frontend compliant with backend

frontend/lib/pages/profile.dart

@@ -9,6 +9,9 @@ class ProfilePage extends StatefulWidget {
 }
 
 class _ProfilePageState extends State<ProfilePage> {
+  Future<UserPreferences> _prefs = loadUserPreferences();
+
+
   @override
   Widget build(BuildContext context) {
     return ListView(
@@ -24,66 +27,82 @@ class _ProfilePageState extends State<ProfilePage> {
           child: Text('Curious traveler', style: TextStyle(fontSize: 24))
         ),
 
-        Padding(padding: EdgeInsets.all(10)),
+        Divider(indent: 25, endIndent: 25, height: 50),
-        Divider(indent: 25, endIndent: 25),
-        Padding(padding: EdgeInsets.all(10)),
 
-        Padding(
+        Center(
-          padding: EdgeInsets.only(left: 10, right: 10, top: 0, bottom: 10),
+          child: Padding(
-          child: Text('Please rate your personal preferences so that we can taylor your experience.', style: TextStyle(fontSize: 18))
+           padding: EdgeInsets.only(left: 10, right: 10, top: 0, bottom: 10),
+            child: Text('For a tailored experience, please rate your discovery preferences.', style: TextStyle(fontSize: 18))
+          ),
         ),
 
-        // Now the sliders
+        FutureBuilder(future: _prefs, builder: futureSliders)
-        ImportanceSliders()
       ]
     );
   }
+
+  Widget futureSliders(BuildContext context, AsyncSnapshot<UserPreferences> snapshot) {
+    if (snapshot.connectionState == ConnectionState.done) {
+      UserPreferences prefs = snapshot.data!;
+
+      return Column(
+        children: [
+          PreferenceSliders(prefs: [prefs.maxTime, prefs.maxDetour]),
+          Divider(indent: 25, endIndent: 25, height: 50),
+          PreferenceSliders(prefs: [prefs.sightseeing, prefs.shopping, prefs.nature])
+        ]
+      );
+    } else {
+      return CircularProgressIndicator();
+    }
+  }
 }
 
 
 
-class ImportanceSliders extends StatefulWidget {
+class PreferenceSliders extends StatefulWidget {
+  final List<SinglePreference> prefs;
+
+  PreferenceSliders({required this.prefs});
 
   @override
-  State<ImportanceSliders> createState() => _ImportanceSlidersState();
+  State<PreferenceSliders> createState() => _PreferenceSlidersState();
 }
 
 
-class _ImportanceSlidersState extends State<ImportanceSliders> {
+class _PreferenceSlidersState extends State<PreferenceSliders> {
-
-  UserPreferences _prefs = UserPreferences();
-
-  List<Card> _createSliders() {
-    List<Card> sliders = [];
-    for (SinglePreference pref in _prefs.preferences) {
-      sliders.add(Card(
-        child: ListTile(
-          leading: pref.icon,
-          title: Text(pref.name),
-          subtitle: Slider(
-            value: pref.value.toDouble(),
-            min: 0,
-            max: 10,
-            divisions: 10,
-            label: pref.value.toString(),
-            onChanged: (double newValue) {
-              setState(() {
-                pref.value = newValue.toInt();
-                _prefs.save();
-              });
-            },
-          )
-        ),
-        margin: const EdgeInsets.only(left: 10, right: 10, top: 10, bottom: 0),
-        shadowColor: Colors.grey,
-      ));
-    }
-    return sliders;
-  }
 
   @override
   Widget build(BuildContext context) {
+    List<Card> sliders = [];
+      for (SinglePreference pref in widget.prefs) {
+      sliders.add(
+        Card(
+          child: ListTile(
+            leading: pref.icon,
+            title: Text(pref.name),
+            subtitle: Slider(
+              value: pref.value.toDouble(),
+              min: pref.minVal.toDouble(),
+              max: pref.maxVal.toDouble(),
+              divisions: pref.maxVal - pref.minVal,
+              label: pref.value.toString(),
+              onChanged: (double newValue) {
+                setState(() {
+                  pref.value = newValue.toInt();
+                  pref.save();
+                });
+              },
+            )
+          ),
+          margin: const EdgeInsets.only(left: 10, right: 10, top: 10, bottom: 0),
+          shadowColor: Colors.grey,
+        )
+      );
+    }
 
