tenders pagination added

lib/view_models/tenders_view_model.dart

@@ -19,11 +19,13 @@ class TendersViewModel with ChangeNotifier {
   }
 
   bool _isLoading = false;
+  bool _isLoadingMore = false;
   String? _errorMessage;
   TendersResponse? _tendersResponse;
   FeedbackData? _feedbackData;
 
   bool get isLoading => _isLoading;
+  bool get isLoadingMore => _isLoadingMore;
   String? get errorMessage => _errorMessage;
   TendersResponse? get tendersResponse => _tendersResponse;
   FeedbackData? get feedbackData => _feedbackData;
@@ -31,6 +33,11 @@ class TendersViewModel with ChangeNotifier {
   List<FeedbackData> feedbacks = [];
 
   int currentPage = 1;
+  int _currentOffset = 0;
+  static const int _pageSize = 10;
+  bool _hasMoreData = true;
+
+  bool get hasMoreData => _hasMoreData;
 
   /// Get feedback for a specific tender
   FeedbackData? getFeedbackForTender(String tenderId) {
@@ -49,13 +56,24 @@ class TendersViewModel with ChangeNotifier {
   Future<void> getTenders() async {
     _isLoading = true;
     _errorMessage = null;
+    _currentOffset = 0;
+    _hasMoreData = true;
     notifyListeners();
 
-    final result = await _tendersRepository.getTenders();
+    final result = await _tendersRepository.getTenders(
+      limit: _pageSize,
+      offset: _currentOffset,
+    );
     switch (result) {
       case Ok<TendersResponse>():
         _tendersResponse = result.value;
-        getTenderFeedback(_tendersResponse!.data!.tenders!.first.id!);
+        // Check if we have more data
+        if (_tendersResponse?.data?.tenders != null) {
+          _hasMoreData = _tendersResponse!.data!.tenders!.length >= _pageSize;
+        }
+        if (_tendersResponse?.data?.tenders?.isNotEmpty == true) {
+          getTenderFeedback(_tendersResponse!.data!.tenders!.first.id!);
+        }
         break;
       case Error<TendersResponse>():
         _errorMessage = result.error.toString();
@@ -67,6 +85,54 @@ class TendersViewModel with ChangeNotifier {
     notifyListeners();
   }
 
+  Future<void> loadMoreTenders() async {
+    if (_isLoadingMore || !_hasMoreData) return;
+
+    _isLoadingMore = true;
+    _errorMessage = null;
+    notifyListeners();
+
+    _currentOffset += _pageSize;
+    final result = await _tendersRepository.getTenders(
+      limit: _pageSize,
+      offset: _currentOffset,
+    );
+
+    switch (result) {
+      case Ok<TendersResponse>():
+        if (result.value.data?.tenders != null &&
+            result.value.data!.tenders!.isNotEmpty) {
+          // Create a new modifiable list by combining existing and new tenders
+          if (_tendersResponse?.data?.tenders != null) {
+            final existingTenders = _tendersResponse!.data!.tenders!;
+            final newTenders = result.value.data!.tenders!;
+            final combinedTenders = [...existingTenders, ...newTenders];
+
+            // Create a new TendersData with the combined list
+            _tendersResponse = _tendersResponse!.copyWith(
+              data: _tendersResponse!.data!.copyWith(tenders: combinedTenders),
+            );
+          } else {
+            _tendersResponse = result.value;
+          }
+          // Check if we have more data
+          _hasMoreData = result.value.data!.tenders!.length >= _pageSize;
+        } else {
+          _hasMoreData = false;
+        }
+        break;
+      case Error<TendersResponse>():
+        _errorMessage = result.error.toString();
+        _currentOffset -= _pageSize; // Revert offset on error
+        break;
+    }
+
+    _isLoadingMore = false;
+    notifyListeners();
+    _errorMessage = null;
+    notifyListeners();
+  }
+
   Future<void> getTenderFeedback(String tenderId) async {
     // _isLoading = true;
     _errorMessage = null;