pedidos-express/services/data_service.py

import json
from math import log
import os
import re
import psycopg2
from config.settings import POSTGRESQL_DB_CONFIG
from typing import List, Dict, Optional, Any
from abc import ABC, abstractmethod
from config.settings import BG_DATA_PATH, DB_PATH, IMAGE_PATH, PRODUCT_DATA_PATH, CURRENT_URL
from logging import getLogger
from datetime import datetime
from cryptography.fernet import Fernet
from config.settings import PIN_KEY
import base64 as b64
# Import models
from models.user import User
from models.items import Product
from models.sales import Sale
from models.blacklist import Blacklist

fernet = Fernet(PIN_KEY.encode())

logger = getLogger(__name__)

"""
ESQUEMA DE BASE DE DATOS SQLITE (data.db)

1. Tabla: users
-----------------------------------
- id           SERIAL PRIMARY KEY
- email       VARCHAR(255) UNIQUE NOT NULL
- name       VARCHAR(255) NOT NULL
- rut          VARCHAR(20) UNIQUE NOT NULL
- pin_hash     TEXT NOT NULL (encriptado)
- kleincoins   TEXT NOT NULL (encriptado, valor por defecto "0")
- created_at   TEXT NOT NULL (fecha de creación en formato ISO 8601)
(Guarda la información del usuario con su pin hasheado y kleincoins encriptadas)

2. Tabla: products
-----------------------------------
- id           INTEGER PRIMARY KEY
- name         VARCHAR(255) NOT NULL
- type         VARCHAR(100) NOT NULL
- description  TEXT NOT NULL
- price        INTEGER NOT NULL
- image        TEXT (URL de la imagen)
- status       INTEGER DEFAULT 1 NOT NULL CHECK (status IN (0, 1)) -- 0: Inactivo, 1: Activo
(Guarda los productos disponibles para venta con su estado activo/inactivo)

3. Tabla: sales
-----------------------------------
- id           SERIAL PRIMARY KEY
- user_id      INTEGER NOT NULL REFERENCES users.id
- total        INTEGER NOT NULL (precio total de la venta)
- fudo_id      TEXT UNIQUE NOT NULL (ID string único por venta)
- date        TEXT NOT NULL (fecha y hora en formato ISO 8601)
- table        INTEGER NOT NULL (número de mesa)
(Guarda cada venta, asociada a un usuario y mesa)

4. Tabla: sale_products
-----------------------------------
- sale_id     INTEGER NOT NULL (relación a sales.id)
- product_id  INTEGER NOT NULL (relación a products.id)
- quantity    INTEGER NOT NULL DEFAULT 1 (cantidad del producto)
(Relación muchos a muchos entre ventas y productos con cantidad)

5. Tabla: blacklist
-----------------------------------
- id           SERIAL PRIMARY KEY
- user_id      INTEGER NOT NULL (relación a users.id)
(Usuarios bloqueados o no autorizados para ciertas acciones)

RELACIONES:
-----------------------------------
- users puede tener muchas sales
- sales puede tener muchos productos (y viceversa), por eso se usa una tabla intermedia (sale_products)
- products pueden repetirse en múltiples sales
"""

# Base abstract class for data access
class BaseDataService(ABC):
    """Abstract base class for data services"""

    def __init__(self):
        self.db_config = POSTGRESQL_DB_CONFIG

    def _get_connection(self):
        """Get database connection"""
        return psycopg2.connect(
            dbname=self.db_config['dbname'],
            user=self.db_config['user'],
            password=self.db_config['password'],
            host=self.db_config['host'],
            port=self.db_config['port']
        )

    @abstractmethod
    def get_all(self) -> List[Any]:
        """Get all records"""
        pass
    
    @abstractmethod
    def get_by_id(self, id: int) -> Optional[Any]:
        """Get record by ID"""
        pass
    
    @abstractmethod
    def create(self, **kwargs) -> int:
        """Create new record"""
        pass
    
    @abstractmethod
    def update(self, id: int, **kwargs) -> bool:
        """Update record"""
        pass
    
    @abstractmethod
    def delete(self, id: int) -> bool:
        """Delete record"""
        pass


