adds syncing

lib/models/sync_enums.dart

@@ -0,0 +1,178 @@
+/// Enumeration for sync status of individual records
+enum SyncStatus {
+  /// Record is newly created and needs to be synced
+  pending,
+
+  /// Record is in sync with remote server
+  synced,
+
+  /// Record has been modified locally and needs to be synced
+  modified,
+
+  /// Record has a conflict that needs resolution
+  conflict,
+
+  /// Record is being synced (temporary state)
+  syncing,
+
+  /// Record sync failed and will be retried
+  failed,
+}
+
+/// Enumeration for overall sync operation status
+enum SyncOperationStatus {
+  /// No sync operation in progress
+  idle,
+
+  /// Currently syncing data
+  syncing,
+
+  /// Last sync completed successfully
+  success,
+
+  /// Last sync failed due to network issues
+  networkError,
+
+  /// Last sync failed due to authentication issues
+  authenticationError,
+
+  /// Last sync failed due to server issues
+  serverError,
+
+  /// Last sync had conflicts that need resolution
+  conflictsDetected,
+
+  /// Sync cancelled by user
+  cancelled,
+}
+
+/// Enumeration for conflict resolution strategies
+enum ConflictResolutionStrategy {
+  /// Always prefer local changes
+  preferLocal,
+
+  /// Always prefer remote changes
+  preferRemote,
+
+  /// Prefer the most recently modified record
+  preferNewer,
+
+  /// Ask user to resolve conflicts manually
+  manual,
+}
+
+/// Enumeration for sync frequency options
+enum SyncFrequency {
+  /// Manual sync only
+  manual,
+
+  /// Sync every 15 minutes
+  every15Minutes,
+
+  /// Sync every hour
+  hourly,
+
+  /// Sync every 6 hours
+  every6Hours,
+
+  /// Sync once per day
+  daily,
+}
+
+/// Extension to get human-readable names for SyncStatus
+extension SyncStatusExtension on SyncStatus {
+  String get displayName {
+    switch (this) {
+      case SyncStatus.pending:
+        return 'Pending Sync';
+      case SyncStatus.synced:
+        return 'Synced';
+      case SyncStatus.modified:
+        return 'Modified';
+      case SyncStatus.conflict:
+        return 'Conflict';
+      case SyncStatus.syncing:
+        return 'Syncing...';
+      case SyncStatus.failed:
+        return 'Sync Failed';
+    }
+  }
+}
+
+/// Extension to get human-readable names for SyncOperationStatus
+extension SyncOperationStatusExtension on SyncOperationStatus {
+  String get displayName {
+    switch (this) {
+      case SyncOperationStatus.idle:
+        return 'Ready';
+      case SyncOperationStatus.syncing:
+        return 'Syncing...';
+      case SyncOperationStatus.success:
+        return 'Sync Complete';
+      case SyncOperationStatus.networkError:
+        return 'Network Error';
+      case SyncOperationStatus.authenticationError:
+        return 'Authentication Failed';
+      case SyncOperationStatus.serverError:
+        return 'Server Error';
+      case SyncOperationStatus.conflictsDetected:
+        return 'Conflicts Detected';
+      case SyncOperationStatus.cancelled:
+        return 'Sync Cancelled';
+    }
+  }
+}
+
+/// Extension to get duration for SyncFrequency
+extension SyncFrequencyExtension on SyncFrequency {
+  Duration get duration {
+    switch (this) {
+      case SyncFrequency.manual:
+        return Duration.zero; // Manual sync only
+      case SyncFrequency.every15Minutes:
+        return const Duration(minutes: 15);
+      case SyncFrequency.hourly:
+        return const Duration(hours: 1);
+      case SyncFrequency.every6Hours:
+        return const Duration(hours: 6);
+      case SyncFrequency.daily:
+        return const Duration(days: 1);
+    }
+  }
+
+  String get displayName {
+    switch (this) {
+      case SyncFrequency.manual:
+        return 'Manual Only';
+      case SyncFrequency.every15Minutes:
+        return 'Every 15 Minutes';
+      case SyncFrequency.hourly:
+        return 'Hourly';
+      case SyncFrequency.every6Hours:
+        return 'Every 6 Hours';
+      case SyncFrequency.daily:
+        return 'Daily';
+    }
+  }
+}
+
+/// Constants for sync operations
+class SyncConstants {
+  static const String syncFileName = 'supplements_sync.json';
+  static const String syncFileBackupName = 'supplements_sync_backup.json';
+  static const int currentSyncVersion = 1;
+  static const int maxRetryAttempts = 3;
+  static const Duration networkTimeout = Duration(seconds: 30);
+  static const Duration conflictResolutionTimeout = Duration(minutes: 5);
+
+  /// Default WebDAV paths for different cloud providers
+  static const String nextcloudWebdavPath = '/remote.php/dav/files/';
+  static const String owncloudWebdavPath = '/remote.php/webdav/';
+
+  /// Supported cloud providers
+  static const List<String> supportedProviders = [
+    'Nextcloud',
+    'ownCloud',
+    'Generic WebDAV',
+  ];
+}