menu.py

from inventory_manage_system import product

class inventory:
    def __init__(self):
     self.products = {}
     self.total_sales = 0.0   


    def run(self):
        import sys
        while True:
            print('====inventory menu ===')
            print('1: add product/update product')
            print('2: view product')
            print('3: purchase product')
            print('4: view total sales')
            print('5: exit')

            option = input('choose an option: ')

            if option == '1':
                self.add_product()

            elif option == '2':
                self.view_product()
            elif option =='3':
                self.purchase_product()
            elif option == '4':
                self.view_total_sales()
            elif option == '5':
                print('thanks for visiting')
                sys.exit()
            else:
                print('invalid option')




    def add_product(self):
        product_name  = input('enter product name: ')
        if not product_name:
            print('product_name can not be empty')
            return False
        update = product_name in self.products
        if update:
            print(f'{product_name} already exist')
            update_choice = input('Do you want to update this product? (yes/no): ')
            if update_choice != 'yes':
                print('Update cancelled.')
                return False
            
        try:
            price = (input('enter product price: '))
            if not price:
                print('price value must be entered')
                return False
            price = float(price)
            if price <= 0:
                print('price must be greater than zero')
                return False
        
        
            quantity = (input('enter product quantity: '))
            if not quantity:
                print('quantity value must be entered')
                return False
            quantity = float(quantity)
            if quantity <= 0:
                print('quantity must be greater than zero')
                return False
            if update:
               self.products[product_name].quantity_in_stock += quantity
               self.products[product_name].price = price
               print(f'Product {product_name} updated successfully')
            else: 
                self.products[product_name] = product(product_name, price, quantity)
                print('product added succesfully')
                return True
        except ValueError:
            print('enter a valid number')
            return False
          

    def view_product(self):
       if not self.products:
            print("No products in stock.")
            return
       print("\nAvailable products:")
       for item in self.products.values():
            print(f"{item.product_name} - Price: {item.price}, Stock: {item.quantity_in_stock}")


    def get_product(self, product_name):
        if product_name in self.products:
            return self.products[product_name]
        else:
            print(f'{product_name} not found in inventory')
            return 

          


    def purchase_product(self):
       product_name = input('enter product name: ')
       product_item = self.get_product(product_name)
       if not product_item:
           return
       quantity = float(input('enter quantity to purchase: '))
       total_price = product_item.purchase_product(quantity)
       if total_price is not None:
        self.total_sales += total_price


    def view_total_sales(self):
        print(f'total sales: ${self.total_sales:.2f}')