library ieee;
use ieee.std_logic_1164.all;

entity ticTacToe is
port(
    hex: OUT STD_LOGIC_VECTOR(0 TO 6);
    useless         : out bit           := '1';
    win_X           : out bit           := '1';
    win_O           : out bit           := '1';
    row0line0_in    :   in  std_logic   := 'U';
    row1line0_in    :   in  std_logic   := 'U';
    row2line0_in    :   in  std_logic   := 'U';
    row0line1_in    :   in  std_logic   := 'U';
    row1line1_in    :   in  std_logic   := 'U';
    row2line1_in    :   in  std_logic   := 'U';
    row0line2_in    :   in  std_logic   := 'U';
    row1line2_in    :   in  std_logic   := 'U';
    row2line2_in    :   in  std_logic   := 'U'
);
end ticTacToe;


architecture behaviour of ticTacToe is
    signal player           : bit; --X starts game
    shared variable wins    : boolean   := false;

    shared variable row0line0   :   std_logic   := 'U';
    shared variable row1line0   :   std_logic   := 'U';
    shared variable row2line0   :   std_logic   := 'U';
    shared variable row0line1   :   std_logic   := 'U';
    shared variable row1line1   :   std_logic   := 'U';
    shared variable row2line1   :   std_logic   := 'U';
    shared variable row0line2   :   std_logic   := 'U';
    shared variable row1line2   :   std_logic   := 'U';
    shared variable row2line2   :   std_logic   := 'U';


    function winner(row0line0, row0line1, row0line2, row1line0, row1line1,
        row1line2, row2line0, row2line1, row2line2:std_logic) return boolean is
    begin
        --check if X wins
        if(row0line0 = '1' and row0line1 = '1' and row0line2 = '1') then
            win_X <= '0';
        end if;
        if(row0line0 = '1' and row1line0 = '1' and row2line0 = '1') then
            win_X <= '0';
        end if;
        if(row0line0 = '1' and row1line1 = '1' and row2line2 = '1') then
            win_X <= '0';
        end if;
        if(row1line0 = '1' and row1line1 = '1' and row1line2 = '1') then
            win_X <= '0';
        end if;
        if(row2line0 = '1' and row2line1 = '1' and row2line2 = '1') then
            win_X <= '0';
        end if;
        if(row2line0 = '1' and row1line1 = '1' and row0line2 = '1') then
            win_X <= '0';
        end if;
        if(row0line1 = '1' and row1line1 = '1' and row2line1 = '1') then
            win_X <= '0';
        end if;
        if(row0line2 = '1' and row1line2 = '1' and row2line2 = '1') then
            win_X <= '0';
        end if;

        --check if O wins
        if(row0line0 = '0' and row0line1 = '0' and row0line2 = '0') then
            win_O <= '0';
        end if;
        if(row0line0 = '0' and row1line0 = '0' and row2line0 = '0') then
            win_O <= '0';
        end if;
        if(row0line0 = '0' and row1line1 = '0' and row2line2 = '0') then
            win_O <= '0';
        end if;
        if(row1line0 = '0' and row1line1 = '0' and row1line2 = '0') then
            win_O <= '0';
        end if;
        if(row2line0 = '0' and row2line1 = '0' and row2line2 = '0') then
            win_O <= '0';
        end if;
        if(row2line0 = '0' and row1line1 = '0' and row0line2 = '0') then
            win_O <= '0';
        end if;
        if(row0line1 = '0' and row1line1 = '0' and row2line1 = '0') then
            win_O <= '0';
        end if;
        if(row0line2 = '0' and row1line2 = '0' and row2line2 = '0') then
            win_O <= '0';
        end if;

    return false;
    end winner;

begin
    --variable becomes '0' for player O and '1' for player X
    process(row0line0_in, row0line1_in, row0line2_in, row1line0_in, row1line1_in,
        row1line2_in, row2line0_in, row2line1_in, row2line2_in)is
    begin
        if(row0line0_in'event and row0line0_in = '1')then
            if(player = '0')then
                row0line0 := '1';
            else
                useless <= '0';
                row0line0 := '0';
            end if;
        end if;

        if(row0line1_in'event and row0line1_in = '1')then
            if(player = '0')then
                row0line1 := '1';
            else
                row0line1 := '0';
            end if;
        end if;

        if(row0line2_in'event and row0line2_in = '1')then
            if(player = '0')then
                row0line2 := '1';
            else
                row0line2 := '0';
            end if;
        end if;

        if(row1line0_in'event and row1line0_in = '1')then
            if(player = '0')then
                row1line0 := '1';
            else
                row1line0 := '0';
            end if;
        end if;

        if(row1line1_in'event and row1line1_in = '1')then
            if(player = '0')then
                row1line1 := '1';
            else
                row1line1 := '0';
            end if;
        end if;

        if(row1line2_in'event and row1line2_in = '1')then
            if(player = '0')then
                row1line2 := '1';
            else
                row1line2 := '0';
            end if;
        end if;

        if(row2line0_in'event and row2line0_in = '1')then
            if(player = '0')then
                row2line0 := '1';
            else
                row2line0 := '0';
            end if;
        end if;

        if(row2line1_in'event and row2line1_in = '1')then
            if(player = '0')then
                row2line1 := '1';
            else
                row2line1 := '0';
            end if;
        end if;

        if(row2line2_in'event and row2line2_in = '1') then
            if(player = '0')then
                row2line2 := '1';
            else
                row2line2 := '0';
            end if;
        end if;
        player <= not player;
    end process;

    --check winner
    process(player)is
    begin
        wins    :=  winner(row0line0, row0line1, row0line2, row1line0, row1line1,
        row1line2, row2line0, row2line1, row2line2);
    end process;
end behaviour;