chore(wip): upgrade dependencies, begin refactor

frontend/lib/old/structs/landmark.dart

@@ -0,0 +1,172 @@
+import 'dart:collection';
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+LandmarkType typeSightseeing = LandmarkType(name: 'sightseeing');
+LandmarkType typeNature = LandmarkType(name: 'nature');
+LandmarkType typeShopping = LandmarkType(name: 'shopping');
+// LandmarkType museum = LandmarkType(name: 'Museum');
+// LandmarkType restaurant = LandmarkType(name: 'Restaurant');
+LandmarkType typeStart = LandmarkType(name: 'start');
+LandmarkType typeFinish = LandmarkType(name: 'finish');
+
+
+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? nameEN;
+  final String? websiteURL;
+  String? imageURL; // not final because it can be patched
+  final String? description;
+  final Duration? duration;
+  bool visited;
+
+  // Next node is implicitly available through the LinkedListEntry mixin
+  // final Landmark? next;
+  Duration? tripTime;
+  // the trip time depends on the next landmark, so it is not final
+
+
+  Landmark({
+    required this.uuid,
+    required this.name,
+    required this.location,
+    required this.type,
+    this.isSecondary,
+
+    this.nameEN,
+    this.websiteURL,
+    this.imageURL,
+    this.description,
+    this.duration,
+    this.visited = false,
+
+    // this.next,
+    this.tripTime,
+  });
+
+
+  factory Landmark.fromJson(Map<String, dynamic> json) {
+    if (json
+      case { // automatically match all the non-optionals and cast them to the right type
+        'uuid': String uuid,
+        'name': String name,
+        'location': List<dynamic> location,
+        'type': String type,
+      }) {
+      // refine the parsing on a few fields
+      List<double> locationFixed = List<double>.from(location);
+      // parse the rest separately, they could be missing
+      LandmarkType typeFixed = LandmarkType(name: type);
+      final isSecondary = json['is_secondary'] as bool?;
+      final nameEN = json['name_en'] as String?;
+      final websiteURL = json['website_url'] as String?;
+      final imageURL = json['image_url'] as String?;
+      final description = json['description'] as String?;
+      var duration = Duration(minutes: json['duration']);
+      final visited = json['visited'] ?? false;
+      var tripTime = Duration(minutes: json['time_to_reach_next'] ?? 0) as Duration?;
+
+      return Landmark(
+        uuid: uuid,
+        name: name,
+        location: locationFixed,
+        type: typeFixed,
+        isSecondary: isSecondary,
+        nameEN: nameEN,
+        websiteURL: websiteURL,
+        imageURL: imageURL,
+        description: description,
+        duration: duration,
+        visited: visited,
+        tripTime: tripTime
+      );
+    } else {
+      throw FormatException('Invalid JSON: $json');
+    }
+  }
+
+
+  @override
+  bool operator ==(Object other) {
+    return other is Landmark && uuid == other.uuid;
+  }
+
+
+  Map<String, dynamic> toJson() => {
+    'uuid': uuid,
+    'name': name,
+    'location': location,
+    'type': type.name,
+    'is_secondary': isSecondary,
+    'name_en': nameEN,
+    'website_url': websiteURL,
+    'image_url': imageURL,
+    'description': description,
+    'duration': duration?.inMinutes,
+    'visited': visited,
+    'trip_time': tripTime?.inMinutes,
+  };
+}
+
+
+class LandmarkType {
+  final String name;
+  // final String description;
+  Icon icon;
+  
+  LandmarkType({required this.name, this.icon = const Icon(Icons.location_on)}) {
+    switch (name) {
+      case 'sightseeing':
+        icon = const Icon(Icons.castle);
+        break;
+      case 'nature':
+        icon = const Icon(Icons.eco);
+        break;
+      case 'shopping':
+        icon = const Icon(Icons.shopping_cart);
+        break;
+      case 'start':
+        icon = const Icon(Icons.play_arrow);
+        break;
+      case 'finish':
+        icon = const Icon(Icons.flag);
+        break;
+      default:
+        icon = const Icon(Icons.location_on);
+    }
+  }
+  @override
+  bool operator ==(Object other) {
+    if (other is LandmarkType) {
+      return name == other.name;
+    } else {
+      return false;
+    }
+  }
+}
+
+
+// Helpers
+// Handling the landmarks requires a little bit of special care because the linked list is not directly representable in json
+(Landmark, String?) getLandmarkFromPrefs(SharedPreferences prefs, String uuid) {
+  String? content = prefs.getString('landmark_$uuid');
+  Map<String, dynamic> json = jsonDecode(content!);
+  String? nextUUID = json['next_uuid'];
+  return (Landmark.fromJson(json), nextUUID);
+}
+
+
+void landmarkToPrefs(SharedPreferences prefs, Landmark current, Landmark? next) {
+  Map<String, dynamic> json = current.toJson();
+  json['next_uuid'] = next?.uuid;
+  prefs.setString('landmark_${current.uuid}', jsonEncode(json));
+}