Initial commit (Security Hardened Slate)

lib/logic/ad_manager.dart

@@ -0,0 +1,153 @@
+import 'dart:async';
+import 'dart:convert';
+import 'package:flutter/foundation.dart';
+import 'package:google_mobile_ads/google_mobile_ads.dart';
+import 'package:paladinvpn/logic/crypto_service.dart';
+import 'package:paladinvpn/logic/hivemind_service.dart';
+import 'package:paladinvpn/logic/app_config.dart';
+
+/// AdManager manages the lifecycle of rewarded video ads.
+/// 
+/// It acts as a strict gatekeeper: users MUST watch an ad to connect.
+/// If an ad is not ready when they click connect, it forces them to wait
+/// while it loads. If they dismiss the ad early, they do not get the connection.
+class AdManager extends ChangeNotifier {
+  RewardedAd? _rewardedAd;
+  
+  bool _isAdLoaded = false;
+  bool get isAdLoaded => _isAdLoaded;
+
+  bool _isAdLoading = false;
+  bool get isAdLoading => _isAdLoading;
+
+  Completer<bool>? _loadCompleter;
+
+  // Google-provided test ad unit
+  static String get _adUnitId => AppConfig.adUnitId;
+
+  AdManager() {
+    _preloadAd();
+  }
+
+  /// Internal helper to load an ad and return a Future when it's ready
+  Future<bool> _preloadAd() async {
+    // If already loaded, return instantly
+    if (_isAdLoaded) return true;
+    
+    // If we're already loading one right now, wait for that same request to finish
+    if (_isAdLoading) return _loadCompleter?.future ?? Future.value(false);
+
+    _isAdLoading = true;
+    _loadCompleter = Completer<bool>();
+    notifyListeners();
+
+    if (kIsWeb) {
+      await Future.delayed(const Duration(milliseconds: 500));
+      _isAdLoaded = true;
+      _isAdLoading = false;
+      notifyListeners();
+      _loadCompleter?.complete(true);
+      return true;
+    }
+
+    RewardedAd.load(
+      adUnitId: _adUnitId,
+      request: const AdRequest(),
+      rewardedAdLoadCallback: RewardedAdLoadCallback(
+        onAdLoaded: (ad) {
+          _rewardedAd = ad;
+          _isAdLoaded = true;
+          _isAdLoading = false;
+          notifyListeners();
+          if (!(_loadCompleter?.isCompleted ?? true)) {
+            _loadCompleter?.complete(true);
+          }
+        },
+        onAdFailedToLoad: (error) {
+          debugPrint('Rewarded ad failed to load: ${error.message}');
+          _isAdLoaded = false;
+          _isAdLoading = false;
+          notifyListeners();
+          if (!(_loadCompleter?.isCompleted ?? true)) {
+            _loadCompleter?.complete(false);
+          }
+        },
+      ),
+    );
+
+    return _loadCompleter!.future;
+  }
+
+  /// Displays the rewarded video ad to the user.
+  Future<bool> showAd(String adType) async {
+    // 1. Ensure the ad is fully loaded before trying to show it
+    if (!_isAdLoaded || _rewardedAd == null) {
+      final loaded = await _preloadAd();
+      if (!loaded || _rewardedAd == null) {
+        debugPrint('[AdManager] Cannot show ad, failed to load.');
+        return false;
+      }
+    }
+
+    // 2. Fetch device credentials for Server-Side Verification (SSV)
+    final deviceId = await CryptoService.getDeviceId();
+    final keys = await CryptoService.getOrCreateKeys();
+    final pubKey = keys['publicKey']!;
+
+    // 3. Attach custom data to the ad so Google sends it back to our Hivemind server
+    _rewardedAd!.serverSideVerificationOptions = ServerSideVerificationOptions(
+      customData: jsonEncode({
+        'device_id': deviceId,
+        'public_key': pubKey,
+        'ad_type': adType,
+      }),
+    );
+
+    Completer<bool> rewardCompleter = Completer<bool>();
+
+    // 4. Setup full screen callbacks to handle dismissal and errors
+    _rewardedAd!.fullScreenContentCallback = FullScreenContentCallback(
+      onAdShowedFullScreenContent: (ad) => debugPrint('[AdManager] Ad showing.'),
+      onAdDismissedFullScreenContent: (ad) {
+        debugPrint('[AdManager] Ad dismissed.');
+        ad.dispose();
+        _isAdLoaded = false;
+        _rewardedAd = null;
+        // Start loading the next ad immediately
+        _preloadAd();
+        if (!rewardCompleter.isCompleted) {
+          rewardCompleter.complete(false); // User closed before earning reward
+        }
+      },
+      onAdFailedToShowFullScreenContent: (ad, error) {
+        debugPrint('[AdManager] Ad failed to show: $error');
+        ad.dispose();
+        _isAdLoaded = false;
+        _rewardedAd = null;
+        if (!rewardCompleter.isCompleted) {
+          rewardCompleter.complete(false);
+        }
+      },
+    );
+
+    // 5. Show the ad
+    await _rewardedAd!.show(
+      onUserEarnedReward: (AdWithoutView ad, RewardItem reward) {
+        debugPrint('[AdManager] Reward earned: ${reward.amount} ${reward.type}');
+        // The SSV callback will hit our server independently. We just need to signal the UI
+        // that the ad was successfully completed.
+        if (!rewardCompleter.isCompleted) {
+          rewardCompleter.complete(true);
+        }
+      },
+    );
+
+    return rewardCompleter.future;
+  }
+
+  @override
+  void dispose() {
+    _rewardedAd?.dispose();
+    super.dispose();
+  }
+}