instant streaming of metadata

lib/data_layer/repositories/metadata_repository_impl.dart

@@ -17,32 +17,42 @@ class MetadataRepositoryImpl implements MetadataRepository {
 
   /// nip05 is automatically verified if present and removed if invalid
   @override
-  Stream<UserMetadata> getMetadataByPubkey(String pubkey) {
+  Stream<UserMetadata> getMetadataByPubkey(String pubkey) async* {
     final myMetadata = dartNdkSource.dartNdk.metadata.loadMetadata(pubkey);
 
     final Stream<ndk_entities.Metadata?> myMetadataStream =
         myMetadata.asStream();
 
-    return myMetadataStream.where((event) => event != null).asyncMap(
-      (event) async {
-        final metadata = UserMetadataModel.fromNDKMetadata(event!);
+    await for (final event in myMetadataStream) {
+      if (event != null) {
+        final metadata = UserMetadataModel.fromNDKMetadata(event);
 
-        // Check if there's a NIP-05 identifier
-        if (metadata.nip05 != null && metadata.nip05!.isNotEmpty) {
+        // Store the original NIP-05 value
+        final originalNip05 = metadata.nip05;
+
+        // Set NIP-05 to null for the first event
+        metadata.nip05 = null;
+
+        // Emit the first event immediately with NIP-05 set to null
+        yield metadata;
+
+        // If there was originally a NIP-05 identifier, perform verification
+        if (originalNip05 != null && originalNip05.isNotEmpty) {
           // Perform NIP-05 verification
           final nip05Result = await dartNdkSource.dartNdk.nip05
-              .check(nip05: metadata.nip05!, pubkey: pubkey);
+              .check(nip05: originalNip05, pubkey: pubkey);
 
-          // If verification fails, set NIP-05 to null
-          if (!nip05Result.valid) {
-            metadata.nip05 = null;
-            return metadata;
+          // If verification succeeds, set NIP-05 to the original value
+          if (nip05Result.valid) {
+            metadata.nip05 = originalNip05;
+            // Emit the second event with verified NIP-05
+            yield metadata;
           }
+          // If verification fails, we don't emit another event
+          // as the NIP-05 is already null from the first event
         }
-
-        return metadata;
-      },
-    );
+      }
+    }
   }
 
   @override