functional datastructure. Needs to be able to write to storage as well

frontend/lib/layout.dart

@@ -2,6 +2,7 @@ import 'package:fast_network_navigation/modules/trips_overview.dart';
 import 'package:fast_network_navigation/pages/new_trip.dart';
 import 'package:fast_network_navigation/pages/tutorial.dart';
 import 'package:fast_network_navigation/structs/trip.dart';
+import 'package:fast_network_navigation/utils/load_trips.dart';
 import 'package:flutter/material.dart';
 
 import 'package:fast_network_navigation/pages/overview.dart';
@@ -11,10 +12,13 @@ import 'package:fast_network_navigation/pages/profile.dart';
 // A side drawer is used to switch between pages
 class BasePage extends StatefulWidget {
   final String mainScreen;
-  final String currentMap;
+  final Trip? trip;
-  final List<Trip> trips;
   
-  const BasePage({super.key, required this.mainScreen, this.currentMap = "map", this.trips = const []});
+  const BasePage({
+    super.key,
+    required this.mainScreen,
+    this.trip
+  });
 
   @override
   State<BasePage> createState() => _BasePageState();
@@ -22,12 +26,15 @@ class BasePage extends StatefulWidget {
 
 class _BasePageState extends State<BasePage> {
 
-
   @override
   Widget build(BuildContext context) {
     Widget currentView = const Text("loading...");
+    Future<List<Trip>> trips = loadTrips();
+    Future<Trip> firstTrip = getFirstTrip(trips);
+    // Future<Trip> trip = Future(trips[0]);
+    
     if (widget.mainScreen == "map") {
-      currentView = NavigationOverview();
+      currentView = NavigationOverview(trip: firstTrip);
     } else if (widget.mainScreen == "tutorial") {
       currentView = TutorialPage();
     } else if (widget.mainScreen == "profile") {
@@ -40,9 +47,6 @@ class _BasePageState extends State<BasePage> {
       appBar: AppBar(title: Text("City Nav")),
       body: Center(child: currentView),
       drawer: Drawer(
-        // Add a ListView to the drawer. This ensures the user can scroll
-        // through the options in the drawer if there isn't enough vertical
-        // space to fit everything.
         child: Column(
           children: [
             DrawerHeader(
@@ -61,20 +65,10 @@ class _BasePageState extends State<BasePage> {
               ),
             ),
             ListTile(
-              title: const Text('Start'),
+              title: const Text('Your Trips'),
               leading: const Icon(Icons.map),
               selected: widget.mainScreen == "map",
-              onTap: () {
+              onTap: () {},
-                Navigator.of(context).push(
-                  MaterialPageRoute(
-                    builder: (context) => BasePage(mainScreen: "map")
-                  )
-                );
-              },
-            ),
-            ListTile(
-              title: const Text('Trip Overview'),
-              leading: const Icon(Icons.list),
               trailing: ElevatedButton(
                 onPressed: () {
                   Navigator.of(context).push(
@@ -86,7 +80,23 @@ class _BasePageState extends State<BasePage> {
                 child: const Text('New'),
               ),
             ),
-            Expanded(child: TripsOverview()),
+
+            // Adds a ListView to the drawer. This ensures the user can scroll
+            // through the options in the drawer if there isn't enough vertical
+            // space to fit everything.
+            Expanded(
+              child: TripsOverview(trips: trips),
+            ),
+            ElevatedButton(
+              onPressed: () {
+                Navigator.of(context).push(
+                  MaterialPageRoute(
+                    builder: (context) => const NewTripPage()
+                  )
+                );
+              },
+              child: const Text('Clear trips'),
+            ),
             const Divider(),
             ListTile(
               title: const Text('How to use'),
@@ -101,6 +111,7 @@ class _BasePageState extends State<BasePage> {
               },
             ),
 
