`Ошибка: ${data.message}`);
            }
        })
        .catch(err => {
            if (err.message !== 'Logout required') {
                alert(`Сетевая ошибка: ${err}`);
            }
        });
    };

    const initializeSession = () => {
        const storedCashier = localStorage.getItem('current_cashier');
        const storedKassa = localStorage.getItem('current_kassa');
        const storedShift = localStorage.getItem('current_shift');
        
        if (storedCashier) session.cashier = JSON.parse(storedCashier);
        if (storedKassa) session.kassa = JSON.parse(storedKassa);
        if (storedShift) session.shift = JSON.parse(storedShift);
        
        updateSessionUI();
        
        if (!editTx) {
            if (!session.cashier) {
                cashierLoginModal.show();
            } else if (!session.shift) {
                document.getElementById('start-shift-cashier-name').textContent = session.cashier.name;
                startShiftModal.show();
            }
        }
    };
    
    document.getElementById('pin-submit-btn').addEventListener('click', () => {
        const pinInput = document.getElementById('cashier-pin-input');
        handleLogin(pinInput.value);
        pinInput.value = '';
    });
    document.getElementById('cashier-pin-input').addEventListener('keypress', (e) => { if(e.key === 'Enter') handleLogin(e.target.value); });
    document.getElementById('start-shift-confirm-btn').addEventListener('click', handleStartShift);
    document.getElementById('logout-btn').addEventListener('click', handleLogout);

    document.getElementById('custom-item-btn').addEventListener('click', () => customItemModal.show());
    document.getElementById('custom-item-form').addEventListener('submit', (e) => {
        e.preventDefault();
        const name = document.getElementById('custom-item-name').value || 'Товар без штрихкода';
        const price = document.getElementById('custom-item-price').value;
        const qty = parseInt(document.getElementById('custom-item-qty').value || 1);
        
        if (parseLocaleNumber(price) > 0 && qty > 0) {
            const customId = 'custom_' + Date.now();
            cart[customId] = {
                productName: name,
                price: String(price).replace('.',','),
                quantity: qty,
                discount: '0',
                isCustom: true
            };
            updateCartView();
            customItemModal.hide();
            e.target.reset();
        } else {
            alert('Введите корректную цену и количество.');
        }
    });

    document.getElementById('add-delivery-btn').addEventListener('click', () => {
        const costStr = prompt('Введите стоимость доставки:', deliveryCost > 0 ? deliveryCost : '');
        if (costStr !== null) {
            const cost = parseLocaleNumber(costStr);
            deliveryCost = cost >= 0 ? cost : 0;
            updateCartView();
        }
    });

    document.getElementById('add-note-btn').addEventListener('click', () => {
        const noteStr = prompt('Введите примечание к накладной:', transactionNote);
        if (noteStr !== null) {
            transactionNote = noteStr;
            alert(noteStr ? 'Заметка добавлена.' : 'Заметка удалена.');
        }
    });

    const updateHeldBillsCount = () => {
        fetch('/api/held_bills')
            .then(res => res.json())
            .then(data => {
                const count = data.length;
                const badge = document.getElementById('held-bills-count');
                if (badge) {
                    if (count > 0) {
                        badge.textContent = count;
                        badge.style.display = '';
                    } else {
                        badge.style.display = 'none';
                    }
                }
            });
    };

    if (document.getElementById('hold-bill-btn')) {
        document.getElementById('hold-bill-btn').addEventListener('click', () => {
            if (Object.keys(cart).length === 0) {
                alert('Корзина пуста. Нечего откладывать.');
                return;
            }
            document.getElementById('hold-bill-form').reset();
            holdBillModal.show();
        });
    }

    document.getElementById('hold-bill-form').addEventListener('submit', (e) => {
        e.preventDefault();
        const name = document.getElementById('hold-bill-name').value.trim();
        if (!name) return;
        
        fetch('/api/hold_bill', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({ name: name, cart: cart })
        })
        .then(res => res.json())
        .then(data => {
            if (data.success) {
                for(const id in cart) delete cart[id];
                deliveryCost = 0;
                transactionNote = '';
                updateCartView();
                updateHeldBillsCount();
                holdBillModal.hide();
            } else {
                alert('Ошибка: ' + data.message);
            }
        });
    });

    if (document.getElementById('list-held-bills-btn')) {
        document.getElementById('list-held-bills-btn').addEventListener('click', () => {
            fetch('/api/held_bills')
                .then(res => res.json())
                .then(bills => {
                    const listEl = document.getElementById('held-bills-list');
                    listEl.innerHTML = '';
                    if (bills.length === 0) {
                        listEl.innerHTML = '<p class="text-center text-muted">Нет отложенных накладных.</p>';
                    } else {
                        bills.forEach(bill => {
                            listEl.innerHTML += `
                                <div class="list-group-item d-flex justify-content-between align-items-center">
                                    <span><strong>${bill.name}</strong> - ${new Date(bill.timestamp).toLocaleTimeString('ru-RU')}</span>
                                    <div>
                                        <button class="btn btn-sm btn-success restore-bill-btn" data-id="${bill.id}">Восстановить</button>
                                        <button class="btn btn-sm btn-danger delete-held-bill-btn ms-2" data-id="${bill.id}">Удалить</button>
                                    </div>
                                </div>`;
                        });
                    }
                    heldBillsListModal.show();
                });
        });
    }

    document.getElementById('held-bills-list').addEventListener('click', (e) => {
        const billId = e.target.dataset.id;
        if (!billId) return;

        if (e.target.classList.contains('restore-bill-btn')) {
            if (Object.keys(cart).length > 0 && !confirm('Текущая корзина будет заменена. Продолжить?')) {
                return;
            }
            fetch(`/api/restore_bill/${billId}`, { method: 'POST' })
                .then(res => res.json())
                .then(data => {
                    if (data.success) {
                        for(const id in cart) delete cart[id];
                        deliveryCost = 0;
                        transactionNote = '';
                        Object.assign(cart, data.bill.cart);
                        updateCartView();
                        updateHeldBillsCount();
                        heldBillsListModal.hide();
                    } else {
                        alert('Ошибка: ' + data.message);
                    }
                });
        }

        if (e.target.classList.contains('delete-held-bill-btn')) {
            if (!confirm('Удалить эту отложенную накладную?')) return;
            fetch(`/api/hold_bill/${billId}`, { method: 'DELETE' })
                .then(res => res.json())
                .then(data => {
                    if (data.success) {
                        e.target.closest('.list-group-item').remove();
                        updateHeldBillsCount();
                        if (document.getElementById('held-bills-list').children.length === 0) {
                            document.getElementById('held-bills-list').innerHTML = '<p class="text-center text-muted">Нет отложенных накладных.</p>';
                        }
                    } else {
                        alert('Ошибка: ' + data.message);
                    }
                });
        }
    });

    updateCartView();
    initializeSession();
    updateHeldBillsCount();
});
</script>
"""

INVENTORY_CONTENT = """
<div class="row mb-4">
    <div class="col-md-3">
        <div class="card text-center">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Наименований</h6>
                <h4 class="card-title">{{ inventory_summary.total_names }} шт.</h4>
            </div>
        </div>
    </div>
    <div class="col-md-3">
        <div class="card text-center">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Единиц товара на складе</h6>
                <h4 class="card-title">{{ inventory_summary.total_units }} шт.</h4>
            </div>
        </div>
    </div>
    {% if session.admin_logged_in %}
    <div class="col-md-3">
        <div class="card text-center">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Сумма по себестоимости</h6>
                <h4 class="card-title">{{ format_currency_py(inventory_summary.total_cost_value) }} ₸</h4>
            </div>
        </div>
    </div>
    <div class="col-md-3">
        <div class="card text-center">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Потенциальная прибыль</h6>
                <h4 class="card-title text-success">{{ format_currency_py(inventory_summary.potential_profit) }} ₸</h4>
            </div>
        </div>
    </div>
    {% endif %}
</div>
<div class="d-flex justify-content-between mb-3">
    <div>
        <button class="btn btn-primary me-2" data-bs-toggle="modal" data-bs-target="#addProductModal"><i class="fas fa-plus me-2"></i>Добавить товар</button>
        <button class="btn btn-success" data-bs-toggle="modal" data-bs-target="#stockInModal"><i class="fas fa-truck-loading me-2"></i>Оприходовать</button>
    </div>
    {% if session.admin_logged_in %}
    <button class="btn btn-warning" data-bs-toggle="modal" data-bs-target="#unpricedItemsModal"><i class="fas fa-exclamation-triangle me-2"></i>Невыставленные цены</button>
    {% endif %}
</div>

<div class="input-group mb-3">
    <input type="text" id="inventory-search" class="form-control" placeholder="Поиск по названию, варианту или штрих-коду...">
    <button type="button" class="btn btn-outline-secondary" id="inventory-scan-btn"><i class="fas fa-barcode"></i></button>
</div>
<div id="inventory-scanner-container" style="display:none;" class="mb-3"></div>