# User Data Service
class UserDataService(BaseDataService):
    """Service for managing user data"""
    #region Create
    def create(self, name: str, email: str, rut: str, pin_hash: str) -> int:
        """Add a new user to the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            cursor.execute(
                "INSERT INTO users (name, email, rut, pin_hash, kleincoins, created_at) VALUES (%s, %s, %s, %s, %s, %s) RETURNING id",
                (name, email, rut, fernet.encrypt(pin_hash.encode()).decode(), fernet.encrypt(b"0").decode(), datetime.now().isoformat())
            )
            conn.commit()

            user_id = cursor.fetchone()[0]
            if user_id:
                logger.info(f"User added with ID: {user_id}")
                return user_id
            else:
                logger.error("Failed to add user.")
                return -1
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to add user: {e}")
            return -1
        finally:
            conn.close()
    #endregion
    #region Read
    def get_all(self) -> List[User]:
        """Get all users from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM users")
        users = cursor.fetchall()
        conn.close()
        return [
            User(
                id=user[0],
                email=user[1],
                name=user[2],
                rut=user[3],
                pin_hash=fernet.decrypt(user[4].encode()).decode(),
                kleincoins=fernet.decrypt(user[5].encode()).decode(),
                created_at=user[6]
            ) for user in users
        ]
    
    def get_by_id(self, user_id: int) -> Optional[User]:
        """Get user data from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))
        user = cursor.fetchone()
        conn.close()
        if user:
            return User(
                id=user[0],
                email=user[1],
                name=user[2],
                rut=user[3],
                pin_hash=fernet.decrypt(user[4].encode()).decode(),
                kleincoins=fernet.decrypt(user[5].encode()).decode(),
                created_at=user[6]
            )
        return None
    
    def get_by_email(self, email: str) -> Optional[User]:
        """Get user by email"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM users WHERE email = %s", (email,))
        user = cursor.fetchone()
        conn.close()
        logger.debug(f"get_by_email: {email}, user: {user}")
        if user:
            return User(
                id=user[0],
                email=user[1],
                name=user[2],
                rut=user[3],
                pin_hash=user[4],
                kleincoins=fernet.decrypt(user[5].encode()).decode(),
                created_at=user[6]
            )
        return None
    
    def login(self, email: str, pin_hashed: str) -> Optional[User]:
        """Login user by email and pin hash"""
        user = self.get_by_email(email)
        if user and fernet.decrypt(user.pin_hash.encode()).decode() == pin_hashed:
            logger.info(f"User {user.email} logged in successfully.")
            return user
        else:
            logger.error("Login failed: Invalid email or pin.")
            return None

    def permissions(self, user_id: int) -> int:
        """Get user permissions"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT permissions FROM users WHERE id = %s", (user_id,))
        result = cursor.fetchone()
        if not result:
            logger.error(f"User with ID {user_id} not found.")
            return 0
        result = result[0]
        conn.close()
        if result:
            return result[0]
        return 0

    def get_by_rut(self, rut: str) -> Optional[User]:
        """Get user by RUT"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM users WHERE rut = %s", (rut,))
        user = cursor.fetchone()
        if not user:
            logger.error(f"User with RUT {rut} not found.")
            conn.close()
            return None
        user = user[0]
        conn.close()
        if user:
            return User(
                id=user[0],
                email=user[1],
                name=user[2],
                rut=user[3],
                pin_hash=fernet.decrypt(user[4].encode()).decode(),
                kleincoins=fernet.decrypt(user[5].encode()).decode(),
                created_at=user[6]
            )
        return None
    #endregion
    #region Update
    def update(self, user_id: int, email=None, name=None, rut=None, pin_hash=None, kleincoins=None) -> bool:
        """Update user information in the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        updates = []
        params = []
        if email:
            updates.append("email = %s")
            params.append(email)
        if name:
            updates.append("name = %s")
            params.append(name)
        if rut:
            updates.append("rut = %s")
            params.append(rut)
        if pin_hash:
            updates.append("pin_hash = %s")
            params.append(fernet.encrypt(pin_hash.encode()).decode())
        if kleincoins is not None:
            updates.append("kleincoins = %s")
            params.append(fernet.encrypt(str(kleincoins).encode()).decode())
        if not updates:
            conn.close()
            return False
        try:
            cursor.execute(f"UPDATE users SET {', '.join(updates)} WHERE id = %s", (*params, user_id))
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"User with ID {user_id} updated.")
            return success
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to update user: {e}")
            return False
        finally:
            conn.close()
        #endregion
    #region Delete
    def delete(self, user_id: int) -> bool:
        """Delete a user from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("DELETE FROM users WHERE id = %s", (user_id,))
        conn.commit()
        conn.close()
        if cursor.rowcount > 0:
            logger.info(f"User with ID {user_id} deleted.")
            return True
        else:
            logger.error(f"Failed to delete user with ID {user_id}.")
            return False
    