+            // settings in the bottom of the drawer
             ListTile(
               title: const Text('Settings'),
               leading: const Icon(Icons.settings),
@@ -113,7 +124,6 @@ class _BasePageState extends State<BasePage> {
                 );
               },
             ),
-            // settings in the bottom of the drawer
           ],
         ),
       ),
@@ -121,3 +131,9 @@ class _BasePageState extends State<BasePage> {
   }
 }
 
+
+
+Future<Trip> getFirstTrip (Future<List<Trip>> trips) async {
+  List<Trip> tripsf = await trips;
+  return tripsf[0];
+}

frontend/lib/main.dart

@@ -17,4 +17,3 @@ class App extends StatelessWidget {
     );
   }
 }
-

frontend/lib/modules/greeter.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 
-Widget Greeter (ThemeData theme, {bool full = false}) {
+Widget Greeter(ThemeData theme, {bool full = false}) {
   String greeterText = "";
   try {
     String cityName = getCityName();

frontend/lib/modules/landmark_card.dart

@@ -32,7 +32,9 @@ class _LandmarkCardState extends State<LandmarkCard> {
               // force a fixed width
               width: 160,
               child: Image.network(
-                widget.landmark.imageURL,
+                widget.landmark.imageURL!,
+                errorBuilder: (context, error, stackTrace) => Icon(Icons.question_mark_outlined),
+                // TODO: make this a switch statement to load a placeholder if null
                 // cover the whole container meaning the image will be cropped
                 fit: BoxFit.cover,
               ),

frontend/lib/modules/landmarks_overview.dart

@@ -1,29 +1,34 @@
+import 'dart:collection';
+
 import 'package:fast_network_navigation/modules/landmark_card.dart';
 import 'package:fast_network_navigation/structs/landmark.dart';
-import 'package:fast_network_navigation/utils/get_landmarks.dart';
+
+import 'package:fast_network_navigation/structs/trip.dart';
 import 'package:flutter/material.dart';
 
 
 
 
-class loadLandmarksOverview extends StatefulWidget {
+class LandmarksOverview extends StatefulWidget {
-  const loadLandmarksOverview({super.key});
+  final Future<Trip>? trip;
+  const LandmarksOverview({super.key, this.trip});
 
   @override
-  State<loadLandmarksOverview> createState() => _loadLandmarksOverviewState();
+  State<LandmarksOverview> createState() => _LandmarksOverviewState();
 }
 
-class _loadLandmarksOverviewState extends State<loadLandmarksOverview> {
+class _LandmarksOverviewState extends State<LandmarksOverview> {
-  final Future<List<Landmark>> _landmarks = fetchLandmarks();
+  // final Future<List<Landmark>> _landmarks = fetchLandmarks();
 
   @override
   Widget build(BuildContext context) {
+    final Future<LinkedList<Landmark>> _landmarks = getLandmarks(widget.trip);
     return DefaultTextStyle(
       style: Theme.of(context).textTheme.displayMedium!,
       textAlign: TextAlign.center,
-      child: FutureBuilder<List<Landmark>>(
+      child: FutureBuilder<LinkedList<Landmark>>(
         future: _landmarks,
-        builder: (BuildContext context, AsyncSnapshot<List<Landmark>> snapshot) {
+        builder: (BuildContext context, AsyncSnapshot<LinkedList<Landmark>> snapshot) {
           List<Widget> children;
           if (snapshot.hasData) {
             children = [landmarksWithSteps(snapshot.data!)];
@@ -42,13 +47,10 @@ class _loadLandmarksOverviewState extends State<loadLandmarksOverview> {
           } else {
             children = [Center(child: CircularProgressIndicator())];
           }
-          return Padding(
+          return Center(
-            padding: const EdgeInsets.all(10),
+            child: Column(
-            child: Center(
+              mainAxisAlignment: MainAxisAlignment.center,
-              child: Column(
+              children: children,
-                mainAxisAlignment: MainAxisAlignment.center,
-                children: children,
-              ),
             ),
           );
         },
@@ -57,12 +59,12 @@ class _loadLandmarksOverviewState extends State<loadLandmarksOverview> {
   }
 }
 
