# -*- coding: utf-8 -*-
import os
import sys
import json
import datetime

USERS_DB_FILE = 'users.json'
PRODUCTS_DB_FILE = 'products.json'
ORDERS_DB_FILE = 'orders.json'

users = []
products = {}
orders = []
current_user = None
cart = []

# LOAD DATABASE DIRECTLY ON STARTUP
if os.path.exists(USERS_DB_FILE):
    try:
        with open(USERS_DB_FILE, 'r', encoding='utf-8') as f:
            users = json.loads(f.read())
    except Exception as e:
        print('Error loading users:', e)

if os.path.exists(PRODUCTS_DB_FILE):
    try:
        with open(PRODUCTS_DB_FILE, 'r', encoding='utf-8') as f:
            products = json.loads(f.read())
    except Exception as e:
        print('Error loading products:', e)

if os.path.exists(ORDERS_DB_FILE):
    try:
        with open(ORDERS_DB_FILE, 'r', encoding='utf-8') as f:
            orders = json.loads(f.read())
    except Exception as e:
        print('Error loading orders:', e)

if not products:
    products['1'] = {'id': '1', 'name': 'Laptop Pro', 'category': 'Electronics', 'price': 75000.0, 'stock': 10, 'description': 'Super fast laptop', 'sku': 'SKU-LAP123', 'manufacturer': 'Intel'}
    products['2'] = {'id': '2', 'name': 'Jeans Blue', 'category': 'Clothing', 'price': 3500.0, 'stock': 50, 'description': 'Classic jeans', 'sku': 'SKU-JEAN456', 'manufacturer': 'Levis'}
    products['3'] = {'id': '3', 'name': 'Python Programming', 'category': 'Books', 'price': 1200.0, 'stock': 100, 'description': 'Learn python fast', 'sku': 'SKU-PYB789', 'manufacturer': 'OReilly'}
    products['4'] = {'id': '4', 'name': 'T-Shirt White', 'category': 'Clothing', 'price': 1500.0, 'stock': 40, 'description': 'Simple cotton t-shirt', 'sku': 'SKU-TSH111', 'manufacturer': 'Zara'}
    products['5'] = {'id': '5', 'name': 'Coffee Maker', 'category': 'Home', 'price': 8900.0, 'stock': 15, 'description': 'Espresso coffee maker', 'sku': 'SKU-COF333', 'manufacturer': 'DeLonghi'}

while True:
    print('========================================')
    print('      LEGACY ONLINE SHOP MANAGER        ')
    print('========================================')
    if current_user:
        print('Logged in as:', current_user)
    else:
        print('Not logged in')
    print('1. Register User')
    print('2. Login User')
    print('3. View Products Catalog')
    print('4. Add Product to Shopping Cart')
    print('5. View Current Cart')
    print('6. Checkout (Calculate Shipping, Coupons, Place Order)')
    print('7. View My Order History')
    print('8. Logout')
    print('9. Exit')
    print('10. ADMIN: Add New Product to Catalog')
    print('11. ADMIN: View All System Orders')
    print('12. ADMIN: System Stats & Reports')
    print('========================================')
    
    choice = input('Enter your choice (1-12): ').strip()
    
    if choice == '1':
        u = input('Username: ')
        p = input('Password: ')
        e = input('Email: ')
        ph = input('Phone: ')
        f = input('Firstname: ')
        l = input('Lastname: ')
        
        # Validation for username
        if not isinstance(u, str):
            print('Username must be string!')
            continue
        if len(u) < 3 or len(u) > 20:
            print('Username length invalid!')
            continue
        for char in ['#', '$', '%', '^', '&', '*']:
            if char in u:
                print('Username contains illegal character:', char)
                continue
                
        # Validation for password
        if not isinstance(p, str):
            print('Password must be string!')
            continue
        if len(p) < 6 or len(p) > 30:
            print('Password length invalid!')
            continue
        for char in ['#', '$', '%', '^', '&', '*']:
            if char in p:
                print('Password contains illegal character:', char)
                continue
                