<div class="accordion" id="inventoryAccordion">
  {% for p in inventory %}
  <div class="accordion-item">
    <h2 class="accordion-header" id="heading-{{ p.id }}">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapse-{{ p.id }}">
        <strong>{{ p.name }}</strong>&nbsp;<small class="text-muted"> ({{ p.barcode }})</small>
      </button>
    </h2>
    <div id="collapse-{{ p.id }}" class="accordion-collapse collapse" data-bs-parent="#inventoryAccordion">
      <div class="accordion-body">
        {% if session.admin_logged_in %}
        <div class="d-flex justify-content-end mb-2">
            <button class="btn btn-sm btn-outline-primary" data-bs-toggle="modal" data-bs-target="#editProductModal-{{ p.id }}"><i class="fas fa-edit me-1"></i>Редактировать товар</button>
            <form action="{{ url_for('delete_product', product_id=p.id) }}" method="POST" class="d-inline ms-2" onsubmit="return confirm('Удалить товар?');">
                <button type="submit" class="btn btn-sm btn-outline-danger"><i class="fas fa-trash"></i></button>
            </form>
        </div>
        {% endif %}
        <table class="table table-sm table-bordered">
            <thead>
                <tr>
                    <th>Фото</th>
                    <th>Вариант</th>
                    <th>Общая</th>
                    <th>Миним.</th>
                    <th>Опт.</th>
                    {% if session.admin_logged_in %}<th>Себест.</th>{% endif %}
                    <th>Остаток</th>
                </tr>
            </thead>
            <tbody>
                {% for v in p.variants %}
                <tr>
                    <td><img src="{{ v.image_url if v.image_url else url_for('static', filename='placeholder.png') }}" class="img-thumbnail" style="width: 40px; height: 40px; object-fit: cover;"></td>
                    <td>{{ v.option_value }}</td>
                    <td>{{ format_currency_py(v.get('price_regular', v.get('price'))) }} ₸</td>
                    <td>{{ format_currency_py(v.get('price_min', '0')) }} ₸</td>
                    <td>{{ format_currency_py(v.get('price_wholesale', '0')) }} ₸</td>
                    {% if session.admin_logged_in %}<td>{{ format_currency_py(v.cost_price) }} ₸</td>{% endif %}
                    <td>{{ v.stock }}</td>
                </tr>
                {% else %}
                <tr><td colspan="{% if session.admin_logged_in %}8{% else %}6{% endif %}" class="text-center text-muted">Нет вариантов</td></tr>
                {% endfor %}
            </tbody>
        </table>
      </div>
    </div>
  </div>
  {% endfor %}
</div>

<div class="modal fade" id="addProductModal" tabindex="-1">
  <div class="modal-dialog modal-xl">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Новый товар</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('inventory_management') }}" method="POST">
        <div class="modal-body">
          <div class="row">
              <div class="col-md-6 mb-3"><label class="form-label">Название</label><input type="text" name="name" class="form-control" required></div>
              <div class="col-md-6 mb-3"><label class="form-label">Штрих-код</label>
                <div class="input-group"><input type="text" name="barcode" class="form-control barcode-input" required><button type="button" class="btn btn-outline-secondary scan-modal-btn"><i class="fas fa-barcode"></i></button></div>
              </div>
          </div>
          <div id="modal-scanner-add" class="mb-2" style="display:none;"></div>
          <hr>
          <h6>Варианты товара</h6>
          <div id="variants-container-add"></div>
          <button type="button" class="btn btn-sm btn-outline-success mt-2" id="add-variant-btn-add">Добавить вариант</button>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить</button></div>
      </form>
    </div>
  </div>
</div>

{% if session.admin_logged_in %}
{% for p in inventory %}
<div class="modal fade" id="editProductModal-{{ p.id }}" tabindex="-1">
  <div class="modal-dialog modal-xl">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Редактировать товар</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('edit_product', product_id=p.id) }}" method="POST">
        <div class="modal-body">
          <div class="row">
              <div class="col-md-6 mb-3"><label class="form-label">Название</label><input type="text" name="name" class="form-control" value="{{ p.name }}" required></div>
              <div class="col-md-6 mb-3"><label class="form-label">Штрих-код</label><input type="text" name="barcode" class="form-control" value="{{ p.barcode }}" required></div>
          </div>
          <hr>
          <h6>Варианты товара</h6>
          <div id="variants-container-edit-{{ p.id }}">
            {% for v in p.variants %}
            <div class="card mb-3 variant-row">
                <div class="card-body">
                    <input type="hidden" name="variant_id[]" value="{{ v.id }}">
                    <div class="row g-2 align-items-center">
                        <div class="col-12 col-md-3">
                            <img src="{{ v.image_url if v.image_url else url_for('static', filename='placeholder.png') }}" class="img-thumbnail variant-preview mb-1" style="width: 80px; height: 80px; object-fit: cover;">
                            <input type="file" class="form-control form-control-sm variant-image-upload" accept="image/*">
                            <input type="hidden" class="variant-image-url-input" name="variant_image_url[]" value="{{ v.image_url }}">
                        </div>
                        <div class="col-12 col-md-9">
                           <div class="row g-2">
                                <div class="col-12"><label>Название варианта</label><input type="text" name="variant_name[]" class="form-control" value="{{ v.option_value }}" required></div>
                                <div class="col-12 col-sm-4"><label>Цена Общая</label><input type="text" name="variant_price_regular[]" class="form-control" value="{{ v.get('price_regular', v.get('price'))|string|replace('.', ',') if v.get('price_regular', v.get('price')) != '0' else '' }}" placeholder="0" inputmode="decimal"></div>
                                <div class="col-12 col-sm-4"><label>Цена Мин.</label><input type="text" name="variant_price_min[]" class="form-control" value="{{ v.get('price_min', '0')|string|replace('.', ',') if v.get('price_min', '0') != '0' else '' }}" placeholder="0" inputmode="decimal"></div>
                                <div class="col-12 col-sm-4"><label>Цена Опт.</label><input type="text" name="variant_price_wholesale[]" class="form-control" value="{{ v.get('price_wholesale', '0')|string|replace('.', ',') if v.get('price_wholesale', '0') != '0' else '' }}" placeholder="0" inputmode="decimal"></div>
                                <div class="col-12 col-sm-6"><label>Себестоимость</label><input type="text" name="variant_cost_price[]" class="form-control" value="{{ v.cost_price|string|replace('.', ',') if v.cost_price != '0' else '' }}" placeholder="0" inputmode="decimal"></div>
                                <div class="col-12 col-sm-6"><label>Остаток</label><input type="number" name="variant_stock[]" class="form-control" value="{{ v.stock if v.stock != 0 else '' }}" placeholder="0"></div>
                           </div>
                        </div>
                         <div class="col-12 text-end">
                            <button type="button" class="btn btn-sm btn-danger remove-variant-btn"><i class="fas fa-times"></i> Удалить вариант</button>
                        </div>
                    </div>
                </div>
            </div>
            {% endfor %}
          </div>
          <button type="button" class="btn btn-sm btn-outline-success mt-2 add-variant-btn-edit" data-target-container="variants-container-edit-{{ p.id }}">Добавить вариант</button>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить</button></div>
      </form>
    </div>
  </div>
</div>
{% endfor %}

<div class="modal fade" id="unpricedItemsModal" tabindex="-1">
  <div class="modal-dialog modal-xl">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Товары без цен</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('update_prices') }}" method="POST">
          <div class="modal-body">
            <input type="text" id="unpriced-search" class="form-control mb-3" placeholder="Поиск по названию...">
            <div class="table-responsive" style="max-height: 60vh;">
                <table class="table table-sm" id="unpriced-table">
                    <thead><tr><th>Товар (Вариант)</th><th>Общая</th><th>Мин.</th><th>Опт.</th><th>Себест.</th></tr></thead>
                    <tbody>
                    {% for p in inventory %}
                        {% for v in p.variants %}
                            {% if v.get('price_regular', v.get('price', '0')) == '0' or v.get('price_regular', v.get('price', '0.00')) == '0.00' or v.cost_price == '0' or v.cost_price == '0.00' %}
                            <tr>
                                <td class="align-middle">{{ p.name }} ({{ v.option_value }})</td>
                                <td><input type="text" name="price_regular[]" class="form-control form-control-sm" value="" placeholder="0" inputmode="decimal"></td>
                                <td><input type="text" name="price_min[]" class="form-control form-control-sm" value="" placeholder="0" inputmode="decimal"></td>
                                <td><input type="text" name="price_wholesale[]" class="form-control form-control-sm" value="" placeholder="0" inputmode="decimal"></td>
                                <td>
                                    <input type="text" name="cost_price[]" class="form-control form-control-sm" value="" placeholder="0" inputmode="decimal">
                                    <input type="hidden" name="variant_id[]" value="{{ v.id }}">
                                </td>
                            </tr>
                            {% endif %}
                        {% endfor %}
                    {% endfor %}
                    </tbody>
                </table>
            </div>
          </div>
          <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить изменения</button></div>
      </form>
    </div>
  </div>
</div>
{% endif %}

