working on filtering

frontend/lib/provider/quote_provider.dart

@@ -7,17 +7,20 @@ import 'package:frontend/repository/quote_repository.dart';
 
 class QuoteProvider extends ChangeNotifier {
   List<Quote> _quotes = [];
+  List<Quote> _filteredQuotes = [];
   Set<String> _authors = {};
   bool _loading = false;
   String? _error;
 
   List<Quote> get quotes => _quotes;
+  List<Quote> get filteredQuotes => _filteredQuotes;
   Set<String> get authors => _authors;
   bool get loading => _loading;
   String? get error => _error;
 
   final QuoteRepository repo = QuoteRepository();
 
+  int filterBy = 0; // 0 = by author, 1 = by quote
   var filterController = TextEditingController(text: '');
 
   void clearFilterController() {
@@ -35,6 +38,25 @@ class QuoteProvider extends ChangeNotifier {
     }
   }
 
+  void filterQuotes() {
+    _filteredQuotes = [];
+    for (var quote in _quotes) {
+      switch (filterBy) {
+        case 0:
+          if (quote.author.toLowerCase() == filterController.text.toLowerCase()) {
+            _filteredQuotes.add(quote);
+          }
+          break;
+        case 1:
+          if (quote.body.toLowerCase().contains(filterController.text.toLowerCase())) {
+            _filteredQuotes.add(quote);
+          }
+          break;
+      }
+    }
+    notifyListeners();
+  }
+
   Future<void> readQuotes() async {
     _loading = true;
     _error = null;
@@ -42,6 +64,7 @@ class QuoteProvider extends ChangeNotifier {
 
     try {
       _quotes = await repo.readQuotes();
+      _filteredQuotes = _quotes;
     } catch (e) {
       _error = e.toString();
     }