Reject incoming QuoteRequest activities (#34480)

app/helpers/context_helper.rb

@@ -25,6 +25,7 @@ module ContextHelper
     voters_count: { 'toot' => 'http://joinmastodon.org/ns#', 'votersCount' => 'toot:votersCount' },
     suspended: { 'toot' => 'http://joinmastodon.org/ns#', 'suspended' => 'toot:suspended' },
     attribution_domains: { 'toot' => 'http://joinmastodon.org/ns#', 'attributionDomains' => { '@id' => 'toot:attributionDomains', '@type' => '@id' } },
+    quote_requests: { 'QuoteRequest' => 'https://w3id.org/fep/044f#QuoteRequest' },
   }.freeze
 
   def full_context

app/lib/activitypub/activity.rb

@@ -57,6 +57,8 @@ class ActivityPub::Activity
         ActivityPub::Activity::Remove
       when 'Move'
         ActivityPub::Activity::Move
+      when 'QuoteRequest'
+        ActivityPub::Activity::QuoteRequest
       end
     end
   end

app/lib/activitypub/activity/quote_request.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::QuoteRequest < ActivityPub::Activity
+  include Payloadable
+
+  def perform
+    return unless Mastodon::Feature.inbound_quotes_enabled?
+    return if non_matching_uri_hosts?(@account.uri, @json['id'])
+
+    quoted_status = status_from_uri(object_uri)
+    return if quoted_status.nil? || !quoted_status.account.local? || !quoted_status.distributable?
+
+    # For now, we don't support being quoted by external servers
+    reject_quote_request!(quoted_status)
+  end
+
+  private
+
+  def reject_quote_request!(quoted_status)
+    quote = Quote.new(
+      quoted_status: quoted_status,
+      quoted_account: quoted_status.account,
+      status: Status.new(account: @account, uri: @json['instrument']),
+      account: @account,
+      activity_uri: @json['id']
+    )
+    json = Oj.dump(serialize_payload(quote, ActivityPub::RejectQuoteRequestSerializer))
+    ActivityPub::DeliveryWorker.perform_async(json, quoted_status.account_id, @account.inbox_url)
+  end
+end

app/serializers/activitypub/quote_request_serializer.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class ActivityPub::QuoteRequestSerializer < ActivityPub::Serializer
+  context_extensions :quote_requests
+
+  attributes :id, :type, :actor, :instrument
+  attribute :virtual_object, key: :object
+
+  def id
+    object.activity_uri || [ActivityPub::TagManager.instance.uri_for(object.target_account), '#quote_requests/', object.id].join
+  end
+
+  def type
+    'QuoteRequest'
+  end
+
+  def actor
+    ActivityPub::TagManager.instance.uri_for(object.account)
+  end
+
+  def virtual_object
+    ActivityPub::TagManager.instance.uri_for(object.quoted_status)
+  end
+
+  def instrument
+    ActivityPub::TagManager.instance.uri_for(object.status)
+  end
+end

app/serializers/activitypub/reject_quote_request_serializer.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class ActivityPub::RejectQuoteRequestSerializer < ActivityPub::Serializer
+  attributes :id, :type, :actor
+
+  has_one :object, serializer: ActivityPub::QuoteRequestSerializer
+
+  def id
+    [ActivityPub::TagManager.instance.uri_for(object.quoted_account), '#rejects/quote_requests/', object.id].join
+  end
+
+  def type
+    'Reject'
+  end
+
+  def actor
+    ActivityPub::TagManager.instance.uri_for(object.quoted_account)
+  end
+end