Feature Pack with bug fixes for V2

lib/services/app_lock_service.dart

@@ -0,0 +1,184 @@
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import 'package:local_auth/local_auth.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// Manages app lock: PIN, biometrics, and two independent lock modes.
+///
+/// Modes (both can be on at the same time):
+/// - **App-wide lock** — shown on cold start (before WebView) and after
+///   background timeout.
+/// - **Messages tab lock** — shown when navigating to Instagram DMs.
+///
+/// Both use the same PIN (stored in secure storage).
+class AppLockService extends ChangeNotifier {
+  static const _pinAppWideKey = 'app_lock_pin_app_wide';
+  static const _pinMessagesKey = 'app_lock_pin_messages';
+  static const _prefAppWide = 'app_lock_app_wide';
+  static const _prefLockMessages = 'app_lock_lock_messages';
+  static const _prefScramble = 'app_lock_scramble_keypad';
+  static const _prefBio = 'app_lock_biometrics_enabled';
+  static const _prefTimeout = 'app_lock_timeout_ms';
+
+  final _secure = const FlutterSecureStorage();
+  final _auth = LocalAuthentication();
+
+  // ─── Mode toggles ──────────────────────────────────────────
+  bool _lockAppWide = false;   // locks the whole app on start / bg timeout
+  bool _lockMessages = false;  // locks only the DMs tab
+
+  // ─── Settings ──────────────────────────────────────────────
+  bool _scramble = false;
+  bool _bioEnabled = true;
+  int _timeoutMs = 120000; // 2 min
+  bool _hasPin = false;
+
+  // ─── Runtime state ─────────────────────────────────────────
+  bool _isShowingLock = false; // true while lock screen is displayed
+  DateTime? _bgAt;
+
+  // ─── Getters ───────────────────────────────────────────────
+  bool get lockAppWide => _lockAppWide;
+  bool get lockMessages => _lockMessages;
+  bool get isShowingLock => _isShowingLock;
+  bool get scrambleKeypad => _scramble;
+  bool get biometricsEnabled => _bioEnabled;
+  bool get hasPin => _hasPin;
+  bool get anyLockEnabled => _lockAppWide || _lockMessages;
+
+  /// Whether the app-wide lock screen should show on cold start.
+  bool get needsUnlockOnStart => _lockAppWide && _hasPin;
+
+  /// Whether the messages tab lock is enabled and can function.
+  bool get messagesLockReady => _lockMessages && _hasPin;
+
+  // ─── Init ──────────────────────────────────────────────────
+  Future<void> init() async {
+    final p = await SharedPreferences.getInstance();
+    _lockAppWide = p.getBool(_prefAppWide) ?? false;
+    _lockMessages = p.getBool(_prefLockMessages) ?? false;
+    _scramble = p.getBool(_prefScramble) ?? false;
+    _bioEnabled = p.getBool(_prefBio) ?? true;
+    _timeoutMs = p.getInt(_prefTimeout) ?? 120000;
+
+    // Check if either PIN exists
+    final hashA = await _secure.read(key: _pinAppWideKey);
+    final hashM = await _secure.read(key: _pinMessagesKey);
+    _hasPin = (hashA != null && hashA.isNotEmpty) ||
+              (hashM != null && hashM.isNotEmpty);
+  }
+
+  // ─── PIN management ────────────────────────────────────────
+  String _hash(String pin) =>
+      utf8.encode('fg_${pin}_salt26')
+          .map((x) => x.toRadixString(16).padLeft(2, '0'))
+          .join();
+
+  /// Set PIN for a specific lock mode.
+  Future<void> setPin(String pin, {required bool forAppWide}) async {
+    final key = forAppWide ? _pinAppWideKey : _pinMessagesKey;
+    await _secure.write(key: key, value: _hash(pin));
+    _hasPin = true;
+    notifyListeners();
+  }
+
+  /// Verify PIN for the given mode.
+  Future<bool> verifyPin(String pin, {required bool forAppWide}) async {
+    final key = forAppWide ? _pinAppWideKey : _pinMessagesKey;
+    final stored = await _secure.read(key: key);
+    return stored != null && stored == _hash(pin);
+  }
+
+  /// Check whether a specific mode has a PIN set.
+  Future<bool> hasPinFor({required bool forAppWide}) async {
+    final key = forAppWide ? _pinAppWideKey : _pinMessagesKey;
+    final hash = await _secure.read(key: key);
+    return hash != null && hash.isNotEmpty;
+  }
+
+  // ─── Toggles ───────────────────────────────────────────────
+  Future<void> setLockAppWide(bool v) async {
+    _lockAppWide = v;
+    (await SharedPreferences.getInstance()).setBool(_prefAppWide, v);
+    if (!v && !_isShowingLock) _isShowingLock = false;
+    notifyListeners();
+  }
+
+  Future<void> setLockMessages(bool v) async {
+    _lockMessages = v;
+    (await SharedPreferences.getInstance()).setBool(_prefLockMessages, v);
+    notifyListeners();
+  }
+
+  Future<void> setScrambleKeypad(bool v) async {
+    _scramble = v;
+    (await SharedPreferences.getInstance()).setBool(_prefScramble, v);
+    notifyListeners();
+  }
+
+  Future<void> setBiometricsEnabled(bool v) async {
+    _bioEnabled = v;
+    (await SharedPreferences.getInstance()).setBool(_prefBio, v);
+    notifyListeners();
+  }
+
+  // ─── Lock / Unlock lifecycle ───────────────────────────────
+
+  /// Call when app-wide lock screen is opened.
+  void onLockScreenShown() {
+    _isShowingLock = true;
+    notifyListeners();
+  }
+
+  /// Call after successful unlock (PIN or biometric).
+  void onUnlocked() {
+    _isShowingLock = false;
+    _bgAt = null;
+    notifyListeners();
+  }
+
+  /// Call when app goes to background.
+  void onBackgrounded() {
+    _bgAt = DateTime.now();
+  }
+
+  /// Whether the app-wide lock should trigger on resume.
+  bool get shouldLockOnResume {
+    if (!_lockAppWide || !_hasPin || _bgAt == null) return false;
+    return DateTime.now().difference(_bgAt!).inMilliseconds >= _timeoutMs;
+  }
+
+  // ─── Biometrics ────────────────────────────────────────────
+  Future<bool> isBiometricsAvailable() async {
+    try {
+      return await _auth.canCheckBiometrics || await _auth.isDeviceSupported();
+    } catch (_) {
+      return false;
+    }
+  }
+
+  Future<bool> authenticateWithBiometrics() async {
+    if (!_bioEnabled) return false;
+    try {
+      return await _auth.authenticate(
+        localizedReason: 'Unlock FocusGram',
+        options: const AuthenticationOptions(
+          biometricOnly: false,
+          stickyAuth: true,
+        ),
+      );
+    } catch (_) {
+      return false;
+    }
+  }
+
+  // ─── Scrambled keypad ──────────────────────────────────────
+  List<int> getScrambledDigits() {
+    final d = List<int>.generate(10, (i) => i);
+    d.shuffle(Random());
+    return d;
+  }
+}