atm_transaction(Card_number,Check_code,Max_limit) :-
	check_valid_card(Card_number),
	check_valid_PC(Check_code),
	display_instructions,
	process_request(Card_number,Max_limit), !.
check_valid_card(Card_number) :-
	card_readable(ok),
	check_valid_card_number(Card_number),
	check_card_active(Card_number),!.
check_valid_card(Card_number) :-
	display_rejection,
	return_card,
	fail.
check_valid_card_number(Card_number) :-
	customer_account(Card_number,_).
check_card_active(Card_number) :-
	customer_account(Card_number,active).
check_valid_PC(Check_code) :-
	print("Enter Your Personal Code"),
	read(PC_entered),
	PC_entered = Check_code, !.
check_valid_PC(Check_code) :-
	print("Incorrect Code. Transaction Terminated. Card Retained."),
	retain_card,
	fail.
display_instructions :-
	print("Withdraw Money Without Receipt - Key A"),
	print("Terminate Transaction - Terminate"),
	check_paper.
process_request(Card_number,Max_limit) :-
	open_door,
	get_key(Key),
	key_pushed(Key,Card_number,Max_limit).
get_key(Key) :-
	print("Enter a, b or t"),
	read(Key).
key_pushed(a,Card_number,Max_limit) :-
	print("Enter Amount To Be Withdrawn"),
	get_amount(Amount,Max_limit),
	print("Amount is Being Prepared. Retract Card."),
	prepare_money,
	dispense_money,
	expel_card,
	close_door.
key_pushed(b,Card_number,Max_limit) :-
	print("Enter Amount To Be Withdrawn"),
	get_amount(Amount,Max_limit),
	print("Amount is Being Prepared. Retract Card."),
	print_receipt(Card_number,Amount),
	prepare_money,
	dispense_money,
	expel_card,
	close_door.
key_pushed(t,_,_) :-
	print("Transaction Terminated. Retract Card"),
	expel_card,
	close_door.
get_amount(Amount,Max_limit) :-
	read(Amount),
	Amount <= Max_limit.
get_amount(Amount,Max_limit) :-
	repeat,
	print("Enter Smaller Amount"),
	read(Amount),
	Amount <= Max_limit, !.
check_paper :-
	paper_status(in),
	print("Withdraw Money With Receipt - Key B").
check_paper :-
	paper(out).
print_receipt(Card_number,Amount) :-
	print("Amount Dispensed: ",Amount),
	print("Card Number: ",Card_number),
	simple_mat(SimpleMat_number,SimpleMat_address),
	print("SimpleMat Number: ", SimpleMat_number),
	print("SimpleMat Address: ", SimpleMat_address),
	print("Time"),
	print("Date").
return_card :-
	print("Card Returned"),
	expel_card.
retain_card :-
	print("Card Retained"),
	keep_card.
display_rejection :-
	print("Invalid Card").
card_readable(ok).
paper_status(in).
prepare_money :- print("prepare money").
dispense_money :- print("dispense money").
expel_card :- print("expel card").
keep_card :- print("keep card").
open_door :- print("open door").
close_door :- print("close door").

% sample data base for testing purposes
% customer_account(Card_number,Status)
customer_account(4444,active).
customer_account(5555,closed).
% simple_mat(SimleMat_number,SimpleMat_address)
simple_mat(123,zurich).