Add support for Link objects in attachment

app/lib/activitypub/activity/create.rb

@@ -44,6 +44,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def process_status
     @tags                 = []
     @mentions             = []
+    @links                = []
     @unresolved_mentions  = []
     @silenced_account_ids = []
     @params               = {}
@@ -72,7 +73,8 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def distribute
     # Spread out crawling randomly to avoid DDoSing the link
-    LinkCrawlWorker.perform_in(rand(1..59).seconds, @status.id)
+    # If there are no links in the attachment property, scan text for links
+    LinkCrawlWorker.perform_in(rand(1..59).seconds, @status.id, @links.first)
 
     # Distribute into home and list feeds and notify mentioned accounts
     ::DistributionWorker.perform_async(@status.id, { 'silenced_account_ids' => @silenced_account_ids }) if @options[:override_timestamps] || @status.within_realtime_window?
@@ -273,6 +275,12 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     media_attachments = []
 
     as_array(@object['attachment']).each do |attachment|
+      if attachment['href'].present?
+        preview_card_parser = ActivityPub::Parser::PreviewCardParser.new(attachment)
+        @links << preview_card_parser.url if preview_card_parser.url.present?
+        next
+      end
+
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
       next if media_attachment_parser.remote_url.blank? || media_attachments.size >= Status::MEDIA_ATTACHMENTS_LIMIT

app/lib/activitypub/parser/preview_card_parser.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class ActivityPub::Parser::PreviewCardParser
+  include JsonLdHelper
+
+  def initialize(json)
+    @json = json
+  end
+
+  # @param [PreviewCard] previous_record
+  def significantly_changes?(previous_record)
+    url != previous_record.url
+  end
+
+  def url
+    url = Addressable::URI.parse(@json['href'])&.normalize&.to_s
+    url unless unsupported_uri_scheme?(url)
+  rescue Addressable::URI::InvalidURIError
+    nil
+  end
+end

app/serializers/activitypub/note_serializer.rb

@@ -135,7 +135,7 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
   end
 
   def virtual_attachments
-    object.ordered_media_attachments
+    object.ordered_media_attachments + [object.preview_card]
   end
 
   def virtual_tags
@@ -253,6 +253,18 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
     }
   end
 
+  class PreviewCardSerializer < ActivityPub::Serializer
+    attributes :type, :href
+
+    def type
+      'Link'
+    end
+
+    def href
+      object.original_url
+    end
+  end
+
   class MediaAttachmentSerializer < ActivityPub::Serializer
     context_extensions :blurhash, :focal_point
 

app/services/activitypub/process_status_update_service.rb

@@ -19,6 +19,8 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
     @quote_changed             = false
     @request_id                = request_id
     @quote                     = nil
+    @next_media_attachments    = []
+    @next_links                = []
 
     # Only native types can be updated at the moment
     return @status if !expected_type? || already_updated_more_recently?
@@ -80,9 +82,14 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
   def update_media_attachments!
     previous_media_attachments     = @status.media_attachments.to_a
     previous_media_attachments_ids = @status.ordered_media_attachment_ids || previous_media_attachments.map(&:id)
-    @next_media_attachments        = []
 
     as_array(@json['attachment']).each do |attachment|
+      if attachment['href'].present?
+        preview_card_parser = ActivityPub::Parser::PreviewCardParser.new(attachment)
+        @next_links << preview_card_parser.url if preview_card_parser.url.present?
+        next
+      end
+
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
       next if media_attachment_parser.remote_url.blank? || @next_media_attachments.size > Status::MEDIA_ATTACHMENTS_LIMIT
@@ -334,7 +341,8 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
 
   def update_counts!
     likes = @status_parser.favourites_count
-    shares =  @status_parser.reblogs_count
+    shares = @status_parser.reblogs_count
+
     return if likes.nil? && shares.nil?
 
     @status.status_stat.tap do |status_stat|
@@ -387,7 +395,7 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
 
   def reset_preview_card!
     @status.reset_preview_card!
-    LinkCrawlWorker.perform_in(rand(1..59).seconds, @status.id)
+    LinkCrawlWorker.perform_in(rand(1..59).seconds, @status.id, @next_links.first)
   end
 
   def broadcast_updates!

app/services/fetch_link_card_service.rb

@@ -15,9 +15,9 @@ class FetchLinkCardService < BaseService
     )
   }iox
 
-  def call(status)
+  def call(status, original_url = nil)
     @status       = status
-    @original_url = parse_urls
+    @original_url = original_url || parse_urls
 
     return if @original_url.nil? || @status.with_preview_card? || @status.with_media? || @status.quote.present?
 

app/workers/link_crawl_worker.rb

@@ -5,8 +5,8 @@ class LinkCrawlWorker
 
   sidekiq_options queue: 'pull', retry: 0
 
-  def perform(status_id)
-    FetchLinkCardService.new.call(Status.find(status_id))
+  def perform(status_id, url = nil)
+    FetchLinkCardService.new.call(Status.find(status_id), url)
   rescue ActiveRecord::RecordNotFound, ActiveRecord::RecordNotUnique
     true
   end