# app.py
import os
import json
import random
import sqlite3
import gradio as gr

from agents import AnalyzerAgent, CoachAgent, PredictiveAgent

# Config
QUESTIONS_JSON = "questions.json"
DB_FILE = "exam.db"
MEDIA_DIR = "media"
MAX_SLOTS = 10  # number of question rows to display (adjust as needed)

os.makedirs(MEDIA_DIR, exist_ok=True)

# Agents
analyzer = AnalyzerAgent()
coach = CoachAgent()
predictor = PredictiveAgent()

# -------------------------
# DB / JSON helpers
# -------------------------
def load_questions_json():
    if not os.path.exists(QUESTIONS_JSON) or os.path.getsize(QUESTIONS_JSON) == 0:
        return []
    try:
        with open(QUESTIONS_JSON, "r", encoding="utf-8") as f:
            return json.load(f)
    except Exception:
        return []

def init_db_and_sync():
    conn = sqlite3.connect(DB_FILE)
    cur = conn.cursor()
    cur.execute("""
    CREATE TABLE IF NOT EXISTS questions (
        id INTEGER PRIMARY KEY,
        text TEXT,
        choices TEXT,
        answer TEXT,
        subject TEXT,
        paper INTEGER,
        year INTEGER,
        image TEXT,
        source TEXT
    )
    """)
    conn.commit()
    conn.close()
    sync_json_to_db()

def sync_json_to_db():
    questions = load_questions_json()
    if not questions:
        return
    conn = sqlite3.connect(DB_FILE)
    cur = conn.cursor()
    for q in questions:
        try:
            qid = int(q.get("id") or 0)
            text = q.get("text", "")
            choices = json.dumps(q.get("choices", []), ensure_ascii=False)
            answer = q.get("answer", "")
            subject = q.get("subject", "")
            paper = int(q.get("paper", 2) or 2)
            year = int(q.get("year", 0) or 0)
            image = q.get("image")
            source = q.get("source", "")
            if qid:
                cur.execute("INSERT OR IGNORE INTO questions (id,text,choices,answer,subject,paper,year,image,source) VALUES (?,?,?,?,?,?,?,?,?)",
                            (qid, text, choices, answer, subject, paper, year, image, source))
            else:
                cur.execute("INSERT INTO questions (text,choices,answer,subject,paper,year,image,source) VALUES (?,?,?,?,?,?,?,?)",
                            (text, choices, answer, subject, paper, year, image, source))
        except Exception:
            continue
    conn.commit()
    conn.close()

def get_pool(subject, paper=2):
    conn = sqlite3.connect(DB_FILE)
    cur = conn.cursor()
    cur.execute("SELECT id, text, choices, answer, subject, paper, year, image, source FROM questions WHERE subject=? AND paper=?", (subject, paper))
    rows = cur.fetchall()
    conn.close()
    pool = []
    for r in rows:
        try:
            choices = json.loads(r[2]) if r[2] else []
        except Exception:
            choices = []
        pool.append({
            "id": r[0],
            "text": r[1],
            "choices": choices,
            "answer": r[3],
            "subject": r[4],
            "paper": r[5],
            "year": r[6],
            "image": r[7],
            "source": r[8]
        })
    return pool

# initialize DB & sync once at startup
init_db_and_sync()

# -------------------------
# Exam functions
# -------------------------
def start_exam(subject, num_questions):
    """
    Returns values mapping to outputs:
     - first MAX_SLOTS strings: markdown question text (include choice lines A/B/C/D)
     - next MAX_SLOTS strings: image file paths or empty ""
     - next MAX_SLOTS values: dropdown default value (None)
     - final output: selected questions (state)
    """
    # ensure any new JSON items are synced
    sync_json_to_db()

    pool = get_pool(subject, paper=2)
    if not pool:
        # return empty placeholders
        markdowns = [f"Q{i+1}: (no question available)" for i in range(MAX_SLOTS)]
        images = ["" for _ in range(MAX_SLOTS)]
        defaults = [None for _ in range(MAX_SLOTS)]
        return markdowns + images + defaults + [[]]

    selected = random.sample(pool, min(num_questions, len(pool)))

    markdowns = []
    images = []
    defaults = []
    for i in range(MAX_SLOTS):
        if i < len(selected):
            q = selected[i]
            # Build question text + choice lines
            text_block = q["text"].strip()
            # If choices exist, append them as labeled lines (A., B., ...)
            if q.get("choices"):
                letters = ["A", "B", "C", "D"]
                choice_lines = []
                for j, opt in enumerate(q["choices"]):
                    if j < 4:
                        # Avoid double-prepending if already includes letter
                        opt_str = opt.strip()
                        if opt_str.upper().startswith(tuple([l + "." for l in letters])):
                            choice_lines.append(opt_str)
                        else:
                            choice_lines.append(f"{letters[j]}. {opt_str}")
                text_block += "\n\n" + "\n".join(choice_lines)
            else:
                text_block += "\n\n(A/B/C/D)"
            markdowns.append(text_block)
            images.append(q.get("image") or "")
            defaults.append(None)
        else:
            markdowns.append("")  # blank row
            images.append("")
            defaults.append(None)

