Setting up basic API Structure

ac_web/lib/Api/AcApi.dart

@@ -0,0 +1,57 @@
+import 'package:ac_web/Api/ApiClient.dart';
+import 'package:ac_web/Api/ApiConfig.dart';
+import 'package:ac_web/Api/Services/AgentsService.dart';
+import 'package:ac_web/Api/Services/ReportsService.dart';
+import 'package:http/http.dart' as http;
+
+/// Single entry point for the whole Rest API of the Artificial Company backend.
+///
+/// Usage:
+/// ```dart
+/// // once during startup, e.g. in main.dart
+/// AcApi.configure(const ApiConfig(host: '192.168.0.10', port: 5000));
+///
+/// // anywhere in the app
+/// final agents = await AcApi.instance.agents.getAgents();
+/// ```
+class AcApi {
+  AcApi({ApiConfig config = ApiConfig.development, http.Client? httpClient})
+      : mClient = ApiClient(config: config, httpClient: httpClient);
+
+  final ApiClient mClient;
+
+  static AcApi? _instance;
+
+  /// Globally shared instance. Created lazily with [ApiConfig.development] if
+  /// [configure] was not called before.
+  static AcApi get instance => _instance ??= AcApi();
+
+  /// Replaces the shared instance, e.g. during app startup or in tests.
+  static AcApi configure(ApiConfig config, {http.Client? httpClient}) {
+    _instance?.dispose();
+    return _instance = AcApi(config: config, httpClient: httpClient);
+  }
+
+  /// Drops the shared instance. Mainly useful for tests.
+  static void reset() {
+    _instance?.dispose();
+    _instance = null;
+  }
+
+  ApiClient get client => mClient;
+
+  ApiConfig get config => mClient.config;
+
+  AgentsService? _agents;
+  ReportsService? _reports;
+
+  /// `/agents` controller.
+  AgentsService get agents => _agents ??= AgentsService(mClient);
+
+  /// `/reports` controller.
+  ReportsService get reports => _reports ??= ReportsService(mClient);
+
+  void dispose() {
+    mClient.dispose();
+  }
+}