app.py

import gradio as gr
import os
import threading
from datetime import datetime, timedelta
from huggingface_hub import InferenceClient

ROWS = [chr(i) for i in range(ord("A"), ord("Z") + 1)]
SEATS_PER_ROW = 26
SECTION_RANGES = {
    "left": range(1, 9),
    "middle": range(9, 19),
    "right": range(19, 27),
}

lock = threading.Lock()
seat_state = {row: {seat: "available" for seat in range(1, 27)} for row in ROWS}
holds = {}
bookings = {}
lock_owner = None
lock_expires_at = None

client = InferenceClient(
    base_url="https://router.huggingface.co/v1",
    token=os.getenv("HF_TOKEN")
)

def seat_label(row, seat):
    return f"{row}{seat}"

def section_for_seat(seat):
    if 1 <= seat <= 8:
        return "left"
    if 9 <= seat <= 18:
        return "middle"
    return "right"

def render_map():
    html = """
    <style>
      .seat-grid { font-family: Arial, sans-serif; display: flex; flex-direction: column; gap: 6px; }
      .row { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
      .row-label { width: 24px; font-weight: bold; }
      .seat {
        display: inline-block;
        min-width: 34px;
        padding: 6px 8px;
        margin: 1px;
        border-radius: 6px;
        text-align: center;
        color: white;
        font-size: 12px;
      }
      .available { background: #2ecc71; }
      .booked { background: #e74c3c; }
      .held { background: #f39c12; }
      .gap {
        display: inline-block;
        width: 18px;
      }
    </style>
    <div class="seat-grid">
    """
    for row in ROWS:
        html += f'<div class="row"><span class="row-label">{row}</span>'
        for seat in range(1, 27):
            status = seat_state[row][seat]
            cls = "available" if status == "available" else "booked" if status == "booked" else "held"
            html += f'<span class="seat {cls}">{seat}</span>'
            if seat in (8, 18):
                html += '<span class="gap"></span>'
        html += "</div>"
    html += "</div>"
    return html

def available_seats():
    out = []
    for row in ROWS:
        for seat in range(1, 27):
            if seat_state[row][seat] == "available":
                out.append(seat_label(row, seat))
    return out

def find_best_block(n):
    for row in ROWS:
        for section_name, seats in SECTION_RANGES.items():
            seats = list(seats)
            run = []
            for s in seats:
                if seat_state[row][s] == "available":
                    run.append(s)
                    if len(run) >= n:
                        return [seat_label(row, x) for x in run[:n]]
                else:
                    run = []
    return None

def acquire_lock(user_id):
    global lock_owner, lock_expires_at
    now = datetime.utcnow()
    if lock_owner and lock_expires_at and now < lock_expires_at and lock_owner != user_id:
        return False, f"Locked by {lock_owner}"
    lock_owner = user_id
    lock_expires_at = now + timedelta(minutes=10)
    return True, f"Lock granted to {user_id}"

def release_lock(user_id):
    global lock_owner, lock_expires_at
    with lock:
        if lock_owner != user_id:
            return f"You do not own the lock."
        lock_owner = None
        lock_expires_at = None
        return "Lock released."

def hold_seats(user_id, count):
    with lock:
        ok, msg = acquire_lock(user_id)
        if not ok:
            return render_map(), msg, "", ""
        seats = find_best_block(count)
        if not seats:
            return render_map(), "Not enough adjacent seats available.", "", ""
        hold_id = f"H{len(holds)+1}"
        for seat in seats:
            row = seat[0]
            num = int(seat[1:])
            seat_state[row][num] = "held"
        holds[hold_id] = {
            "user_id": user_id,
            "seats": seats,
            "expires_at": datetime.utcnow() + timedelta(minutes=5),
        }
        return render_map(), f"Hold created: {hold_id}", hold_id, ", ".join(seats)

def confirm_hold(user_id, hold_id):
    global lock_owner, lock_expires_at
    with lock:
        h = holds.get(hold_id)
        if not h:
            return render_map(), "Hold not found.", ""
        if h["user_id"] != user_id:
            return render_map(), "You do not own this hold.", ""
        for seat in h["seats"]:
            row = seat[0]
            num = int(seat[1:])
            seat_state[row][num] = "booked"
        booking_id = f"B{len(bookings)+1}"
        bookings[booking_id] = h
        del holds[hold_id]
        lock_owner = None
        lock_expires_at = None
        return render_map(), f"Confirmed. Booking ID: {booking_id}. Seats: {', '.join(h['seats'])}", ", ".join(h["seats"])

def ai_chat(message, history):
    messages = [{"role": "system", "content": "You are a ticketing assistant for a venue seat booking app."}]
    for user_msg, bot_msg in history:
        messages.append({"role": "user", "content": user_msg})
        messages.append({"role": "assistant", "content": bot_msg})
    messages.append({"role": "user", "content": message})

    if os.getenv("HF_TOKEN"):
        resp = client.chat.completions.create(
            model="meta-llama/Llama-3.1-8B-Instruct",
            messages=messages,
            max_tokens=200,
            temperature=0.2,
        )
        return resp.choices[0].message.content

    return "HF_TOKEN is not configured."

def hold_action(user_id, group_size):
    return hold_seats(user_id, int(group_size))

def confirm_action(user_id, hold_id):
    return confirm_hold(user_id, hold_id)

def release_action(user_id):
    msg = release_lock(user_id)
    return render_map(), msg

with gr.Blocks() as demo:
    gr.Markdown("# Venue Ticketing System")

    with gr.Row():
        user_id = gr.Textbox(label="User ID", value="user1")
        group_size = gr.Number(label="Seats needed", value=2, precision=0)

    with gr.Row():
        btn_hold = gr.Button("Hold Seats")
        btn_confirm = gr.Button("Confirm Booking")
        btn_release = gr.Button("Release Lock")

    with gr.Row():
        hold_id = gr.Textbox(label="Hold ID")
        seats_text = gr.Textbox(label="Seats", interactive=False)

    status = gr.Textbox(label="Status", interactive=False)
    seat_map = gr.HTML(label="Seat Map")

    ai = gr.ChatInterface(fn=ai_chat, title="AI Assistant")

    btn_hold.click(
        hold_action,
        inputs=[user_id, group_size],
        outputs=[seat_map, status, hold_id, seats_text],
    )

    btn_confirm.click(
        confirm_action,
        inputs=[user_id, hold_id],
        outputs=[seat_map, status, seats_text],
    )

    btn_release.click(
        release_action,
        inputs=[user_id],
        outputs=[seat_map, status],
    )

    demo.load(render_map, outputs=seat_map)
    demo.queue(default_concurrency_limit=1)

demo.launch()