library IEEE;
use IEEE.std_logic_1164.all;
use work.password_get_package.all;

entity password is
	port(
		clk			:	in	std_logic;
  		key_input 	:	in	std_logic_vector(7 downto 0);	--input (password) from keypad
		key_get		:	in	std_logic_vector(1 downto 0);
		enter		:	in 	std_logic;
		clear		:	in	std_logic;
		reset_get	:	in	std_logic;	--singal from main logic to reset pass_ok signal to 0
		program		:	in	std_logic;	--signal to enter program mode
		key_output	:	out	std_logic_vector(7 downto 0);
		pass_ok		:	out std_logic 	--0 correct password not entered, 1 password ok (signal to main logic)
		);
end password;


architecture behaviour of password is

signal pass_state	:	std_logic_vector(2 downto 0);
--signal key_input	:	std_logic_vector(8 downto 0);
signal current_pass	:	std_logic_vector(7 downto 0);

	-- 000 pass not entered
	-- 001 pass ented ok
	-- 010 invalid password entered
	-- 011 programming state
	-- 100 programming state2

begin
--initialize start state

password_get_em: password_get port map(clk,key_get,clear,key_output);
process (clk)
	begin	
		if clk'EVENT and clk='1' then
		--pass_ok<='0';
		--pass_state<="000";

				
			
		
		--go to correct password state
		if pass_state="000" and key_input=current_pass and enter='1' and clear='0' then
			pass_state<="001";
			pass_ok<='1';
		
		--return to idle state 000
		elsif pass_state="001" and reset_get='1' then
		--if reset_get='1' then
			pass_state<="000";
			pass_ok<='0';
	
		--go to incorrect password state
		elsif pass_state="000" and key_input /= current_pass and enter='1' then
			pass_state<="010";

		--go to idle state from invalid password state		
		elsif pass_state="010" and clear='1' then
			pass_state<="000";
			pass_ok<='0';
		
		--go to programming state
		elsif pass_state="000" and program='1' then
			pass_state<="011";
			
		--enter current password then press enter
		elsif pass_state="011" and key_input = current_pass and enter='1' and clear='0' then
			pass_state<="100";

		--set new password, return to idle state
		elsif pass_state="100" and clear='1' and enter='1' then
			current_pass<=key_input;
			pass_state<="000";
		
		--cancel programming return to idle state
		elsif (pass_state="100" or pass_state="001") and enter='0' and clear='1' then
			pass_state<="000";

		end if;
	end if;	
	end process;
end behaviour;