Initial commit with Flutter and Node.js code

whatsapp_app/lib/models/message_model.dart

@@ -0,0 +1,75 @@
+class MessageModel {
+  final String id;
+  final String body;
+  final bool fromMe;
+  final int timestamp;
+  final String type; // "chat"|"image"|"video"|"audio"|"document"|"sticker"
+  final bool hasMedia;
+  final bool isForwarded;
+  final String? author;
+  final int ack; // 0=error/none 1=pending 2=sent 3=delivered 4=read
+
+  MessageModel({
+    required this.id,
+    required this.body,
+    required this.fromMe,
+    required this.timestamp,
+    required this.type,
+    required this.hasMedia,
+    required this.isForwarded,
+    this.author,
+    required this.ack,
+  });
+
+  factory MessageModel.fromJson(Map<String, dynamic> json) {
+    return MessageModel(
+      id: json['id'] ?? '',
+      body: json['body'] ?? '',
+      fromMe: json['fromMe'] ?? false,
+      timestamp: json['timestamp'] ?? 0,
+      type: json['type'] ?? 'chat',
+      hasMedia: json['hasMedia'] ?? false,
+      isForwarded: json['isForwarded'] ?? false,
+      author: json['author'],
+      ack: json['ack'] ?? 0,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'body': body,
+      'fromMe': fromMe,
+      'timestamp': timestamp,
+      'type': type,
+      'hasMedia': hasMedia,
+      'isForwarded': isForwarded,
+      'author': author,
+      'ack': ack,
+    };
+  }
+
+  MessageModel copyWith({
+    String? id,
+    String? body,
+    bool? fromMe,
+    int? timestamp,
+    String? type,
+    bool? hasMedia,
+    bool? isForwarded,
+    String? author,
+    int? ack,
+  }) {
+    return MessageModel(
+      id: id ?? this.id,
+      body: body ?? this.body,
+      fromMe: fromMe ?? this.fromMe,
+      timestamp: timestamp ?? this.timestamp,
+      type: type ?? this.type,
+      hasMedia: hasMedia ?? this.hasMedia,
+      isForwarded: isForwarded ?? this.isForwarded,
+      author: author ?? this.author,
+      ack: ack ?? this.ack,
+    );
+  }
+}