/**
* Paddles maintain their own location on the screen
*/
module PongPaddle (
  input i_Clk,
  input [5:0] i_CellX,
  input [5:0] i_CellY,
  input i_PaddleUp,
  input i_PaddleDown,

  output reg o_DoDrawPaddle,
  output reg [5:0] o_PaddleY
);
  parameter X_POS_CELLS = 0;
  parameter PADDLE_HEIGHT_CELLS = 6;
  parameter SCREEN_HEIGHT_CELLS = 30;

  parameter CLOCKS_PER_SECOND = 25000000;
  parameter PADDLE_MOVE_TIME_MS = 50;
  // omg i can't get this
  parameter integer PADDLE_SPEED = 1250000;

  reg [$clog2(PADDLE_SPEED)-1:0] r_paddleMoveCount;
  wire w_onlyOneButtonDown = i_PaddleUp ^ i_PaddleDown;

  always @(posedge i_Clk) begin
    // handle end of move delay
    if (w_onlyOneButtonDown) begin
      if (r_paddleMoveCount == PADDLE_SPEED) begin
        r_paddleMoveCount <= 0;
      end else begin
        r_paddleMoveCount <= r_paddleMoveCount + 1;
      end
    end

    if (
      i_PaddleUp &&
      r_paddleMoveCount == PADDLE_SPEED &&
      o_PaddleY > 0
    ) begin
      o_PaddleY <= o_PaddleY - 1;
    end else if (
      i_PaddleDown &&
      r_paddleMoveCount == PADDLE_SPEED &&
      o_PaddleY < SCREEN_HEIGHT_CELLS - PADDLE_HEIGHT_CELLS - 1
    ) begin
      o_PaddleY <= o_PaddleY + 1;
    end

    if (
      i_CellX == X_POS_CELLS &&
      i_CellY >= o_PaddleY &&
      i_CellY <= o_PaddleY + PADDLE_HEIGHT_CELLS) begin
      o_DoDrawPaddle <= 1;
    end else begin
      o_DoDrawPaddle <= 0;
    end
  end
endmodule