Renamed gui to frontend

frontend/lib/utils/rest_api_utility.dart

@@ -0,0 +1,35 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+
+class RestApiUtility {
+  String _baseUrl;
+
+  RestApiUtility(this._baseUrl);
+
+  void updateBaseURL(String newBaseURL) {
+    _baseUrl = newBaseURL;
+  }
+
+  Future<Map<String, dynamic>> get(String endpoint) async {
+    final response = await http.get(Uri.parse('$_baseUrl/$endpoint'));
+    if (response.statusCode == 200) {
+      return json.decode(response.body);
+    } else {
+      throw Exception('Failed to load data');
+    }
+  }
+
+  Future<Map<String, dynamic>> post(
+      String endpoint, Map<String, dynamic> payload) async {
+    final response = await http.post(
+      Uri.parse('$_baseUrl/$endpoint'),
+      body: json.encode(payload),
+      headers: {"Content-Type": "application/json"},
+    );
+    if (response.statusCode == 200 || response.statusCode == 201) {
+      return json.decode(response.body);
+    } else {
+      throw Exception('Failed to post data');
+    }
+  }
+}