<div class="modal fade" id="stockInModal" tabindex="-1" style="overflow-y: visible;">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Оприходование товара</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('stock_in') }}" method="POST">
        <div class="modal-body">
            <div class="mb-3" style="position: relative;">
                <label class="form-label">Товар (Поиск или Скан)</label>
                <div class="input-group">
                    <input type="text" id="stockin-search-input" class="form-control" placeholder="Название или штрихкод">
                    <button type="button" class="btn btn-outline-secondary" id="stockin-scan-btn"><i class="fas fa-barcode"></i></button>
                </div>
                <div id="stockin-scanner-container" style="display:none;" class="mt-2"></div>
                <div id="stockin-search-results" class="list-group mt-1" style="position:absolute; z-index:1000; width:100%; display:none; max-height:200px; overflow-y:auto; box-shadow: 0 4px 6px rgba(0,0,0,0.1);"></div>
                <input type="hidden" id="stockin-product" name="product_id" required>
            </div>
            <div class="mb-3">
                <label class="form-label">Выбранный товар</label>
                <input type="text" id="stockin-selected-product-name" class="form-control bg-light" readonly disabled>
            </div>
            <div class="mb-3">
                <label for="stockin-variant" class="form-label">Вариант</label>
                <select id="stockin-variant" name="variant_id" class="form-select" required disabled>
                    <option value="">-- Сначала выберите товар --</option>
                </select>
            </div>
            <div class="row">
                <div class="col-md-{% if session.admin_logged_in %}6{% else %}12{% endif %} mb-3">
                    <label for="stockin-quantity" class="form-label">Количество</label>
                    <input type="number" id="stockin-quantity" name="quantity" class="form-control" placeholder="1" required min="1">
                </div>
                {% if session.admin_logged_in %}
                <div class="col-md-6 mb-3">
                    <label for="stockin-cost" class="form-label">Себестоимость (за ед.)</label>
                    <input type="text" id="stockin-cost" name="cost_price" class="form-control" inputmode="decimal" placeholder="0">
                </div>
                {% endif %}
            </div>
            {% if session.admin_logged_in %}
            <div class="mb-3">
                <label for="stockin-delivery" class="form-label">Стоимость доставки (общая)</label>
                <input type="text" id="stockin-delivery" name="delivery_cost" class="form-control" inputmode="decimal" placeholder="0">
                <div class="form-text">Эта сумма будет добавлена в расходы как "Дорога" и учтена в себестоимости.</div>
            </div>
            {% endif %}
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Оприходовать</button></div>
      </form>
    </div>
  </div>
</div>
"""

INVENTORY_SCRIPTS = """
<script>
document.addEventListener('DOMContentLoaded', () => {
    let currentScanner = null;
    let currentScannerContainer = null;
    const placeholderImg = "{{ url_for('static', filename='placeholder.png') }}";
    const inventoryData = {{ inventory|tojson|safe }};
    const isAdmin = {{ 'true' if session.admin_logged_in else 'false' }};

    function startScannerFor(containerId, inputElement, callback) {
        const scannerContainer = document.getElementById(containerId);
        if (currentScanner) {
            try { currentScanner.stop(); } catch(e) {}
            currentScanner = null;
            if(currentScannerContainer) currentScannerContainer.style.display = 'none';
            return;
        }
        scannerContainer.style.display = 'block';
        currentScannerContainer = scannerContainer;
        const scannerId = containerId + '-reader';
        if(!document.getElementById(scannerId)) scannerContainer.innerHTML = `<div id="${scannerId}" style="width: 100%;"></div>`;

        const html5QrCode = new Html5Qrcode(scannerId);
        currentScanner = html5QrCode;
        html5QrCode.start({ facingMode: "environment" }, { fps: 10, qrbox: { width: 250, height: 250 } }, (decodedText) => {
            if(inputElement) inputElement.value = decodedText;
            try { html5QrCode.stop(); } catch(e) {}
            currentScanner = null;
            scannerContainer.style.display = 'none';
            if(callback) callback(decodedText);
        });
    }

    document.querySelectorAll('.scan-modal-btn').forEach(btn => {
        btn.addEventListener('click', e => {
            const form = e.target.closest('form');
            const container = form.querySelector('[id^="modal-scanner-"]');
            const input = form.querySelector('.barcode-input');
            startScannerFor(container.id, input, null);
        });
    });

    const invScanBtn = document.getElementById('inventory-scan-btn');
    if (invScanBtn) {
        invScanBtn.addEventListener('click', () => {
            const input = document.getElementById('inventory-search');
            startScannerFor('inventory-scanner-container', input, (text) => {
                input.dispatchEvent(new Event('input'));
            });
        });
    }

    const stockinSearchInput = document.getElementById('stockin-search-input');
    const stockinSearchResults = document.getElementById('stockin-search-results');
    const stockinProductHidden = document.getElementById('stockin-product');
    const stockinProductName = document.getElementById('stockin-selected-product-name');
    const stockinVariantSelect = document.getElementById('stockin-variant');

    function selectStockInProduct(product) {
        stockinSearchInput.value = '';
        stockinSearchResults.style.display = 'none';
        stockinProductHidden.value = product.id;
        stockinProductName.value = product.name;
        
        stockinVariantSelect.innerHTML = '<option value="">-- Выберите вариант --</option>';
        if (product.variants && product.variants.length > 0) {
            product.variants.forEach(v => {
                const option = document.createElement('option');
                option.value = v.id;
                option.textContent = v.option_value;
                stockinVariantSelect.appendChild(option);
            });
            stockinVariantSelect.disabled = false;
        } else {
            stockinVariantSelect.disabled = true;
        }
    }

    if (stockinSearchInput) {
        stockinSearchInput.addEventListener('input', e => {
            const term = e.target.value.toLowerCase().trim();
            if (!term) {
                stockinSearchResults.style.display = 'none';
                return;
            }
            const filtered = inventoryData.filter(p => p.name.toLowerCase().includes(term) || (p.barcode && p.barcode.toLowerCase().includes(term)));
            stockinSearchResults.innerHTML = '';
            if (filtered.length > 0) {
                filtered.forEach(p => {
                    const a = document.createElement('a');
                    a.href = '#';
                    a.className = 'list-group-item list-group-item-action';
                    a.textContent = p.name + (p.barcode ? ' (' + p.barcode + ')' : '');
                    a.addEventListener('click', (ev) => {
                        ev.preventDefault();
                        selectStockInProduct(p);
                    });
                    stockinSearchResults.appendChild(a);
                });
                stockinSearchResults.style.display = 'block';
            } else {
                stockinSearchResults.innerHTML = '<div class="list-group-item text-muted">Не найдено</div>';
                stockinSearchResults.style.display = 'block';
            }
        });

        document.addEventListener('click', e => {
            if (!stockinSearchInput.contains(e.target) && !stockinSearchResults.contains(e.target)) {
                stockinSearchResults.style.display = 'none';
            }
        });
    }

    const stockinScanBtn = document.getElementById('stockin-scan-btn');
    if (stockinScanBtn) {
        stockinScanBtn.addEventListener('click', () => {
            startScannerFor('stockin-scanner-container', stockinSearchInput, (text) => {
                const found = inventoryData.find(p => p.barcode === text);
                if (found) {
                    selectStockInProduct(found);
                } else {
                    alert('Товар с таким штрихкодом не найден');
                }
            });
        });
    }
    
    document.querySelectorAll('.modal').forEach(modal => {
        modal.addEventListener('hidden.bs.modal', () => {
             if (currentScanner) {
                try { currentScanner.stop(); } catch(e) {}
                currentScanner = null;
             }
             if(currentScannerContainer) {
                 currentScannerContainer.style.display = 'none';
                 currentScannerContainer.innerHTML = '';
             }
        });
    });
    
    const handleImageUpload = (fileInput) => {
        const file = fileInput.files[0];
        if (!file) return;

        const row = fileInput.closest('.variant-row');
        const preview = row.querySelector('.variant-preview');
        const urlInput = row.querySelector('.variant-image-url-input');

        const formData = new FormData();
        formData.append('image', file);
        
        preview.src = "data:image/gif;base64,R0lGODlhAQABAIAAAHd3dwAAACH5BAAAAAAALAAAAAABAAEAAAICRAEAOw==";

        fetch("{{ url_for('upload_image') }}", {
            method: 'POST',
            body: formData
        })
        .then(response => response.json())
        .then(data => {
            if (data.success) {
                preview.src = data.url;
                urlInput.value = data.url;
            } else {
                alert('Ошибка загрузки: ' + data.message);
                preview.src = placeholderImg;
            }
        })
        .catch(error => {
            console.error('Upload error:', error);
            alert('Сетевая ошибка при загрузке изображения.');
            preview.src = placeholderImg;
        });
    };

