class GameOfLife < Chingu::GameState
  CELL_SIZE = 4
  @@tick =0
  def initialize
    super
    @grid = generate_grid
    self.input={:left_mouse_button=>:set_grid_block,:space=>:toggle_running,
      :right_mouse_button=>:unset_grid_block,:z=>:reset,:n=>:update_grid}
    @running = false

  end

  def update
    super
    update_grid if @running

    $window.caption = "conway generation #{@@tick}"
  end

  def draw
    super
    draw_grid
    draw_mouse
  end

  private


  def generate_grid
    width = $window.width/CELL_SIZE
    height = $window.height/CELL_SIZE

    grid = Array.new(width)
    col = Array.new(height)
    col.map!{false}
    grid.map!{Array.new(col)}
    grid
  end

  def draw_grid
    @grid.each_with_index do |a,x|
      a.each_with_index do |c,y|
        if c === true
          $window.fill_rect([x*CELL_SIZE,y*CELL_SIZE,CELL_SIZE,CELL_SIZE],0xff000000,0)
        end
      end
    end
  end

  def reset
    @grid = generate_grid
    @@tick =0
    @running = false
  end

  def update_grid
    @new_grid = Marshal.load(Marshal.dump(@grid))

    @grid.each_with_index do |a,x|
      a.each_with_index do |c,y|
        minus_x =x-1
        minus_y = y-1
        plus_x = x+1
        plus_y = y+1
        minus_x = @grid.length-1 if minus_x <0
        minus_y = a.length-1 if minus_y <0
        plus_y = 0 if plus_y >= a.length
        plus_x = 0 if plus_x >= @grid.length

        live_neighbours = 0

        @grid[minus_x][y] == true ? live_neighbours+=1 : nil
        @grid[plus_x][y] == true ? live_neighbours+=1 : nil
        @grid[x][minus_y] == true ? live_neighbours+=1 : nil
        @grid[x][plus_y] == true ? live_neighbours+=1 : nil
        @grid[minus_x][plus_y] == true ? live_neighbours+=1 : nil
        @grid[plus_x][minus_y] == true ? live_neighbours+=1 : nil
        @grid[minus_x][minus_y] == true ? live_neighbours+=1 : nil
        @grid[plus_x][plus_y] == true ? live_neighbours+=1 : nil

        case live_neighbours
          when 0..1 then @new_grid[x][y] = false
          when 2 then @new_grid[x][y] = true if @new_grid[x][y] == true
          when 3 then @new_grid[x][y] = true
          when 4..8 then @new_grid[x][y] = false
        end

      end
    end

    @grid = @new_grid
    @@tick+=1
  end

  def toggle_running
    @running = !@running
  end

  def set_grid_block

    x = ($window.mouse_x/CELL_SIZE).floor
    y = ($window.mouse_y/CELL_SIZE).floor

    @grid[x][y]=true

  end

  def unset_grid_block
    x = ($window.mouse_x/CELL_SIZE).floor
    y = ($window.mouse_y/CELL_SIZE).floor

    @grid[x][y]=false
  end
  def draw_mouse
    $window.fill_rect([($window.mouse_x/CELL_SIZE).floor*CELL_SIZE,($window.mouse_y/CELL_SIZE).floor*CELL_SIZE,CELL_SIZE,CELL_SIZE],0xaa0000ff,0)
  end
end