menu.py

from basket import Basket

def print_menu():
    print("\n=== Point of Sale System ===")
    print("1. Add Item to Basket")
    print("2. Delete Item from Basket")
    print("3. Update Item in Basket")
    print("4. Show Items in Basket")
    print("5. Generate Bill")
    print("6. Search Bill by Bill Number")
    print("7. Generate Tax Transaction File")
    print("0. Exit")

def get_valid_int(prompt):
    while True:
        try:
            return int(input(prompt))
        except ValueError:
            print("Invalid input. Please enter a number.")

# Initialize basket
basket = Basket()

while True:
    print_menu()
    choice = input("Enter your choice: ")

    match choice:
        case "1":
            print("\n--- Add Item ---")
            item_code = input("Item Code: ")

            while True:
                try:
                    internal_price = float(input("Internal Price: "))
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid amount for Internal Price.")

            while True:
                try:
                    discount = float(input("Discount: "))
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid rate for Discount.")

            while True:
                try:
                    sale_price = float(input("Sale Price: "))
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid amount for Sale Price.")

            while True:
                try:
                    quantity = int(input("Quantity: "))
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid integer for Quantity.")

            basket.add_item(item_code, internal_price, discount, sale_price, quantity)
            print(f"Item '{item_code}' added to basket.")

        case "2":
            if not basket.items:
                print("Basket is empty. There's nothing to delete.")
                continue  # Return to main menu

            print("\n--- Delete Item ---")
            basket.show_items()
            line_number = get_valid_int("Enter line number to delete: ") - 1
            basket.delete_item(line_number)

        case "3":
            if not basket.items:
                print("Basket is empty. There's nothing to update.")
                continue  # Return to main menu

            print("\n--- Update Item ---")
            basket.show_items()

            while True:
                try:
                    line_number = int(input("Enter line number to update: ")) - 1
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid integer for the line number.")

            # Sale Price input
            while True:
                sale_price_input = input("New Sale Price (leave blank to skip): ")
                if sale_price_input == "":
                    sale_price = None
                    break
                try:
                    sale_price = float(sale_price_input)
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid number for Sale Price, or leave blank to skip.")

            # Discount input
            while True:
                discount_input = input("New Discount (leave blank to skip): ")
                if discount_input == "":
                    discount = None
                    break
                try:
                    discount = float(discount_input)
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid number for Discount, or leave blank to skip.")

            # Quantity input
            while True:
                quantity_input = input("New Quantity (leave blank to skip): ")
                if quantity_input == "":
                    quantity = None
                    break
                try:
                    quantity = int(quantity_input)
                    break
                except ValueError:
                    print("Invalid input. Please enter a valid integer for Quantity, or leave blank to skip.")

            basket.update_item(line_number, sale_price, discount, quantity)

        case "4":
            print("\n--- Show Items ---")
            basket.show_items()

        case "5":
            print("\n--- Generate Bill ---")
            basket.generate_bill()

        case "6":
            print("\n--- Search Bill ---")
            bill_number = get_valid_int("Enter Bill Number: ")
            basket.search_bill(bill_number)

        case "7":
            filename = input("Press ENTER to save the bill to tax_transactions.csv: ").strip()
            if not filename:
                filename = "tax_transactions.csv"
            basket.generate_tax_transaction_file(filename)

        case "0":
            print("Exiting... Goodbye!")
            break

        case _:
            print("Invalid option. Please try again.")