major refactor

lib/services/api_service.dart

@@ -0,0 +1,106 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+
+typedef TokenProvider = String? Function();
+typedef UnauthorizedHandler = Future<void> Function();
+
+class ApiService {
+  final String baseUrl;
+  TokenProvider? _getToken;
+  UnauthorizedHandler? _onUnauthorized;
+
+  ApiService({required this.baseUrl});
+
+  void setTokenProvider(TokenProvider provider) {
+    _getToken = provider;
+  }
+
+  void setUnauthorizedHandler(UnauthorizedHandler handler) {
+    _onUnauthorized = handler;
+  }
+
+  Map<String, String> _buildHeaders(Map<String, String>? extra) {
+    final token = _getToken?.call();
+    final headers = {'accept': 'application/json', ...?extra};
+    if (token != null && token.isNotEmpty) {
+      headers['Authorization'] = 'Bearer $token';
+    }
+    return headers;
+  }
+
+  Future<dynamic> get(String endpoint, {Map<String, String>? headers}) async {
+    final response = await http.get(
+      Uri.parse('$baseUrl$endpoint'),
+      headers: _buildHeaders(headers),
+    );
+    return _processResponse(response);
+  }
+
+  Future<dynamic> post(
+    String endpoint,
+    dynamic data, {
+    Map<String, String>? headers,
+  }) async {
+    final hasBody = data != null;
+    final response = await http.post(
+      Uri.parse('$baseUrl$endpoint'),
+      headers: _buildHeaders(hasBody ? _jsonHeaders(headers) : headers),
+      body: hasBody ? jsonEncode(data) : null,
+    );
+    return _processResponse(response);
+  }
+
+  Future<dynamic> postForm(String endpoint, Map<String, String> data) async {
+    final response = await http.post(
+      Uri.parse('$baseUrl$endpoint'),
+      headers: _buildHeaders({
+        'Content-Type': 'application/x-www-form-urlencoded',
+        'accept': 'application/json',
+      }),
+      body: data, // http package handles form-encoding for Map<String, String>
+    );
+    return _processResponse(response);
+  }
+
+  Future<dynamic> put(
+    String endpoint,
+    dynamic data, {
+    Map<String, String>? headers,
+  }) async {
+    final hasBody = data != null;
+    final response = await http.put(
+      Uri.parse('$baseUrl$endpoint'),
+      headers: _buildHeaders(hasBody ? _jsonHeaders(headers) : headers),
+      body: hasBody ? jsonEncode(data) : null,
+    );
+    return _processResponse(response);
+  }
+
+  Future<dynamic> delete(
+    String endpoint, {
+    Map<String, String>? headers,
+  }) async {
+    final response = await http.delete(
+      Uri.parse('$baseUrl$endpoint'),
+      headers: _buildHeaders(headers),
+    );
+    return _processResponse(response);
+  }
+
+  Map<String, String> _jsonHeaders(Map<String, String>? extra) {
+    return {'Content-Type': 'application/json', if (extra != null) ...extra};
+  }
+
+  Future<dynamic> _processResponse(http.Response res) async {
+    final body = res.body.isNotEmpty ? jsonDecode(res.body) : null;
+    if (res.statusCode >= 200 && res.statusCode < 300) {
+      return body;
+    }
+
+    if (res.statusCode == 401 && _onUnauthorized != null) {
+      await _onUnauthorized!();
+    }
+
+    throw Exception('API error ${res.statusCode}: $body');
+  }
+}