    def update_kleincoins(self, user_id: int, kleincoins: int) -> bool:
        """Update user's kleincoins"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            cursor.execute(
                "UPDATE users SET kleincoins = %s WHERE id = %s", 
                (fernet.encrypt(str(kleincoins).encode()).decode(), user_id)
            )
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Kleincoins updated for user {user_id}: {kleincoins}")
            return success
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to update kleincoins: {e}")
            return False
        finally:
            conn.close()
    
    def get_kleincoins(self, user_id: int) -> Optional[int]:
        """Get user's kleincoins"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT kleincoins FROM users WHERE id = %s", (user_id,))
        result = cursor.fetchone()
        conn.close()
        if result:
            try:
                return int(fernet.decrypt(result[0].encode()).decode())
            except Exception as e:
                logger.error(f"Failed to decrypt kleincoins for user {user_id}: {e}")
                return None
        return None
    #endregion

# Blacklist Data Service
class BlacklistDataService(BaseDataService):
    """Service for managing blacklisted users"""
    #region Create
    def create(self, user_id: int) -> int:
        """Add a user to the blacklist"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            cursor.execute("INSERT INTO blacklist (user_id) VALUES (%s) RETURNING id", (user_id,))
            conn.commit()
            blacklist_id = cursor.fetchone()[0]
            if blacklist_id:
                logger.info(f"User with ID {user_id} added to blacklist.")
                return blacklist_id
            else:
                logger.error(f"Failed to add user with ID {user_id} to blacklist.")
                return -1
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to add user to blacklist: {e}")
            return -1
        finally:
            conn.close()
    #endregion
    #region Read
    def get_all(self) -> List[Blacklist]:
        """Get all blacklisted users"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT b.id, b.user_id, u.email, u.name, u.rut 
            FROM blacklist b 
            LEFT JOIN users u ON b.user_id = u.id
        """)
        blacklisted = cursor.fetchall()
        conn.close()
        return [
            Blacklist(
                id=row[0],
                user_id=row[1],
                email=row[2],
                name=row[3],
                rut=row[4]
            ) for row in blacklisted
        ]
    
    def get_by_id(self, id: int) -> Optional[Blacklist]:
        """Get blacklist entry by ID"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT b.id, b.user_id, u.email, u.name, u.rut 
            FROM blacklist b 
            LEFT JOIN users u ON b.user_id = u.id 
            WHERE b.id = %s
        """, (id,))
        row = cursor.fetchone()
        conn.close()
        if row:
            return Blacklist(
                id=row[0],
                user_id=row[1],
                email=row[2],
                name=row[3],
                rut=row[4]
            )
        return None
    
    def get_blacklisted_user_ids(self) -> List[int]:
        """Get a list of blacklisted user IDs"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT user_id FROM blacklist")
        blacklisted_users = [row[0] for row in cursor.fetchall()]
        conn.close()
        return blacklisted_users
    
    def is_user_blacklisted(self, user_id: int) -> bool:
        """Check if a user is blacklisted"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM blacklist WHERE user_id = ?", (user_id,))
        blacklisted = cursor.fetchone() is not None
        conn.close()
        return blacklisted
    #endregion
    #region Update
    def update(self, id: int, **kwargs) -> bool:
        """Update blacklist entry (not commonly used)"""
        # Blacklist entries typically don't need updates
        return False
    #endregion
    #region Delete
    def delete(self, id: int) -> bool:
        """Remove a blacklist entry by ID"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("DELETE FROM blacklist WHERE id = %s", (id,))
        conn.commit()
        success = cursor.rowcount > 0
        conn.close()
        if success:
            logger.info(f"Blacklist entry with ID {id} removed.")
        else:
            logger.error(f"Failed to remove blacklist entry with ID {id}.")
        return success
    
    def remove_user_from_blacklist(self, user_id: int) -> bool:
        """Remove a user from the blacklist"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("DELETE FROM blacklist WHERE user_id = %s", (user_id,))
        conn.commit()
        success = cursor.rowcount > 0
        conn.close()
        if success:
            logger.info(f"User with ID {user_id} removed from blacklist.")
        else:
            logger.error(f"Failed to remove user with ID {user_id} from blacklist.")
        return success
    #endregion

