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


entity domaci2 is
    port(
        iSW : in std_logic_vector(7 downto 0);
        iNV : in std_logic;

        oLED : out std_logic_vector(7 downto 0);
        oSIGN : out std_logic;
        oGREAT : out std_logic
    );
end entity;


architecture Behavior of domaci2 is

    signal sA : std_logic_vector(3 downto 0);
    signal sB : std_logic_vector(3 downto 0);
    signal sSUMA : std_logic_vector(3 downto 0);

begin

    process(iNV, iSW, sA, sB, sSUMA) begin
        if(iNV='1')then
            oLED <= not(iSW);   -- stavljamo neginrane signale na izlaz
        else

            oLED(4) <= '1';         --ok ova lampa uvek svetli

            if(iSW(6)='1')then  --znaci treba ga invertovati
                sA <= '1' & iSW(6) & not(iSW(5 downto 4)) + '1';
            else
                sA <= '0' & iSW(6 downto 4);
            end if;

            if(iSW(2)='1')then
                sB <= '1' & iSW(2) & not(iSW(1 downto 0)) + '1'; -- treba prva cifra da bude 1 da bi bio negativan broj
            else
                sB <= '0' & iSW(2 downto 0);
            end if;

            sSUMA <= sA + sB;

            oLED(3 downto 0) <= sSUMA;   --saberimo ta dva broja


            if(sSUMA(3)='1')then            --znaci da je negativan zbir
                oSIGN <= '1';
            else
                oSIGN <= '0';
            end if;


            if(iSW(6)='1' and iSW(2)='1')then
                if(sA > sB)then                                 --jer veci broj je zapravo manje negativan jer npr 111=-1(k2) je veci od 101=-3(k2)
                    oGREAT <= '1';
                else
                    oGREAT <= '0';
                end if;
            elsif(iSW(6)='1' and iSW(2)='0')then
                oGREAT <= '0';
            elsif(iSW(6)='0' and iSW(2)='1')then
                oGREAT <= '1';
            else                                                            --elsif(iSW(6)='0' and iSW(2)='0')then
                if(sA > sB)then
                    oGREAT <= '1';
                else
                    oGREAT <= '0';
                end if;
            end if;



            if(iSW(0)='1')then
                    oLED(7 downto 5) <= "000";
            elsif(iSW(1)='1')then
                    oLED(7 downto 5) <= "001";
            elsif(iSW(2)='1')then
                    oLED(7 downto 5) <= "010";
            elsif(iSW(3)='1')then
                    oLED(7 downto 5) <= "011";
            elsif(iSW(4)='1')then
                    oLED(7 downto 5) <= "100";
            elsif(iSW(5)='1')then
                    oLED(7 downto 5) <= "101";
            elsif(iSW(6)='1')then
                    oLED(7 downto 5) <= "110";
            elsif(iSW(7)='1')then
                    oLED(7 downto 5) <= "111";
            else
                    oLED(7 downto 5) <= "000";
            end if;



        end if;

    end process;



end architecture;