more cr suggestions

lib/data/models/nostr_event.dart

@@ -1,6 +1,6 @@
 import 'dart:convert';
 import 'package:mostro_mobile/data/models/enums/order_type.dart';
-import 'package:mostro_mobile/data/rating.dart';
+import 'package:mostro_mobile/data/models/rating.dart';
 import 'package:timeago/timeago.dart' as timeago;
 import 'package:dart_nostr/dart_nostr.dart';
 import 'package:mostro_mobile/data/models/order.dart';

lib/data/models/payment_request.dart

@@ -16,31 +16,36 @@ class PaymentRequest implements Content {
       throw ArgumentError('At least one parameter must be provided');
     }
   }
-  
+
   @override
   Map<String, dynamic> toJson() {
     final typeKey = type;
     final List<dynamic> values = [];
-    
+
     values.add(order?.toJson());
     values.add(lnInvoice);
-    
+
     if (amount != null) {
       values.add(amount);
     }
-
-    final result = {
-      typeKey: values
-    };
+
+    final result = {typeKey: values};
 
     return result;
   }
 
   factory PaymentRequest.fromJson(List<dynamic> json) {
+    if (json.length < 2) {
+      throw FormatException('Invalid JSON format: insufficient elements');
+    }
+    final orderJson = json[0];
+    final Order? order = orderJson != null ? Order.fromJson(orderJson) : null;
+    final amount = json.length > 2 ? json[2] as int? : null;
     return PaymentRequest(
-        order: json[0] ?? Order.fromJson(json[0]),
-        lnInvoice: json[1],
-        amount: json[2]);
+      order: order,
+      lnInvoice: json[1],
+      amount: amount,
+    );
   }
 
   @override

lib/data/models/rating.dart

@@ -0,0 +1,73 @@
+import 'dart:convert';
+
+class Rating {
+  final int totalReviews;
+  final double totalRating;
+  final int lastRating;
+  final int maxRate;
+  final int minRate;
+
+  Rating(
+      {required this.totalReviews,
+      required this.totalRating,
+      required this.lastRating,
+      required this.maxRate,
+      required this.minRate});
+
+  factory Rating.deserialized(String data) {
+    if (data.isEmpty) {
+      throw FormatException('Empty data string provided');
+    }
+    if (data == 'none') {
+      return Rating(
+          totalReviews: 0,
+          totalRating: 0.0,
+          lastRating: 0,
+          maxRate: 0,
+          minRate: 0);
+    }
+    try {
+      final json = jsonDecode(data) as Map<String, dynamic>;
+      final rating = json['rating'] as Map<String, dynamic>?;
+
+      if (rating == null) {
+        throw FormatException('Missing rating object in JSON');
+      }
+
+      return Rating(
+        totalReviews: _parseIntField(rating, 'total_reviews'),
+        totalRating: _parseDoubleField(rating, 'total_rating'),
+        lastRating: _parseIntField(rating, 'last_rating'),
+        maxRate: _parseIntField(rating, 'max_rate'),
+        minRate: _parseIntField(rating, 'min_rate'),
+      );
+    } on FormatException {
+      rethrow;
+    } catch (e) {
+      throw FormatException('Failed to parse rating data: $e');
+    }
+  }
+  static int _parseIntField(Map<String, dynamic> json, String field) {
+    final value = json[field];
+    if (value == null) {
+      throw FormatException('Missing required field: $field');
+    }
+    if (value is! num) {
+      throw FormatException(
+          'Invalid type for $field: expected number, got ${value.runtimeType}');
+    }
+    return value.toInt();
+  }
+
+  static double _parseDoubleField(Map<String, dynamic> json, String field) {
+    final value = json[field];
+    if (value == null) {
+      throw FormatException('Missing required field: $field');
+    }
+    if (value is! num) {
+      throw FormatException(
+          'Invalid type for $field: expected number, got ${value.runtimeType}');
+    }
+    return value.toDouble();
+  }
+}