-    return Column(children: _createSliders());
+    return Column(
+      children: sliders);
   }
 }
+

frontend/lib/structs/preferences.dart

@@ -3,80 +3,102 @@ import 'package:shared_preferences/shared_preferences.dart';
 
 
 class SinglePreference {
+  String slug;
   String name;
   String description;
   int value;
+  int minVal;
+  int maxVal;
   Icon icon;
-  String key;
 
   SinglePreference({
+    required this.slug,
     required this.name,
     required this.description,
     required this.value,
     required this.icon,
-    required this.key,
+    this.minVal = 0,
+    this.maxVal = 5,
   });
-}
-
-
-class UserPreferences {
-  List<SinglePreference> preferences = [
-    SinglePreference(
-      name: "Sightseeing",
-      description: "How much do you like sightseeing?",
-      value: 0,
-      icon: Icon(Icons.church),
-      key: "sightseeing",
-    ),
-    SinglePreference(
-      name: "Shopping",
-      description: "How much do you like shopping?",
-      value: 0,
-      icon: Icon(Icons.shopping_bag),
-      key: "shopping",
-    ),
-    SinglePreference(
-      name: "Foods & Drinks",
-      description: "How much do you like eating?",
-      value: 0,
-      icon: Icon(Icons.restaurant),
-      key: "eating",
-    ),
-    SinglePreference(
-      name: "Nightlife",
-      description: "How much do you like nightlife?",
-      value: 0,
-      icon: Icon(Icons.wine_bar),
-      key: "nightlife",
-    ),
-    SinglePreference(
-      name: "Nature",
-      description: "How much do you like nature?",
-      value: 0,
-      icon: Icon(Icons.landscape),
-      key: "nature",
-    ),
-    SinglePreference(
-      name: "Culture",
-      description: "How much do you like culture?",
-      value: 0,
-      icon: Icon(Icons.palette),
-      key: "culture",
-    ),
-  ];
-
 
   void save() async {
     SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
-    for (SinglePreference pref in preferences) {
+      sharedPrefs.setInt('pref_$slug', value);
-      sharedPrefs.setInt(pref.key, pref.value);
-    }
   }
 
   void load() async {
     SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
-    for (SinglePreference pref in preferences) {
+      value = sharedPrefs.getInt('pref_$slug') ?? minVal;
-      pref.value = sharedPrefs.getInt(pref.key) ?? 0;
+  }
+}
+
+
+class UserPreferences {
+  SinglePreference sightseeing = SinglePreference(
+    name: "Sightseeing",
+    slug: "sightseeing",
+    description: "How much do you like sightseeing?",
+    value: 0,
+    icon: Icon(Icons.church),
+  );
+  SinglePreference shopping = SinglePreference(
+    name: "Shopping",
+    slug: "shopping",
+    description: "How much do you like shopping?",
+    value: 0,
+    icon: Icon(Icons.shopping_bag),
+  );
+  SinglePreference nature = SinglePreference(
+    name: "Nature",
+    slug: "nature",
+    description: "How much do you like nature?",
+    value: 0,
+    icon: Icon(Icons.landscape),
+  );
+
+  SinglePreference maxTime = SinglePreference(
+    name: "Trip duration",
+    slug: "duration",
+    description: "How long do you want your trip to be?",
+    value: 30,
+    minVal: 30,
+    maxVal: 720,
+    icon: Icon(Icons.timer),
+  );
+  SinglePreference maxDetour = SinglePreference(
+    name: "Trip detours",
+    slug: "detours",
+    description: "Are you okay with roaming even if makes the trip longer?",
+    value: 0,
+    maxVal: 30,
+    icon: Icon(Icons.loupe_sharp),
+  );
+
+
+
+  Future<void> load() async {
+    for (SinglePreference pref in [sightseeing, shopping, nature, maxTime, maxDetour]) {
+      pref.load();
     }
   }
+
+  String 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}
+    }
+    ''';
+  }
+}
+
+
+Future<UserPreferences> loadUserPreferences() async {
+  UserPreferences prefs = UserPreferences();
+  await prefs.load();
+  return prefs;
 }

frontend/lib/utils/fetch_trip.dart

@@ -28,8 +28,8 @@ Future<Trip> fetchTrip(
   final response = await dio.post(
     "/trip/new",
     data: {
-      // 'preferences': preferences.toJson(),
+      'preferences': preferences.toJson(),
-      'start': [48,2.3]
+      'start': startPoint
     }
   );