Gab Social. All are welcome.

app/services/activitypub/process_collection_service.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+class ActivityPub::ProcessCollectionService < BaseService
+  include JsonLdHelper
+
+  def call(body, account, **options)
+    @account = account
+    @json    = Oj.load(body, mode: :strict)
+    @options = options
+
+    return unless supported_context?
+    return if different_actor? && verify_account!.nil?
+    return if @account.suspended? || @account.local?
+
+    case @json['type']
+    when 'Collection', 'CollectionPage'
+      process_items @json['items']
+    when 'OrderedCollection', 'OrderedCollectionPage'
+      process_items @json['orderedItems']
+    else
+      process_items [@json]
+    end
+  rescue Oj::ParseError
+    nil
+  end
+
+  private
+
+  def different_actor?
+    @json['actor'].present? && value_or_id(@json['actor']) != @account.uri
+  end
+
+  def process_items(items)
+    items.reverse_each.map { |item| process_item(item) }.compact
+  end
+
+  def supported_context?
+    super(@json)
+  end
+
+  def process_item(item)
+    activity = ActivityPub::Activity.factory(item, @account, @options)
+    activity&.perform
+  end
+
+  def verify_account!
+    @options[:relayed_through_account] = @account
+    @account = ActivityPub::LinkedDataSignature.new(@json).verify_account!
+  rescue JSON::LD::JsonLdError => e
+    Rails.logger.debug "Could not verify LD-Signature for #{value_or_id(@json['actor'])}: #{e.message}"
+    nil
+  end
+end