import json
import os
from datetime import datetime

class SimpleDB:
    def __init__(self):
        self.products_file = 'products.json'
        self.suppliers_file = 'suppliers.json'
        self.categories_file = 'categories.json'
        self.incoming_file = 'incoming_orders.json'
        self._init_files()
    
    def _init_files(self):
        files = [self.products_file, self.suppliers_file, self.categories_file, self.incoming_file]
        for file in files:
            if not os.path.exists(file):
                with open(file, 'w', encoding='utf-8') as f:
                    json.dump([], f)
    
    # ==================== ТОВАРЫ ====================
    def get_products(self):
        try:
            with open(self.products_file, 'r', encoding='utf-8') as f:
                return json.load(f)
        except:
            return []
    
    def get_product_by_id(self, product_id):
        products = self.get_products()
        for product in products:
            if product.get('id') == product_id:
                return product
        return None
    
    def save_product(self, product):
        products = self.get_products()
        product['id'] = len(products) + 1
        products.append(product)
        with open(self.products_file, 'w', encoding='utf-8') as f:
            json.dump(products, f, ensure_ascii=False, indent=2)
        return product
    
    def update_product(self, product_id, updated_data):
        products = self.get_products()
        for i, product in enumerate(products):
            if product.get('id') == product_id:
                products[i].update(updated_data)
                break
        with open(self.products_file, 'w', encoding='utf-8') as f:
            json.dump(products, f, ensure_ascii=False, indent=2)
        return True
    
    def delete_product(self, product_id):
        products = self.get_products()
        products = [p for p in products if p.get('id') != product_id]
        with open(self.products_file, 'w', encoding='utf-8') as f:
            json.dump(products, f, ensure_ascii=False, indent=2)
    
    def update_stock(self, product_id, quantity_change):
        products = self.get_products()
        for product in products:
            if product.get('id') == product_id:
                product['stock_quantity'] = product.get('stock_quantity', 0) + quantity_change
                break
        with open(self.products_file, 'w', encoding='utf-8') as f:
            json.dump(products, f, ensure_ascii=False, indent=2)
    
    # ==================== ПОСТАВЩИКИ ====================
    def get_suppliers(self):
        try:
            with open(self.suppliers_file, 'r', encoding='utf-8') as f:
                return json.load(f)
        except:
            return []
    
    def get_supplier_by_id(self, supplier_id):
        suppliers = self.get_suppliers()
        for supplier in suppliers:
            if supplier.get('id') == supplier_id:
                return supplier
        return None
    
    def save_supplier(self, supplier):
        suppliers = self.get_suppliers()
        supplier['id'] = len(suppliers) + 1
        suppliers.append(supplier)
        with open(self.suppliers_file, 'w', encoding='utf-8') as f:
            json.dump(suppliers, f, ensure_ascii=False, indent=2)
        return supplier
    
    def update_supplier(self, supplier_id, updated_data):
        suppliers = self.get_suppliers()
        for i, supplier in enumerate(suppliers):
            if supplier.get('id') == supplier_id:
                suppliers[i].update(updated_data)
                break
        with open(self.suppliers_file, 'w', encoding='utf-8') as f:
            json.dump(suppliers, f, ensure_ascii=False, indent=2)
        return True
    
    def delete_supplier(self, supplier_id):
        suppliers = self.get_suppliers()
        suppliers = [s for s in suppliers if s.get('id') != supplier_id]
        with open(self.suppliers_file, 'w', encoding='utf-8') as f:
            json.dump(suppliers, f, ensure_ascii=False, indent=2)
    
    # ==================== КАТЕГОРИИ ====================
    def get_categories(self):
        try:
            with open(self.categories_file, 'r', encoding='utf-8') as f:
                return json.load(f)
        except:
            return []
    
    # ==================== ПРИХОДНЫЕ НАКЛАДНЫЕ ====================
    def get_incoming_orders(self, sort_by='date', order='desc'):
        try:
            with open(self.incoming_file, 'r', encoding='utf-8') as f:
                orders = json.load(f)
            
            if sort_by == 'date':
                orders.sort(key=lambda x: x.get('date', ''), reverse=(order == 'desc'))
            elif sort_by == 'total':
                orders.sort(key=lambda x: x.get('final_total', x.get('total', 0)), reverse=(order == 'desc'))
            elif sort_by == 'supplier':
                orders.sort(key=lambda x: x.get('supplier_name', ''), reverse=(order == 'desc'))
            return orders
        except:
            return []
    
    def save_incoming_order(self, order):
        orders = self.get_incoming_orders()
        order['id'] = len(orders) + 1
        order['date'] = datetime.now().strftime('%d.%m.%Y %H:%M')
        orders.append(order)
        with open(self.incoming_file, 'w', encoding='utf-8') as f:
            json.dump(orders, f, ensure_ascii=False, indent=2)
        return order

db = SimpleDB()