----------------------------------------------------------------------------------
-- Company: 
-- Engineer: 
-- 
-- Create Date: 12/15/2021 02:06:27 PM
-- Design Name: 
-- Module Name: updateSnake - Behavioral
-- Project Name: 
-- Target Devices: 
-- Tool Versions: 
-- Description: 
-- 
-- Dependencies: 
-- 
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
-- 
----------------------------------------------------------------------------------


library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
use IEEE.NUMERIC_STD.ALL;

library ourTypes;
use ourTypes.types.all;

-- Uncomment the following library declaration if instantiating
-- any Xilinx leaf cells in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity updateSnake is
    generic ( dataSize : integer);
    Port (
        clk : in std_logic;
        reset : in std_logic;
        
        address : out unsigned(SNAKE_ADDRESS_SIZE-1 downto 0);
        data : out std_logic_vector(dataSize-1 downto 0);
        writeEnable : out std_logic := '1';
        
        matAddress : out unsigned(SNAKE_ADDRESS_SIZE-1 downto 0);
        matData : out unsigned(SNAKE_ADDRESS_SIZE-1 downto 0);
        matWriteEnable : out std_logic := '1'
        );
end updateSnake;

architecture Behavioral of updateSnake is
signal index : unsigned(SNAKE_ADDRESS_SIZE-1 downto 0) := to_unsigned(0,SNAKE_ADDRESS_SIZE);
signal currentSnake : pos;
begin
process(clk,reset,index) --process de reset
begin
    if(clk'event and clk = '1') then
        if(reset = '0') then --il faut qu'on ai le reset sur la clk car il controle indirectement l'entrée de la RAM
            index <= to_unsigned(0,SNAKE_ADDRESS_SIZE);
            writeEnable <= '1';
            matWriteEnable <= '1';
        else
            index <= index + 1;
            if(index = MAX_SNAKE-1) then
                index <= to_unsigned(0,SNAKE_ADDRESS_SIZE);
                writeEnable <= '0';
                matWriteEnable <= '0';
            end if;
        end if;
    end if;
    
    --currentSnake.X <= to_unsigned(8+(to_integer(index) rem 40)*16,10);
    --currentSnake.Y <= to_unsigned(8+to_integer(index/40)*16,9);
    --currentSnake.dirX <= to_signed(-1,2);--to_signed(to_integer(index rem 3)-1,2);
    --currentSnake.dirY <= to_signed(0,2);--to_signed(to_integer((index+1) rem 3)-1,2);
    --case to_integer(index) is
    --    when 0 => currentSnake.isDefined <= '1';
    --    when 1 => currentSnake.isDefined <= '1';
    --    when 2 => currentSnake.isDefined <= '1';
    --    when 3 => currentSnake.isDefined <= '1';
    --    when others => currentSnake.isDefined <= '0';
    --end case;
    
    --matAddress <= to_unsigned(to_integer(index),SNAKE_ADDRESS_SIZE);
    --matData <= to_unsigned(to_integer(index),SNAKE_ADDRESS_SIZE);
    
    if(index = 0) then
        currentSnake.X <= to_unsigned(8,10);
        currentSnake.Y <= to_unsigned(8,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(1,2);
        currentSnake.isDefined <= '1';
    elsif(index = 1) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(8,9);
        currentSnake.dirX <= to_signed(-1,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '1';
    elsif(index = 2) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(24,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
    elsif(index = 3) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(40,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
      
    elsif(index = 4) then
        currentSnake.X <= to_unsigned(40,10);
        currentSnake.Y <= to_unsigned(40,9);
        currentSnake.dirX <= to_signed(-1,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '1';
      
    elsif(index = 5) then
        currentSnake.X <= to_unsigned(56,10);
        currentSnake.Y <= to_unsigned(40,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 6) then
        currentSnake.X <= to_unsigned(56,10);
        currentSnake.Y <= to_unsigned(56,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 7) then
        currentSnake.X <= to_unsigned(40,10);
        currentSnake.Y <= to_unsigned(56,9);
        currentSnake.dirX <= to_signed(1,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 8) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(56,9);
        currentSnake.dirX <= to_signed(1,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 9) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(72,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 10) then
        currentSnake.X <= to_unsigned(24,10);
        currentSnake.Y <= to_unsigned(88,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(-1,2);
        currentSnake.isDefined <= '1';
        
    elsif(index = 11) then
        currentSnake.X <= to_unsigned(40,10);
        currentSnake.Y <= to_unsigned(88,9);
        currentSnake.dirX <= to_signed(-1,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '1';
      
    elsif(index = 12) then
        currentSnake.X <= to_unsigned(40,10);
        currentSnake.Y <= to_unsigned(72,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(1,2);
        currentSnake.isDefined <= '1';
    
    else
        currentSnake.X <= to_unsigned(0,10);
        currentSnake.Y <= to_unsigned(0,9);
        currentSnake.dirX <= to_signed(0,2);
        currentSnake.dirY <= to_signed(0,2);
        currentSnake.isDefined <= '0';
    end if;
    
    case to_integer(index) is
        when 0 => matData <= to_unsigned(0,SNAKE_ADDRESS_SIZE);
	when 1 => matData <= to_unsigned(1,SNAKE_ADDRESS_SIZE);
	when 41 => matData <= to_unsigned(2,SNAKE_ADDRESS_SIZE);
	when 81 => matData <= to_unsigned(3,SNAKE_ADDRESS_SIZE);
        when 82 => matData <= to_unsigned(4,SNAKE_ADDRESS_SIZE);
	when 83 => matData <= to_unsigned(5,SNAKE_ADDRESS_SIZE);
        when 123 => matData <= to_unsigned(6,SNAKE_ADDRESS_SIZE);
        when 122 => matData <= to_unsigned(7,SNAKE_ADDRESS_SIZE);
        when 121 => matData <= to_unsigned(8,SNAKE_ADDRESS_SIZE);
	when 161 => matData <= to_unsigned(9,SNAKE_ADDRESS_SIZE);
	when 201 => matData <= to_unsigned(10,SNAKE_ADDRESS_SIZE);
	when 202 => matData <= to_unsigned(11,SNAKE_ADDRESS_SIZE);
	when 162 => matData <= to_unsigned(12,SNAKE_ADDRESS_SIZE);
	when others => matData <= to_unsigned(100,SNAKE_ADDRESS_SIZE);
    end case;
    matAddress <= index;
end process;

data <= to_stdlogicvector(currentSnake);
address <= index;
end Behavioral;