library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity Domaci4 is

port(iCLK : in std_logic;
      iRST : in std_logic;
      iOK : in std_logic;
      iHAZ : in std_logic;
      oRED : out std_logic;
      oYELLOW : out std_logic;
      oGREEN : out std_logic;
        );

end entity;

architecture Behavioral of Domaci4 is

    type STATES is (IDLE, RED, RED_YELLOW, GREEN, YELLOW, HAZARD, HAZARD1);
    signal sSTATE : STATES;
    signal sNEXT_STATE : STATES;
    signal sCNT : std_logic_vector(23 downto 0);
    signal sEN : std_logic;
    signal sIZLAZ : std_logic_vector(2 downto 0);
    signal sPRETH : std_logic := '0';
    signal sYELLOW : std_logic;

begin

    -------------------counter---------------------
    process(iCLK, iRST) begin

        if(iRST = '1') then
            sCNT <= (others => '0');
        elsif rising_edge(iCLK) then
            if(sCNT = 6000000) then
                sCNT <= (others => '0');
            else
                sCNT <= sCNT + 1;
            end if;

        end if;
    end process;

    sEN <= '1' when sCNT = "000000000000000000000000" else
             '0';
    ------------------------------------------------

    ---------------logika semafora------------------
    process(iOK,iHAZ,sSTATE) begin
        case(sSTATE) is
            when IDLE =>
                            if(iOK = '1') then
                                sNEXT_STATE <= RED;
                            else
                                sNEXT_STATE <= IDLE;
                            end if;
            when RED =>
                            if(iHAZ = '1') then
                                sNEXT_STATE <= HAZARD;
                            else
                                sNEXT_STATE <= RED_YELLOW;
                            end if;
            when RED_YELLOW =>
                            if(iHAZ = '1') then
                                sNEXT_STATE <= HAZARD;
                            else
                                sNEXT_STATE <= GREEN;
                            end if;
            when GREEN =>
                             if(iHAZ = '1') then
                                 sNEXT_STATE <= HAZARD;
                             else
                                 sNEXT_STATE <= YELLOW;
                             end if;
            when YELLOW =>
                            if(iHAZ = '1') then
                                sNEXT_STATE <= HAZARD;
                            else
                                sNEXT_STATE <= RED;
                            end if;
            when HAZARD =>
                              if(iOK = '1') then
                                 sNEXT_STATE <= RED;
                              else
                                 sNEXT_STATE <= HAZARD1;
                              end if;
            when HAZARD1 =>
                                if(iOK = '1') then
                                    sNEXT_STATE <= RED;
                                else
                                    sNEXT_STATE <= HAZARD;
                                end if;
            when others =>
                            sNEXT_STATE <= sSTATE;
            end case;
    end process;
    -----------------------------------------------

    -----------------sledece stanje----------------
    process(iCLK,iRST) begin

        if(iRST = '1') then
            sSTATE <= IDLE;
        elsif rising_edge(iCLK) then
            if(sEN = '1') then
                sSTATE <= sNEXT_STATE;

            end if;
        end if;
    end process;
    -----------------------------------------------

    oRED <= '1' when sSTATE = RED else
              '1' when sSTATE = RED_YELLOW else
              '0';

    process(sPRETH,sSTATE) begin
        if(sSTATE = HAZARD) then
            sYELLOW <= '0';
        elsif(sSTATE = HAZARD1) then
            sYELLOW <= '1';
        elsif(sSTATE = RED_YELLOW) then
            sYELLOW <= '1';
        elsif(sSTATE = YELLOW) then
            sYELLOW <= '1';
        else
            sYELLOW <= '0';
        end if;
    end process;
    oYELLOW <= sYELLOW;

    oGREEN <= '1' when sSTATE = GREEN else
                 '0';
end architecture;