# Product Data Service
class ProductDataService(BaseDataService):
    """Service for managing products"""
    #region Create
    def create(self, id: int, name: str, price: float, type: Optional[str] = None, description: Optional[str] = None, image: Optional[str] = None, status: int = 1) -> int:
        """Add a new product to the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        if image and "base64" in image:
            extension = re.search(r'data:image/(.*%s);base64,', image)
            image_name = f"{id}_img"
            if extension:
                image_name += f".{extension.group(1)}"
            image = self._image_process(image_name, image)
        try:
            cursor.execute(
                "INSERT INTO products (id, name, type, description, price, image, status) VALUES (%s, %s, %s, %s, %s, %s, %s) RETURNING id",
                (id, name, type, description, price, image, status)
            )
            conn.commit()
            product_id = cursor.fetchone()[0]
            if product_id:
                logger.info(f"Product added with ID: {product_id}")
                return product_id
            else:
                logger.error("Failed to add product.")
                return -1
        except psycopg2.Error as e:
            logger.error(f"Failed to add product: {e}")
            return -1
        finally:
            conn.close()
    def load_data(self, products: List[Dict[str, str]]) -> None:
        """Load multiple products from a list of dictionaries"""
        conn = self._get_connection()
        cursor = conn.cursor()
        for product in products:
            try:
                self.create(
                    id=int(product['id']),
                    name=product['name'],
                    price=int(product['price']),
                    type=product.get('type'),
                    description=product.get('description'),
                    image=product.get('image'),
                    status=int(product.get('status', 1))  # Default to active (1)
                )
            except Exception as e:
                logger.error(f"Failed to load product {product['name']}: {e}")
        conn.close()
    #endregion
    #region Read
    def get_all(self) -> List[Product]:
        """Get all products from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products")
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    
    def     get_by_id(self, product_id: int) -> Optional[Product]:
        """Get product by ID"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products WHERE id = %s", (product_id,))
        product = cursor.fetchone()
        conn.close()
        if product:
            return Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            )
        return None
    
    def get_by_type(self, product_type: str) -> List[Product]:
        """Get products by type"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products WHERE type = %s", (product_type,))
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    
    def search_by_name(self, name: str) -> List[Product]:
        """Search products by name"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products WHERE name LIKE %s", (f"%{name}%",))
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    
    def get_products(self, product_ids: List[int]) -> List[Product]:
        """Get multiple products by their IDs"""
        if not product_ids:
            return []
        placeholders = ', '.join('%s' for _ in product_ids)
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute(f"SELECT * FROM products WHERE id IN ({placeholders})", product_ids)
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    #endregion
    #region Update
    def _image_process(self, image: str, base64: str) -> str:
        """Process image for storage"""
        if not image or not base64:
            raise ValueError("Image and base64 data must be provided")
        image_path = os.path.join(IMAGE_PATH, image)
        if not os.path.exists(IMAGE_PATH):
            os.makedirs(IMAGE_PATH)
        with open(image_path, 'wb') as img_file:
            img_file.write(b64.b64decode(base64.split(',')[1]))
        return CURRENT_URL+"/images/" + image  # Return url

    def update(self, product_id: int, name=None, type=None, description=None, price=None, image=None, status=None) -> bool:
        """Update product information"""
        conn = self._get_connection()
        cursor = conn.cursor()
        product = self.get_by_id(product_id)
        if not product:
            logger.error(f"Product with ID {product_id} not found.")
            return False
        updates = []
        params = []
        if name is not None:
            updates.append("name = %s")
            params.append(name)
        if type is not None:
            updates.append("type = %s")
            params.append(type)
        if description is not None:
            updates.append("description = %s")
            params.append(description)
        if price is not None:
            updates.append("price = %s")
            params.append(price)
        if image is not None:
            if product.image and product.image != image:
                if os.path.exists(os.path.join(IMAGE_PATH, product.image)):
                    os.remove(os.path.join(IMAGE_PATH, product.image))
                try:
                    extension = re.search(r'data:image/(.*%s);base64,', image)
                    if not extension:
                        raise ValueError("Invalid image format")
                    extension = extension.group(1)
                    image = self._image_process(f"{product.id}_img.{extension}", image)
                except ValueError as e:
                    logger.error(f"Failed to process image: {e}")
                    return False
            updates.append("image = %s")
            params.append(image)
        if status is not None:
            updates.append("status = %s")
            params.append(status)
        if not updates:
            conn.close()
            return False
        try:
            cursor.execute(f"UPDATE products SET {', '.join(updates)} WHERE id = %s", (*params, product_id))
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Product with ID {product_id} updated.")
            return success
        except psycopg2.Error as e:
            logger.error(f"Failed to update product: {e}")
            return False
        finally:
            conn.close()
    
    def get_active_products(self) -> List[Product]:
        """Get only active products (status = 1)"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products WHERE status = 1")
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    
    def get_inactive_products(self) -> List[Product]:
        """Get only inactive products (status = 0)"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT * FROM products WHERE status = 0")
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6]
            ) for product in products
        ]
    
