feat: add local backup export import core

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/application/ports.dart

@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import '../domain/domain.dart';
 
 abstract interface class Clock {
@@ -34,6 +36,213 @@ final class TagUsage {
   final int count;
 }
 
+enum LocalBackupImportMode { merge, replaceAll }
+
+enum LocalBackupValidationError {
+  invalidFile,
+  incompatibleFormat,
+  newerVersion,
+  corrupted,
+  activeWorkoutInProgress,
+  importFailedNoMutation,
+}
+
+final class LocalBackupException implements Exception {
+  const LocalBackupException(this.error);
+
+  final LocalBackupValidationError error;
+
+  @override
+  String toString() => error.name;
+}
+
+final class LocalBackupDocument {
+  const LocalBackupDocument({required this.fileName, required this.bytes});
+
+  final String fileName;
+  final Uint8List bytes;
+}
+
+final class LocalBackupCounts {
+  const LocalBackupCounts({
+    required this.exercises,
+    required this.programs,
+    required this.workoutTemplates,
+    required this.workoutHistories,
+    required this.mediaAssets,
+    required this.embeddedMediaFiles,
+  });
+
+  final int exercises;
+  final int programs;
+  final int workoutTemplates;
+  final int workoutHistories;
+  final int mediaAssets;
+  final int embeddedMediaFiles;
+}
+
+final class LocalBackupPreview {
+  const LocalBackupPreview({
+    required this.exportedAt,
+    required this.counts,
+    required this.hasEmbeddedMedia,
+    required this.missingMediaCount,
+    required this.hasNameDuplicates,
+  });
+
+  final DateTime exportedAt;
+  final LocalBackupCounts counts;
+  final bool hasEmbeddedMedia;
+  final int missingMediaCount;
+  final bool hasNameDuplicates;
+}
+
+final class LocalBackupImportResult {
+  const LocalBackupImportResult({
+    required this.insertedCount,
+    required this.updatedCount,
+    required this.ignoredOlderCount,
+    required this.deletedByReplaceCount,
+    required this.missingMediaCount,
+  });
+
+  final int insertedCount;
+  final int updatedCount;
+  final int ignoredOlderCount;
+  final int deletedByReplaceCount;
+  final int missingMediaCount;
+
+  LocalBackupImportResult copyWith({int? missingMediaCount}) {
+    return LocalBackupImportResult(
+      insertedCount: insertedCount,
+      updatedCount: updatedCount,
+      ignoredOlderCount: ignoredOlderCount,
+      deletedByReplaceCount: deletedByReplaceCount,
+      missingMediaCount: missingMediaCount ?? this.missingMediaCount,
+    );
+  }
+}
+
+final class LocalBackupResource {
+  const LocalBackupResource({
+    required this.id,
+    required this.updatedAt,
+    required this.payload,
+  });
+
+  final String id;
+  final DateTime updatedAt;
+  final Map<String, Object?> payload;
+
+  LocalBackupResource copyWith({Map<String, Object?>? payload}) {
+    return LocalBackupResource(
+      id: id,
+      updatedAt: updatedAt,
+      payload: payload ?? this.payload,
+    );
+  }
+}
+
+final class LocalDataExportSnapshot {
+  const LocalDataExportSnapshot({
+    required this.exportedAt,
+    required this.appSchemaVersion,
+    required this.originDeviceId,
+    required this.mediaAssets,
+    required this.exercises,
+    required this.programs,
+    required this.workoutTemplates,
+    required this.workoutHistories,
+    this.mediaFiles = const [],
+  });
+
+  final DateTime exportedAt;
+  final int appSchemaVersion;
+  final String originDeviceId;
+  final List<LocalBackupResource> mediaAssets;
+  final List<LocalBackupResource> exercises;
+  final List<LocalBackupResource> programs;
+  final List<LocalBackupResource> workoutTemplates;
+  final List<LocalBackupResource> workoutHistories;
+  final List<EmbeddedBackupMediaFile> mediaFiles;
+
+  LocalBackupCounts get counts => LocalBackupCounts(
+    exercises: exercises.length,
+    programs: programs.length,
+    workoutTemplates: workoutTemplates.length,
+    workoutHistories: workoutHistories.length,
+    mediaAssets: mediaAssets.length,
+    embeddedMediaFiles: mediaFiles.length,
+  );
+
+  LocalDataExportSnapshot copyWith({
+    List<LocalBackupResource>? mediaAssets,
+    List<EmbeddedBackupMediaFile>? mediaFiles,
+  }) {
+    return LocalDataExportSnapshot(
+      exportedAt: exportedAt,
+      appSchemaVersion: appSchemaVersion,
+      originDeviceId: originDeviceId,
+      mediaAssets: mediaAssets ?? this.mediaAssets,
+      exercises: exercises,
+      programs: programs,
+      workoutTemplates: workoutTemplates,
+      workoutHistories: workoutHistories,
+      mediaFiles: mediaFiles ?? this.mediaFiles,
+    );
+  }
+}
+
+final class EmbeddedBackupMediaFile {
+  const EmbeddedBackupMediaFile({
+    required this.mediaAssetId,
+    required this.role,
+    required this.fileName,
+    required this.mimeType,
+    required this.sizeBytes,
+    required this.base64,
+  });
+
+  final String mediaAssetId;
+  final String role;
+  final String fileName;
+  final String? mimeType;
+  final int sizeBytes;
+  final String base64;
+}
+
+final class RestoredMediaFile {
+  const RestoredMediaFile({
+    required this.mediaAssetId,
+    required this.localUri,
+    required this.sizeBytes,
+  });
+
+  final String mediaAssetId;
+  final String localUri;
+  final int sizeBytes;
+}
+
+abstract interface class LocalDataBackupRepository {
+  Future<LocalDataExportSnapshot> readExportSnapshot(DateTime exportedAt);
+  Future<bool> hasOpenActiveWorkoutSession();
+  Future<bool> hasAnyUserData();
+  Future<LocalBackupImportResult> applyImportSnapshot({
+    required LocalDataExportSnapshot snapshot,
+    required LocalBackupImportMode mode,
+    required DateTime importedAt,
+  });
+}
+
+abstract interface class LocalBackupMediaStore {
+  Future<List<EmbeddedBackupMediaFile>> readEmbeddableFiles(
+    List<LocalBackupResource> mediaAssets,
+  );
+  Future<Map<String, RestoredMediaFile>> restoreEmbeddedFiles(
+    List<EmbeddedBackupMediaFile> files,
+  );
+}
+
 enum ProgressionPeriod { fourWeeks, threeMonths, all }
 
 enum ProgressionMeasure { manualScore, stopwatchScore, reps, time }