-Widget landmarksWithSteps(List<Landmark> landmarks) {
+Widget landmarksWithSteps(LinkedList<Landmark> landmarks) {
   List<Widget> children = [];
-  for (int i = 0; i < landmarks.length; i++) {
+  for (Landmark landmark in landmarks) {
-    children.add(LandmarkCard(landmarks[i]));
+    children.add(LandmarkCard(landmark));
-    if (i < landmarks.length - 1) {
+    if (landmark.next != null) {
-      Widget step = stepBetweenLandmarks(landmarks[i], landmarks[i + 1]);
+      Widget step = stepBetweenLandmarks(landmark, landmark.next!);
       children.add(step);
     }
   }
@@ -110,3 +112,8 @@ Widget stepBetweenLandmarks(Landmark before, Landmark after) {
     ),
   );
 }
+
+Future<LinkedList<Landmark>> getLandmarks (Future<Trip>? trip) async {
+  Trip tripf = await trip!;
+  return tripf.landmarks;
+}

frontend/lib/modules/map.dart

@@ -1,9 +1,18 @@
+import 'dart:collection';
+
 import 'package:fast_network_navigation/structs/landmark.dart';
-import 'package:fast_network_navigation/utils/get_landmarks.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
 import 'package:flutter/material.dart';
 import 'package:google_maps_flutter/google_maps_flutter.dart';
 
 class MapWidget extends StatefulWidget {
+
+  final Future<Trip>? trip;
+
+  MapWidget({
+    this.trip
+  });
+
   @override
   State<MapWidget> createState() => _MapWidgetState();
 }
@@ -31,7 +40,8 @@ class _MapWidgetState extends State<MapWidget> {
 
   void drawLandmarks() async {
     // (re)draws landmarks on the map
-    List<Landmark> landmarks = await fetchLandmarks();
+    Trip? trip = await widget.trip;
+    LinkedList<Landmark> landmarks = trip!.landmarks;
     setState(() {
       for (Landmark landmark in landmarks) {
         markers.add(Marker(
@@ -55,4 +65,3 @@ class _MapWidgetState extends State<MapWidget> {
     );
   }
 }
-

frontend/lib/modules/trips_overview.dart

@@ -2,19 +2,21 @@ import 'package:flutter/material.dart';
 
 import 'package:fast_network_navigation/layout.dart';
 import 'package:fast_network_navigation/structs/trip.dart';
-import 'package:fast_network_navigation/utils/get_trips.dart';
 
 
 class TripsOverview extends StatefulWidget {
-  
+  final Future<List<Trip>> trips;
-  const TripsOverview({super.key});
+  const TripsOverview({
+    super.key,
+    required this.trips,
+    });
 
   @override
   State<TripsOverview> createState() => _TripsOverviewState();
 }
 
 class _TripsOverviewState extends State<TripsOverview> {
-  final Future<List<Trip>> _trips = loadTrips();
+  // final Future<List<Trip>> _trips = loadTrips();
 
 
   Widget listBuild (BuildContext context, AsyncSnapshot<List<Trip>> snapshot) {
@@ -23,12 +25,12 @@ class _TripsOverviewState extends State<TripsOverview> {
       children = List<Widget>.generate(snapshot.data!.length, (index) {
         Trip trip = snapshot.data![index];
         return ListTile(
-          title: Text("Trip to ${trip.cityName} (${trip.landmarks.length} stops)"),
+          title: Text("Trip to ${trip.cityName}"),
           leading: Icon(Icons.pin_drop),
           onTap: () {
             Navigator.of(context).push(
               MaterialPageRoute(
-                builder: (context) => BasePage(mainScreen: "map") //, trip: trip)
+                builder: (context) => BasePage(mainScreen: "map", trip: trip)
               )
             );
           },
@@ -58,7 +60,7 @@ class _TripsOverviewState extends State<TripsOverview> {
   @override
   Widget build(BuildContext context) {
     return FutureBuilder(
-      future: _trips,
+      future: widget.trips,
       builder: listBuild,
     );
   }

frontend/lib/pages/overview.dart

@@ -1,4 +1,5 @@
 import 'package:fast_network_navigation/modules/greeter.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
 import 'package:flutter/material.dart';
 import 'package:sliding_up_panel/sliding_up_panel.dart';
 
