netoctone/tetris

module Tetris

  class MainWindow < Gosu::Window
    UPDATE_INTERVAL = 75

    CAPTION = 'Tetris'

    def initialize
      super Drawer::WIDTH, Drawer::HEIGHT, false, UPDATE_INTERVAL
      self.caption = CAPTION

      @drawer = Drawer.new(self)

      @shape_store = Shapes::Store.new
      @cur_shape = @shape_store.pick

      @brick_space = BrickSpace.new(Drawer::H_BLOCK_NUM, Drawer::V_BLOCK_NUM)
      @position = ShapePosition.new(@brick_space, -4, 6)
      @cur_shape.position = @position

      @level_manager = LevelManager.new do
        # speed up on level up
        @timer.reduce_periods!
      end

      @timer = Timer.new
      @timer.on_fall do
        relese_completed_rows

        # if shape cannot move
        unless @cur_shape.down
          stop_current_shape
          start_new_shape
        end
      end

      @timer.on_move do
        apply_user_action
      end
    end

    def update
      @timer.tick
    end

    def button_down id
      @last_button = id
    end

    def draw
      @drawer.prepare
      draw_brick_space
      draw_shape
    end

    private

    def draw_brick_space
      @drawer.draw(Drawer::H_BLOCK_NUM, Drawer::V_BLOCK_NUM) do |canvas|
        @brick_space.brick_matrix.each_with_index do |row, y|
          row.each_with_index { |color, x| canvas.(x, y, color) if color }
        end
      end
    end

    def draw_shape
      @drawer.draw(5, 5, offset: @cur_shape.position.to_a) do |canvas|
        @cur_shape.raw_points.each { |y, x| canvas.(x, y, @cur_shape.color) }
      end
    end

    def stop_current_shape
      # make shape points static (migrate points to @brick_space)
      @cur_shape.points.each do |p|
        close if p[0] < 0
        @brick_space.brick_matrix[p[0]][p[1]] = @cur_shape.color
      end

      # paint just completed row(s) with white and remember it
      @completed = @brick_space.paint_filled :white
    end

    def start_new_shape
      # get new shape
      @cur_shape = @shape_store.pick

      # place new shape on top of screen
      @cur_shape.position ||= @position
      @position.reset!
    end

    def relese_completed_rows
      # @completed - one or many completed rows
      if @completed && @completed.size
        @brick_space.delete @completed
        @level_manager.add_score(@completed.size)
        @completed = nil
      end
    end

    def apply_user_action
      pressed = if @last_button
        lambda { |id| @last_button == id }
      else
        lambda { |id| button_down? id }
      end

      if pressed[Gosu::KbLeft] or pressed[Gosu::GpLeft]
        @cur_shape.left
      elsif pressed[Gosu::KbRight] or pressed[Gosu::GpRight]
        @cur_shape.right
      elsif @last_button == Gosu::KbUp or @last_button == Gosu::GpUp
        @cur_shape.rotate
      elsif pressed[Gosu::KbDown] or pressed[Gosu::GpDown]
        @cur_shape.down
      end

      @last_button = nil
    end
  end

end