    const createVariantRow = () => {
        const div = document.createElement('div');
        div.className = 'card mb-3 variant-row';
        let adminInputs = '';
        if (isAdmin) {
            adminInputs = `
                <div class="col-12 col-sm-4"><label>Цена Мин.</label><input type="text" name="variant_price_min[]" class="form-control" value="" placeholder="0" inputmode="decimal"></div>
                <div class="col-12 col-sm-4"><label>Цена Опт.</label><input type="text" name="variant_price_wholesale[]" class="form-control" value="" placeholder="0" inputmode="decimal"></div>
                <div class="col-12 col-sm-6"><label>Себестоимость</label><input type="text" name="variant_cost_price[]" class="form-control" value="" placeholder="0" inputmode="decimal"></div>
            `;
        }
        div.innerHTML = `
            <div class="card-body">
                <input type="hidden" name="variant_id[]" value="">
                <div class="row g-2 align-items-center">
                    <div class="col-12 col-md-3">
                        <img src="${placeholderImg}" class="img-thumbnail variant-preview mb-1" style="width: 80px; height: 80px; object-fit: cover;">
                        <input type="file" class="form-control form-control-sm variant-image-upload" accept="image/*">
                        <input type="hidden" class="variant-image-url-input" name="variant_image_url[]" value="">
                    </div>
                    <div class="col-12 col-md-9">
                       <div class="row g-2">
                            <div class="col-12"><label>Название варианта</label><input type="text" name="variant_name[]" class="form-control" placeholder="Напр. Синий, 42" required></div>
                            <div class="col-12 col-sm-4"><label>Цена Общая</label><input type="text" name="variant_price_regular[]" class="form-control" value="" placeholder="0" inputmode="decimal"></div>
                            ${adminInputs}
                            <div class="col-12 col-sm-6"><label>Остаток</label><input type="number" name="variant_stock[]" class="form-control" value="" placeholder="0"></div>
                       </div>
                    </div>
                    <div class="col-12 text-end">
                        <button type="button" class="btn btn-sm btn-danger remove-variant-btn"><i class="fas fa-times"></i> Удалить вариант</button>
                    </div>
                </div>
            </div>
        `;
        return div;
    };
    
    document.body.addEventListener('change', e => {
        if (e.target.classList.contains('variant-image-upload')) {
            handleImageUpload(e.target);
        }
    });

    document.body.addEventListener('click', e => {
        if (e.target.closest('#add-variant-btn-add')) {
            document.getElementById('variants-container-add').appendChild(createVariantRow());
            return;
        }
        
        const editAddBtn = e.target.closest('.add-variant-btn-edit');
        if (editAddBtn) {
            const containerId = editAddBtn.dataset.targetContainer;
            document.getElementById(containerId).appendChild(createVariantRow());
            return;
        }
        
        if (e.target.closest('.remove-variant-btn')) {
            e.target.closest('.variant-row').remove();
            return;
        }
    });
    
    const addProductModal = document.getElementById('addProductModal');
    if(addProductModal){
        addProductModal.addEventListener('shown.bs.modal', () => {
            const container = document.getElementById('variants-container-add');
            if (container.children.length === 0) {
                container.appendChild(createVariantRow());
            }
        });
    }

    document.getElementById('inventory-search').addEventListener('input', e => {
        const term = e.target.value.toLowerCase();
        document.querySelectorAll('#inventoryAccordion .accordion-item').forEach(item => {
            const productName = item.querySelector('.accordion-button strong').textContent.toLowerCase();
            const barcode = item.querySelector('.accordion-button small').textContent.toLowerCase();
            const variantNameElements = item.querySelectorAll('.accordion-body table tbody tr td:nth-child(2)');
            const variantMatch = Array.from(variantNameElements).some(td => td.textContent.toLowerCase().includes(term));
            const show = productName.includes(term) || barcode.includes(term) || variantMatch;
            item.style.display = show ? '' : 'none';
        });
    });

    const unpricedSearch = document.getElementById('unpriced-search');
    if(unpricedSearch){
        unpricedSearch.addEventListener('input', e => {
            const term = e.target.value.toLowerCase();
            document.querySelectorAll('#unpriced-table tbody tr').forEach(row => {
                const text = row.cells[0].textContent.toLowerCase();
                row.style.display = text.includes(term) ? '' : 'none';
            });
        });
    }
});
</script>
"""

TRANSACTIONS_CONTENT = """
<div class="card mb-4">
    <div class="card-body">
        <form method="GET" class="row g-2 align-items-end">
            <div class="col-auto">
                <label for="date-filter" class="form-label">Дата</label>
                <input type="date" id="date-filter" name="date" value="{{ selected_date }}" class="form-control">
            </div>
            <div class="col-auto">
                <label for="kassa-filter" class="form-label">Касса</label>
                <select id="kassa-filter" name="kassa" class="form-select">
                    <option value="">Все кассы</option>
                    {% for k in kassas %}
                    <option value="{{ k.id }}" {% if k.id == selected_kassa_id %}selected{% endif %}>{{ k.name }}</option>
                    {% endfor %}
                </select>
            </div>
            <div class="col-auto">
                <button type="submit" class="btn btn-primary">Показать</button>
            </div>
        </form>
        <hr>
        {% set selected_kassa = kassas|selectattr('id', 'equalto', selected_kassa_id)|first %}
        <div class="d-flex justify-content-between align-items-center flex-wrap">
            <h4 class="mb-0">Общая выручка за {{ selected_date }}{% if selected_kassa %} (Касса: {{ selected_kassa.name }}){% endif %}: <span class="text-success">{{ format_currency_py(total_sales) }} ₸</span></h4>
            <h5 class="mb-0 text-muted">Продано пар: <span class="fw-bold text-dark">{{ total_quantity_sold }}</span></h5>
        </div>
    </div>
</div>
<div class="card">
    <div class="card-body">
        <div class="table-responsive">
            <table class="table table-sm table-hover">
                <thead><tr><th>ID</th><th>Дата</th><th>Тип</th><th>Кассир</th><th>Касса</th><th>Сумма</th><th>Статус</th><th>Позиции</th><th></th></tr></thead>
                <tbody>
                {% for t in transactions %}
                <tr class="{% if t.type == 'return' %}table-danger{% endif %}">
                    <td><a href="{{ url_for('view_receipt', transaction_id=t.id) if t.invoice_html or t.receipt_html else '#' }}" target="_blank"><small class="text-muted">{{ t.id[:8] }}</small></a></td>
                    <td>{{ t.timestamp[11:16] }}</td>
                    <td>
                        {% if t.type == 'sale' %}
                            {% set display_type = 'Наличные' if t.payment_method == 'cash' else 'Карта' %}
                            {% set badge_class = 'primary' if t.payment_method == 'cash' else 'info' %}
                        {% elif t.type == 'return' %}
                            {% set display_type = 'Возврат' %}
                            {% set badge_class = 'danger' %}
                        {% endif %}
                        <span class="badge bg-{{ badge_class }}">{{ display_type }}</span>
                    </td>
                    <td>{{ t.user_name }}</td><td>{{ t.kassa_name }}</td>
                    <td class="fw-bold">{{ format_currency_py(t.total_amount) }} ₸</td>
                    <td>
                        {% if t.status == 'completed' %}<span class="badge bg-success">Завершено</span>
                        {% elif t.status == 'returned' %}<span class="badge bg-danger">Возвращено</span>
                        {% elif t.status == 'partially_returned' %}<span class="badge bg-warning text-dark">Частичный возврат</span>
                        {% else %}<span class="badge bg-secondary">{{t.status}}</span>
                        {% endif %}
                    </td>
                    <td>
                        <ul class="list-unstyled mb-0 small">
                        {% for item in t['items'] %}<li>{{ item.name }} ({{ item.quantity }}x{{ format_currency_py(item.price_at_sale) }}{% if item.get('discount_per_item', '0')|float > 0 %} -{{ format_currency_py(item.discount_per_item) }}{% endif %})</li>{% endfor %}
                        </ul>
                    </td>
                    <td>
                        {% if session.admin_logged_in %}
                            <form action="{{ url_for('delete_transaction', transaction_id=t.id) }}" method="POST" class="d-inline ms-1" onsubmit="return confirm('Удалить эту транзакцию? Действие необратимо.');">
                                <button type="submit" class="btn btn-xs btn-outline-danger py-0 px-1"><i class="fas fa-trash"></i></button>
                            </form>
                        {% endif %}
                    </td>
                </tr>
                {% else %}
                <tr><td colspan="9" class="text-center">Нет транзакций за выбранную дату.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
"""

TRANSACTIONS_SCRIPTS = ""

REPORTS_CONTENT = """
<div class="card mb-4">
    <div class="card-body">
        <form method="GET" action="{{ url_for('reports') }}">
            <div class="row g-2 align-items-end">
                <div class="col-md-4"><label for="start_date" class="form-label">Начало периода</label><input type="date" id="start_date" name="start_date" value="{{ start_date }}" class="form-control"></div>
                <div class="col-md-4"><label for="end_date" class="form-label">Конец периода</label><input type="date" id="end_date" name="end_date" value="{{ end_date }}" class="form-control"></div>
                <div class="col-md-4"><button type="submit" class="btn btn-primary w-100">Сформировать отчет</button></div>
            </div>
        </form>
    </div>
</div>