    def activate_product(self, product_id: int) -> bool:
        """Activate a product (set status to 1)"""
        return self.update(product_id, status=1)
    
    def deactivate_product(self, product_id: int) -> bool:
        """Deactivate a product (set status to 0)"""
        return self.update(product_id, status=0)
    
    def is_product_active(self, product_id: int) -> Optional[bool]:
        """Check if a product is active"""
        product = self.get_by_id(product_id)
        if product:
            return product.status == 1
        return None
        #endregion
    #region Delete
    def delete(self, product_id: int) -> bool:
        """Delete a product from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        product = self.get_by_id(product_id)
        if product and product.image:
            os.remove(os.path.join(IMAGE_PATH, product.image.removeprefix(CURRENT_URL + "/images/")))
        cursor.execute("DELETE FROM products WHERE id = %s", (product_id,))
        conn.commit()
        success = cursor.rowcount > 0
        conn.close()
        if success:
            logger.info(f"Product with ID {product_id} deleted.")
        else:
            logger.error(f"Failed to delete product with ID {product_id}.")
        return success
    #endregion

# Sales Data Service
class SalesDataService(BaseDataService):
    """Service for managing sales"""
    #region C
    def create(self, user_id: int, fudo_id: str, total: float, table: int, product_ids: List[int], quantities: Optional[List[int]] = None) -> int:
        """Create a new sale with products and quantities"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            fecha = datetime.now().isoformat()
            
            # Insert sale
            cursor.execute(
                "INSERT INTO sales (user_id, total, fudo_id, date, table_number) VALUES (%s, %s, %s, %s, %s) RETURNING id",
                (user_id, total, fudo_id, fecha, table)
            )
            last_sale = cursor.fetchone()
            sale_id = last_sale[0] if last_sale else None
            
            if sale_id and product_ids:
                # Insert sale-product relationships with quantities
                if quantities is None:
                    quantities = [1] * len(product_ids)  # Default quantity 1
                
                for i, product_id in enumerate(product_ids):
                    quantity = quantities[i] if i < len(quantities) else 1
                    cursor.execute(
                        "INSERT INTO sale_products (sale_id, product_id, quantity) VALUES (%s, %s, %s)",
                        (sale_id, product_id, quantity)
                    )
            
            conn.commit()
            if sale_id:
                logger.info(f"Sale created with ID: {sale_id}, fudo_id: {fudo_id}")
                return sale_id
            else:
                logger.error("Failed to create sale.")
                return -1
        except psycopg2.Error as e:
            logger.error(f"Failed to create sale: {e}")
            conn.rollback()
            return -1
        finally:
            conn.close()
    

    def add_product_to_sale(self, sale_id: int, product_id: int, quantity: int = 1) -> bool:
        """Add a product to an existing sale with quantity"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            cursor.execute(
                "INSERT INTO sale_products (sale_id, product_id, quantity) VALUES (%s, %s, %s)",
                (sale_id, product_id, quantity)
            )
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Product {product_id} (qty: {quantity}) added to sale {sale_id}.")
            return success
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to add product to sale: {e}")
            return False
        finally:
            conn.close()
    
    def add_products_to_sale(self, sale_id: int, product_ids: List[int], quantities: Optional[List[int]] = None) -> bool:
        """Add multiple products to an existing sale with quantities"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            if quantities is None:
                quantities = [1] * len(product_ids)  # Default quantity 1
            
            for i, product_id in enumerate(product_ids):
                quantity = quantities[i] if i < len(quantities) else 1
                cursor.execute(
                    "INSERT INTO sale_products (sale_id, product_id, quantity) VALUES (%s, %s, %s)",
                    (sale_id, product_id, quantity)
                )
            
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Products added to sale {sale_id}.")
            return success
        except psycopg2.IntegrityError as e:
            logger.error(f"Failed to add products to sale: {e}")
            return False
        finally:
            conn.close()
    #endregion
    #region R
    def get_all(self) -> List[Sale]:
        """Get all sales from the database"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT s.id, s.user_id, s.total, s.fudo_id, s.date, s.table, u.name, u.email
            FROM sales s
            LEFT JOIN users u ON s.user_id = u.id
            ORDER BY s.date DESC
        """)
        sales = cursor.fetchall()
        conn.close()
        return [
            Sale(
                id=sale[0],
                user_id=sale[1],
                total=sale[2],
                fudo_id=sale[3],
                date=sale[4],
                table=sale[5],
                username=sale[6],
                user_email=sale[7],
                products=self.get_sale_products(sale[0])
            ) for sale in sales
        ]
    
