import sqlite3
import json
from datetime import datetime, timedelta
from typing import List, Optional, Dict
import pandas as pd

class Database:
    def __init__(self, db_path: str = "data/indiscan.db"):
        self.db_path = db_path
        self.init_db()

    def init_db(self):
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()

        # Create products table
        c.execute('''
        CREATE TABLE IF NOT EXISTS products (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            barcode TEXT UNIQUE,
            name TEXT,
            brand TEXT,
            category TEXT,
            ingredients TEXT,
            nutrition_info TEXT,
            health_score INTEGER,
            last_updated TIMESTAMP,
            image_url TEXT,
            product_type TEXT,
            added_by TEXT,
            is_verified BOOLEAN DEFAULT 0
        )
        ''')

        # Create ingredients table
        c.execute('''
        CREATE TABLE IF NOT EXISTS ingredients (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            name TEXT UNIQUE,
            risk_score INTEGER,
            description TEXT,
            category TEXT,
            concerns TEXT
        )
        ''')

        # Create users table for admin control
        c.execute('''
        CREATE TABLE IF NOT EXISTS users (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            username TEXT UNIQUE,
            password_hash TEXT,
            is_admin BOOLEAN DEFAULT 0
        )
        ''')

        # Create price tracking table
        c.execute('''
        CREATE TABLE IF NOT EXISTS price_tracking (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            product_id INTEGER,
            platform TEXT,
            price REAL,
            timestamp TIMESTAMP,
            url TEXT,
            FOREIGN KEY (product_id) REFERENCES products (id)
        )
        ''')

        conn.commit()
        conn.close()

    def add_product(self, product_data: Dict) -> int:
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()
        
        product_data['last_updated'] = datetime.now().isoformat()
        if 'ingredients' in product_data and isinstance(product_data['ingredients'], list):
            product_data['ingredients'] = json.dumps(product_data['ingredients'])
        if 'nutrition_info' in product_data and isinstance(product_data['nutrition_info'], dict):
            product_data['nutrition_info'] = json.dumps(product_data['nutrition_info'])

        columns = ', '.join(product_data.keys())
        placeholders = ', '.join(['?' for _ in product_data])
        values = tuple(product_data.values())

        try:
            c.execute(f"INSERT INTO products ({columns}) VALUES ({placeholders})", values)
            product_id = c.lastrowid
            conn.commit()
            return product_id
        except sqlite3.IntegrityError:
            # Update existing product
            update_cols = ', '.join([f"{k}=?" for k in product_data.keys()])
            c.execute(f"UPDATE products SET {update_cols} WHERE barcode=?",
                     (*values, product_data['barcode']))
            conn.commit()
            return c.lastrowid
        finally:
            conn.close()

    def get_product(self, barcode: str) -> Optional[Dict]:
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()
        
        c.execute("SELECT * FROM products WHERE barcode=?", (barcode,))
        result = c.fetchone()
        
        if result:
            columns = [description[0] for description in c.description]
            product = dict(zip(columns, result))
            
            # Parse JSON strings back to Python objects
            if product['ingredients']:
                product['ingredients'] = json.loads(product['ingredients'])
            if product['nutrition_info']:
                product['nutrition_info'] = json.loads(product['nutrition_info'])
                
            conn.close()
            return product
        
        conn.close()
        return None

    def update_prices(self, product_id: int, prices: List[Dict]):
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()
        
        timestamp = datetime.now().isoformat()
        
        for price_data in prices:
            c.execute("""
                INSERT INTO price_tracking (product_id, platform, price, timestamp, url)
                VALUES (?, ?, ?, ?, ?)
            """, (product_id, price_data['platform'], price_data['price'], timestamp, price_data['url']))
        
        conn.commit()
        conn.close()

    def get_products_for_update(self) -> List[str]:
        """Get products that haven't been updated in 60 days"""
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()
        
        sixty_days_ago = (datetime.now() - timedelta(days=60)).isoformat()
        
        c.execute("""
            SELECT barcode FROM products 
            WHERE last_updated < ? OR last_updated IS NULL
        """, (sixty_days_ago,))
        
        barcodes = [row[0] for row in c.fetchall()]
        conn.close()
        return barcodes

    def export_to_csv(self, filepath: str):
        """Export the database to CSV files"""
        conn = sqlite3.connect(self.db_path)
        
        # Export products
        pd.read_sql_query("SELECT * FROM products", conn).to_csv(f"{filepath}/products.csv", index=False)
        
        # Export ingredients
        pd.read_sql_query("SELECT * FROM ingredients", conn).to_csv(f"{filepath}/ingredients.csv", index=False)
        
        # Export price tracking
        pd.read_sql_query("SELECT * FROM price_tracking", conn).to_csv(f"{filepath}/price_tracking.csv", index=False)
        
        conn.close()

    def import_from_csv(self, filepath: str):
        """Import data from CSV files"""
        conn = sqlite3.connect(self.db_path)
        
        # Import products
        products_df = pd.read_csv(f"{filepath}/products.csv")
        products_df.to_sql('products', conn, if_exists='append', index=False)
        
        # Import ingredients
        ingredients_df = pd.read_csv(f"{filepath}/ingredients.csv")
        ingredients_df.to_sql('ingredients', conn, if_exists='append', index=False)
        
        # Import price tracking
        price_df = pd.read_csv(f"{filepath}/price_tracking.csv")
        price_df.to_sql('price_tracking', conn, if_exists='append', index=False)
        
        conn.commit()
        conn.close()

    def verify_admin(self, username: str, password_hash: str) -> bool:
        conn = sqlite3.connect(self.db_path)
        c = conn.cursor()
        
        c.execute("SELECT is_admin FROM users WHERE username=? AND password_hash=?",
                 (username, password_hash))
        result = c.fetchone()
        
        conn.close()
        return bool(result and result[0])