module SpriteFactory
  module Style

    #----------------------------------------------------------------------------

    def self.css(selector, name, attributes)
      "#{selector}#{name} { #{css_style(attributes)}; }"
    end

    def self.css_style(attributes)
      attributes.join("; ")
    end

    def self.css_comment(comment)
      return "/*\n#{comment}\n*/"
    end

    def self.retina_style_start
      "@media only screen and (-webkit-min-device-pixel-ratio: 1.5),
only screen and (-moz-min-device-pixel-ratio: 1.5),
only screen and (-o-min-device-pixel-ratio: 3/2),
only screen and (min-device-pixel-ratio: 1.5) {"
    end

    def self.retina_style_end
      "}"
    end

    #----------------------------------------------------------------------------

    def self.scss(selector, name, attributes)
      css(selector, name, attributes) # scss is a superset of css, but we dont actually need any of the extra bits, so just defer to the css generator instead
    end

    def self.scss_style(attributes)
      css_style(attributes)
    end

    def self.scss_comment(comment)
      css_comment(comment)
    end

    #----------------------------------------------------------------------------

    def self.sass(selector, name, attributes)
      "#{selector}#{name}\n" + sass_style(attributes)
    end

    def self.sass_style(attributes)
      attributes.map{|a| "  #{a}"}.join("\n") + "\n"
    end

    def self.sass_comment(comment)
      return "/* #{comment.rstrip} */" # SASS has peculiar indenting requirements in order to recognise closing block comment
    end

    #----------------------------------------------------------------------------

    def self.generate(style_name, selector, url, images, custom_styles, config, max)
      styles = []
      divider = config[:retina] ? 2 : 1
      images.each do |image|
        puts "DIV #{divider}"
        attr = [
          "width: #{image[:cssw] / divider}px",
          "height: #{image[:cssh] / divider}px",
          "background: #{url} #{-image[:cssx] / divider}px #{-image[:cssy] / divider}px no-repeat",
          custom_styles
        ]
        attr << "background-size: #{max[:width]/2}px #{max[:height]/2}px" if config[:retina]
        image[:selector] = selector                          # make selector available for (optional) custom rule generators
        image[:style]    = send("#{style_name}_style", attr) # make pure style available for (optional) custom rule generators (see usage of yield inside Runner#style)
        styles << send(style_name, selector, image[:name].gsub('@2x', ''), attr)
      end
      styles << ""
      styles.join("\n")
    end

    #----------------------------------------------------------------------------

    def self.comment(style_name, comment)
      send("#{style_name}_comment", comment)
    end

    #----------------------------------------------------------------------------

    def self.retina_wrapper_start
      send('retina_style_start')
    end

    def self.retina_wrapper_end
      send('retina_style_end')
    end

  end
end