<div class="row">
    <div class="col-lg-7">
        <div class="card mb-4">
            <div class="card-header"><h5 class="mb-0">Сводный отчет за период</h5></div>
            <div class="card-body">
                <ul class="list-group list-group-flush">
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-chart-bar me-2 text-primary"></i>Выручка (за вычетом возвратов)</span> <strong>{{ format_currency_py(stats.total_revenue) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-undo me-2 text-danger"></i>Возвраты ({{ stats.total_returns_count }} шт.)</span> <strong class="text-danger">-{{ format_currency_py(stats.total_returns_amount) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-cogs me-2 text-secondary"></i>Себестоимость проданных товаров</span> <strong>{{ format_currency_py(stats.total_cogs) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-piggy-bank me-2 text-info"></i>Валовая прибыль</span> <strong class="text-info">{{ format_currency_py(stats.gross_profit) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-receipt me-2 text-warning"></i>Расходы (операционные)</span> <strong class="text-warning">-{{ format_currency_py(stats.total_expenses) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-user-tie me-2" style="color: orange;"></i>Расходы (личные)</span> <strong class="text-warning">-{{ format_currency_py(stats.total_personal_expenses) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between"><span><i class="fas fa-users-cog me-2 text-danger"></i>Расходы (зарплаты)</span> <strong class="text-danger">-{{ format_currency_py(stats.total_salary_expenses) }} ₸</strong></li>
                    <li class="list-group-item d-flex justify-content-between fs-5"><span><i class="fas fa-check-circle me-2 text-success"></i>Чистая прибыль</span> <strong class="text-success">{{ format_currency_py(stats.net_profit) }} ₸</strong></li>
                </ul>
            </div>
        </div>
        <div class="card mb-4">
            <div class="card-header"><h5 class="mb-0">Расчеты с кассирами за период</h5></div>
            <div class="card-body p-0">
                <div class="table-responsive"><table class="table table-sm mb-0">
                    <thead><tr><th>Кассир</th><th class="text-end">К выплате</th></tr></thead>
                    <tbody>
                    {% for name, payout in stats.cashier_payouts %}
                    <tr><td>{{ name }}</td><td class="text-end">{{ format_currency_py(payout) }} ₸</td></tr>
                    {% else %}<tr><td colspan="2" class="text-center text-muted">Нет данных для расчета.</td></tr>
                    {% endfor %}
                    </tbody>
                </table></div>
            </div>
        </div>
    </div>
    <div class="col-lg-5">
        <div class="card mb-4">
            <div class="card-header"><h5 class="mb-0">Продажи по кассирам</h5></div>
            <div class="card-body p-0">
                <div class="table-responsive"><table class="table table-hover mb-0">
                    <thead><tr><th>Кассир</th><th>Чеков</th><th class="text-end">Сумма</th></tr></thead>
                    <tbody>
                    {% for name, data in stats.sales_by_cashier %}
                    <tr><td>{{ name }}</td><td>{{ data.count }}</td><td class="text-end">{{ format_currency_py(data.total) }} ₸</td></tr>
                    {% else %}<tr><td colspan="3" class="text-center text-muted">Нет продаж за выбранный период.</td></tr>
                    {% endfor %}
                    </tbody>
                </table></div>
            </div>
        </div>
        <div class="card mb-4">
            <div class="card-header"><h5 class="mb-0">Операционные расходы за период</h5></div>
            <div class="card-body p-0">
                <div class="table-responsive" style="max-height: 200px; overflow-y: auto;"><table class="table table-sm mb-0">
                    <thead><tr><th>Дата</th><th>Описание</th><th class="text-end">Сумма</th></tr></thead>
                    <tbody>
                    {% for expense in expenses %}
                    <tr>
                        <td><small>{{ expense.timestamp[:10] }}</small></td>
                        <td>{{ expense.description }}</td>
                        <td class="text-end">{{ format_currency_py(expense.amount) }} ₸</td>
                    </tr>
                    {% else %}<tr><td colspan="3" class="text-center text-muted">Нет расходов за выбранный период.</td></tr>
                    {% endfor %}
                    </tbody>
                </table></div>
            </div>
        </div>
        <div class="card mb-4">
            <div class="card-header"><h5 class="mb-0">Личные расходы за период</h5></div>
            <div class="card-body p-0">
                <div class="table-responsive" style="max-height: 200px; overflow-y: auto;"><table class="table table-sm mb-0">
                    <thead><tr><th>Дата</th><th>Описание</th><th class="text-end">Сумма</th></tr></thead>
                    <tbody>
                    {% for expense in personal_expenses %}
                    <tr>
                        <td><small>{{ expense.timestamp[:10] }}</small></td>
                        <td>{{ expense.description }}</td>
                        <td class="text-end">{{ format_currency_py(expense.amount) }} ₸</td>
                    </tr>
                    {% else %}<tr><td colspan="3" class="text-center text-muted">Нет личных расходов за выбранный период.</td></tr>
                    {% endfor %}
                    </tbody>
                </table></div>
            </div>
        </div>
    </div>
</div>
"""

REPORTS_SCRIPTS = ""

EMPLOYEE_REPORT_CONTENT = """
<div class="card mb-4">
    <div class="card-body">
        <form method="GET" action="{{ url_for('employee_report') }}">
            <div class="row g-2 align-items-end">
                <div class="col-md-3"><label class="form-label">Начало периода</label><input type="date" name="start_date" value="{{ start_date }}" class="form-control"></div>
                <div class="col-md-3"><label class="form-label">Конец периода</label><input type="date" name="end_date" value="{{ end_date }}" class="form-control"></div>
                <div class="col-md-4">
                    <label class="form-label">Сотрудник</label>
                    <select name="user_id" class="form-select">
                        <option value="">-- Выберите кассира --</option>
                        {% for u in users %}
                        <option value="{{ u.id }}" {% if u.id == selected_user %}selected{% endif %}>{{ u.name }}</option>
                        {% endfor %}
                    </select>
                </div>
                <div class="col-md-2"><button type="submit" class="btn btn-primary w-100">Показать</button></div>
            </div>
        </form>
    </div>
</div>

{% if selected_user %}
<div class="row mb-4">
    <div class="col-md-4">
        <div class="card text-center bg-light">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Продажи</h6>
                <h4 class="card-title text-success">{{ format_currency_py(totals.sales) }} ₸</h4>
            </div>
        </div>
    </div>
    <div class="col-md-4">
        <div class="card text-center bg-light">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Возвраты</h6>
                <h4 class="card-title text-danger">-{{ format_currency_py(totals.returns) }} ₸</h4>
            </div>
        </div>
    </div>
    <div class="col-md-4">
        <div class="card text-center bg-light">
            <div class="card-body">
                <h6 class="card-subtitle mb-2 text-muted">Итоговая выручка</h6>
                <h4 class="card-title text-primary">{{ format_currency_py(totals.net) }} ₸</h4>
            </div>
        </div>
    </div>
</div>

<div class="card">
    <div class="card-header"><h5 class="mb-0">Детализация операций</h5></div>
    <div class="card-body p-0">
        <div class="table-responsive">
            <table class="table table-hover table-sm mb-0">
                <thead class="table-light">
                    <tr>
                        <th>Дата/Время</th>
                        <th>Тип</th>
                        <th>Чек</th>
                        <th>Метод</th>
                        <th>Позиции (Товар, Кол-во, Цена)</th>
                        <th class="text-end">Сумма</th>
                    </tr>
                </thead>
                <tbody>
                {% for t in transactions %}
                    <tr class="{% if t.type == 'return' %}table-danger{% endif %}">
                        <td>{{ t.timestamp[:16]|replace('T', ' ') }}</td>
                        <td><span class="badge bg-{{ 'primary' if t.type == 'sale' else 'danger' }}">{{ 'Продажа' if t.type == 'sale' else 'Возврат' }}</span></td>
                        <td><a href="{{ url_for('view_receipt', transaction_id=t.id) if t.invoice_html or t.receipt_html else '#' }}" target="_blank">{{ t.id[:8] }}</a></td>
                        <td>{{ 'Наличные' if t.payment_method == 'cash' else 'Карта' }}</td>
                        <td>
                            <ul class="list-unstyled mb-0 small">
                            {% for item in t.items %}
                                <li>{{ item.name }} &times; {{ item.quantity }} шт. ({{ format_currency_py(item.price_at_sale) }} ₸/шт.)</li>
                            {% endfor %}
                            </ul>
                        </td>
                        <td class="text-end fw-bold">{{ format_currency_py(t.total_amount) }} ₸</td>
                    </tr>
                {% else %}
                    <tr><td colspan="6" class="text-center">Нет операций за выбранный период.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
{% else %}
<div class="alert alert-info">Выберите сотрудника и период для формирования детального отчета.</div>
{% endif %}
"""

ITEM_MOVEMENT_CONTENT = """
<div class="card mb-4">
    <div class="card-body">
        <form method="GET" action="{{ url_for('item_movement_report') }}" id="movement-form">
            <div class="row g-2 align-items-end">
                <div class="col-md-5" style="position: relative;">
                    <label class="form-label">Товар</label>
                    <input type="text" id="movement-search" class="form-control" placeholder="Поиск по названию или штрихкоду" value="{{ selected_product.name if selected_product else '' }}">
                    <div id="movement-search-results" class="list-group mt-1" style="position:absolute; z-index:1000; width:100%; display:none; max-height:250px; overflow-y:auto; box-shadow: 0 4px 6px rgba(0,0,0,0.1);"></div>
                    <input type="hidden" id="movement-product-id" name="product_id" value="{{ product_id }}">
                </div>
                <div class="col-md-5">
                    <label class="form-label">Вариант</label>
                    <select id="movement-variant-id" name="variant_id" class="form-select">
                        <option value="">Все варианты</option>
                        {% if selected_product %}
                            {% for v in selected_product.variants %}
                                <option value="{{ v.id }}" {% if variant_id == v.id %}selected{% endif %}>{{ v.option_value }}</option>
                            {% endfor %}
                        {% endif %}
                    </select>
                </div>
                <div class="col-md-2">
                    <button type="submit" class="btn btn-primary w-100">Показать</button>
                </div>
            </div>
        </form>
    </div>
</div>

