fix: added check for duplicate checking

Author: samruddhi-Rahegaonkar

lib/providers/badge_message_provider.dart

@@ -101,7 +101,7 @@ class BadgeMessageProvider {
   ) async {
     final scanProvider = Provider.of<BadgeScanProvider>(context, listen: false);
 
-    final BleState? initialState = ScanState(
+    final BleState initialState = ScanState(
       manager: manager,
       mode: scanProvider.mode,
       allowedNames: scanProvider.badgeNames,

lib/view/badgeScanSettingsWidget.dart

@@ -50,27 +50,41 @@ class _BadgeScanSettingsWidgetState extends State<BadgeScanSettingsWidget> {
   void _onSave() {
     final updatedNames = <String>[];
     final Map<String, String> aliases = {};
+    final Set<String> realNameSet = {};
+    final Set<String> aliasSet = {};
 
     for (int i = 0; i < _nameControllers.length; i++) {
       final name = _nameControllers[i].text.trim();
       final alias = _aliasControllers[i].text.trim();
+
       if (name.isNotEmpty) {
+        if (realNameSet.contains(name.toLowerCase())) {
+          ScaffoldMessenger.of(context).showSnackBar(
+            SnackBar(content: Text('Duplicate real badge name: "$name"')),
+          );
+          return;
+        }
+        realNameSet.add(name.toLowerCase());
         updatedNames.add(name);
+
         if (alias.isNotEmpty) {
+          if (aliasSet.contains(alias.toLowerCase())) {
+            ScaffoldMessenger.of(context).showSnackBar(
+              SnackBar(content: Text('Duplicate alias: "$alias"')),
+            );
+            return;
+          }
+          aliasSet.add(alias.toLowerCase());
           aliases[name] = alias;
         }
       }
     }
-
-    // Save mode and names
     final scanProvider = Provider.of<BadgeScanProvider>(context, listen: false);
     scanProvider.setMode(_mode);
     scanProvider.setBadgeNames(updatedNames);
-
-    // Save aliases
     final aliasProvider =
         Provider.of<BadgeAliasProvider>(context, listen: false);
-    aliasProvider.clearAll(); // optional: reset aliases
+    aliasProvider.clearAll();
     aliases.forEach((name, alias) => aliasProvider.setAlias(name, alias));
 
     ScaffoldMessenger.of(context).showSnackBar(