Add experimental basic quote post authoring (#35355)

app/lib/activitypub/activity/accept.rb

@@ -4,10 +4,13 @@ class ActivityPub::Activity::Accept < ActivityPub::Activity
   def perform
     return accept_follow_for_relay if relay_follow?
     return accept_follow!(follow_request_from_object) unless follow_request_from_object.nil?
+    return accept_quote!(quote_request_from_object) unless quote_request_from_object.nil?
 
     case @object['type']
     when 'Follow'
       accept_embedded_follow
+    when 'QuoteRequest'
+      accept_embedded_quote_request
     end
   end
 
@@ -31,6 +34,29 @@ class ActivityPub::Activity::Accept < ActivityPub::Activity
     RemoteAccountRefreshWorker.perform_async(request.target_account_id) if is_first_follow
   end
 
+  def accept_embedded_quote_request
+    approval_uri = value_or_id(first_of_value(@json['result']))
+    return if approval_uri.nil?
+
+    quote = quote_from_request_json(@object)
+    return unless quote.present? && quote.status.local?
+
+    accept_quote!(quote)
+  end
+
+  def accept_quote!(quote)
+    approval_uri = value_or_id(first_of_value(@json['result']))
+    return if unsupported_uri_scheme?(approval_uri) || quote.quoted_account != @account || !quote.status.local?
+
+    # NOTE: we are not going through `ActivityPub::VerifyQuoteService` as the `Accept` is as authoritative
+    # as the stamp, but this means we are not checking the stamp, which may lead to inconsistencies
+    # in case of an implementation bug
+    quote.update!(state: :accepted, approval_uri: approval_uri)
+
+    DistributionWorker.perform_async(quote.status_id, { 'update' => true })
+    ActivityPub::StatusUpdateDistributionWorker.perform_async(quote.status_id, { 'updated_at' => Time.now.utc.iso8601 })
+  end
+
   def accept_follow_for_relay
     relay.update!(state: :accepted)
   end