{% if product_id %}
<div class="card">
    <div class="card-header"><h5 class="mb-0">История движения: {{ selected_product.name }} {% if selected_variant %}({{ selected_variant.option_value }}){% endif %}</h5></div>
    <div class="card-body p-0">
        <div class="table-responsive">
            <table class="table table-hover table-sm mb-0">
                <thead class="table-light">
                    <tr>
                        <th>Дата/Время</th>
                        <th>Операция</th>
                        <th>Вариант</th>
                        <th>Документ/Чек</th>
                        <th>Исполнитель</th>
                        <th class="text-end">Цена/Себест.</th>
                        <th class="text-end">Изменение остатка</th>
                    </tr>
                </thead>
                <tbody>
                {% for m in movements %}
                    <tr>
                        <td>{{ m.timestamp[:16]|replace('T', ' ') }}</td>
                        <td>
                            {% if m.type == 'sale' %}<span class="badge bg-primary">Продажа</span>
                            {% elif m.type == 'return' %}<span class="badge bg-danger">Возврат от пок.</span>
                            {% elif m.type == 'stock_in' %}<span class="badge bg-success">Оприходование</span>
                            {% else %}<span class="badge bg-secondary">{{ m.type }}</span>{% endif %}
                        </td>
                        <td>{{ m.variant_name }}</td>
                        <td>{{ m.doc_id }}</td>
                        <td>{{ m.user }}</td>
                        <td class="text-end">{{ format_currency_py(m.price) }} ₸</td>
                        <td class="text-end fw-bold {% if m.qty > 0 %}text-success{% elif m.qty < 0 %}text-danger{% endif %}">
                            {{ '+' if m.qty > 0 else '' }}{{ m.qty }}
                        </td>
                    </tr>
                {% else %}
                    <tr><td colspan="7" class="text-center">Нет данных о движении для выбранного товара.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
{% else %}
<div class="alert alert-info">Выберите товар для просмотра истории его движения.</div>
{% endif %}
"""

ITEM_MOVEMENT_SCRIPTS = """
<script>
document.addEventListener('DOMContentLoaded', () => {
    const inventoryData = {{ inventory|tojson|safe }};
    const searchInput = document.getElementById('movement-search');
    const searchResults = document.getElementById('movement-search-results');
    const productIdInput = document.getElementById('movement-product-id');
    const variantSelect = document.getElementById('movement-variant-id');

    if (searchInput) {
        searchInput.addEventListener('input', e => {
            const term = e.target.value.toLowerCase().trim();
            if (!term) {
                searchResults.style.display = 'none';
                return;
            }
            const filtered = inventoryData.filter(p => p.name.toLowerCase().includes(term) || (p.barcode && p.barcode.toLowerCase().includes(term)));
            searchResults.innerHTML = '';
            if (filtered.length > 0) {
                filtered.forEach(p => {
                    const a = document.createElement('a');
                    a.href = '#';
                    a.className = 'list-group-item list-group-item-action';
                    a.textContent = p.name + (p.barcode ? ' (' + p.barcode + ')' : '');
                    a.addEventListener('click', (ev) => {
                        ev.preventDefault();
                        searchInput.value = p.name;
                        productIdInput.value = p.id;
                        searchResults.style.display = 'none';
                        
                        variantSelect.innerHTML = '<option value="">Все варианты</option>';
                        if (p.variants) {
                            p.variants.forEach(v => {
                                const opt = document.createElement('option');
                                opt.value = v.id;
                                opt.textContent = v.option_value;
                                variantSelect.appendChild(opt);
                            });
                        }
                    });
                    searchResults.appendChild(a);
                });
                searchResults.style.display = 'block';
            } else {
                searchResults.innerHTML = '<div class="list-group-item text-muted">Не найдено</div>';
                searchResults.style.display = 'block';
            }
        });

        document.addEventListener('click', e => {
            if (!searchInput.contains(e.target) && !searchResults.contains(e.target)) {
                searchResults.style.display = 'none';
            }
        });
    }
});
</script>
"""

PRODUCT_ROI_CONTENT = """
<div class="card">
    <div class="card-header"><h5 class="mb-0">Окупаемость по товарам</h5></div>
    <div class="card-body p-0">
        <div class="table-responsive">
            <table class="table table-hover table-sm mb-0">
                <thead class="table-light">
                    <tr>
                        <th>Товар (вариант)</th>
                        <th class="text-end">Продано, шт</th>
                        <th class="text-end">Выручка</th>
                        <th class="text-end">Стоимость на складе</th>
                        <th class="text-end">Общие вложения</th>
                        <th class="text-end">Результат (Окупаемость)</th>
                    </tr>
                </thead>
                <tbody>
                {% for item in stats %}
                    <tr>
                        <td><strong>{{ item.name }}</strong><br><small class="text-muted">{{ item.variant_name }}</small></td>
                        <td class="text-end">{{ item.total_qty_sold }}</td>
                        <td class="text-end">{{ format_currency_py(item.total_revenue) }} ₸</td>
                        <td class="text-end">{{ format_currency_py(item.inventory_value) }} ₸</td>
                        <td class="text-end text-secondary">{{ format_currency_py(item.total_investment) }} ₸</td>
                        <td class="text-end fw-bold 
                            {% if item.payback > 0 %}payback-positive
                            {% elif item.payback < 0 %}payback-negative
                            {% else %}payback-zero{% endif %}">
                            {{ format_currency_py(item.payback) }} ₸ 
                        </td>
                    </tr>
                {% else %}
                    <tr><td colspan="6" class="text-center">Нет данных для анализа.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
    <div class="card-footer small text-muted">
        <i class="fas fa-info-circle me-1"></i>
        <strong>Общие вложения</strong> = Себестоимость проданных товаров + Стоимость текущих остатков на складе.
        <strong>Результат</strong> = Выручка - Общие вложения.
    </div>
</div>
"""

ADMIN_CONTENT = """
<div class="row">
    <div class="col-12 mb-4">
        <a href="{{ url_for('admin_shifts') }}" class="btn btn-info"><i class="fas fa-history me-2"></i>История смен кассиров</a>
    </div>
    <div class="col-md-6 mb-4">
        <div class="card h-100">
            <div class="card-header d-flex justify-content-between align-items-center"><h5 class="mb-0">Кассиры</h5><button class="btn btn-primary btn-sm" data-bs-toggle="modal" data-bs-target="#addUserModal"><i class="fas fa-plus"></i></button></div>
            <div class="card-body">
                <ul class="list-group">
                    {% for u in users %}
                    <li class="list-group-item d-flex justify-content-between align-items-center">
                        <div>{{ u.name }} <br>
                        <small class="text-muted">
                        {% if u.payment_type == 'salary' %}Зарплата: {{ format_currency_py(u.payment_value) }} ₸/мес.
                        {% elif u.payment_type == 'percentage' %}Процент: {{ u.payment_value }}%
                        {% endif %}
                        </small>
                        </div>
                        <div>
                            <button class="btn btn-sm btn-outline-primary" data-bs-toggle="modal" data-bs-target="#editUserModal-{{ u.id }}"><i class="fas fa-edit"></i></button>
                            <form action="{{ url_for('manage_user') }}" method="POST" class="d-inline" onsubmit="return confirm('Удалить кассира?');"><input type="hidden" name="action" value="delete"><input type="hidden" name="id" value="{{ u.id }}"><button type="submit" class="btn btn-sm btn-outline-danger"><i class="fas fa-trash"></i></button></form>
                        </div>
                    </li>
                    {% endfor %}
                </ul>
            </div>
        </div>
    </div>
    <div class="col-md-6 mb-4">
        <div class="card h-100">
            <div class="card-header"><h5 class="mb-0">Кассы</h5></div>
            <div class="card-body">
                <form action="{{ url_for('manage_kassa') }}" method="POST" class="mb-3">
                    <input type="hidden" name="action" value="add">
                    <div class="input-group">
                        <input type="text" name="name" class="form-control" placeholder="Название кассы" required>
                        <input type="text" name="balance" class="form-control" placeholder="Начальный баланс" value="" inputmode="decimal">
                        <button type="submit" class="btn btn-primary">Добавить</button>
                    </div>
                </form>
                <ul class="list-group">
                    {% for k in kassas %}
                    <li class="list-group-item d-flex justify-content-between align-items-center">
                        <div>{{ k.name }} <br><small class="fw-bold">{{ format_currency_py(k.balance) }} ₸</small></div>
                        <form action="{{ url_for('manage_kassa') }}" method="POST" onsubmit="return confirm('Удалить кассу?');"><input type="hidden" name="action" value="delete"><input type="hidden" name="id" value="{{ k.id }}"><button type="submit" class="btn btn-sm btn-danger"><i class="fas fa-trash"></i></button></form>
                    </li>
                    {% endfor %}
                </ul>
            </div>
        </div>
    </div>
    