@@ -8,6 +9,12 @@ import 'package:fast_network_navigation/modules/map.dart';
 
 
 class NavigationOverview extends StatefulWidget {
+  final Future<Trip> trip;
+
+  NavigationOverview({
+    required this.trip
+  });
+
   @override
   State<NavigationOverview> createState() => _NavigationOverviewState();
 }
@@ -23,7 +30,7 @@ class _NavigationOverviewState extends State<NavigationOverview> {
         renderPanelSheet: false,
         panel: _floatingPanel(theme),
         collapsed: _floatingCollapsed(theme),
-        body: MapWidget()
+        body: MapWidget(trip: widget.trip)
     );
   }
 
@@ -58,7 +65,7 @@ class _NavigationOverviewState extends State<NavigationOverview> {
           child: Column(
             children: <Widget>[
               Greeter(theme, full: true),
-              loadLandmarksOverview(),
+              LandmarksOverview(trip: widget.trip),
             ],
           ),
         ),

frontend/lib/pages/profile.dart

@@ -51,13 +51,7 @@ class ImportanceSliders extends StatefulWidget {
 
 class _ImportanceSlidersState extends State<ImportanceSliders> {
 
-  final UserPreferences _prefs = UserPreferences();
+  UserPreferences _prefs = UserPreferences();
-
-  @override
-  void initState() {
-    _prefs.load();
-    super.initState();
-  }
 
   List<Card> _createSliders() {
     List<Card> sliders = [];
@@ -89,6 +83,7 @@ class _ImportanceSlidersState extends State<ImportanceSliders> {
 
   @override
   Widget build(BuildContext context) {
+
     return Column(children: _createSliders());
   }
 }

frontend/lib/structs/landmark.dart

@@ -1,56 +1,69 @@
-class Landmark {
+import 'dart:collection';
-  final String name;
+import 'dart:convert';
-  final List location;
-  final LandmarkType type;
-  final String imageURL;
-  // final String description;
-  // final Duration duration;
-  // final bool visited;
 
-  const Landmark({
+import 'package:shared_preferences/shared_preferences.dart';
+
+final class Landmark extends LinkedListEntry<Landmark>{
+  // A linked node of a list of Landmarks
+  final String uuid;
+  final String name;
+  final List<double> location;
+  final LandmarkType type;
+  final bool? isSecondary;
+
+  // description to be shown in the overview
+  final String? imageURL;
+  final String? description;
+  final Duration? duration;
+  final bool? visited;
+
+  // Next node
+  // final Landmark? next;
+  final Duration? tripTime;
+
+  Landmark({
+    required this.uuid,
     required this.name,
     required this.location,
     required this.type,
-    this.imageURL = 'https://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/Tour_Eiffel_Wikimedia_Commons.jpg/1037px-Tour_Eiffel_Wikimedia_Commons.jpg',
+    this.isSecondary,
-    // required this.description,
+
-    // required this.duration,
+    this.imageURL,
-    // required this.visited,
+    this.description,
+    this.duration,
+    this.visited,
+
+    // this.next,
+    this.tripTime,
   });
 
   factory Landmark.fromJson(Map<String, dynamic> json) {
-    return switch (json) {
+    if (json
-      {
+      case { // automatically match all the non-optionals and cast them to the right type
-        'loc': List location,
+        'uuid': String uuid,
         'name': String name,
-        'type': String type,
+        'location': List<double> location,
-        // 'description': String description,
+        'type': LandmarkType type,
-        // 'duration': int duration,
+      }) {
-        // 'visited': bool visited
+        // parse the rest separately, they could be missing
+        final isSecondary = json['is_secondary'] as bool?;
+        final imageURL = json['image_url'] as String?;
+        final description = json['description'] as String?;
+        final duration = json['duration'] as Duration?;
+        final visited = json['visited'] as bool?;
         
