module DynamicSitemaps
  class Generator
    class << self
      def generate
        instance_eval open(DynamicSitemaps.config_path).read
        generate_index
      end

      def generate_index
        IndexGenerator.new(sitemaps).generate
      end

      def sitemap(*args, &block)
        args << {} unless args.last.is_a?(Hash)
        args.last[:host] ||= host
        args.last[:folder] ||= folder
        sitemap = Sitemap.new(*args, &block)
        sitemaps << SitemapGenerator.new(sitemap).generate
      end

      def sitemap_for(collection, options = {}, &block)
        raise "The collection given to `sitemap_for` must respond to #find_each. This is for performance. Use `Model.scoped` to get an ActiveRecord relation that responds to #find_each." unless collection.respond_to?(:find_each)

        name = options.delete(:name) || collection.model_name.underscore.pluralize.to_sym
        options[:collection] = collection

        sitemap(name, options, &block)
      end

      # Array of SitemapResult
      def sitemaps
        @sitemaps ||= []
      end

      def host(*args)
        if args.any?
          @host = args.first
          Rails.application.routes.default_url_options[:host] = @host
        else
          @host
        end
      end

      def folder(*args)
        if args.any?
          @folder = args.first
          raise ArgumentError, "Folder can't be blank." if @folder.blank?

          FileUtils.rm_rf Dir.glob("#{DynamicSitemaps.path}/#{folder}/*")
        else
          # Ensure that the default folder is set and cleaned.
          folder DynamicSitemaps.folder if @folder.blank?

          @folder
        end
      end
    end
  end
end