    <div class="col-12 mb-4">
        <div class="card">
            <div class="card-header"><h5 class="mb-0">Ссылки в накладных</h5></div>
            <div class="card-body">
                <form action="{{ url_for('manage_link') }}" method="POST" class="mb-3">
                    <input type="hidden" name="action" value="add">
                    <div class="row g-2 align-items-end">
                        <div class="col-md-5"><label class="form-label">Название (текст ссылки)</label><input type="text" name="name" class="form-control" placeholder="Напр: Наш Instagram" required></div>
                        <div class="col-md-5"><label class="form-label">URL (адрес)</label><input type="url" name="url" class="form-control" placeholder="https://..." required></div>
                        <div class="col-md-2"><button type="submit" class="btn btn-primary w-100">Добавить</button></div>
                    </div>
                </form>
                <ul class="list-group">
                    {% for l in links %}
                    <li class="list-group-item d-flex justify-content-between align-items-center">
                        <a href="{{ l.url }}" target="_blank">{{ l.name }}</a>
                        <form action="{{ url_for('manage_link') }}" method="POST" onsubmit="return confirm('Удалить ссылку?');">
                            <input type="hidden" name="action" value="delete">
                            <input type="hidden" name="id" value="{{ l.id }}">
                            <button type="submit" class="btn btn-sm btn-danger"><i class="fas fa-trash"></i></button>
                        </form>
                    </li>
                    {% endfor %}
                </ul>
            </div>
        </div>
    </div>
    
    <div class="col-12 mb-4">
        <div class="card">
            <div class="card-header"><h5 class="mb-0">Операции по кассе (Внесение/Изъятие)</h5></div>
            <div class="card-body">
                <form action="{{ url_for('kassa_operation') }}" method="POST">
                    <div class="row g-2 align-items-end">
                        <div class="col-md-3"><label class="form-label">Касса</label><select name="kassa_id" class="form-select" required><option value="">-- Выберите --</option>{% for k in kassas %}<option value="{{k.id}}">{{k.name}}</option>{% endfor %}</select></div>
                        <div class="col-md-2"><label class="form-label">Операция</label><select name="op_type" class="form-select" required><option value="deposit">Внесение</option><option value="withdrawal">Изъятие</option></select></div>
                        <div class="col-md-2"><label class="form-label">Сумма</label><input type="text" name="amount" class="form-control" required inputmode="decimal" placeholder="0"></div>
                        <div class="col-md-3"><label class="form-label">Описание</label><input type="text" name="description" class="form-control"></div>
                        <div class="col-md-2"><button type="submit" class="btn btn-success w-100">Выполнить</button></div>
                    </div>
                </form>
            </div>
        </div>
    </div>
     <div class="col-lg-6 mb-4">
        <div class="card h-100">
            <div class="card-header"><h5 class="mb-0">Учет расходов (операционные)</h5></div>
            <div class="card-body d-flex flex-column">
                <form action="{{ url_for('manage_expense') }}" method="POST" class="mb-4">
                    <div class="row g-2 align-items-end">
                        <div class="col-md-4"><label class="form-label">Сумма</label><input type="text" name="amount" class="form-control" required inputmode="decimal" placeholder="0"></div>
                        <div class="col-md-8"><label class="form-label">Описание</label><input type="text" name="description" class="form-control" required placeholder="Напр: Аренда за май"></div>
                        <div class="col-12"><button type="submit" class="btn btn-warning w-100 mt-2">Добавить расход</button></div>
                    </div>
                </form>
                <h6>Все расходы:</h6>
                <div class="table-responsive flex-grow-1" style="max-height: 400px; overflow-y: auto;">
                    <table class="table table-sm table-striped">
                        <thead><tr><th>Дата</th><th>Описание</th><th class="text-end">Сумма</th><th></th></tr></thead>
                        <tbody>
                        {% for e in expenses %}
                        <tr>
                            <td><small>{{ e.timestamp[:10] }}</small></td>
                            <td>{{ e.description }}</td>
                            <td class="text-end fw-bold">{{ format_currency_py(e.amount) }} ₸</td>
                            <td class="text-end">
                                <form action="{{ url_for('delete_expense', expense_id=e.id) }}" method="POST" onsubmit="return confirm('Удалить этот расход?');">
                                    <button type="submit" class="btn btn-sm btn-outline-danger py-0 px-1"><i class="fas fa-trash"></i></button>
                                </form>
                            </td>
                        </tr>
                        {% else %}
                        <tr><td colspan="4" class="text-center">Расходов пока нет</td></tr>
                        {% endfor %}
                        </tbody>
                    </table>
                </div>
            </div>
        </div>
    </div>
    <div class="col-lg-6 mb-4">
        <div class="card h-100">
            <div class="card-header"><h5 class="mb-0">Учет расходов (личные)</h5></div>
            <div class="card-body d-flex flex-column">
                <form action="{{ url_for('manage_personal_expense') }}" method="POST" class="mb-4">
                    <div class="row g-2 align-items-end">
                        <div class="col-md-4"><label class="form-label">Сумма</label><input type="text" name="amount" class="form-control" required inputmode="decimal" placeholder="0"></div>
                        <div class="col-md-8"><label class="form-label">Описание</label><input type="text" name="description" class="form-control" required placeholder="Напр: Обед"></div>
                        <div class="col-12"><button type="submit" class="btn btn-info w-100 mt-2">Добавить расход</button></div>
                    </div>
                </form>
                <h6>Все расходы:</h6>
                <div class="table-responsive flex-grow-1" style="max-height: 400px; overflow-y: auto;">
                    <table class="table table-sm table-striped">
                        <thead><tr><th>Дата</th><th>Описание</th><th class="text-end">Сумма</th><th></th></tr></thead>
                        <tbody>
                        {% for e in personal_expenses %}
                        <tr>
                            <td><small>{{ e.timestamp[:10] }}</small></td>
                            <td>{{ e.description }}</td>
                            <td class="text-end fw-bold">{{ format_currency_py(e.amount) }} ₸</td>
                            <td class="text-end">
                                <form action="{{ url_for('delete_personal_expense', expense_id=e.id) }}" method="POST" onsubmit="return confirm('Удалить этот расход?');">
                                    <button type="submit" class="btn btn-sm btn-outline-danger py-0 px-1"><i class="fas fa-trash"></i></button>
                                </form>
                            </td>
                        </tr>
                        {% else %}
                        <tr><td colspan="4" class="text-center">Расходов пока нет</td></tr>
                        {% endfor %}
                        </tbody>
                    </table>
                </div>
            </div>
        </div>
    </div>
    <div class="col-12">
        <div class="card">
            <div class="card-header"><h5 class="mb-0">Резервное копирование</h5></div>
            <div class="card-body">
                <p>Данные периодически сохраняются в облако. Можно сделать это вручную.</p>
                <form method="POST" action="{{ url_for('backup_hf') }}" class="d-inline-block me-2">
                    <button type="submit" class="btn btn-outline-primary"><i class="fas fa-cloud-upload-alt me-2"></i>Сохранить в облако</button>
                </form>
                <form method="GET" action="{{ url_for('download_hf') }}" class="d-inline-block" onsubmit="return confirm('ВНИМАНИЕ! Это действие заменит все локальные данные данными из облака. Продолжить?');">
                    <button type="submit" class="btn btn-outline-danger"><i class="fas fa-cloud-download-alt me-2"></i>Загрузить из облака</button>
                </form>
            </div>
        </div>
    </div>
</div>

<div class="modal fade" id="addUserModal" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Новый кассир</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('manage_user') }}" method="POST">
        <input type="hidden" name="action" value="add">
        <div class="modal-body">
          <div class="mb-3"><label class="form-label">Имя</label><input type="text" name="name" class="form-control" required></div>
          <div class="mb-3"><label class="form-label">ПИН-код</label><input type="password" name="pin" class="form-control" required></div>
          <div class="mb-3"><label class="form-label">Тип оплаты</label><select name="payment_type" class="form-select"><option value="percentage">Процент от продаж</option><option value="salary">Фиксированная зарплата</option></select></div>
          <div class="mb-3"><label class="form-label">Значение</label><input type="text" name="payment_value" class="form-control" inputmode="decimal" placeholder="0" required><small class="form-text text-muted">Для процентов - число (напр. 5), для зарплаты - сумма в тенге.</small></div>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить</button></div>
      </form>
    </div>
  </div>
</div>
{% for u in users %}
<div class="modal fade" id="editUserModal-{{ u.id }}" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Редактировать кассира</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('manage_user') }}" method="POST">
        <input type="hidden" name="action" value="edit">
        <input type="hidden" name="id" value="{{ u.id }}">
        <div class="modal-body">
          <div class="mb-3"><label class="form-label">Имя</label><input type="text" name="name" value="{{ u.name }}" class="form-control" required></div>
          <div class="mb-3"><label class="form-label">ПИН-код</label><input type="password" name="pin" value="{{ u.pin }}" class="form-control" required></div>
          <div class="mb-3"><label class="form-label">Тип оплаты</label><select name="payment_type" class="form-select">
            <option value="percentage" {% if u.payment_type == 'percentage' %}selected{% endif %}>Процент от продаж</option>
            <option value="salary" {% if u.payment_type == 'salary' %}selected{% endif %}>Фиксированная зарплата</option></select>
          </div>
          <div class="mb-3"><label class="form-label">Значение</label><input type="text" name="payment_value" class="form-control" value="{{ u.payment_value }}" inputmode="decimal" required></div>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить</button></div>
      </form>
    </div>
  </div>
</div>
{% endfor %}
"""

