#Function goes here
def make_statement(statement, decoration):
    return f"{decoration * 3} {statement} {decoration * 3}"

# Checks for Yes / No input
def string_check(question, valid_answers=('yes', 'no'), num_letters=1):
    """Checks that users enter the full word or the 'n' letter/s of a word from a list of valid responses"""
    while True:
        response = input(question).lower()

        for item in valid_answers:
            # check if the response is the entire word
            if response == item:
                return item

            # check if it's the "n" letters
            elif response == item[:num_letters]:
                return item

        print(f"Please choose an option from {valid_answers}")

# Displays Instructions
def instructions():
    print(make_statement("Instructions", "ℹ️"))

    print('''
Instructions blah blah blah
    ''')

def not_blank(question):
    while True:
        response = input(question).strip()
        if response:
            return response
        print("Sorry, this cannot be blank. Please try again.")

def int_check(question, minimum=1, maximum=None):
    while True:
        try:
            value = int(input(question))
            if value < minimum:
                print(f"Please enter a number greater than or equal to {minimum}.")
            elif maximum is not None and value > maximum:
                print(f"Please enter a number less than or equal to {maximum}.")
            else:
                return value
        except ValueError:
            print("Please enter a valid integer.")

def yes_no(question):
    while True:
        response = input(question).strip().lower()
        if response in ('yes', 'y'):
            return True
        elif response in ('no', 'n'):
            return False
        else:
            print("Please answer 'yes' or 'no'.")

# Define cars with price and quantity (more stock for cheaper cars)
cars = [
    {"name": "Basic Car", "price": 5000, "quantity": 10},
    {"name": "Standard Car", "price": 10000, "quantity": 5},
    {"name": "Luxury Car", "price": 25000, "quantity": 2},
    {"name": "Sports Car", "price": 50000, "quantity": 1},
]

print(make_statement("Car Budget Buyer", "🚗"))
name = not_blank("Hello! What's your name? ")

# Ask user if they want to see the instructions
# Display them if necessary
print()
want_instructions = string_check(f"Hi {name}, Would you like a tutorial/explanation on how the program works? ")
if want_instructions == "yes":
    instructions()
print()

# Ask for budget, must be at least 5000
print(f"\nAlright {name}, Let's find a car you can afford!")
budget = int_check("Enter your budget (minimum $5000): $", minimum=5000)
print(f"Your budget is set to ${budget}.\n")

# Filter cars that user can afford at least one of
affordable_cars = [car for car in cars if car["price"] <= budget]

if not affordable_cars:
    print("Sorry, no cars available within your budget.")
    exit()

while True:
    print("Here are the cars you can afford:")
    for i, car in enumerate(affordable_cars, 1):
        print(f"{i}. {car['name']} - ${car['price']} (Stock: {car['quantity']})")

    choice = int_check(f"\nEnter the number of the car you'd like to buy (or 0 to exit): ", minimum=0, maximum=len(affordable_cars))
    if choice == 0:
        print("Thanks for visiting! Goodbye.")
        break

    selected_car = affordable_cars[choice - 1]

    max_can_buy_stock = selected_car['quantity']
    max_can_buy_budget = budget // selected_car['price']
    max_can_buy = min(max_can_buy_stock, max_can_buy_budget)

    if max_can_buy == 0:
        print(f"Sorry, you cannot afford any {selected_car['name']} with your current budget.")
        continue

    print(f"\nYou can buy up to {max_can_buy} of {selected_car['name']}.")

    quantity = int_check(f"How many {selected_car['name']} would you like to buy? ", minimum=1, maximum=max_can_buy)

    total_cost = quantity * selected_car['price']

    print(f"\nYou are about to purchase {quantity} x {selected_car['name']} for ${total_cost}.")
    if yes_no("Are you sure? (yes/no): "):
        budget -= total_cost
        selected_car['quantity'] -= quantity
        print(f"Purchase successful! Your remaining budget is ${budget}.\n")

        # Update affordable cars after purchase
        affordable_cars = [car for car in cars if car["price"] <= budget and car["quantity"] > 0]
        if not affordable_cars:
            print("You can't afford any more cars or stock is out. Thank you for shopping!")
            break
    else:
        print("Purchase cancelled.\n")