Separate Exception Handler class from main [skip ci]

lib/utils/exception_handler.dart

@@ -0,0 +1,104 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:cake_wallet/generated/i18n.dart';
+import 'package:cake_wallet/main.dart';
+import 'package:cake_wallet/src/widgets/alert_with_two_actions.dart';
+import 'package:cake_wallet/utils/show_pop_up.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_mailer/flutter_mailer.dart';
+import 'package:path_provider/path_provider.dart';
+
+class ExceptionHandler {
+  static bool _hasError = false;
+
+  static void _saveException(String? error, StackTrace? stackTrace) async {
+    final appDocDir = await getApplicationDocumentsDirectory();
+
+    final file = File('${appDocDir.path}/error.txt');
+    final exception = {
+      "${DateTime.now()}": {
+        "Error": error,
+        "StackTrace": stackTrace.toString(),
+      }
+    };
+
+    const String separator = '''\n\n==========================================================
+      ==========================================================\n\n''';
+
+    await file.writeAsString(
+      jsonEncode(exception) + separator,
+      mode: FileMode.append,
+    );
+  }
+
+  static void _sendExceptionFile() async {
+    try {
+      final appDocDir = await getApplicationDocumentsDirectory();
+
+      final file = File('${appDocDir.path}/error.txt');
+
+      final MailOptions mailOptions = MailOptions(
+        subject: 'Mobile App Issue',
+        recipients: ['support@cakewallet.com'],
+        attachments: [file.path],
+      );
+
+      final result = await FlutterMailer.send(mailOptions);
+
+      // Clear file content if the error was sent or saved.
+      // On android we can't know if it was sent or saved
+      if (result.name == MailerResponse.sent.name ||
+          result.name == MailerResponse.saved.name ||
+          result.name == MailerResponse.android.name) {
+        file.writeAsString("", mode: FileMode.write);
+      }
+    } catch (e, s) {
+      _saveException(e.toString(), s);
+    }
+  }
+
+  static void onError(FlutterErrorDetails errorDetails) {
+    if (_isErrorFromUser(errorDetails.exception.toString())) {
+      return;
+    }
+
+    _saveException(errorDetails.exception.toString(), errorDetails.stack);
+
+    if (_hasError) {
+      return;
+    }
+    _hasError = true;
+
+    WidgetsBinding.instance.addPostFrameCallback(
+      (timeStamp) async {
+        await showPopUp<void>(
+          context: navigatorKey.currentContext!,
+          builder: (context) {
+            return AlertWithTwoActions(
+              isDividerExist: true,
+              alertTitle: S.of(context).error,
+              alertContent: S.of(context).error_dialog_content,
+              rightButtonText: S.of(context).send,
+              leftButtonText: S.of(context).do_not_send,
+              actionRightButton: () {
+                Navigator.of(context).pop();
+                _sendExceptionFile();
+              },
+              actionLeftButton: () {
+                Navigator.of(context).pop();
+              },
+            );
+          },
+        );
+
+        _hasError = false;
+      },
+    );
+  }
+
+  /// User related errors to be added as exceptions here to not report
+  static bool _isErrorFromUser(String error) {
+    return error.contains("Software caused connection abort"); // User connection issue
+  }
+}