module ImageMosaic
  module Image
    #Takes an array of images and metrics and then returns a single image of composited images.
    class Parent
      def initialize(items, colour:, width:)
        @items = items
        @colour = colour
        @width = width
      end

      def create
        image.run_command(:convert, '-size', dimensions, "xc:#{@colour}", image.path)
        @items.each { |item| @image = add_image(item) }
        Mosaic.new(image)
      end

      private

      def dimensions
        # Parent image is always square for time being.
        "#{@width}x#{@width}"
      end

      def add_image(image)
        Operations::Compositor.new(@image, image).save
      end

      def temp_file
        @temp_file ||= Tempfile.new(['image_mosaic', '.png'])
      end

      def image
        @image ||= MiniMagick::Image.new(temp_file.path)
      end
    end
  end
end