    # Return markdowns (MAX) + images (MAX) + defaults (MAX) + [selected]
    return markdowns + images + defaults + [selected]

def submit_exam(*args):
    """
    args: first MAX_SLOTS dropdown answers (strings or None), last arg = selected questions list
    returns: score_text, wrong_details_str, ai_advice_str
    """
    if len(args) < MAX_SLOTS + 1:
        return "Submission error (bad input format).", "", ""

    answers = list(args[:MAX_SLOTS])
    selected = args[MAX_SLOTS] or []

    total = len(selected)
    correct = 0
    wrong_list = []
    wrong_ids = []

    for i, q in enumerate(selected):
        ans = (answers[i] or "").strip()
        expected = str(q.get("answer") or "").strip()
        is_correct = False
        if expected == "":
            is_correct = False
        else:
            # If expected is single letter (A/B/C/D)
            if len(expected) == 1 and expected.upper() in ["A","B","C","D"]:
                if ans.upper() == expected.upper():
                    is_correct = True
            else:
                # compare free-text
                if ans.lower() == expected.lower():
                    is_correct = True

        if is_correct:
            correct += 1
        else:
            # Prepare readable correct label
            corr_display = expected
            if expected and len(expected) == 1 and q.get("choices"):
                idx = ord(expected.upper()) - ord("A")
                if 0 <= idx < len(q["choices"]):
                    corr_display = f"{expected.upper()}. {q['choices'][idx]}"
            wrong_list.append(f"Q{i+1} (id:{q['id']}): Your = {ans or '(no answer)'}  |  Correct = {corr_display}")
            wrong_ids.append(q['id'])

    score_text = f"Score: {correct} / {total}   (Correct {correct}, Wrong {total - correct})"

    # Ask coach agent for advice
    try:
        context = {"subject": selected[0]["subject"] if total>0 else None,
                   "total": total, "correct": correct, "wrong": total-correct, "wrong_ids": wrong_ids}
        advice = coach.coach(json.dumps(context, ensure_ascii=False))
    except Exception as e:
        advice = f"(AI coach not available) {e}"

    wrong_str = "\n".join(wrong_list) if wrong_list else "All correct!"
    return score_text, wrong_str, advice

# -------------------------
# Build UI (side-by-side layout)
# -------------------------
# Prepare subjects list from DB
conn = sqlite3.connect(DB_FILE)
cur = conn.cursor()
cur.execute("SELECT DISTINCT subject FROM questions")
rows = cur.fetchall()
conn.close()
SUBJECTS = [r[0] for r in rows] or ["BM", "English", "Math", "History", "Science", "MoralStudies"]

with gr.Blocks(title="SPM Paper 2 Simulator — Side-by-Side UI") as demo:
    gr.Markdown("# 🧾 SPM Paper 2 — Simulator (Form 5)")
    gr.Markdown("Each question is displayed with its answer selector to the right (select A/B/C/D). Diagrams (if any) show below the question text.")

    with gr.Row():
        subject_dd = gr.Dropdown(SUBJECTS, label="Subject", value=SUBJECTS[0])
        num_q = gr.Slider(1, MAX_SLOTS, value=10, step=1, label="Number of Questions")
        start_btn = gr.Button("Start Simulation")

    # Create MAX_SLOTS rows, each row has Markdown (left), Image (below left), Dropdown (right)
    q_markdowns = []
    q_images = []
    q_dropdowns = []

    for i in range(MAX_SLOTS):
        with gr.Row():
            md = gr.Markdown(f"Q{i+1}: (not loaded)")
            dd = gr.Dropdown(choices=["A","B","C","D"], label=f"Select answer Q{i+1}", value=None)
        img = gr.Image(type="filepath", visible=False)
        q_markdowns.append(md)
        q_images.append(img)
        q_dropdowns.append(dd)

    # state to hold selected question dicts
    selected_state = gr.State([])

    # Outputs mapping: [*q_markdowns, *q_images, *q_dropdowns, selected_state]
    start_btn.click(
        fn=start_exam,
        inputs=[subject_dd, num_q],
        outputs=[*q_markdowns, *q_images, *q_dropdowns, selected_state]
    )

    submit_btn = gr.Button("Submit Answers")
    score_out = gr.Textbox(label="Score Summary")
    wrong_out = gr.Textbox(label="Wrong Answers", lines=8)
    advice_out = gr.Textbox(label="AI Advice", lines=6)

    submit_btn.click(
        fn=submit_exam,
        inputs=[*q_dropdowns, selected_state],
        outputs=[score_out, wrong_out, advice_out]
    )

if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", server_port=7860)