    def get_by_id(self, sale_id: int) -> Optional[Sale]:
        """Get sale by ID"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT s.id, s.user_id, s.total, s.fudo_id, s.date, s.table, u.name, u.email
            FROM sales s
            LEFT JOIN users u ON s.user_id = u.id
            WHERE s.id = %s
        """, (sale_id,))
        sale = cursor.fetchone()
        conn.close()
        if sale:
            return Sale(
                id=sale[0],
                user_id=sale[1],
                total=sale[2],
                fudo_id=sale[3],
                date=sale[4],
                table=sale[5],
                username=sale[6],
                user_email=sale[7]
            )
        return None
    
    def get_by_fudo_id(self, fudo_id: str) -> Optional[Sale]:
        """Get sale by fudo_id"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT s.id, s.user_id, s.total, s.fudo_id, s.date, s.table, u.name, u.email
            FROM sales s
            LEFT JOIN users u ON s.user_id = u.id
            WHERE s.fudo_id = %s
        """, (fudo_id,))
        sale = cursor.fetchone()
        conn.close()
        if sale:
            return Sale(
                id=sale[0],
                user_id=sale[1],
                total=sale[2],
                fudo_id=sale[3],
                date=sale[4],
                table=sale[5],
                username=sale[6],
                user_email=sale[7]
            )
        return None
    
    def get_by_user(self, user_id: int) -> List[Sale]:
        """Get sales by user ID"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute(
            """
            SELECT s.id, s.user_id, s.total, s.fudo_id, s.date, s.table_number, u.name, u.email
            FROM sales s
            LEFT JOIN users u ON s.user_id = u.id
            WHERE s.user_id = %s
            ORDER BY s.date DESC
            """,
            (user_id,)
        )

        sales = cursor.fetchall()
        conn.close()

        return [
            Sale(
                id=sale[0],
                user_id=sale[1],
                total=sale[2],
                fudo_id=sale[3],
                date=sale[4],
                table=sale[5],
                username=sale[6],
                user_email=sale[7],
                products=self.get_sale_products(sale[0])
            ) for sale in sales
        ]
    
    def get_sale_products_ids(self, sale_id: int) -> List[int]:
        """Get product IDs for a specific sale"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT product_id FROM sale_products WHERE sale_id = %s
        """, (sale_id,))
        products = cursor.fetchall()
        conn.close()
        return [product[0] for product in products]

    def get_sale_products(self, sale_id: int) -> List[Product]:
        """Get products for a specific sale with quantities"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute("""
            SELECT p.id, p.name, p.type, p.description, p.price, p.image, p.status, sp.quantity
            FROM sale_products sp
            JOIN products p ON sp.product_id = p.id
            WHERE sp.sale_id = %s
        """, (sale_id,))
        products = cursor.fetchall()
        conn.close()
        return [
            Product(
                id=product[0],
                name=product[1],
                type=product[2],
                description=product[3],
                price=product[4],
                image=product[5],
                status=product[6],
                quantity=product[7]
            ) for product in products
        ]
    
    def get_by_table(self, table: int) -> List[Sale]:
        """Get sales by table number"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute(
            """
            SELECT s.id, s.user_id, s.total, s.fudo_id, s.date, s.table_number, u.name, u.email
            FROM sales s
            LEFT JOIN users u ON s.user_id = u.id
            WHERE s.table_number = %s
            ORDER BY s.date DESC
            """,
            (table,)
        )
        sales = cursor.fetchall()
        conn.close()
        return [
            Sale(
                id=sale[0],
                user_id=sale[1],
                total=sale[2],
                fudo_id=sale[3],
                date=sale[4],
                table=sale[5],
                username=sale[6],
                user_email=sale[7]
            ) for sale in sales
        ]
    
    def update_product_quantity(self, sale_id: int, product_id: int, new_quantity: int) -> bool:
        """Update quantity of a product in a sale"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            cursor.execute(
                "UPDATE sale_products SET quantity = %s WHERE sale_id = %s AND product_id = %s",
                (new_quantity, sale_id, product_id)
            )
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Updated quantity to {new_quantity} for product {product_id} in sale {sale_id}.")
            return success
        except psycopg2.Error as e:
            logger.error(f"Failed to update product quantity: {e}")
            return False
        finally:
            conn.close()
    