-      } =>
+        return Landmark(
-        Landmark(
+          uuid: uuid, name: name, location: location, type: type, isSecondary: isSecondary, imageURL: imageURL, description: description, duration: duration, visited: visited);
-          name: name,
+    } else {
-          location: location,
+      throw FormatException('Invalid JSON: $json');
-          type: LandmarkType(name: type)
+    }
-          // description: description,
-          // duration: Duration(minutes: duration),
-          // visited: visited
-        ),
-      _ => throw const FormatException('Failed to load destination.'),
-    };
   }
 
 
-    Map<String, dynamic> toJson() {
+  @override
-      return {
+  bool operator ==(Object other) {
-        'name': name,
+    return other is Landmark && uuid == other.uuid;
-        'location': location,
+  }
-        'type': type.name,
-        // 'description': description,
-        // 'duration': duration.inMinutes,
-        // 'visited': visited
-      };
-    }
 }
 
 
@@ -67,3 +80,12 @@ class LandmarkType {
 }
 
 
+
+// Helper
+(Landmark, String?) getLandmarkFromPrefs(SharedPreferences prefs, String uuid) {
+  String? content = prefs.getString('landmark_$uuid');
+  Map<String, dynamic> json = jsonDecode(content!);
+  String? nextUUID = json['next_uuid'];
+  return (Landmark.fromJson(json), nextUUID);
+}
+

frontend/lib/structs/linked_landmarks.dart

@@ -0,0 +1,46 @@
+// import "package:fast_network_navigation/structs/landmark.dart";
+
+// class Linked<Landmark> {
+//   Landmark? head;
+  
+//   Linked();
+
+//   // class methods
+//   bool get isEmpty => head == null;
+
+//   // Add a new node to the end of the list
+//   void add(Landmark value) {
+//     if (isEmpty) {
+//       // If the list is empty, set the new node as the head
+//       head = value;
+//     } else {
+//       Landmark? current = head;
+//       while (current!.next != null) {
+//         // Traverse the list to find the last node
+//         current = current.next;
+//       }
+//       current.next = value; // Set the new node as the next node of the last node
+//     }
+//   }
+
+//   // Remove the first node with the given value
+//   void remove(Landmark value) {
+//     if (isEmpty) return;
+
+//     // If the value is in the head node, update the head to the next node
+//     if (head! == value) {
+//       head = head.next;
+//       return;
+//     }
+
+//     var current = head;
+//     while (current!.next != null) {
+//       if (current.next! == value) {
+//         // If the value is found in the next node, skip the next node
+//         current.next = current.next.next;
+//         return;
+//       }
+//       current = current.next;
+//     }
+//   }
+// }

frontend/lib/structs/preferences.dart

@@ -67,16 +67,16 @@ class UserPreferences {
 
 
   void save() async {
-    SharedPreferences prefs = await SharedPreferences.getInstance();
+    SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
     for (SinglePreference pref in preferences) {
-      prefs.setInt(pref.key, pref.value);
+      sharedPrefs.setInt(pref.key, pref.value);
     }
   }
 
   void load() async {
-    SharedPreferences prefs = await SharedPreferences.getInstance();
+    SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
     for (SinglePreference pref in preferences) {
-      pref.value = prefs.getInt(pref.key) ?? 0;
+      pref.value = sharedPrefs.getInt(pref.key) ?? 0;
     }
   }
 }

frontend/lib/structs/trip.dart

@@ -1,25 +1,49 @@
 // Represents a collection of landmarks that represent a journey
 // Different instances of a Trip can be saved and loaded by the user
 
