AngularJS / Firebase Service with offline mobile storage

I need a re-usable AngularJS service developed that integrates with Firebase and implements all CRUD operations. The service must implement an offline storage capability allowing for continued use when the device is used without a network connection. Persisting in LocalStorage is sufficient. When connected, model changes are to be pushed to the firebase server. The service must watch for data change events coming from firebase and update / sync the model accordingly. Sample JSON will be provided to the developer.