    def get_product_quantity_in_sale(self, sale_id: int, product_id: int) -> Optional[int]:
        """Get quantity of a specific product in a sale"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute(
            "SELECT quantity FROM sale_products WHERE sale_id = %s AND product_id = %s",
            (sale_id, product_id)
        )
        result = cursor.fetchone()
        conn.close()
        return result[0] if result else None
    #endregion
    #region U
    def update(self, sale_id: int, user_id=None, total=None, table=None) -> bool:
        """Update sale information (products should be updated via specific methods)"""
        conn = self._get_connection()
        cursor = conn.cursor()
        updates = []
        params = []
        if user_id is not None:
            updates.append("user_id = %s")
            params.append(user_id)
        if total is not None:
            updates.append("total = %s")
            params.append(total)
        if table is not None:
            updates.append("table = %s")
            params.append(table)
        if not updates:
            conn.close()
            return False
        try:
            cursor.execute(f"UPDATE sales SET {', '.join(updates)} WHERE id = %s", (*params, sale_id))
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Sale with ID {sale_id} updated.")
            return success
        except psycopg2.Error as e:
            logger.error(f"Failed to update sale: {e}")
            return False
        finally:
            conn.close()
        #endregion
    #region D
    def delete(self, sale_id: int) -> bool:
        """Delete a sale and its product relationships"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            # Delete sale-product relationships first
            cursor.execute("DELETE FROM sale_products WHERE sale_id = %s", (sale_id,))
            # Delete the sale
            cursor.execute("DELETE FROM sales WHERE id = %s", (sale_id,))
            conn.commit()
            success = cursor.rowcount > 0
            if success:
                logger.info(f"Sale with ID {sale_id} deleted.")
            else:
                logger.error(f"Failed to delete sale with ID {sale_id}.")
            return success
        except psycopg2.Error as e:
            logger.error(f"Failed to delete sale: {e}")
            return False
        finally:
            conn.close()
    
    def remove_product_from_sale(self, sale_id: int, product_id: int) -> bool:
        """Remove a product from a sale (removes all quantity)"""
        conn = self._get_connection()
        cursor = conn.cursor()
        cursor.execute(
            "DELETE FROM sale_products WHERE sale_id = %s AND product_id = %s",
            (sale_id, product_id)
        )
        conn.commit()
        success = cursor.rowcount > 0
        conn.close()
        if success:
            logger.info(f"Product {product_id} removed from sale {sale_id}.")
        else:
            logger.error(f"Failed to remove product {product_id} from sale {sale_id}.")
        return success
    
    def decrease_product_quantity(self, sale_id: int, product_id: int, decrease_by: int = 1) -> bool:
        """Decrease quantity of a product in a sale, removes if quantity becomes 0 or less"""
        conn = self._get_connection()
        cursor = conn.cursor()
        try:
            # Get current quantity
            cursor.execute(
                "SELECT quantity FROM sale_products WHERE sale_id = %s AND product_id = %s",
                (sale_id, product_id)
            )
            result = cursor.fetchone()
            if not result:
                return False
            
            current_quantity = result[0]
            new_quantity = current_quantity - decrease_by
            
            if new_quantity <= 0:
                # Remove the product completely
                cursor.execute(
                    "DELETE FROM sale_products WHERE sale_id = %s AND product_id = %s",
                    (sale_id, product_id)
                )
                logger.info(f"Product {product_id} removed from sale {sale_id} (quantity reached 0).")
            else:
                # Update with new quantity
                cursor.execute(
                    "UPDATE sale_products SET quantity = %s WHERE sale_id = %s AND product_id = %s",
                    (new_quantity, sale_id, product_id)
                )
                logger.info(f"Product {product_id} quantity decreased to {new_quantity} in sale {sale_id}.")
            
            conn.commit()
            return True
        except psycopg2.Error as e:
            logger.error(f"Failed to decrease product quantity: {e}")
            return False
        finally:
            conn.close()

    #endregion

# Factory class to get service instances
class DataServiceFactory:
    """Factory class to create data service instances"""
    
    @staticmethod
    def get_user_service() -> UserDataService:
        """Get user data service instance"""
        return UserDataService()
    
    @staticmethod
    def get_blacklist_service() -> BlacklistDataService:
        """Get blacklist data service instance"""
        return BlacklistDataService()
    
    @staticmethod
    def get_product_service() -> ProductDataService:
        """Get product data service instance"""
        return ProductDataService()
    
    @staticmethod
    def get_sales_service() -> SalesDataService:
        """Get sales data service instance"""
        return SalesDataService()


