module JsDuck

  # Reads categories info from config file
  class FileCategories
    def initialize(filename, relations)
      @filename = filename
      @relations = relations
    end

    # Parses categories in JSON file
    def generate
      @categories = JsonDuck.read(@filename)

      # Don't crash if old syntax is used.
      if @categories.is_a?(Hash) && @categories["categories"]
        Logger.instance.warn(nil, 'Update categories file to contain just the array inside {"categories": [...]}')
        @categories = @categories["categories"]
      end

      # Perform expansion on all class names containing * wildcard
      @categories.each do |cat|
        cat["groups"].each do |group|
          group["classes"] = group["classes"].map do |name|
            expand(name) # name =~ /\*/ ? expand(name) : name
          end.flatten
        end
      end

      validate

      @categories
    end

    # Expands class name like 'Foo.*' into multiple class names.
    def expand(name)
      re = Regexp.new("^" + name.split(/\*/, -1).map {|part| Regexp.escape(part) }.join('.*') + "$")
      classes = @relations.to_a.find_all {|cls| re =~ cls[:name] && !cls[:private] }.map {|cls| cls[:name] }.sort
      if classes.length == 0
        Logger.instance.warn(:cat_no_match, "No class found matching a pattern '#{name}' in categories file.")
      end
      classes
    end

    # Prints warnings for missing classes in categories file
    def validate
      # Build a map of all classes listed in categories
      listed_classes = {}
      @categories.each do |cat|
        cat["groups"].each do |group|
          group["classes"].each do |cls_name|
            listed_classes[cls_name] = true
          end
        end
      end

      # Check that each existing non-private class is listed
      @relations.each do |cls|
        unless listed_classes[cls[:name]] || cls[:private]
          Logger.instance.warn(:cat_class_missing, "Class '#{cls[:name]}' not found in categories file")
        end
      end
    end
  end

end