+import 'dart:collection';
+import 'dart:convert';
+
 import 'package:fast_network_navigation/structs/landmark.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class Trip {
   final String uuid;
   final String cityName;
-  final List<Landmark> landmarks;
+  // TODO: cityName should be inferred from coordinates of the Landmarks
+  final LinkedList<Landmark> landmarks;
+  // could be empty as well
 
-
+  Trip({
-  Trip({required this.uuid, required this.cityName, required this.landmarks});
+    required this.uuid,
+    required this.cityName,
+    required this.landmarks,
+    });
 
   factory Trip.fromJson(Map<String, dynamic> json) {
-    List<Landmark> landmarks = [];
-    for (var landmark in json['landmarks']) {
-      landmarks.add(Landmark.fromJson(landmark));
-    }
     return Trip(
       uuid: json['uuid'],
       cityName: json['cityName'],
-      landmarks: landmarks,
+      landmarks: LinkedList()
     );
   }
+
+  factory Trip.fromPrefs(SharedPreferences prefs, String uuid) {
+    String? content = prefs.getString('trip_$uuid');
+    Map<String, dynamic> json = jsonDecode(content!);
+    Trip trip = Trip.fromJson(json);
+    String? firstUUID = json['entry_uuid'];
+    appendLandmarks(trip.landmarks, prefs, firstUUID);
+    return trip;
+  }
+}
+
+// Helper
+
+appendLandmarks(LinkedList<Landmark> landmarks, SharedPreferences prefs, String? firstUUID) {
+  while (firstUUID != null) {
+    var (head, nextUUID) = getLandmarkFromPrefs(prefs, firstUUID);
+    landmarks.add(head);
+    firstUUID = nextUUID;
+  }
 }

frontend/lib/utils/fetch_landmarks.dart

@@ -0,0 +1,52 @@
+// import "package:fast_network_navigation/structs/landmark.dart";
+// import 'package:http/http.dart' as http;
+
+
+// Future<List<Landmark>> fetchLandmarks() async {
+//   // final response = await http
+//   //     .get(Uri.parse('https://nav.kluster.moll.re/v1/destination/1'));
+
+//   // if (response.statusCode == 200) {
+//     // If the server did return a 200 OK response,
+//     // then parse the JSON.
+//     List<Landmark> landmarks = [
+//       // 48°51′29.6″N 2°17′40.2″E
+//       Landmark(
+//         name: "Eiffel Tower",
+//         location: [48.51296, 2.17402],
+//         type: LandmarkType(name: "Tower"),
+//         imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/Tour_Eiffel_Wikimedia_Commons.jpg/1037px-Tour_Eiffel_Wikimedia_Commons.jpg"
+//         ),
+//       Landmark(
+//         name: "Notre Dame Cathedral",
+//         location: [48.8530, 2.3498],
+//         type: LandmarkType(name: "Monument"),
+//         imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Notre-Dame_de_Paris%2C_4_October_2017.jpg/440px-Notre-Dame_de_Paris%2C_4_October_2017.jpg"
+//         ),
+//       Landmark(
+//         name: "Louvre palace",
+//         location: [48.8606, 2.3376],
+//         type: LandmarkType(name: "Museum"),
+//         imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Louvre_Museum_Wikimedia_Commons.jpg/540px-Louvre_Museum_Wikimedia_Commons.jpg"
+//         ),
+//       Landmark(
+//         name: "Pont-des-arts",
+//         location: [48.5130, 2.2015],
+//         type: LandmarkType(name: "Bridge"),
+//         imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Pont_des_Arts%2C_6e_Arrondissement%2C_Paris_%28HDR%29_20140320_1.jpg/560px-Pont_des_Arts%2C_6e_Arrondissement%2C_Paris_%28HDR%29_20140320_1.jpg"),
+//       Landmark(
+//         name: "Panthéon",
+//         location: [48.5046, 2.2046],
+//         type: LandmarkType(name: "Monument"),
+//         imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Pantheon_of_Paris_007.JPG/1280px-Pantheon_of_Paris_007.JPG"
+//         ),
+//     ];
+//     // sleep 10 seconds
+//     await Future.delayed(Duration(seconds: 5));
+//     return landmarks;
+//   // } else {
+//   //   // If the server did not return a 200 OK response,
+//   //   // then throw an exception.
+//   //   throw Exception('Failed to load destination');
+//   // }
+// }

