adds syncing

lib/models/supplement.dart

@@ -1,6 +1,10 @@
-import 'ingredient.dart';
 import 'dart:convert';
 
+import 'package:uuid/uuid.dart';
+
+import 'ingredient.dart';
+import 'sync_enums.dart';
+
 class Supplement {
   final int? id;
   final String name;
@@ -14,6 +18,12 @@ class Supplement {
   final DateTime createdAt;
   final bool isActive;
 
+  // Sync metadata
+  final String syncId;
+  final DateTime lastModified;
+  final SyncStatus syncStatus;
+  final bool isDeleted;
+
   Supplement({
     this.id,
     required this.name,
@@ -26,7 +36,12 @@ class Supplement {
     this.notes,
     required this.createdAt,
     this.isActive = true,
-  });
+    String? syncId,
+    DateTime? lastModified,
+    this.syncStatus = SyncStatus.pending,
+    this.isDeleted = false,
+  }) : syncId = syncId ?? const Uuid().v4(),
+       lastModified = lastModified ?? DateTime.now();
 
   // Helper getters
   double get totalDosagePerIntake {
@@ -40,7 +55,7 @@ class Supplement {
     if (ingredients.isEmpty) {
       return 'No ingredients specified';
     }
-    return ingredients.map((ingredient) => 
+    return ingredients.map((ingredient) =>
       '${ingredient.amount * numberOfUnits}${ingredient.unit} ${ingredient.name}'
     ).join(', ');
   }
@@ -66,12 +81,16 @@ class Supplement {
       'notes': notes,
       'createdAt': createdAt.toIso8601String(),
       'isActive': isActive ? 1 : 0,
+      'syncId': syncId,
+      'lastModified': lastModified.toIso8601String(),
+      'syncStatus': syncStatus.name,
+      'isDeleted': isDeleted ? 1 : 0,
     };
   }
 
   factory Supplement.fromMap(Map<String, dynamic> map) {
     List<Ingredient> ingredients = [];
-    
+
     // Try to parse ingredients if they exist
     if (map['ingredients'] != null && map['ingredients'].isNotEmpty) {
       try {
@@ -98,6 +117,17 @@ class Supplement {
       notes: map['notes'],
       createdAt: DateTime.parse(map['createdAt']),
       isActive: map['isActive'] == 1,
+      syncId: map['syncId'] ?? const Uuid().v4(),
+      lastModified: map['lastModified'] != null
+          ? DateTime.parse(map['lastModified'])
+          : DateTime.now(),
+      syncStatus: map['syncStatus'] != null
+          ? SyncStatus.values.firstWhere(
+              (e) => e.name == map['syncStatus'],
+              orElse: () => SyncStatus.pending,
+            )
+          : SyncStatus.pending,
+      isDeleted: (map['isDeleted'] ?? 0) == 1,
     );
   }
 
@@ -113,6 +143,10 @@ class Supplement {
     String? notes,
     DateTime? createdAt,
     bool? isActive,
+    String? syncId,
+    DateTime? lastModified,
+    SyncStatus? syncStatus,
+    bool? isDeleted,
   }) {
     return Supplement(
       id: id ?? this.id,
@@ -126,6 +160,34 @@ class Supplement {
       notes: notes ?? this.notes,
       createdAt: createdAt ?? this.createdAt,
       isActive: isActive ?? this.isActive,
+      syncId: syncId ?? this.syncId,
+      lastModified: lastModified ?? this.lastModified,
+      syncStatus: syncStatus ?? this.syncStatus,
+      isDeleted: isDeleted ?? this.isDeleted,
+    );
+  }
+
+  /// Create a new supplement with updated sync status and timestamp
+  Supplement markAsModified() {
+    return copyWith(
+      lastModified: DateTime.now(),
+      syncStatus: SyncStatus.modified,
+    );
+  }
+
+  /// Create a new supplement marked as synced
+  Supplement markAsSynced() {
+    return copyWith(
+      syncStatus: SyncStatus.synced,
+    );
+  }
+
+  /// Create a new supplement marked for deletion
+  Supplement markAsDeleted() {
+    return copyWith(
+      isDeleted: true,
+      lastModified: DateTime.now(),
+      syncStatus: SyncStatus.modified,
     );
   }
 }