ADMIN_SCRIPTS = ""

SHIFTS_CONTENT = """
<div class="card">
    <div class="card-header"><h5 class="mb-0">История смен</h5></div>
    <div class="card-body p-0">
        <div class="table-responsive">
            <table class="table table-hover table-sm mb-0">
                <thead class="table-light">
                    <tr>
                        <th>Кассир</th>
                        <th>Касса</th>
                        <th>Начало смены</th>
                        <th>Конец смены</th>
                        <th class="text-end">Продажи (наличные)</th>
                        <th class="text-end">Продажи (карта)</th>
                        <th class="text-end">Итого продаж</th>
                    </tr>
                </thead>
                <tbody>
                {% for s in shifts %}
                    <tr>
                        <td>{{ s.user_name }}</td>
                        <td>{{ s.kassa_name }}</td>
                        <td>{{ s.start_time[:16]|replace('T', ' ') }}</td>
                        <td>{{ (s.end_time[:16]|replace('T', ' ')) if s.end_time else '<span class="badge bg-success">Активна</span>' }}</td>
                        <td class="text-end">{{ format_currency_py(s.get('cash_sales', 0)) }} ₸</td>
                        <td class="text-end">{{ format_currency_py(s.get('card_sales', 0)) }} ₸</td>
                        <td class="text-end fw-bold">{{ format_currency_py(s.get('total_sales', 0)) }} ₸</td>
                    </tr>
                {% else %}
                    <tr><td colspan="7" class="text-center">Нет данных о сменах.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
"""

ADMIN_LOGIN_CONTENT = """
<div class="row justify-content-center mt-5">
    <div class="col-md-6 col-lg-4">
        <div class="card">
            <div class="card-body">
                <h4 class="card-title text-center">Вход для администратора</h4>
                <form method="POST">
                    <div class="mb-3">
                        <label for="password" class="form-label">Пароль</label>
                        <input type="password" name="password" id="password" class="form-control" required autofocus>
                    </div>
                    <div class="d-grid">
                        <button type="submit" class="btn btn-primary">Войти</button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>
"""

CASHIER_LOGIN_CONTENT = """
<div class="row justify-content-center">
    <div class="col-md-6 col-lg-4">
        <div class="card">
            <div class="card-body">
                <h4 class="card-title text-center">Вход для кассира</h4>
                <form method="POST" action="{{ url_for('cashier_login') }}">
                    <div class="mb-3">
                        <label for="pin" class="form-label">Введите ваш ПИН-код</label>
                        <input type="password" name="pin" id="pin" class="form-control form-control-lg text-center" required autofocus>
                    </div>
                    <div class="d-grid">
                        <button type="submit" class="btn btn-primary btn-lg">Войти</button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>
"""

CASHIER_DASHBOARD_CONTENT = """
<div class="card">
    <div class="card-body">
        <div class="table-responsive">
            <table class="table table-sm table-hover">
                <thead><tr><th>ID</th><th>Дата</th><th>Тип</th><th>Сумма</th><th>Статус</th><th>Действие</th></tr></thead>
                <tbody>
                {% for t in transactions %}
                <tr class="{% if t.type == 'return' %}table-danger{% endif %}">
                    <td><a href="{{ url_for('view_receipt', transaction_id=t.id) if t.invoice_html or t.receipt_html else '#' }}" target="_blank"><small class="text-muted">{{ t.id[:8] }}</small></a></td>
                    <td>{{ t.timestamp[:16]|replace('T', ' ') }}</td>
                    <td><span class="badge bg-{{'primary' if t.type == 'sale' else 'warning'}}">{{'Продажа' if t.type == 'sale' else 'Возврат'}}</span></td>
                    <td class="fw-bold">{{ format_currency_py(t.total_amount) }} ₸</td>
                    <td>
                       {% if t.status == 'completed' %}<span class="badge bg-success">Завершено</span>
                        {% elif t.status == 'returned' %}<span class="badge bg-danger">Возвращено</span>
                        {% elif t.status == 'partially_returned' %}<span class="badge bg-warning text-dark">Частичный возврат</span>
                        {% else %}<span class="badge bg-secondary">{{t.status}}</span>
                        {% endif %}
                    </td>
                    <td>
                        {% if t.type == 'sale' and t.status in ['completed', 'partially_returned'] %}
                        <a href="{{ url_for('return_transaction', transaction_id=t.id, cashier_id=user.id) }}" class="btn btn-sm btn-warning">Возврат</a>
                        {% endif %}
                    </td>
                </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>
"""

RETURN_PAGE_CONTENT = """
<div class="card">
    <div class="card-header">
        <h5 class="mb-0">Оформление возврата по накладной <a href="{{ url_for('view_receipt', transaction_id=transaction.id) }}" target="_blank">{{ transaction.id[:8] }}</a></h5>
    </div>
    <div class="card-body">
        <form method="POST" action="{{ url_for('return_transaction', transaction_id=transaction.id) }}">
            <input type="hidden" name="cashier_id" value="{{ cashier_id }}">
            <div class="table-responsive">
                <table class="table table-bordered">
                    <thead>
                        <tr>
                            <th>Товар</th>
                            <th class="text-center">Цена за шт.</th>
                            <th class="text-center">Продано</th>
                            <th class="text-center">Вернуть (шт.)</th>
                        </tr>
                    </thead>
                    <tbody>
                        {% for item in items %}
                        <tr>
                            <td>{{ item.name }}</td>
                            <td class="text-center">{{ format_currency_py(item.price_at_sale) }} ₸</td>
                            <td class="text-center">{{ item.quantity }}</td>
                            <td>
                                <input type="number" name="return_qty_{{ item.variant_id }}" class="form-control" value="0" min="0" max="{{ item.max_returnable }}">
                                <small class="form-text text-muted">Доступно: {{ item.max_returnable }} шт.</small>
                            </td>
                        </tr>
                        {% else %}
                        <tr>
                            <td colspan="4" class="text-center">Нет товаров, доступных для возврата.</td>
                        </tr>
                        {% endfor %}
                    </tbody>
                </table>
            </div>
            {% if items %}
            <div class="mt-3 d-flex justify-content-end">
                <a href="{{ url_for('cashier_dashboard', user_id=cashier_id) }}" class="btn btn-secondary me-2">Отмена</a>
                <button type="submit" class="btn btn-warning">Оформить возврат</button>
            </div>
            {% endif %}
        </form>
    </div>
</div>
"""

CUSTOMERS_CONTENT = """
<div class="card">
    <div class="card-header d-flex justify-content-between align-items-center">
        <h5 class="mb-0">Клиенты</h5>
        <button class="btn btn-primary btn-sm" data-bs-toggle="modal" data-bs-target="#addCustomerModal"><i class="fas fa-plus me-2"></i>Добавить клиента</button>
    </div>
    <div class="card-body">
        <div class="table-responsive">
            <table class="table table-hover">
                <thead><tr><th>Имя</th><th>Телефон</th><th></th></tr></thead>
                <tbody>
                {% for c in customers %}
                <tr>
                    <td>{{ c.name }}</td>
                    <td>{{ c.phone }}</td>
                    <td class="text-end">
                        <form action="{{ url_for('manage_customer') }}" method="POST" onsubmit="return confirm('Удалить этого клиента?');">
                            <input type="hidden" name="action" value="delete">
                            <input type="hidden" name="id" value="{{ c.id }}">
                            <button type="submit" class="btn btn-sm btn-outline-danger"><i class="fas fa-trash"></i></button>
                        </form>
                    </td>
                </tr>
                {% else %}
                <tr><td colspan="3" class="text-center">Список клиентов пуст.</td></tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>
</div>

<div class="modal fade" id="addCustomerModal" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header"><h5 class="modal-title">Новый клиент</h5><button type="button" class="btn-close" data-bs-dismiss="modal"></button></div>
      <form action="{{ url_for('manage_customer') }}" method="POST">
        <input type="hidden" name="action" value="add">
        <div class="modal-body">
          <div class="mb-3"><label class="form-label">Имя</label><input type="text" name="name" class="form-control" required></div>
          <div class="mb-3"><label class="form-label">Телефон</label><input type="tel" name="phone" class="form-control" placeholder="7071234567" required></div>
        </div>
        <div class="modal-footer"><button type="submit" class="btn btn-primary">Сохранить</button></div>
      </form>
</div>
  </div>
</div>
"""

if __name__ == '__main__':
    backup_thread = threading.Thread(target=periodic_backup, daemon=True)
    backup_thread.start()
    for key in DATA_FILES.keys():
        load_json_data(key)
    app.run(debug=False, host='0.0.0.0', port=7860, use_reloader=False)