from flask import Flask, request, jsonify, render_template
from flask_cors import CORS
import sqlite3
import uuid
import time
import base64
import os
from dotenv import load_dotenv
from captcha import generate_captcha_image

load_dotenv()

app = Flask(__name__)
CORS(app)
DB_FILE = os.getenv("DB_FILE", "captchas.db")
CAPTCHA_DIR = os.getenv("CAPTCHA_DIR", "data/captcha_data")
FONT_PATH = os.getenv("FONT_PATH", "captcha.ttf")
EXPIRY_SECONDS = int(os.getenv("CAPTCHA_EXPIRY_SECONDS", "90"))

def init_db():
    with sqlite3.connect(DB_FILE) as conn:
        conn.execute('''
            CREATE TABLE IF NOT EXISTS captchas (
                token TEXT PRIMARY KEY,
                answers TEXT,
                expires_at REAL
            )
        ''')
init_db()


@app.route('/')
def index():
    return render_template("index.html")

@app.route('/generate', methods=['GET', 'POST'])
def generate():
    try:
        positions, blob = generate_captcha_image(
            captcha_dir=CAPTCHA_DIR,
            font_path=FONT_PATH
        )
    except Exception as e:
        return jsonify({"error": str(e)}), 500

    token = str(uuid.uuid4())
    answers_str = ",".join(map(str, sorted(positions)))
    expires_at = time.time() + EXPIRY_SECONDS
    with sqlite3.connect(DB_FILE) as conn:
        conn.execute('INSERT INTO captchas (token, answers, expires_at) VALUES (?, ?, ?)',
                     (token, answers_str, expires_at))

    b64_img = base64.b64encode(blob).decode('utf-8')

    return jsonify({
        "token": token,
        "image": f"data:image/jpeg;base64,{b64_img}",
        "expires_in": EXPIRY_SECONDS
    })

@app.route('/verify', methods=['POST'])
def verify():
    data = request.json
    if not data or 'token' not in data or 'answers' not in data:
        return jsonify({"error": "Missing token or answers"}), 400

    token = data['token']
    user_answers = data['answers']

    if not isinstance(user_answers, list):
        return jsonify({"error": "answers must be a list of integers"}), 400

    with sqlite3.connect(DB_FILE) as conn:
        cursor = conn.cursor()
        conn.execute('pragma journal_mode=wal')
        cursor.execute('SELECT answers, expires_at FROM captchas WHERE token = ?', (token,))
        row = cursor.fetchone()
        if not row:
            return jsonify({"error": "Invalid token"}), 404
        answers_str, expires_at = row
        cursor.execute('DELETE FROM captchas WHERE token = ?', (token,))

        if time.time() > expires_at:
            return jsonify({"error": "Captcha expired"}), 400
        correct_answers = [int(x) for x in answers_str.split(',')]
        user_answers_sorted = sorted([int(x) for x in user_answers])

        if correct_answers == user_answers_sorted:
            return jsonify({"success": True})
        else:
            return jsonify({"success": False, "error": "Incorrect answers"})

if __name__ == '__main__':
    app.run(debug=True, port=int(os.getenv("PORT", 5000)))