module Scrivito
  class CmsRestApi
    module AttributeSerializer
      class << self

        def generate_widget_pool_changes(widget_hash)
          widget_pool_changes = {}

          widget_hash.each do |widget, attributes|
            if attributes.present?
              widget_pool_changes[widget.id] =
                self.convert(attributes)
            else # Empty hash or nil
              widget_pool_changes[widget.id] = attributes
            end
          end

          widget_pool_changes
        end

        def convert(attributes)
          Hash[
            attributes.map do |attribute_name, value|
              attribute_name = attribute_name.to_s

              converted_value = if value.nil? || value == []
                nil
              elsif link_array?(value)
                convert_links(value)
              elsif value.is_a?(Link)
                convert_link(value)
              elsif value.is_a?(BasicObj)
                value.id
              elsif widget_array?(value)
                convert_widgets(value)
              elsif obj_array?(value)
                value.map(&:id)
              elsif value.is_a?(Time) || value.is_a?(Date)
                convert_time(value)
              elsif value.is_a?(Array)
                value.map(&:to_s)
              elsif value.is_a?(File)
                Scrivito::CmsRestApi.upload_file(value)
              else
                value.to_s
              end

              [attribute_name, converted_value]
            end
          ]
        end

        def convert_time(point_in_time)
          time_object = if point_in_time.instance_of?(Date)
            point_in_time.to_time
          else
            point_in_time.to_time.utc
          end

          time_object.strftime("%Y%m%d%H%M%S")
        end

        private

        def widget_array?(value)
          value.is_a?(Array) && value.all? do |element|
            element.is_a?(BasicWidget)
          end
        end

        def convert_widgets(value)
          converted_widgets = value.map do |widget|
            { 'widget' => widget.id }
          end

          { 'list' => converted_widgets }
        end

        def link_array?(value)
          value.is_a?(Array) && value.all? do |element|
            element.is_a?(Link)
          end
        end

        def obj_array?(value)
          value.is_a?(Array) && value.all? do |element|
            element.is_a?(BasicObj)
          end
        end

        def convert_links(links)
          links.map do |link|
            convert_link(link)
          end
        end

        def convert_link(link)
          link.to_cms_api_linklist_params
        end
      end
    end
  end
end