module Scrivito
  class ObjParamsParser < Struct.new(:host, :port, :context)
    class UnknownWidgetAction < ScrivitoError
    end

    def parse(params)
      params = params.deep_dup
      convert_params(params)
      params
    end

    private

    def convert_field_params(params, attribute_definitions)
      params.each_pair do |key, value|
        params[key] = case type = attribute_definitions[key.to_s].try(:type)
          when 'binary'     then parse_binary_params(value)
          when 'html'       then ContentConversion.convert_html_links(value, host, port)
          when 'link'       then ContentConversion.convert_link(value, host, port)
          when 'linklist'   then ContentConversion.convert_linklist_urls(value, host, port)
          when 'widgetlist' then parse_widgetlist_params(value)
          when 'date'       then DateAttribute.deserialize_from_client(value)
          else value
          end
      end
    end

    def parse_widgetlist_params(params)
      params.map do |widget_id_or_params|
        if widget_id_or_params.is_a?(Hash)
          parse_widgetlist_params_with_action(widget_id_or_params)
        else
          widget = obj.widgets[widget_id_or_params]
          raise_widget_not_found_error(widget_id_or_params) unless widget
          widget
        end
      end
    end

    def parse_widgetlist_params_with_action(params)
      action, widget_params = params.flatten
      case action
      when 'create' then Widget.new(widget_params, context.slice(:scrivito_user))
      when 'copy'
        widget_id = widget_params['widget_id']
        widget = Workspace.find(widget_params['workspace_id'])
          .objs.find(widget_params['obj_id'])
          .widgets[widget_id]
        raise_widget_not_found_error(widget_id) unless widget
        widget.copy
      else raise UnknownWidgetAction
      end
    end

    def parse_binary_params(params)
      return unless params

      if params[:copy]
        parse_copy_binary_params(params[:copy])
      else
        UploadedBinary.new(params)
      end
    end

    def parse_copy_binary_params(params)
      obj = Obj.find(params[:obj_id])

      if widget_id = params[:widget_id]
        widget = obj.widgets[widget_id]
        raise_widget_not_found_error(widget_id) unless widget
      end

      if binary = (widget || obj)[params[:attribute_name]]
        binary.copy(params.slice(:filename, :content_type).compact)
      end
    end

    def raise_widget_not_found_error(widget_id)
      raise ResourceNotFound, "Could not find Widget with id #{widget_id}"
    end
  end
end