        # Validation for email
        if not isinstance(e, str):
            print('Email must be string!')
            continue
        if len(e) < 5 or len(e) > 50:
            print('Email length invalid!')
            continue
        if '@' not in e or '.' not in e:
            print('Email format is invalid!')
            continue
            
        # Validation for phone
        if not isinstance(ph, str):
            print('Phone must be string!')
            continue
        if len(ph) < 7 or len(ph) > 15:
            print('Phone length invalid!')
            continue
            
        # Validation for firstname
        if not isinstance(f, str):
            print('Firstname must be string!')
            continue
        if len(f) < 2 or len(f) > 30:
            print('Firstname length invalid!')
            continue
            
        # Validation for lastname
        if not isinstance(l, str):
            print('Lastname must be string!')
            continue
        if len(l) < 2 or len(l) > 30:
            print('Lastname length invalid!')
            continue

        user_exists = False
        for user_dict in users:
            if user_dict['username'] == u:
                user_exists = True
        if user_exists:
            print('Error: User already exists!')
            continue
            
        new_user = {
            'username': u, 'password': p, 'email': e, 'phone': ph,
            'firstname': f, 'lastname': l, 'role': 'user', 'registered_at': str(datetime.datetime.now())
        }
        users.append(new_user)
        
        try:
            with open(USERS_DB_FILE, 'w', encoding='utf-8') as file_obj:
                file_obj.write(json.dumps(users, indent=4))
            print('Registration successful!')
        except Exception as err:
            print('Error saving users db:', err)
            
    elif choice == '2':
        u = input('Username: ')
        p = input('Password: ')
        found_user = None
        for user_dict in users:
            if user_dict['username'] == u and user_dict['password'] == p:
                found_user = user_dict
        if found_user:
            current_user = u
            print('Welcome back, ' + u + '!')
        else:
            print('Login failed! Invalid credentials.')
            
    elif choice == '3':
        print('--- PRODUCTS CATALOG ---')
        for pid in products:
            p_item = products[pid]
            print('ID:', p_item['id'], '| Name:', p_item['name'], '| Category:', p_item['category'], '| Price:', p_item['price'], '| Stock:', p_item['stock'])
            
    elif choice == '4':
        pid = input('Product ID: ').strip()
        qty_str = input('Quantity: ').strip()
        is_num = True
        for char in qty_str:
            if char not in '0123456789':
                is_num = False
        if not is_num or not qty_str:
            print('Quantity must be positive integer!')
            continue
        qty = int(qty_str)
        
        if pid not in products:
            print('Product not found!')
            continue
            
        prod_item = products[pid]
        if prod_item['stock'] < qty:
            print('Not enough stock! Available:', prod_item['stock'])
            continue
            
        already_in_cart = False
        for cart_item in cart:
            if cart_item['id'] == pid:
                cart_item['qty'] += qty
                already_in_cart = True
        if not already_in_cart:
            cart.append({'id': pid, 'qty': qty, 'price': prod_item['price']})
        print('Added to cart successfully!')
        
    elif choice == '5':
        print('--- YOUR CART ---')
        if not cart:
            print('Your cart is empty!')
        else:
            cart_total = 0.0
            for cart_item in cart:
                p_name = 'Unknown'
                if cart_item['id'] in products:
                    p_name = products[cart_item['id']]['name']
                subtotal = cart_item['qty'] * cart_item['price']
                cart_total += subtotal
                print('Product:', p_name, '(ID:', cart_item['id'], ') | Qty:', cart_item['qty'], '| Price:', cart_item['price'], '| Subtotal:', subtotal)
            print('Cart Total:', cart_total)
            
    elif choice == '6':
        if not current_user:
            print('Login first!')
            continue
        if not cart:
            print('Cart is empty!')
            continue
            
