pushDelta method

@override Future<void> pushDelta({ required String collection, required String recordId, required Map<String, dynamic> delta, required int baseVersion, required DateTime timestamp, })

Push delta (partial update) to backend.

Only sends changed fields instead of the entire document, reducing bandwidth by up to 98%.

Parameters:

• collection: Collection name
• recordId: Document ID
• delta: Only the fields that changed
• baseVersion: Version before this update
• timestamp: When the update occurred

If the backend doesn't support delta sync, this should fall back to a regular push() with the full document.

Implementation

@override
Future<void> pushDelta({
  required String collection,
  required String recordId,
  required Map<String, dynamic> delta,
  required int baseVersion,
  required DateTime timestamp,
}) async {
  // Firebase Firestore supports partial updates natively
  // We can use merge: true to only update changed fields
  final updateData = <String, dynamic>{};

  // Prefix each delta field with 'data.' for nested update
  for (final entry in delta.entries) {
    updateData['data.${entry.key}'] = entry.value;
  }

  updateData['updatedAt'] = Timestamp.fromDate(timestamp);
  updateData['version'] = FieldValue.increment(1);

  await firestore.collection(collection).doc(recordId).set(
        updateData,
        SetOptions(merge: true),
      );
}