Add support for importing raivo codes

lib/ui/settings/data/import/ravio_plain_text_import.dart

@@ -0,0 +1,152 @@
+import 'dart:async';
+import 'dart:io';
+import 'dart:ui';
+
+import 'package:ente_auth/ente_theme_data.dart';
+import 'package:ente_auth/l10n/l10n.dart';
+import 'package:ente_auth/models/code.dart';
+import 'package:ente_auth/services/authenticator_service.dart';
+import 'package:ente_auth/store/code_store.dart';
+import 'package:ente_auth/ui/components/dialog_widget.dart';
+import 'package:ente_auth/ui/components/models/button_type.dart';
+import 'package:ente_auth/utils/dialog_util.dart';
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:logging/logging.dart';
+
+class PlainTextImport extends StatelessWidget {
+  const PlainTextImport({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    return Column(
+      children: [
+        Text(
+          l10n.importInstruction,
+        ),
+        const SizedBox(
+          height: 20,
+        ),
+        Container(
+          color: Theme.of(context).colorScheme.gNavBackgroundColor,
+          child: Padding(
+            padding: const EdgeInsets.all(8),
+            child: Text(
+              "otpauth://totp/provider.com:you@email.com?secret=YOUR_SECRET",
+              style: TextStyle(
+                fontFeatures: const [FontFeature.tabularFigures()],
+                fontFamily: Platform.isIOS ? "Courier" : "monospace",
+                fontSize: 13,
+              ),
+            ),
+          ),
+        ),
+        const SizedBox(
+          height: 20,
+        ),
+        Text(l10n.importCodeDelimiterInfo),
+      ],
+    );
+  }
+
+}
+
+
+Future<void> showImportInstructionDialog(BuildContext context) async {
+  final l10n = context.l10n;
+  final AlertDialog alert = AlertDialog(
+    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+    title: Text(
+      l10n.importCodes,
+      style: Theme.of(context).textTheme.headline6,
+    ),
+    content: const SingleChildScrollView(
+      child: PlainTextImport(),
+    ),
+    actions: [
+      TextButton(
+        child: Text(
+          l10n.cancel,
+          style: const TextStyle(
+            color: Colors.red,
+          ),
+        ),
+        onPressed: () {
+          Navigator.of(context, rootNavigator: true).pop('dialog');
+        },
+      ),
+      TextButton(
+        child: Text(l10n.selectFile),
+        onPressed: () {
+          Navigator.of(context, rootNavigator: true).pop('dialog');
+          _pickImportFile(context);
+        },
+      ),
+    ],
+  );
+
+  return showDialog(
+    context: context,
+    builder: (BuildContext context) {
+      return alert;
+    },
+    barrierColor: Colors.black12,
+  );
+}
+
+
+Future<void> _pickImportFile(BuildContext context) async {
+  final l10n = context.l10n;
+  FilePickerResult? result = await FilePicker.platform.pickFiles();
+  if (result == null) {
+    return;
+  }
+  final progressDialog = createProgressDialog(context, l10n.pleaseWait);
+  await progressDialog.show();
+  try {
+    File file = File(result.files.single.path!);
+    final codes = await file.readAsString();
+    List<String> splitCodes = codes.split(",");
+    if (splitCodes.length == 1) {
+      splitCodes = codes.split("\n");
+    }
+    final parsedCodes = [];
+    for (final code in splitCodes) {
+      try {
+        parsedCodes.add(Code.fromRawData(code));
+      } catch (e) {
+        Logger('PlainText').severe("Could not parse code", e);
+      }
+    }
+    for (final code in parsedCodes) {
+      await CodeStore.instance.addCode(code, shouldSync: false);
+    }
+    unawaited(AuthenticatorService.instance.sync());
+    await progressDialog.hide();
+    final DialogWidget dialog = choiceDialog(
+      title: context.l10n.importSuccessTitle,
+      body: context.l10n.importSuccessDesc(parsedCodes.length),
+      // body: "You have imported " + parsedCodes.length.toString() + " codes!",
+      firstButtonLabel: l10n.ok,
+      firstButtonOnTap: () async {
+        Navigator.of(context, rootNavigator: true).pop('progressDialog');
+      },
+      firstButtonType: ButtonType.primary,
+    );
+    await showConfettiDialog(
+      context: context,
+      dialogBuilder: (BuildContext context) {
+        return dialog;
+      },
+    );
+  } catch (e) {
+    await progressDialog.hide();
+    await showErrorDialog(
+      context,
+      context.l10n.sorry,
+      context.l10n.importFailureDesc,
+    );
+  }
+}