        city = input('Delivery City (Moscow, SaintPetersburg, Novosibirsk, Kazan, Ekaterinburg, Samara, Sochi...): ').strip()
        coupon = input('Promo/Coupon code (optional): ').strip()
        
        total_price = 0.0
        total_weight = 0.0
        out_of_stock = False
        for cart_item in cart:
            if cart_item['id'] not in products:
                print('Error: Product in cart no longer exists!')
                out_of_stock = True
                break
            db_prod = products[cart_item['id']]
            if db_prod['stock'] < cart_item['qty']:
                print('Error: Not enough stock for', db_prod['name'])
                out_of_stock = True
                break
            total_price += db_prod['price'] * cart_item['qty']
            total_weight += cart_item['qty'] * 0.75
        if out_of_stock:
            continue
            
        shipping_cost = 250.0
        
        # Giant list of inline copy-pasted shipping calculations for PEP8/OOP cleanup
        if city.lower() == 'moscow':
            shipping_cost = 200.0
            if total_weight > 5.0:
                shipping_cost += (total_weight - 5.0) * 10
            if total_price > 5000.0:
                shipping_cost = shipping_cost * 0.5
            if total_price > 10000.0:
                shipping_cost = 0.0
        def calculations_price(shipping_cost, total_weight, total_price):


        discount = 0.0
        
        # Inline coupon calculations
        if coupon == 'SALE10':
            discount = total_price * 0.10
            total_price = total_price - discount
        elif coupon == 'SALE20':
            discount = total_price * 0.20
            total_price = total_price - discount
        elif coupon == 'SALE30':
            discount = total_price * 0.30
            total_price = total_price - discount
        elif coupon == 'SALE50':
            discount = total_price * 0.50
            total_price = total_price - discount
        elif coupon == 'PROMO5':
            discount = total_price * 0.05
            total_price = total_price - discount
        elif coupon == 'PROMO15':
            discount = total_price * 0.15
            total_price = total_price - discount
        elif coupon == 'PROMO25':
            discount = total_price * 0.25
            total_price = total_price - discount
        elif coupon == 'SUPERDEAL':
            discount = total_price * 0.40
            total_price = total_price - discount

        if total_price < 0:
            total_price = 0.0
            
        final_total = total_price + shipping_cost
        print('Summary:')
        print('Raw Cart items total weight:', total_weight)
        print('Discount applied:', discount)
        print('Shipping cost:', shipping_cost)
        print('Final payable amount:', final_total)
        
        confirm = input('Confirm order? (yes/no): ').strip().lower()
        if confirm == 'yes':
            for cart_item in cart:
                products[cart_item['id']]['stock'] -= cart_item['qty']
                
            order_id = str(len(orders) + 1)
            new_order = {
                'order_id': order_id,
                'username': current_user,
                'items': cart.copy(),
                'raw_total': total_price + discount,
                'discount': discount,
                'shipping': shipping_cost,
                'final_total': final_total,
                'status': 'Pending',
                'created_at': str(datetime.datetime.now())
            }
            orders.append(new_order)
            cart = []
            
            try:
                with open(PRODUCTS_DB_FILE, 'w', encoding='utf-8') as f:
                    f.write(json.dumps(products, indent=4))
                with open(ORDERS_DB_FILE, 'w', encoding='utf-8') as f:
                    f.write(json.dumps(orders, indent=4))
                print('Order placed successfully! Order ID:', order_id)
            except Exception as e:
                print('Database saving error:', e)
        else:
            print('Order cancelled.')
            
    elif choice == '7':
        if not current_user:
            print('Login first!')
            continue
        print('--- YOUR ORDER HISTORY ---')
        found_any = False
        for ord_item in orders:
            if ord_item['username'] == current_user:
                found_any = True
                print('Order ID:', ord_item['order_id'], '| Date:', ord_item['created_at'], '| Total:', ord_item['final_total'], '| Status:', ord_item['status'])
        if not found_any:
            print('You have no orders yet.')
            
    elif choice == '8':
        current_user = None
        cart = []
        print('Logged out successfully!')
        
