require 'dxopal/sprite/collision_check'
require 'dxopal/sprite/physics'

module DXOpal
  class Sprite
    extend DXOpal::Sprite::CollisionCheck::ClassMethods
    include DXOpal::Sprite::CollisionCheck
    include DXOpal::Sprite::Physics

    # Call #update on each sprite (unless it is vanished or do not have #update)
    def self.update(sprites)
      sprites.each do |sprite|
        next if !sprite.respond_to?(:update)
        next if sprite.respond_to?(:vanished?) && sprite.vanished?
        sprite.update
      end
    end

    # Remove vanished sprites (and nils) from the array, destructively
    def self.clean(sprites)
      sprites.reject!{|sprite|
        sprite.nil? || sprite.vanished?
      }
    end

    # Draw each of the given sprites (unless it is vanished)
    def self.draw(sprites)
      sprites.flatten.sort_by(&:z).each do |sprite|
        next if sprite.respond_to?(:vanished?) && sprite.vanished?
        sprite.draw
      end
    end

    def initialize(x=0, y=0, image=nil)
      @x, @y, @image = x, y, image
      @z = 0
      @angle = 0
      @scale_x = @scale_y = 1.0
      if image
        @center_x = image.width / 2
        @center_y = image.height / 2
      end

      @visible = true
      @vanished = false
      _init_collision_info(@image)
    end
    attr_accessor :z, :visible

    # Set angle (0~360, default: 0)
    attr_accessor :angle
    # Set horizontal/vertical scale (default: 1.0)
    attr_accessor :scale_x, :scale_y
    # Set rotation center (default: center of `image`)
    attr_accessor :center_x, :center_y
    # Set alpha (0~255, default: nil)
    attr_accessor :alpha
    # Set blend type (Any of :alpha(default), :add)
    # (:none, :add2 and :sub are not implemented yet; Pull request is welcome)
    attr_accessor :blend

    attr_reader :x, :y

    def x=(newx)
      @x = newx
      _move_matter_body if @_matter_body
    end

    def y=(newy)
      @y = newy
      _move_matter_body if @_matter_body
    end

    def image; @image; end
    def image=(img)
      @image = img
      if @collision.nil?
        self.collision = [0, 0, img.width-1, img.height-1]
      end
      if @center_x.nil?
        @center_x = img.width / 2
        @center_y = img.height / 2
      end
    end

    def vanish; @vanished = true; end
    def vanished?; @vanished; end

    # Draw this sprite to Window
    def draw
      raise "image not set to Sprite" if @image.nil?
      return if !@visible

      Window.draw_ex(@x, @y, @image,
                     scale_x: @scale_x, scale_y: @scale_y,
                     alpha: @alpha, blend: @blend,
                     angle: @angle, center_x: @center_x, center_y: @center_y)
    end
  end
end