Many minor improvements

lib/models/appconfig.dart

@@ -0,0 +1,56 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:json_annotation/json_annotation.dart';
+import 'package:path_provider/path_provider.dart';
+import 'package:path/path.dart' as p;
+
+part 'appconfig.g.dart';
+
+@JsonSerializable()
+class AppConfig {
+  List<Device> devices = [];
+
+  AppConfig._constructor();
+  static AppConfig _instance = AppConfig._constructor();
+
+  factory AppConfig({Map<String, dynamic>? json}) {
+    if (json != null) {
+      _instance = _$AppConfigFromJson(json);
+    }
+
+    return _instance;
+  }
+
+  Map<String, dynamic> toJson() => _$AppConfigToJson(this);
+
+  /// Saves configuration to file.
+  ///
+  /// WARN: This method assumes the config file already exists.
+  Future<void> save() async {
+    final appDocsDir = await getApplicationDocumentsDirectory();
+    var configFile = File(p.join(appDocsDir.path, "app.json"));
+    await configFile.writeAsString(jsonEncode(toJson()));
+  }
+}
+
+@JsonSerializable()
+class Device {
+  String name;
+  String routerSsid;
+  String routerBssid;
+  String networkPassword;
+  String? ip;
+  String? bssid;
+
+  Device({
+    required this.name,
+    required this.routerSsid,
+    required this.routerBssid,
+    this.networkPassword = "",
+  });
+
+  factory Device.fromJson(Map<String, dynamic> json) => _$DeviceFromJson(json);
+
+  Map<String, dynamic> toJson() => _$DeviceToJson(this);
+}

lib/models/appconfig.g.dart

@@ -0,0 +1,35 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'appconfig.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+AppConfig _$AppConfigFromJson(Map<String, dynamic> json) => AppConfig()
+  ..devices = (json['devices'] as List<dynamic>)
+      .map((e) => Device.fromJson(e as Map<String, dynamic>))
+      .toList();
+
+Map<String, dynamic> _$AppConfigToJson(AppConfig instance) => <String, dynamic>{
+  'devices': instance.devices,
+};
+
+Device _$DeviceFromJson(Map<String, dynamic> json) =>
+    Device(
+        name: json['name'] as String,
+        routerSsid: json['routerSsid'] as String,
+        routerBssid: json['routerBssid'] as String,
+        networkPassword: json['networkPassword'] as String? ?? "",
+      )
+      ..ip = json['ip'] as String?
+      ..bssid = json['bssid'] as String?;
+
+Map<String, dynamic> _$DeviceToJson(Device instance) => <String, dynamic>{
+  'name': instance.name,
+  'routerSsid': instance.routerSsid,
+  'routerBssid': instance.routerBssid,
+  'networkPassword': instance.networkPassword,
+  'ip': instance.ip,
+  'bssid': instance.bssid,
+};

lib/models/device_status.dart

@@ -0,0 +1,16 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'device_status.g.dart';
+
+@JsonSerializable()
+class DeviceStatus {
+  bool entryNfc = false;
+  bool exitNfc = false;
+
+  DeviceStatus({this.entryNfc = false, this.exitNfc = false});
+
+  factory DeviceStatus.fromJson(Map<String, dynamic> json) =>
+      _$DeviceStatusFromJson(json);
+
+  Map<String, dynamic> toJson() => _$DeviceStatusToJson(this);
+}