frontend/lib/utils/get_landmarks.dart

@@ -1,52 +0,0 @@
-import "package:fast_network_navigation/structs/landmark.dart";
-import 'package:http/http.dart' as http;
-
-
-Future<List<Landmark>> fetchLandmarks() async {
-  // final response = await http
-  //     .get(Uri.parse('https://nav.kluster.moll.re/v1/destination/1'));
-
-  // if (response.statusCode == 200) {
-    // If the server did return a 200 OK response,
-    // then parse the JSON.
-    List<Landmark> landmarks = [
-      // 48°51′29.6″N 2°17′40.2″E
-      Landmark(
-        name: "Eiffel Tower",
-        location: [48.51296, 2.17402],
-        type: LandmarkType(name: "Tower"),
-        imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/Tour_Eiffel_Wikimedia_Commons.jpg/1037px-Tour_Eiffel_Wikimedia_Commons.jpg"
-        ),
-      Landmark(
-        name: "Notre Dame Cathedral",
-        location: [48.8530, 2.3498],
-        type: LandmarkType(name: "Monument"),
-        imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Notre-Dame_de_Paris%2C_4_October_2017.jpg/440px-Notre-Dame_de_Paris%2C_4_October_2017.jpg"
-        ),
-      Landmark(
-        name: "Louvre palace",
-        location: [48.8606, 2.3376],
-        type: LandmarkType(name: "Museum"),
-        imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Louvre_Museum_Wikimedia_Commons.jpg/540px-Louvre_Museum_Wikimedia_Commons.jpg"
-        ),
-      Landmark(
-        name: "Pont-des-arts",
-        location: [48.5130, 2.2015],
-        type: LandmarkType(name: "Bridge"),
-        imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Pont_des_Arts%2C_6e_Arrondissement%2C_Paris_%28HDR%29_20140320_1.jpg/560px-Pont_des_Arts%2C_6e_Arrondissement%2C_Paris_%28HDR%29_20140320_1.jpg"),
-      Landmark(
-        name: "Panthéon",
-        location: [48.5046, 2.2046],
-        type: LandmarkType(name: "Monument"),
-        imageURL: "https://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Pantheon_of_Paris_007.JPG/1280px-Pantheon_of_Paris_007.JPG"
-        ),
-    ];
-    // sleep 10 seconds
-    await Future.delayed(Duration(seconds: 5));
-    return landmarks;
-  // } else {
-  //   // If the server did not return a 200 OK response,
-  //   // then throw an exception.
-  //   throw Exception('Failed to load destination');
-  // }
-}

