1 files changed, 51 insertions, 0 deletions
diff --git a/lib/gitlab/auth/omniauth_identity_linker_base.rb b/lib/gitlab/auth/omniauth_identity_linker_base.rb
new file mode 100644
index 00000000000..f79ce6bb809
--- /dev/null
+++ b/lib/gitlab/auth/omniauth_identity_linker_base.rb
@@ -0,0 +1,51 @@
+module Gitlab
+  module Auth
+    class OmniauthIdentityLinkerBase
+      attr_reader :current_user, :oauth
+
+      def initialize(current_user, oauth)
+        @current_user = current_user
+        @oauth = oauth
+        @changed = false
+      end
+
+      def link
+        save if identity.new_record?
+      end
+
+      def changed?
+        @changed
+      end
+
+      def failed?
+        error_message.present?
+      end
+
+      def error_message
+        identity.validate
+
+        identity.errors.full_messages.join(', ')
+      end
+
+      private
+
+      def save
+        @changed = identity.save
+      end
+
+      def identity
+        @identity ||= current_user.identities
+                                  .with_extern_uid(provider, uid)
+                                  .first_or_initialize(extern_uid: uid)
+      end
+
+      def provider
+        oauth['provider']
+      end
+
+      def uid
+        oauth['uid']
+      end
+    end
+  end
+end