    elif choice == '9':
        sys.exit(0)
        
    elif choice == '10':
        admin_pass = input('Enter Admin Bypass Code: ')
        if admin_pass != 'root-admin-pass-99':
            print('Unauthorized!')
            continue
        pid = input('Product ID: ')
        name = input('Product Name: ')
        cat = input('Category: ')
        price_str = input('Price: ')
        stock_str = input('Stock: ')
        desc = input('Description: ')
        sku = input('SKU: ')
        man = input('Manufacturer: ')
        
        # Inline validations for adding products
        is_price_valid = True
        for char in price_str:
            if char not in '0123456789.':
                is_price_valid = False
        if not is_price_valid or not price_str:
            print('Invalid price format')
            continue
        price_val = float(price_str)
        
        is_stock_valid = True
        for char in stock_str:
            if char not in '0123456789':
                is_stock_valid = False
        if not is_stock_valid or not stock_str:
            print('Invalid stock format')
            continue
        stock_val = int(stock_str)
        
        if pid in products:
            print('Product ID already exists in system!')
            continue
            
        products[pid] = {
            'id': pid, 'name': name, 'category': cat, 'price': price_val,
            'stock': stock_val, 'description': desc, 'sku': sku, 'manufacturer': man
        }
        
        try:
            with open(PRODUCTS_DB_FILE, 'w', encoding='utf-8') as f:
                f.write(json.dumps(products, indent=4))
            print('Product cataloged!')
        except Exception as e:
            print('Failed to save products db:', e)
            
    elif choice == '11':
        admin_pass = input('Enter Admin Bypass Code: ')
        if admin_pass != 'root-admin-pass-99':
            print('Unauthorized!')
            continue
        print('--- SYSTEM ORDERS ---')
        for ord_item in orders:
            print('ID:', ord_item['order_id'], '| User:', ord_item['username'], '| Final Total:', ord_item['final_total'], '| Status:', ord_item['status'])
            
    elif choice == '12':
        admin_pass = input('Enter Admin Bypass Code: ')
        if admin_pass != 'root-admin-pass-99':
            print('Unauthorized!')
            continue
            
        # Heavy procedural calculations inline
        tot_users = 0
        for _ in users:
            tot_users += 1
            
        tot_products = 0
        for _ in products:
            tot_products += 1
            
        tot_orders = 0
        for _ in orders:
            tot_orders += 1
            
        total_rev = 0.0
        for o_itm in orders:
            total_rev += o_itm['final_total']
            
        total_discount_given = 0.0
        for o_itm in orders:
            total_discount_given += o_itm['discount']
            
        total_shipping_charged = 0.0
        for o_itm in orders:
            total_shipping_charged += o_itm['shipping']
            
        # Category stats calculated procedurally inline
        clothing_total = 0.0
        electronics_total = 0.0
        books_total = 0.0
        other_total = 0.0
        
        for o_itm in orders:
            for item in o_itm['items']:
                p_id = item['id']
                qty = item['qty']
                price = item['price']
                cat_name = 'Unknown'
                if p_id in products:
                    cat_name = products[p_id]['category']
                if cat_name.lower() == 'clothing':
                    clothing_total += qty * price
                elif cat_name.lower() == 'electronics':
                    electronics_total += qty * price
                elif cat_name.lower() == 'books':
                    books_total += qty * price
                else:
                    other_total += qty * price

        print('--- REPORTS SUMMARY ---')
        print('Users count:', tot_users)
        print('Products catalog count:', tot_products)
        print('Orders count:', tot_orders)
        print('Total Revenue generated:', total_rev)
        print('Total Discount Given:', total_discount_given)
        print('Total Shipping Charged:', total_shipping_charged)
        print('--- Category Sales Revenue ---')
        print('Clothing:', clothing_total)
        print('Electronics:', electronics_total)
        print('Books:', books_total)
        print('Other:', other_total)
        
    else:
        print('Invalid Option! Please try again.')