bare implementation of comuncation with the api

frontend/lib/modules/greeter.dart

@@ -20,26 +20,40 @@ class Greeter extends StatefulWidget {
 class _GreeterState extends State<Greeter> {
   Widget greeterBuild (BuildContext context, AsyncSnapshot<Trip> snapshot) {
     ThemeData theme = Theme.of(context);
-    String cityName = "";
+    Widget topGreeter;
     if (snapshot.hasData) {
-      cityName = snapshot.data?.cityName ?? '...';
+      topGreeter = Padding(
+        padding: const EdgeInsets.only(top: 20, bottom: 20),
+        child: Text(
+          'Welcome to ${snapshot.data?.cityName}!',
+          style: TextStyle(color: theme.primaryColor, fontWeight: FontWeight.bold, fontSize: 24),
+        )
+      );
     } else if (snapshot.hasError) {
-      cityName = "error";
-    } else { // still awaiting the cityname
-      cityName = "...";
+      topGreeter = const Padding(
+        padding: EdgeInsets.only(top: 20, bottom: 20),
+        child: Text('Error while fetching trip')
+      );
+    } else {
+      // still awaiting the cityname
+      // Show a linear loader at the bottom and an info message above
+      topGreeter = Column(
+        mainAxisAlignment: MainAxisAlignment.end,
+        children: [
+          Padding(
+            padding: const EdgeInsets.only(top: 20, bottom: 20),
+            child: const Text('Generating your trip...', style: TextStyle(fontSize: 20),)
+          ),
+          const LinearProgressIndicator()
+        ]
+      );
     }
 
-    Widget topGreeter = Text(
-      'Welcome to $cityName!',
-      style: TextStyle(color: theme.primaryColor, fontWeight: FontWeight.bold, fontSize: 24),
-    );
+    
 
     if (widget.standalone) {
       return Center(
-        child: Padding(
-          padding: EdgeInsets.only(top: 24.0),
         child: topGreeter,
-        ),
       );
     } else {
       return Center(

frontend/lib/pages/new_trip.dart

@@ -63,9 +63,8 @@ class _NewTripPageState extends State<NewTripPage> {
                         double.parse(latController.text),
                         double.parse(lonController.text)
                       ];
-                      UserPreferences preferences = UserPreferences();
-                      preferences.load();
-                      Future<Trip> trip = fetchTrip(startPoint, preferences);
+                      Future<UserPreferences> preferences = loadUserPreferences();
+                      Future<Trip>? trip = fetchTrip(startPoint, preferences);
                         Navigator.of(context).push(
                           MaterialPageRoute(
                             builder: (context) => BasePage(mainScreen: "map", trip: trip)

frontend/lib/structs/preferences.dart

@@ -82,17 +82,15 @@ class UserPreferences {
     }
   }
 
-  String toJson() {
+  Map<String, dynamic> toJson() {
       // This is "opinionated" JSON, corresponding to the backend's expectations
-    return '''
-    {
-      "sightseeing": {"type": "sightseeing", "score": ${sightseeing.value}},
-      "shopping": {"type": "shopping", "score": ${shopping.value}},
-      "nature": {"type": "nature", "score": ${nature.value}},
-      "max_time_minutes": ${maxTime.value},
-      "detour_tolerance_minute": ${maxDetour.value}
-    }
-    ''';
+      return {
+        "sightseeing": {"type": "sightseeing", "score": sightseeing.value},
+        "shopping": {"type": "shopping", "score": shopping.value},
+        "nature": {"type": "nature", "score": nature.value},
+        "max_time_minute": maxTime.value,
+        "detour_tolerance_minute": maxDetour.value
+      };
     }
 }
 

frontend/lib/structs/trip.dart

@@ -11,6 +11,7 @@ class Trip {
   final String uuid;
   final String cityName;
   // TODO: cityName should be inferred from coordinates of the Landmarks
+  final int totalTime;
   final LinkedList<Landmark> landmarks;
   // could be empty as well
 
@@ -19,15 +20,18 @@ class Trip {
     required this.uuid,
     required this.cityName,
     required this.landmarks,
+    this.totalTime = 0
   });
 
 
   factory Trip.fromJson(Map<String, dynamic> json) {
-    return Trip(
+    Trip trip = Trip(
       uuid: json['uuid'],
-      cityName: json['city_name'],
+      cityName: json['city_name'] ?? 'Not communicated',
       landmarks: LinkedList()
     );
+
+    return trip;
   }
 
 
@@ -44,7 +48,7 @@ class Trip {
   Map<String, dynamic> toJson() => {
     'uuid': uuid,
     'city_name': cityName,
-    'entry_uuid': landmarks.first?.uuid ?? ''
+    'first_landmark_uuid': landmarks.first.uuid
   };
 
 

frontend/lib/utils/fetch_trip.dart

@@ -1,16 +1,19 @@
+import "dart:convert";
+import "dart:developer";
+
 import 'package:dio/dio.dart';
 import 'package:anyway/constants.dart';
 import "package:anyway/structs/landmark.dart";
 import "package:anyway/structs/trip.dart";
 import "package:anyway/structs/preferences.dart";
 
-import "package:anyway/structs/linked_landmarks.dart";
 
 Dio dio = Dio(
     BaseOptions(
       baseUrl: API_URL_BASE,
+      // baseUrl: 'http://localhost:8000',
       connectTimeout: const Duration(seconds: 5),
-      receiveTimeout: const Duration(seconds: 60),
+      receiveTimeout: const Duration(seconds: 120),
       // api is notoriously slow
       // headers: {
       //   HttpHeaders.userAgentHeader: 'dio',
@@ -18,19 +21,25 @@ Dio dio = Dio(
       // },
       contentType: Headers.jsonContentType,
       responseType: ResponseType.json,
+        
   ),
 );
 
-Future<Trip> fetchTrip(
+Future<Trip>? fetchTrip(
   List<double> startPoint,
-  UserPreferences preferences,
+  Future<UserPreferences> preferences,
 ) async {
+  UserPreferences prefs = await preferences;
+  Map<String, dynamic> data = {
+    "preferences": prefs.toJson(),
+    "start": startPoint
+  };
+  String dataString = jsonEncode(data);
+  log(dataString);
+
   final response = await dio.post(
     "/trip/new",
-    data: {
-      'preferences': preferences.toJson(),
-      'start': startPoint
-    }
+    data: data
   );
 
   // handle errors
@@ -40,6 +49,37 @@ Future<Trip> fetchTrip(
   if (response.data["error"] != null) {
     throw Exception(response.data["error"]);
   }
-  return Trip.fromJson(response.data);
+  log(response.data.toString());
+  Map<String, dynamic> json = response.data;
+
+  // only fetch the trip "meta" data for now
+  Trip trip = Trip.fromJson(json);
+
+  String? nextUUID = json["first_landmark_uuid"];
+  while (nextUUID != null) {
+    var (landmark, newUUID) = await fetchLandmark(nextUUID);
+    trip.landmarks.add(landmark);
+    nextUUID = newUUID;
+  }
+  return trip;
 }
 
+
+
+Future<(Landmark, String?)> fetchLandmark(String uuid) async {
+  final response = await dio.get(
+    "/landmark/$uuid"
+  );
+
+  // handle errors
+  if (response.statusCode != 200) {
+    throw Exception('Failed to load landmark');
+  }
+  if (response.data["error"] != null) {
+    throw Exception(response.data["error"]);
+  }
+  log(response.data.toString());
+  Map<String, dynamic> json = response.data;
+  String? nextUUID = json["next_uuid"];
+  return (Landmark.fromJson(json), nextUUID);
+}