class window.Parallax
  constructor: (id, layers, params = (->)) ->
    @id     = id
    @canvas = document.getElementById id
    @zindex = params['zindex'] || 0
    @ctx    = @canvas.getContext '2d'
    @layers = []
    @offset = $('#' + @id).offset().left
    @delta  = 600 - 478 # размер полного изображения - размер лайаута
    @sens = params.sensitivity || []


    imgready = 0; # количество загруженных изображений
    for i in layers
      img = new Image();
      img.src = i
      @layers.push img
      img.onload = =>
        imgready++;
        if imgready is layers.length then @render()

    createAvatar = (ava) =>
      img = new Image();
      img.src = ava
      img.onload = =>
        if imgready is layers.length then @render()
      img.onerror = =>
        img.src = "http://www.cheloveche.ru/images/missing/transparents/120.png"
        Notify.append I18n.notify.error.avatar, 'noaction'
      return img
    @avatar = false
    if params.avatar then @avatar = createAvatar(params.avatar)

    @checkParallax()

  updateLayers: (layers) ->
    @layers = []
    imgready = 0; # количество загруженных изображений
    for i in layers
      img = new Image();
      img.src = i
      @layers.push img
      img.onload = =>
        imgready++;
        if imgready is layers.length then @render()


  render: ->
    window.cnv = @canvas
    @canvas.width = @canvas.width;
    delta2 = -Math.round(@delta/2); # половина соотношения - центр
    draw = (x) =>
      nullShift = x-50; # нулевой сдвиг
      @canvas.width = @canvas.width;

      if @avatar && @zindex
        shift = @sens[1];
        avatar = delta2 + nullShift/shift
        @ctx.drawImage @avatar, Math.round(avatar) + 90, 30, 120, 120

      for i, j in @layers
        shift = @sens[j]||(@layers.length - j);
        layerX = delta2 + nullShift/shift
        @ctx.drawImage i, Math.round(layerX), 0, 600, 150

      if @avatar && !@zindex
        shift = @sens[j]||(@layers.length - 1);
        avatar = delta2 + nullShift/shift
        @ctx.drawImage @avatar, Math.round(avatar) + 90, 30, 120, 120

    draw(50);
    $('#' + @id).mousemove (event) =>
      left = Math.round((event.clientX - @offset) / 478 * 100)
      draw(left);

  checkParallax: ->
    @interval = setInterval =>
      if $('#' + @id).length is 0
        @destruct()
    , 1000

  destruct: ->
    p 'Canvas: Remove parallax object of #' + @id
    $('#' + @id).unbind 'mousemove'
    clearInterval @interval
    delete @