feat: add alot

lib/viewmodels/admin_pin_view_model.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/foundation.dart';
 
+import '../models/app_error.dart';
 import '../services/admin_pin_service.dart';
+import '../services/pin_lock_service.dart';
 
 class AdminPinViewModel extends ChangeNotifier {
   final AdminPinService adminPinService;
@@ -11,7 +13,7 @@ class AdminPinViewModel extends ChangeNotifier {
   bool _isUnlocked = false;
   bool _isLoading = false;
   bool _hasLoaded = false;
-  String? _errorMessage;
+  AppError? _error;
 
   bool get isPinSet => _isPinSet;
 
@@ -21,7 +23,7 @@ class AdminPinViewModel extends ChangeNotifier {
 
   bool get hasLoaded => _hasLoaded;
 
-  String? get errorMessage => _errorMessage;
+  AppError? get error => _error;
 
   Future<void> ensureLoaded() async {
     if (_hasLoaded || _isLoading) return;
@@ -33,14 +35,14 @@ class AdminPinViewModel extends ChangeNotifier {
     if (_isLoading) return;
 
     _isLoading = true;
-    _errorMessage = null;
+    _error = null;
     notifyListeners();
 
     try {
       _isPinSet = await adminPinService.hasPin();
     } catch (e) {
       debugPrint('AdminPinViewModel: load error: $e');
-      _errorMessage = 'Could not check PIN status.';
+      _error = AppError.checkPinStatus;
     } finally {
       _hasLoaded = true;
       _isLoading = false;
@@ -49,7 +51,7 @@ class AdminPinViewModel extends ChangeNotifier {
   }
 
   Future<bool> setPin(String pin) async {
-    _errorMessage = null;
+    _error = null;
 
     try {
       await adminPinService.setPin(pin);
@@ -59,14 +61,14 @@ class AdminPinViewModel extends ChangeNotifier {
       return true;
     } catch (e) {
       debugPrint('AdminPinViewModel: setPin error: $e');
-      _errorMessage = 'Could not save PIN.';
+      _error = AppError.savePin;
       notifyListeners();
       return false;
     }
   }
 
   Future<bool> verify(String pin) async {
-    _errorMessage = null;
+    _error = null;
 
     try {
       final matches = await adminPinService.verifyPin(pin);
@@ -77,12 +79,16 @@ class AdminPinViewModel extends ChangeNotifier {
         return true;
       }
 
-      _errorMessage = 'Incorrect PIN.';
+      _error = AppError.incorrectPin;
+      notifyListeners();
+      return false;
+    } on PinLockedOutException {
+      _error = AppError.tooManyPinAttempts;
       notifyListeners();
       return false;
     } catch (e) {
       debugPrint('AdminPinViewModel: verify error: $e');
-      _errorMessage = 'Could not verify PIN.';
+      _error = AppError.verifyPin;
       notifyListeners();
       return false;
     }
@@ -92,17 +98,23 @@ class AdminPinViewModel extends ChangeNotifier {
     required String currentPin,
     required String newPin,
   }) async {
-    final currentMatches = await adminPinService.verifyPin(currentPin);
-
-    if (!currentMatches) {
-      _errorMessage = 'Current PIN is incorrect.';
-      notifyListeners();
-      return false;
-    }
+    if (!await _verifyCurrentPin(currentPin)) return false;
 
     return setPin(newPin);
   }
 
+  Future<bool> _verifyCurrentPin(String pin) async {
+    try {
+      if (await adminPinService.verifyPin(pin)) return true;
+      _error = AppError.currentPinIncorrect;
+    } on PinLockedOutException {
+      _error = AppError.tooManyPinAttempts;
+    }
+
+    notifyListeners();
+    return false;
+  }
+
   void lock() {
     if (!_isUnlocked) return;