require 'jsduck/tag_registry'
require 'jsduck/logger'
require 'fileutils'

module JsDuck
  module Web
    class ClassIcons
      class << self
        # Returns CSS class name for an icon of class
        def get(cls)
          class_icon_providers.each do |tag|
            if cls[tag.tagname]
              return "icon-#{tag.tagname}"
            end
          end

          return "icon-class"
        end

        # Generates CSS for class icons
        def css
          css = []
          class_icon_providers.each do |tag|
            css << <<-EOCSS
              #center-container h1.icon-#{tag.tagname} .class-source-link {
                  background-image: url(class-icons/#{tag.tagname}.png);
                  background-repeat: no-repeat;
                  background-size: 42px 42px;
                  background-position: 10px 0; }
              #treecontainer .x-grid-cell-inner .icon-#{tag.tagname} {
                  background: url(class-icons/#{tag.tagname}.png) no-repeat; }
              #search-dropdown .icon-#{tag.tagname} {
                  background: url(class-icons/#{tag.tagname}.png) no-repeat; }
              #search-dropdown .icon-#{tag.tagname}-redirect {
                  background: url(class-icons/#{tag.tagname}-redirect.png) no-repeat; }
              .doctabs .icon-#{tag.tagname} {
                  background: url(class-icons/#{tag.tagname}.png) no-repeat; }
            EOCSS
          end
          css.join("\n")
        end

        # Copies all class icons to given destination dir.
        def write(dir)
          FileUtils.mkdir(dir)

          icons = {}
          class_icon_providers.each do |tag|
            icons[tag.class_icon[:icon]] = "#{dir}/#{tag.tagname}.png"
          end

          icons.each_pair do |source, target|
            if File.exists?(source)
              FileUtils.cp(source, target)
            else
              Logger.warn(nil, "Class icon file not found", {:filename => source})
            end
          end
        end

        private

        def class_icon_providers
          @providers ||= generate_class_icon_providers
        end

        # Find tags with #class_icon and sort them from highest priority to lowest
        def generate_class_icon_providers
          TagRegistry.tags.find_all {|t| t.class_icon }.sort do |a, b|
            a.class_icon[:priority] <=> b.class_icon[:priority]
          end.reverse
        end
      end
    end

  end
end