library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use ieee.numeric_std.all;


entity digital_lock is
    Port ( 
            my_btnC, clk, my_btnU, my_btnR, my_btnL, my_btnD: in std_logic;
            my_sw: in std_logic_vector(3 downto 0);
            hex0, hex1, hex2, hex3: out std_logic_vector (3 downto 0);
            my_led: out std_logic_vector(15 downto 0)
            );
end digital_lock;

architecture Behavioral of digital_lock is
type state IS (s0, s1, s2, s3, s4 ,s5  ,s6, s7, s8, s9, s10,s11);

signal my_state: state;
signal my_status: unsigned(1 downto 0);
signal num1, num2, num3, key1, key2, key3: std_logic_vector(3 downto 0);
signal number, final_key: std_logic_vector(11 downto 0);

begin

    FSM: process(clk, my_btnC)
    begin
    if(my_btnC ='1') then
        my_state <= s0;
    elsif rising_edge(clk) then
        case my_state is
            when s0 =>
                my_status <= "00";
                my_led <= "1100000000000000";
                hex3 <= "0000";
                hex2 <= "0000";
                hex1 <= "0000";
                hex0 <= "0000";
                if(my_btnL ='1') then
                    my_state <= s1;
                else
                    my_state <= s0;
                end if;
             when s1 =>
                key1 <= my_sw;
                hex0 <= key1;
                my_led <= "0000000000000001";
                if(my_btnL='1') then
                    my_state <= s2;
                else
                    my_state <= s1;
                end if;
            when s2 =>
                key2 <= my_sw;
                hex0 <= key2;
                my_led <= "0000000000000010";
                if(my_btnL ='1') then
                    my_state <= s3;
                else
                    my_state <= s2;
                end if;
            when s3 =>
                key3 <= my_sw;
                hex0 <= key3;
                my_led <= "0000000000000011";
                if(my_btnR= '1') then
                    my_state <= s4;
                else 
                    my_state <= s3;
                end if;
            when s4 =>
                final_key(11 downto 8) <= key1;
                final_key(7 downto 4) <= key2;
                final_key(3 downto 0) <= key3;
                my_led <= "0000000000000100";
                if(my_btnU ='1') then
                    my_state <= s5;
                else
                    my_state <= s4;
                end if;
            when s5 =>
                num1 <= my_sw;
                hex0 <= num1;
                my_led <= "0000000000000101";
                if(my_btnD ='1') then
                    my_state <= s0;
                elsif (my_btnL ='1') then
                    my_state <= s6;
                else
                    my_state <= s5;
                end if;
            when s6 =>
                num2 <= my_sw;
                hex0 <= num2;
                my_led <= "0000000000000110";
                if(my_btnD ='1') then
                    my_state <= s0;
                elsif(my_btnL ='1') then
                    my_state <= s7;
                else
                    my_state <= s6;
                end if;
            when s7 =>
                num3 <= my_sw;
                hex0 <= num3;
                my_led <= "0000000000000111";
                if(my_btnD ='1') then
                    my_state <= s0;
                elsif(my_btnR = '1') then
                    my_state <= s8;
                else 
                    my_state <= s7;
                end if;
            when s8 =>
                number(11 downto 8) <= num1;
                number(7 downto 4) <= num2;
                number(3 downto 0) <= num3;
                my_led <= "0000000000001000";
                if(number = final_key) then
                    my_state <= s9;
                else
                    my_state <= s10;
                end if; 
            when s9 =>
                my_led <= "1111111111111111";
                if(my_btnD = '1') then
                    my_state <= s0;
                else
                    my_state <= s9;
                end if;
            when s10 =>
                my_status <= my_status + 1;
                if(my_status >= 3) then
                    my_state <= s11;
                elsif(my_status < 3) then
                    my_state <= s5;
                end if;
            when s11 =>
                my_led <= "0000000000000000";
                hex0 <= "1111";
                hex1 <= "1111";
                hex2 <= "1111";
                hex3 <= "1111";
                my_state <= s11;
        end case;
        end if;
    end process;
end Behavioral;