Add sync queue orchestration and local mutation envelopes

2026-02-15 16:56:55 +01:00
parent aaabc51d2d
commit d711f270dd
8 changed files with 1411 additions and 101 deletions
@@ -0,0 +1,133 @@
+import 'dart:convert';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:relationship_saver/features/sync/sync_state.dart';
+import 'package:relationship_saver/integrations/backend/models/backend_models.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// Persists queued local mutations and sync cursor metadata.
+class SyncQueueRepository extends AsyncNotifier<SyncState> {
+  static const String _storageKey = 'sync_queue_state_v1';
+
+  @override
+  Future<SyncState> build() async {
+    final SharedPreferences prefs = await SharedPreferences.getInstance();
+    final String? raw = prefs.getString(_storageKey);
+    if (raw == null || raw.isEmpty) {
+      return SyncState.empty;
+    }
+
+    try {
+      final Map<String, dynamic> json = jsonDecode(raw) as Map<String, dynamic>;
+      return SyncState.fromJson(json);
+    } on FormatException {
+      await prefs.remove(_storageKey);
+      return SyncState.empty;
+    }
+  }
+
+  Future<void> enqueue(ChangeEnvelope change) async {
+    final SyncState current = await _currentState();
+    final List<ChangeEnvelope> pending = <ChangeEnvelope>[
+      change,
+      ...current.pendingChanges,
+    ];
+    await _setState(current.copyWith(pendingChanges: pending));
+  }
+
+  Future<void> enqueueAll(Iterable<ChangeEnvelope> changes) async {
+    final List<ChangeEnvelope> values = changes.toList(growable: false);
+    if (values.isEmpty) {
+      return;
+    }
+
+    final SyncState current = await _currentState();
+    final List<ChangeEnvelope> pending = <ChangeEnvelope>[
+      ...values,
+      ...current.pendingChanges,
+    ];
+    await _setState(current.copyWith(pendingChanges: pending));
+  }
+
+  Future<void> applyPushResult(SyncPushResult result, {DateTime? at}) async {
+    final SyncState current = await _currentState();
+    final DateTime now = at ?? DateTime.now();
+    final Set<String> completedMutationIds = <String>{
+      ...result.accepted.map((MutationAck ack) => ack.clientMutationId),
+      ...result.rejected.map(
+        (MutationRejection rejection) => rejection.clientMutationId,
+      ),
+    };
+    final List<ChangeEnvelope> pending = current.pendingChanges
+        .where(
+          (ChangeEnvelope change) =>
+              !completedMutationIds.contains(change.clientMutationId),
+        )
+        .toList(growable: false);
+
+    final String? rejectionMessage = result.rejected.isEmpty
+        ? null
+        : 'Push rejected ${result.rejected.length} change(s).';
+
+    await _setState(
+      current.copyWith(
+        cursor: result.cursor,
+        pendingChanges: pending,
+        lastAttemptAt: now,
+        lastSyncAt: now,
+        lastError: rejectionMessage,
+        lastRejected: result.rejected,
+      ),
+    );
+  }
+
+  Future<void> applyPullResult(SyncPullResult result, {DateTime? at}) async {
+    final SyncState current = await _currentState();
+    final DateTime now = at ?? DateTime.now();
+    await _setState(
+      current.copyWith(
+        cursor: result.cursor,
+        lastAttemptAt: now,
+        lastSyncAt: now,
+        lastError: null,
+        lastRejected: const <MutationRejection>[],
+      ),
+    );
+  }
+
+  Future<void> markFailure(Object error, {DateTime? at}) async {
+    final SyncState current = await _currentState();
+    final DateTime now = at ?? DateTime.now();
+    await _setState(current.copyWith(lastAttemptAt: now, lastError: '$error'));
+  }
+
+  Future<void> clearQueue() async {
+    final SyncState current = await _currentState();
+    await _setState(
+      current.copyWith(
+        pendingChanges: const <ChangeEnvelope>[],
+        lastRejected: const <MutationRejection>[],
+      ),
+    );
+  }
+
+  Future<SyncState> _currentState() async {
+    final SyncState? value = state.asData?.value;
+    if (value != null) {
+      return value;
+    }
+    return future;
+  }
+
+  Future<void> _setState(SyncState next) async {
+    state = AsyncData<SyncState>(next);
+    final SharedPreferences prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_storageKey, jsonEncode(next.toJson()));
+  }
+}
+
+final AsyncNotifierProvider<SyncQueueRepository, SyncState>
+syncQueueRepositoryProvider =
+    AsyncNotifierProvider<SyncQueueRepository, SyncState>(
+      SyncQueueRepository.new,
+    );