TF-3344 Handle separator when pasting list of mail addresses

core/lib/utils/string_convert.dart

@@ -1,10 +1,41 @@
+import 'dart:convert';
+
+import 'app_logger.dart';
+
 class StringConvert {
- static String? writeEmptyToNull(String text) {
+  static const String separatorPattern = r'[ ,;]+';
+
+  static String? writeEmptyToNull(String text) {
     if (text.isEmpty) return null;
     return text;
   }
 
- static String writeNullToEmpty(String? text) {
+  static String writeNullToEmpty(String? text) {
     return text ?? '';
   }
+
+  static List<String> extractStrings(String input) {
+    try {
+      // Check if the input is URL encoded
+      if (input.contains('%')) {
+        input = Uri.decodeComponent(input); // Decode URL encoding
+      }
+
+      // Check if the input is Base64 encoded
+      if (input.length % 4 == 0 && RegExp(r'^[A-Za-z0-9+/=]+$').hasMatch(input)) {
+        input = utf8.decode(base64.decode(input)); // Decode Base64 encoding
+      }
+
+      final RegExp separator = RegExp(separatorPattern);
+      final listStrings = input
+          .replaceAll('\n', ' ')
+          .split(separator)
+          .where((value) => value.trim().isNotEmpty)
+          .toList();
+      log('StringConvert::extractStrings:listStrings = $listStrings');
+      return listStrings;
+    } catch (e) {
+      return [];
+    }
+  }
 }