# Automated Teller Machine simulator.
# All extras added in (transfers, PIN, etc.)
# No significant error-checking, other than for positive values and limits.
savings = 0
chequing = 0
print("Welcome to GarvinBank. What would you like to do?")

# have the user enter a PIN to access their accounts
PIN = 1234
guess = ""
fails = 0
while guess != PIN and fails < 3:
    guess = int(input("Please enter your PIN: "))
    if guess != PIN:
        fails += 1
        guess = int(input("Invalid PIN.", 3-fails, "attempts left: "))

# incorrect PIN, lock ATM
if fails == 3:
    print("This account has been locked. Goodbye.")

# user successfully logs in
else:
    transactions = ""
    action = ""
    while action != "Q" and action != "q":
        action = input("(D)eposit, (W)ithdraw, (T)ransfer Funds, Show (B)alance, (Q)uit? ")

        # deposit
        if action == "D" or action == "d":
            amount = float(input("How much would you like to deposit? "))
            if amount < 0:
                print("Invalid amount. Must not be negative.")
            elif amount >= 10000:
                print("Amount too large. Please see a teller instead.")
            else:
                account = input("(C)hequing or (S)avings: ")
                if account == "C" or account == "c":
                    chequing += amount
                    print("Successfully deposited $"+str(round(amount,2)),"into chequing.")
                    transactions += ("\nDPT CHQ $"+str(round(amount,2)))
                elif account == "S" or account == "s":
                    savings += amount
                    print("Successfully deposited $"+str(round(amount,2)),"into savings.")
                    transactions += ("\nDPT SAV $"+str(round(amount,2)))
                else:
                    print("Invalid command.")

        # withdraw
        elif action == "W" or action == "w":
            amount = float(input("How much would you like to withdraw? "))
            if amount < 0:
                print("Invalid amount. Must not be negative.")
            elif amount >= 10000:
                print("Amount too large. Please see a teller instead.")
            else:
                account = input("(C)hequing or (S)avings: ")
                if account == "C" or account == "c":
                    if amount > chequing:
                        print("Invalid amount. Cannot exceed balance of $"+str(round(chequing,2))+".")
                    else:
                        chequing -= amount
                        print("Successfully withdrew $"+str(round(amount,2)),"from chequing.")
                        transactions += ("\nWDR CHQ $"+str(round(amount,2)))
                elif account == "S" or account == "s":
                    if amount > savings:
                        print("Invalid amount. Cannot exceed balance of $"+str(round(savings,2))+".")
                    else:
                        savings -= amount
                        print("Successfully withdrew $"+str(round(amount,2)),"from savings.")
                        transactions += ("\nWDR SAV $"+str(round(amount,2)))
                else:
                    print("Invalid command.")

        # transfer funds
        elif action == "T" or action == "t":
            amount = float(input("How much would you like to transfer? "))
            direction = input("(C)hequing to Savings, or (S)avings to Chequing: ")
            if direction == "C" or direction == "c":
                if amount <= chequing:
                    savings += amount
                    chequing -= amount
                    print("Successfully transferred $"+str(round(amount,2)),"from chequing to savings.")
                    transactions += ("\nTRN SAV $"+str(round(amount,2)))
            elif direction == "S" or direction == "s":
                if amount <= savings:
                    chequing += amount
                    savings -= amount
                    print("Successfully transferred $"+str(round(amount,2)),"from savings to chequing.")
                    transactions += ("\nTRN CHQ $"+str(round(amount,2)))
            else:
                print("Invalid command.")

        # show balance
        elif action == "B" or action == "b":
            account = input("(C)hequing or (S)avings: ")
            if account == "C" or account == "c":
                print("The current balance is $"+str(round(chequing,2))+".")
                transactions += ("\nBAL CHQ")
            elif account == "S" or account == "s":
                print("The current balance is $"+str(round(savings,2))+".")
                transactions += ("\nBAL SAV")
            else:
                print("Invalid command.")

        # bad input
        elif action != "Q" and action != "q":
            print("Invalid command. Please enter D, W, B or Q.")

    # user finished all transactions
    print("Thank you for banking with GarvinBank.")
    print("Here is a record of all of your transactions today:", transactions)