import 'dart:collection';
import 'dart:convert';

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.isSecondary,

    this.imageURL,
    this.description,
    this.duration,
    this.visited,

    // 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<double> location,
        'type': LandmarkType type,
      }) {
        // 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(
          uuid: uuid, name: name, location: location, type: type, isSecondary: isSecondary, imageURL: imageURL, description: description, duration: duration, visited: visited);
    } else {
      throw FormatException('Invalid JSON: $json');
    }
  }


  @override
  bool operator ==(Object other) {
    return other is Landmark && uuid == other.uuid;
  }
}


class LandmarkType {
  final String name;
  // final String description;
  // final Icon icon;
  
  const LandmarkType({
    required this.name,
    // required this.description,
    // required this.icon,
  });
}



// 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);
}