feat: Implement message management features including sending, deleting, updating, and reacting to messages

lib/data/models/message.dart

@@ -1,15 +1,81 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+
 class Message {
-  final String text; 
+  final String id;
+  final String text;
   final DateTime timestamp;
   final String senderId;
   final String senderName;
   final String groupId;
+  final Map<String, String> reactions; // userId -> emoji
+  final DateTime? editedAt;
+  final bool isEdited;
 
   Message({
+    this.id = '',
     required this.text,
     required this.timestamp,
     required this.senderId,
     required this.senderName,
     required this.groupId,
+    this.reactions = const {},
+    this.editedAt,
+    this.isEdited = false,
   });
+
+  factory Message.fromFirestore(DocumentSnapshot doc) {
+    final data = doc.data() as Map<String, dynamic>;
+    final timestamp = data['timestamp'] as Timestamp?;
+    final editedAtTimestamp = data['editedAt'] as Timestamp?;
+    final reactionsData = data['reactions'] as Map<String, dynamic>?;
+
+    return Message(
+      id: doc.id,
+      text: data['text'] ?? '',
+      timestamp: timestamp?.toDate() ?? DateTime.now(),
+      senderId: data['senderId'] ?? '',
+      senderName: data['senderName'] ?? 'Anonyme',
+      groupId: data['groupId'] ?? '',
+      reactions: reactionsData?.map((key, value) => MapEntry(key, value.toString())) ?? {},
+      editedAt: editedAtTimestamp?.toDate(),
+      isEdited: data['isEdited'] ?? false,
+    );
+  }
+
+  Map<String, dynamic> toFirestore() {
+    return {
+      'text': text,
+      'senderId': senderId,
+      'senderName': senderName,
+      'timestamp': Timestamp.fromDate(timestamp),
+      'groupId': groupId,
+      'reactions': reactions,
+      'editedAt': editedAt != null ? Timestamp.fromDate(editedAt!) : null,
+      'isEdited': isEdited,
+    };
+  }
+
+  Message copyWith({
+    String? id,
+    String? text,
+    DateTime? timestamp,
+    String? senderId,
+    String? senderName,
+    String? groupId,
+    Map<String, String>? reactions,
+    DateTime? editedAt,
+    bool? isEdited,
+  }) {
+    return Message(
+      id: id ?? this.id,
+      text: text ?? this.text,
+      timestamp: timestamp ?? this.timestamp,
+      senderId: senderId ?? this.senderId,
+      senderName: senderName ?? this.senderName,
+      groupId: groupId ?? this.groupId,
+      reactions: reactions ?? this.reactions,
+      editedAt: editedAt ?? this.editedAt,
+      isEdited: isEdited ?? this.isEdited,
+    );
+  }
 }