frontend/lib/utils/get_trips.dart

@@ -1,37 +0,0 @@
-import 'dart:convert';
-
-import 'package:fast_network_navigation/structs/trip.dart';
-import 'package:fast_network_navigation/structs/landmark.dart';
-import 'package:shared_preferences/shared_preferences.dart';
-
-Future<List<Trip>> loadTrips() async {
-  SharedPreferences prefs = await SharedPreferences.getInstance();
-
-  Set<String> keys = prefs.getKeys();
-  List<Trip> itineraries = [];
-  for (String key in keys) {
-    if (key.startsWith("itinerary_")) {
-      String json = prefs.getString(key)!;
-      itineraries.add(Trip.fromJson(jsonDecode(json)));
-    }
-  }
-  itineraries.add(Trip(uuid: "1", cityName: "Paris", landmarks: [
-      Landmark(name: "Landmark 1", location: [48.85, 2.35], type: LandmarkType(name: "Type 1")),
-      Landmark(name: "Landmark 2", location: [48.86, 2.36], type: LandmarkType(name: "Type 2")),
-      Landmark(name: "Landmark 3", location: [48.75, 2.3], type: LandmarkType(name: "Type 3")),
-      Landmark(name: "Landmark 4", location: [48.9, 2.4], type: LandmarkType(name: "Type 4")),
-      Landmark(name: "Landmark 5", location: [48.91, 2.45], type: LandmarkType(name: "Type 5")),
-    ]));
-  itineraries.add(Trip(uuid: "2", cityName: "Vienna", landmarks: []));
-  itineraries.add(Trip(uuid: "3", cityName: "London", landmarks: []));
-  itineraries.add(Trip(uuid: "4", cityName: "Madrid", landmarks: []));
-  itineraries.add(Trip(uuid: "5", cityName: "Tokyo", landmarks: []));
-  itineraries.add(Trip(uuid: "6", cityName: "New York", landmarks: []));
-  itineraries.add(Trip(uuid: "7", cityName: "Los Angeles", landmarks: []));
-  itineraries.add(Trip(uuid: "8", cityName: "Zurich", landmarks: []));
-  itineraries.add(Trip(uuid: "9", cityName: "Orschwiller", landmarks: []));
-
-  await Future.delayed(Duration(seconds: 3));
-
-  return itineraries;
-}

frontend/lib/utils/load_trips.dart

@@ -0,0 +1,44 @@
+import 'dart:collection';
+
+import 'package:fast_network_navigation/structs/linked_landmarks.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
+import 'package:fast_network_navigation/structs/landmark.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+Future<List<Trip>> loadTrips() async {
+  SharedPreferences prefs = await SharedPreferences.getInstance();
+
+  List<Trip> trips = [];
+  Set<String> keys = prefs.getKeys();
+  for (String key in keys) {
+    if (key.startsWith('trip_')) {
+      String uuid = key.replaceFirst('trip_', '');
+      trips.add(Trip.fromPrefs(prefs, uuid));
+    }
+  }
+
+  if (trips.isEmpty) {
+    String now = DateTime.now().toString();
+    trips.add(
+      Trip(uuid: '1', cityName: 'Paris (generated $now)', landmarks: LinkedList<Landmark>())
+    );
+    //   Trip(uuid: "1", cityName: "Paris", landmarks: [
+    //     Landmark(name: "Landmark 1", location: [48.85, 2.35], type: LandmarkType(name: "Type 1")),
+    //     Landmark(name: "Landmark 2", location: [48.86, 2.36], type: LandmarkType(name: "Type 2")),
+    //     Landmark(name: "Landmark 3", location: [48.75, 2.3], type: LandmarkType(name: "Type 3")),
+    //     Landmark(name: "Landmark 4", location: [48.9, 2.4], type: LandmarkType(name: "Type 4")),
+    //     Landmark(name: "Landmark 5", location: [48.91, 2.45], type: LandmarkType(name: "Type 5")),
+    //   ]));
+    // trips.add(Trip(uuid: "2", cityName: "Vienna", landmarks: []));
+    // trips.add(Trip(uuid: "3", cityName: "London", landmarks: []));
+    // trips.add(Trip(uuid: "4", cityName: "Madrid", landmarks: []));
+    // trips.add(Trip(uuid: "5", cityName: "Tokyo", landmarks: []));
+    // trips.add(Trip(uuid: "6", cityName: "New York", landmarks: []));
+    // trips.add(Trip(uuid: "7", cityName: "Los Angeles", landmarks: []));
+    // trips.add(Trip(uuid: "8", cityName: "Zurich", landmarks: []));
+    // trips.add(Trip(uuid: "9", cityName: "Orschwiller", landmarks: []));
+
+  }
+
+  return trips;
+}