# Helper functions for background data
def load_bg_data() -> List[Dict[str, str]]:
    """Load background data for AI assistant"""
    try:
        with open(BG_DATA_PATH, 'r', encoding='utf-8') as f:
            return json.load(f)
    except FileNotFoundError:
        logger.error(f"Data file not found at {BG_DATA_PATH}. Serving with empty data.")
        return []
    except json.JSONDecodeError:
        logger.error(f"Could not decode JSON from {BG_DATA_PATH}. Serving with empty data.")
        return []
    
def initialize_db():

    # En PostgreSQL, no se crea el archivo de base de datos, así que verificamos si las tablas existen.
    try:
        conn = psycopg2.connect(
            dbname=POSTGRESQL_DB_CONFIG['dbname'],
            user=POSTGRESQL_DB_CONFIG['user'],
            password=POSTGRESQL_DB_CONFIG['password'],
            host=POSTGRESQL_DB_CONFIG['host'],
            port=POSTGRESQL_DB_CONFIG['port']
        )
        cursor = conn.cursor()
        # Verificar si la tabla 'users' ya existe
        cursor.execute("""
            SELECT EXISTS (
                SELECT FROM information_schema.tables 
                WHERE table_name = 'users'
            );
        """)
        exists = cursor.fetchone()
        if exists:
            logger.info("La base de datos ya está inicializada, no se necesita inicializar.")
            conn.close()
            return
        conn.close()
    except Exception as e:
        logger.error(f"Error comprobando la existencia de tablas: {e}")
        # Si hay error, continuamos con la inicialización

    conn = psycopg2.connect(
        dbname=POSTGRESQL_DB_CONFIG['dbname'],
        user=POSTGRESQL_DB_CONFIG['user'],
        password=POSTGRESQL_DB_CONFIG['password'],
        host=POSTGRESQL_DB_CONFIG['host'],
        port=POSTGRESQL_DB_CONFIG['port']
    )
    cursor = conn.cursor()
    # Crear tabla de usuarios
    logger.info("Inicializando base de datos...")
    logger.info("Creando tabla de usuarios...")
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS users (
        id SERIAL PRIMARY KEY,
        email VARCHAR(255) UNIQUE NOT NULL,
        name VARCHAR(255) NOT NULL,
        rut VARCHAR(20) UNIQUE NOT NULL,
        pin_hash TEXT NOT NULL,
        kleincoins TEXT NOT NULL,
        created_at TEXT NOT NULL,
        permissions INTEGER DEFAULT 0 NOT NULL CHECK (permissions IN (0, 1, 2)) -- 0: Usuario normal, 1: Administrador, 2: Superusuario
    );
    """)

    # Crear tabla de productos
    logger.info("Creando tabla de products...")
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS products (
        id INTEGER PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        type VARCHAR(100) NOT NULL,
        description TEXT NOT NULL,
        price INTEGER NOT NULL,
        image TEXT,
        status INTEGER DEFAULT 1 NOT NULL CHECK (status IN (0, 1)) -- 0: Inactivo, 1: Activo
    );
    """)

    # Crear tabla de ventas
    logger.info("Creando tabla de sales...")
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS sales (
        id SERIAL PRIMARY KEY,
        user_id INTEGER NOT NULL,
        total INTEGER NOT NULL,
        fudo_id TEXT UNIQUE NOT NULL,
        date TEXT NOT NULL,
        table_number INTEGER NOT NULL,
        FOREIGN KEY (user_id) REFERENCES users(id)
    );
    """)

    # Crear tabla intermedia para ventas y productos
    logger.info("Creando tabla intermedia de sale_products...")
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS sale_products (
        sale_id INTEGER NOT NULL,
        product_id INTEGER NOT NULL,
        quantity INTEGER NOT NULL DEFAULT 1,
        FOREIGN KEY (sale_id) REFERENCES sales(id),
        FOREIGN KEY (product_id) REFERENCES products(id)
    );
    """)

    # Crear tabla de blacklist
    logger.info("Creando tabla de blacklist...")
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS blacklist (
        id SERIAL PRIMARY KEY,
        user_id INTEGER NOT NULL,
        FOREIGN KEY (user_id) REFERENCES users(id)
    );
    """)

    logger.info("Todas las tablas creadas correctamente.")
    logger.info("Cargando datos de productos desde el archivo JSON...")
    products_json = json.loads(open(PRODUCT_DATA_PATH, 'r', encoding='utf-8').read())
    product_service = ProductDataService()
    product_service.load_data(products_json)
    conn.commit()

    
    conn.close()
    logger.info("Base de datos inicializada correctamente.")

data_bg_loaded = load_bg_data()