1 files changed, 109 insertions, 0 deletions
diff --git a/lib/util/file_handler.dart b/lib/util/file_handler.dart
new file mode 100644
index 0000000..0344c60
--- /dev/null
+++ b/lib/util/file_handler.dart
@@ -0,0 +1,109 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+
+import 'package:kulinar_app/constants.dart';
+import 'package:kulinar_app/util/notifications.dart';
+import 'package:kulinar_app/widgets/toastbar_widget.dart';
+import 'package:kulinar_app/models/data/recipe_data_class.dart';
+import 'package:kulinar_app/models/data/settings_data_class.dart';
+
+import 'package:file_picker/file_picker.dart';
+import 'package:external_path/external_path.dart';
+import 'package:permission_handler/permission_handler.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+enum ExportType {
+  settings,
+  recipes,
+  recipe,
+  full,
+}
+
+/// Handles all the things related to file serialization / deserialization and other file interaction.
+class FileHandler {
+  /// Serializes the given `data` into a json style File. Sends a confirmation Toast to the given `context` afterwards.
+  static Future<void> serializeFile(BuildContext context, Map<String, dynamic> data) async {
+    if (await Permission.storage.request().isGranted) {
+      try {
+        final _directory = await ExternalPath.getExternalStoragePublicDirectory(ExternalPath.DIRECTORY_DOWNLOADS);
+        final _file = File("$_directory/Export-${DateTime.now().toUtc().toString().split(" ")[0]}.kulinar");
+
+        await _file.writeAsString(jsonEncode(await encodeDataAsMap(ExportType.full, data)));
+
+        ToastBar.showToastBar(context, AppLocalizations.of(context)!.exportSuccess);
+        Notifications.notify(AppLocalizations.of(context)!.exportSuccess, AppLocalizations.of(context)!.tapHint, _file.path);
+      } catch (e) {
+        print(e);
+        ToastBar.showToastBar(context, AppLocalizations.of(context)!.exportError);
+      }
+    }
+  }
+
+  /// Deserializes the given `file` into the returned Map. Sends a confirmation Toast to the given `context` afterwards.
+  static Future<Map<String, String>> deserializeFile(BuildContext context, File file) async {
+    final dynamic _content = jsonDecode(await file.readAsString());
+
+    SettingsData.decode(_content["settings"]);
+    RecipeData.decode(_content["recipes"]);
+
+    ToastBar.showToastBar(context, AppLocalizations.of(context)!.importSuccess);
+
+    return _content;
+  }
+
+  /// Parses a given possible deserializable `file` for useful information and returns a map of it.
+  static Future<Map<String, String>> deserializeFileInformation(File file) async {
+    final Map<dynamic, dynamic> _content = jsonDecode(await file.readAsString());
+    Map<String, String> _map = Map<String, String>();
+
+    _map["version"] = _content["version"];
+    _map["type"] = _content["type"].split(".")[1];
+    _map["size"] = "${await file.length()} Bytes";
+
+    if (_content["type"] == ExportType.full.toString()) {
+      int a = jsonDecode(_content["recipes"]).length;
+      int b = jsonDecode(_content["settings"]).length;
+
+      _map["entries"] = (a + b).toString();
+    }
+
+    return _map;
+  }
+
+  /// Opens the native file picker and returns the picked `.kulinar` file.
+  static Future<File?> pickDeserializableFile(BuildContext context) async {
+    if (await Permission.storage.request().isGranted) {
+      try {
+        FilePickerResult? result = await FilePicker.platform.pickFiles(type: FileType.custom, allowedExtensions: ["kulinar"]);
+
+        if (result != null) {
+          return File(result.files.single.path!);
+        }
+      } catch (e) {
+        print(e);
+        ToastBar.showToastBar(context, AppLocalizations.of(context)!.importError);
+      }
+    }
+
+    return null;
+  }
+
+  /// Encodes the given `data` together with some additional information into a serializable map.
+  static Future<Map<String, String>> encodeDataAsMap(ExportType type, Map<String, dynamic> data) async {
+    Map<String, String> _map = Map<String, String>();
+
+    _map["version"] = cVersion;
+    _map["type"] = type.toString();
+    // TODO: IMPLEMENT: Base64 Images and image count on export
+    // map["imageCount"] = getImageCount;
+    _map.addAll(data as Map<String, String>);
+
+    return _map;
+  }
+
+  /// Decodes the given `map` into
+  /// TODO: IMPLEMENT: decodeExportMap
+  // static Future<Map<String, String>> decodeMapToData(ExportType type) async {}
+}