class Middleman::Sitemap::Extensions::OnDisk

def initialize(sitemap)
  @sitemap = sitemap
  @app     = @sitemap.app
  @file_paths_on_disk = Set.new
  scoped_self = self
  @waiting_for_ready = true
  # Register file change callback
  @app.files.changed do |file|
    scoped_self.touch_file(file)
  end
  # Register file delete callback
  @app.files.deleted do |file|
    scoped_self.remove_file(file)
  end
  @app.ready do
    scoped_self.waiting_for_ready = false
    # Make sure the sitemap is ready for the first request
    sitemap.ensure_resource_list_updated!
  end
end

def manipulate_resource_list(resources)
  resources + @file_paths_on_disk.map do |file|
    ::Middleman::Sitemap::Resource.new(
      @sitemap,
      @sitemap.file_to_path(file),
      File.join(@app.root, file)
    )
  end
end

def remove_file(file, rebuild=true)
  if @file_paths_on_disk.delete?(file)
    @sitemap.rebuild_resource_list!(:removed_file)
    unless waiting_for_ready || @app.build?
      # Force sitemap rebuild so the next request is ready to go.
      # Skip this during build because the builder will control sitemap refresh.
      @sitemap.ensure_resource_list_updated!
    end
  end
end

def touch_file(file, rebuild=true)
  return false if File.directory?(file)
  path = @sitemap.file_to_path(file)
  return false unless path
  ignored = @app.config[:ignored_sitemap_matchers].any? do |name, callback|
    if callback.arity == 1
      callback.call(file)
    else
      callback.call(file, @app)
    end
  end
  @file_paths_on_disk << file unless ignored
  # Rebuild the sitemap any time a file is touched
  # in case one of the other manipulators
  # (like asset_hash) cares about the contents of this file,
  # whether or not it belongs in the sitemap (like a partial)
  @sitemap.rebuild_resource_list!(:touched_file)
  unless waiting_for_ready || @app.build?
    # Force sitemap rebuild so the next request is ready to go.
    # Skip this during build because the builder will control sitemap refresh.
    @sitemap.ensure_resource_list_updated!
  end
end