import os
import sqlite3
import requests
from flask import Flask, render_template, request, jsonify, redirect, url_for, flash, send_from_directory
from flask_socketio import SocketIO, emit
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
from werkzeug.security import generate_password_hash, check_password_hash

app = Flask(__name__)
app.config['SECRET_KEY'] = 'seki_super_secret_key_99' # Change this if you have actual friends
socketio = SocketIO(app, cors_allowed_origins="*")

# Auth Setup
login_manager = LoginManager(app)
login_manager.login_view = 'login'

DB_FILE = 'pos_database.db'
CACHE_DIR = 'static/cache'
os.makedirs(CACHE_DIR, exist_ok=True)

# --- MODELS ---
class User(UserMixin):
    def __init__(self, id, username):
        self.id = id
        self.username = username

# --- DATABASE LOGIC ---
def init_db():
    with sqlite3.connect(DB_FILE) as conn:
        conn.execute('''CREATE TABLE IF NOT EXISTS users 
                        (id INTEGER PRIMARY KEY, username TEXT UNIQUE, password TEXT)''')
        conn.execute('''CREATE TABLE IF NOT EXISTS products 
                        (barcode TEXT PRIMARY KEY, name TEXT, price REAL, image_url TEXT)''')
        
        # Default user: admin / Pass: choripan1234
        user = conn.execute('SELECT * FROM users WHERE username = ?', ('admin',)).fetchone()
        if not user:
            hashed_pw = generate_password_hash('choripan1234')
            conn.execute('INSERT INTO users (username, password) VALUES (?, ?)', ('admin', hashed_pw))
        conn.commit()

@login_manager.user_loader
def load_user(user_id):
    with sqlite3.connect(DB_FILE) as conn:
        user = conn.execute('SELECT id, username FROM users WHERE id = ?', (user_id,)).fetchone()
    return User(user[0], user[1]) if user else None

# --- HELPERS ---
def download_image(url, barcode):
    if not url or not url.startswith('http'): return url
    local_filename = f"{barcode}.jpg"
    local_path = os.path.join(CACHE_DIR, local_filename)
    if os.path.exists(local_path): return f"/static/cache/{local_filename}"
    try:
        headers = {'User-Agent': 'SekiPOS/1.0'}
        r = requests.get(url, headers=headers, stream=True, timeout=5)
        if r.status_code == 200:
            with open(local_path, 'wb') as f:
                for chunk in r.iter_content(1024): f.write(chunk)
            return f"/static/cache/{local_filename}"
    except: pass
    return url

def fetch_from_openfoodfacts(barcode):
    url = f"https://world.openfoodfacts.org/api/v2/product/{barcode}.json"
    try:
        headers = {'User-Agent': 'SekiPOS/1.0'}
        resp = requests.get(url, headers=headers, timeout=5).json()
        if resp.get('status') == 1:
            p = resp.get('product', {})
            name = p.get('product_name_es') or p.get('product_name') or p.get('brands', 'Unknown')
            imgs = p.get('selected_images', {}).get('front', {}).get('display', {})
            img_url = imgs.get('es') or imgs.get('en') or p.get('image_url', '')
            local_img = download_image(img_url, barcode)
            return {"name": name, "image": local_img}
    except: pass
    return None

# --- ROUTES ---
@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        user_in = request.form.get('username')
        pass_in = request.form.get('password')
        with sqlite3.connect(DB_FILE) as conn:
            user = conn.execute('SELECT * FROM users WHERE username = ?', (user_in,)).fetchone()
        if user and check_password_hash(user[2], pass_in):
            login_user(User(user[0], user[1]))
            return redirect(url_for('index'))
        flash('Invalid credentials.')
    return render_template('login.html')

@app.route('/logout')
@login_required
def logout():
    logout_user(); return redirect(url_for('login'))

@app.route('/')
@login_required
def index():
    with sqlite3.connect(DB_FILE) as conn:
        products = conn.execute('SELECT * FROM products').fetchall()
    return render_template('index.html', products=products, user=current_user)

@app.route('/upsert', methods=['POST'])
@login_required
def upsert():
    d = request.form
    with sqlite3.connect(DB_FILE) as conn:
        conn.execute('''INSERT INTO products (barcode, name, price, image_url) VALUES (?,?,?,?)
                        ON CONFLICT(barcode) DO UPDATE SET name=excluded.name, 
                        price=excluded.price, image_url=excluded.image_url''',
                     (d['barcode'], d['name'], d['price'], d['image_url']))
        conn.commit()
    return redirect(url_for('index'))

@app.route('/delete/<barcode>', methods=['POST'])
@login_required
def delete(barcode):
    with sqlite3.connect(DB_FILE) as conn:
        conn.execute('DELETE FROM products WHERE barcode = ?', (barcode,))
        conn.commit()
    # Clean up cache
    img_p = os.path.join(CACHE_DIR, f"{barcode}.jpg")
    if os.path.exists(img_p): os.remove(img_p)
    socketio.emit('product_deleted', {"barcode": barcode})
    return redirect(url_for('index'))

@app.route('/scan', methods=['GET'])
def scan():
    barcode = request.args.get('content', '').replace('{content}', '')
    if not barcode: return jsonify({"err": "empty"}), 400
    
    with sqlite3.connect(DB_FILE) as conn:
        p = conn.execute('SELECT * FROM products WHERE barcode = ?', (barcode,)).fetchone()
    
    if p:
        socketio.emit('new_scan', {"barcode": p[0], "name": p[1], "price": int(p[2]), "image": p[3]})
        return jsonify({"status": "ok"})
    else:
        ext = fetch_from_openfoodfacts(barcode)
        if ext:
            socketio.emit('scan_error', {"barcode": barcode, "name": ext['name'], "image": ext['image']})
        else:
            socketio.emit('scan_error', {"barcode": barcode})
        return jsonify({"status": "not_found"}), 404

@app.route('/static/cache/<path:filename>')
def serve_cache(filename):
    return send_from_directory(CACHE_DIR, filename)

if __name__ == '__main__':
    init_db()
    socketio.run(app, host='0.0.0.0', port=5000, debug=True)