feat: add equality operators, make history screen paginated, random performance updates

lib/viewmodels/history_view_model.dart

@@ -8,9 +8,16 @@ class HistoryViewModel extends ChangeNotifier {
 
   HistoryViewModel({required this.barTabService});
 
+  static const int _pageSize = 20;
+
   List<ClosedTab> _closedTabs = [];
+  List<String> _customerNames = [];
+  String? _selectedCustomer;
+  int _offset = 0;
+  int _totalCount = 0;
   bool _isLoading = false;
   bool _hasLoaded = false;
+  bool _isLoadingMore = false;
   String? _errorMessage;
   String _searchQuery = '';
 
@@ -26,10 +33,18 @@ class HistoryViewModel extends ChangeNotifier {
         .toList();
   }
 
+  List<String> get customerNames => _customerNames;
+
+  String? get selectedCustomer => _selectedCustomer;
+
   bool get isLoading => _isLoading;
 
   bool get hasLoaded => _hasLoaded;
 
+  bool get isLoadingMore => _isLoadingMore;
+
+  bool get hasMore => _closedTabs.length < _totalCount;
+
   String? get errorMessage => _errorMessage;
 
   Future<void> ensureLoaded() async {
@@ -46,7 +61,18 @@ class HistoryViewModel extends ChangeNotifier {
     notifyListeners();
 
     try {
-      _closedTabs = await barTabService.getClosedTabs();
+      final results = await Future.wait([
+        _fetchPage(offset: 0),
+        barTabService.getClosedTabCount(
+          customerName: _selectedCustomer,
+        ),
+        barTabService.getDistinctCustomerNames(),
+      ]);
+
+      _closedTabs = results[0] as List<ClosedTab>;
+      _totalCount = results[1] as int;
+      _customerNames = results[2] as List<String>;
+      _offset = _closedTabs.length;
     } catch (_) {
       _errorMessage = 'Could not load tab history.';
     } finally {
@@ -56,8 +82,43 @@ class HistoryViewModel extends ChangeNotifier {
     }
   }
 
+  Future<void> loadMore() async {
+    if (_isLoadingMore || !hasMore) return;
+
+    _isLoadingMore = true;
+    notifyListeners();
+
+    try {
+      final more = await _fetchPage(offset: _offset);
+      _closedTabs = [..._closedTabs, ...more];
+      _offset = _closedTabs.length;
+    } catch (_) {
+      _errorMessage = 'Could not load more tabs.';
+    } finally {
+      _isLoadingMore = false;
+      notifyListeners();
+    }
+  }
+
+  Future<List<ClosedTab>> _fetchPage({required int offset}) {
+    return barTabService.getClosedTabsPaginated(
+      limit: _pageSize,
+      offset: offset,
+      customerName: _selectedCustomer,
+    );
+  }
+
   void search(String query) {
     _searchQuery = query;
     notifyListeners();
   }
-}
+
+  Future<void> filterByCustomer(String? customerName) async {
+    _selectedCustomer = customerName;
+    _searchQuery = '';
+    _offset = 0;
+    _closedTabs = [];
+
+    await load();
+  }
+}