feat: Refactor sync status handling and improve synchronization feedback in the app

lib/data/note_repository.dart

@@ -6,6 +6,7 @@ import 'package:notas/models/note.dart';
 import 'package:notas/models/category.dart';
 
 import 'package:notas/data/note_encryption.dart';
+import 'package:notas/widgets/sync_status.dart';
 
 class NoteRepository {
   NoteRepository({
@@ -89,8 +90,17 @@ class NoteRepository {
 
   /// Sincroniza notas con el servidor.
   /// Requiere que el usuario esté autenticado (token válido).
-  Future<Map<String, dynamic>> performSync({bool forceFull = false}) async {
+  Future<Map<String, dynamic>> performSync({
+    bool forceFull = false,
+    void Function(SyncStatus status, {double? progress, String? message})?
+    onProgress,
+  }) async {
     try {
+      onProgress?.call(
+        SyncStatus.preparing,
+        message: 'Preparando sincronización...',
+      );
+
       // Get last sync timestamp
       final DateTime? lastSync = await _authApi.getLastSyncAt();
       final DateTime? lastSyncForRequest = forceFull
@@ -113,10 +123,21 @@ class NoteRepository {
         );
       }
 
+      final int totalNotesToEncrypt = unsyncedNotes.length;
+
       // Build sync request (note: we send encrypted data, but locally we have plaintext)
       // Encrypt all notes before sending
       final List<SyncNotePayload> encryptedNotesPayload = [];
-      for (final dbNote in unsyncedNotes) {
+      if (totalNotesToEncrypt == 0) {
+        onProgress?.call(
+          SyncStatus.encrypting,
+          progress: 1.0,
+          message: 'No hay notas pendientes de encriptar.',
+        );
+      }
+
+      for (var index = 0; index < unsyncedNotes.length; index += 1) {
+        final DbNote dbNote = unsyncedNotes[index];
         final note = _fromDbNote(dbNote);
         final encryptedTitle = await NoteEncryption.encryptNote(
           note.title,
@@ -133,6 +154,13 @@ class NoteRepository {
             encryptedBody: encryptedBody,
           ),
         );
+
+        onProgress?.call(
+          SyncStatus.encrypting,
+          progress: (index + 1) / totalNotesToEncrypt,
+          message:
+              'Encriptando notas para subir: ${index + 1} de $totalNotesToEncrypt',
+        );
       }
 
       final List<SyncCategoryPayload> categoriesPayload = unsyncedCategories
@@ -148,6 +176,10 @@ class NoteRepository {
       );
 
       // Call sync API
+      onProgress?.call(
+        SyncStatus.uploading,
+        message: 'Subiendo datos al servidor...',
+      );
       final Map<String, dynamic> syncResult = await _authApi.sync(syncRequest);
 
       if (syncResult['error'] == true) {
@@ -157,7 +189,23 @@ class NoteRepository {
       final SyncResponse response = syncResult['data'] as SyncResponse;
 
       // Apply server changes to local database
-      await _applySyncResponse(response);
+      onProgress?.call(
+        SyncStatus.waitingResponse,
+        message: 'Esperando respuesta del servidor...',
+      );
+
+      await _applySyncResponse(
+        response,
+        onDecryptProgress: (int processed, int total) {
+          onProgress?.call(
+            SyncStatus.decrypting,
+            progress: total == 0 ? 1.0 : processed / total,
+            message: total == 0
+                ? 'Desencriptando datos recibidos...'
+                : 'Desencriptando respuesta: $processed de $total',
+          );
+        },
+      );
 
       // Update lastSyncAt
       await _authApi.setLastSyncAt(response.serverTimestamp);
@@ -173,7 +221,10 @@ class NoteRepository {
     }
   }
 
-  Future<void> _applySyncResponse(SyncResponse response) async {
+  Future<void> _applySyncResponse(
+    SyncResponse response, {
+    void Function(int processed, int total)? onDecryptProgress,
+  }) async {
     // Apply categories from server
     for (final SyncCategoryResponse catResponse
         in response.changes.categories) {
@@ -189,7 +240,9 @@ class NoteRepository {
     }
 
     // Apply notes from server
-    for (final SyncNoteResponse noteResponse in response.changes.notes) {
+    final int totalNotesToDecrypt = response.changes.notes.length;
+    for (var index = 0; index < response.changes.notes.length; index += 1) {
+      final SyncNoteResponse noteResponse = response.changes.notes[index];
       final existingNote = await (_database.select(
         _database.notes,
       )..where((n) => n.uuid.equals(noteResponse.id))).getSingleOrNull();
@@ -245,6 +298,8 @@ class NoteRepository {
               ),
             );
       }
+
+      onDecryptProgress?.call(index + 1, totalNotesToDecrypt);
     }
   }