Implemented way to fetch stations in batches

lib/services/api.dart

@@ -8,7 +8,7 @@ class Api {
   static const String _rootUrl =
       'https://environment.data.gov.uk/flood-monitoring';
 
-  static Future<List<FloodStation>> fetchStations() async {
+  static Future<List<FloodStation>> fetchAllStations() async {
     List<FloodStation> stations = [];
     final response = await http.get(Uri.parse('$_rootUrl/id/stations'));
     if (response.statusCode == 200) {
@@ -20,6 +20,23 @@ class Api {
     return stations;
   }
 
+  /// [limit] limits the number of entries that are requested from the API and [offset] returns the
+  /// list starting from the specified number
+
+  static Future<List<FloodStation>> fetchStationsByRange(
+      int limit, int offset) async {
+    List<FloodStation> stations = [];
+    final response = await http
+        .get(Uri.parse('$_rootUrl/id/stations?_limit=$limit&_offset=$offset'));
+    if (response.statusCode == 200) {
+      final Map<String, dynamic> jsonStr = jsonDecode(response.body);
+      for (final str in jsonStr['items']) {
+        stations.add(FloodStation.fromMap(str));
+      }
+    }
+    return stations;
+  }
+
   static Future<List<Reading>> fetchReadingsFromStation(
       String stationId) async {
     List<Reading> readings = [];

lib/services/flood_station_provider.dart

@@ -4,13 +4,31 @@ import '../model/flood_station.dart';
 import 'api.dart';
 
 class FloodStationProvider extends ChangeNotifier {
-  List<FloodStation> _allStations = [];
   FloodStation? selectedStation;
 
+  List<FloodStation> _allStations = [];
+
   List<FloodStation> get allStations => _allStations;
 
+  Future loadAllStationsInBatches({silent = false}) {
+    int offset = 0;
+    return Future.doWhile(() async {
+      final stations = await Api.fetchStationsByRange(500, offset);
+      if (stations.isNotEmpty) {
+        _allStations.addAll(stations);
+        if (!silent) {
+          notifyListeners();
+        }
+        offset += 500;
+        return true;
+      } else {
+        return false;
+      }
+    });
+  }
+
   Future loadAllStations({silent = false}) {
-    return Api.fetchStations().then(
+    return Api.fetchAllStations().then(
       (value) {
         _allStations = value;
         if (!silent) {