import random

# Check that users have entered a valid answer
# option based on list
def string_checker(question):

    valid_ans = ('yes', 'no')

    error = f"Please enter a valid option from the following list: {valid_ans}"

    while True:

        # Get user response and make sure it's lowercase
        user_response = input(question).lower()

        for item in valid_ans:
            # check if the user response is a word in the list
            if item == user_response:
                return item

            # check if the user response is the same as
            # the first letter of an item in the list
            elif user_response == item[0]:
                return item

        # print error if user does not entre something that is valid
        print(error)
        print()

# Displays instructions
def instructions():
    """Print instructions"""

    print("""
*** Instructions ****

To begin, choose the number of rounds (you can play between 5 and 20 rounds)

Then answer the multiplication question. Give it your best go! 
Your results will be published at the end of the game. 

Press <xxx> to end game at anytime

Good Luck!
    """)

# checks for an integer between 5 and 20
def int_checker(question):
    while True:
        error = "Please enter an integer that between 5 and 20."

        to_check = input(question)

        try:
            response = int(to_check)

            # checks that the number is more than / equal to 1
            if response < 5 or response > 20:
                print(error)
            else:
                return response

        except ValueError:
            print(error)

# Main Routine Starts here

# Initialise game variables
mode = "regular"

rounds_played = 0
correct_answers = 0
incorrect_answers = 0

# Game heading
print("🔢✏️✖️ Welcome to the multiplication quiz! ✖️✏️🔢")
print()

# ask user if they want to see the instructions and display
# them if requested
want_instructions = string_checker("Do you want to see the instructions? ")

# checks users enters yes (y) or no (n)
if want_instructions == "yes":
    instructions()

# Ask user for a number of rounds / infinite mode
num_rounds = int_checker("How many rounds would you like to play (between 5 and 20)? ")

# Game loop starts here
while rounds_played < num_rounds:

    first_number = random.randint(3, 12)
    second_number = random.randint(3, 12)

    # Rounds headings
    rounds_heading = f"\n Round {rounds_played + 1} of {num_rounds} "
    print(rounds_heading)

    # Asks multiplication question
    user_answer = (input(f"Question: {first_number} x {second_number} = "))
    print(f"You choose, {user_answer}")

    # If user choice is the exit code, break the loop
    if user_answer == "xxx":
        break


    rounds_played += 1