auto-label UTXOs from transaction notes

lib/db/isar/main_db.dart

@@ -324,7 +324,9 @@ class MainDB {
 
     await isar.writeTxn(() async {
       final set = utxos.toSet();
+      final noteValues = <String, String?>{};
       for (final utxo in utxos) {
+        UTXO persistedUtxo = utxo;
         // check if utxo exists in db and update accordingly
         final storedUtxo = await isar.utxos
             .where()
@@ -342,24 +344,36 @@ class MainDB {
               !storedUtxo.isBlocked &&
               !storedUtxo.userUnfroze;
           set.remove(utxo);
-          set.add(
-            storedUtxo.copyWith(
-              value: utxo.value,
-              address: utxo.address,
-              blockTime: utxo.blockTime,
-              blockHeight: utxo.blockHeight,
-              blockHash: utxo.blockHash,
-              // passing null keeps the stored value
-              isBlocked: applyAutoBlock ? true : null,
-              blockedReason: applyAutoBlock ? utxo.blockedReason : null,
-              name: applyAutoBlock && storedUtxo.name.isEmpty
-                  ? utxo.name
-                  : null,
-            ),
+          persistedUtxo = storedUtxo.copyWith(
+            value: utxo.value,
+            address: utxo.address,
+            blockTime: utxo.blockTime,
+            blockHeight: utxo.blockHeight,
+            blockHash: utxo.blockHash,
+            // passing null keeps the stored value
+            isBlocked: applyAutoBlock ? true : null,
+            blockedReason: applyAutoBlock ? utxo.blockedReason : null,
+            name: applyAutoBlock && storedUtxo.name.isEmpty ? utxo.name : null,
           );
+          set.add(persistedUtxo);
         } else {
           newUTXO = true;
         }
+
+        if (persistedUtxo.name.isEmpty) {
+          final noteValue = noteValues.containsKey(utxo.txid)
+              ? noteValues[utxo.txid]
+              : (await isar.transactionNotes.getByTxidWalletId(
+                  utxo.txid,
+                  walletId,
+                ))?.value;
+          noteValues[utxo.txid] = noteValue;
+          if (noteValue?.isNotEmpty == true) {
+            set
+              ..remove(persistedUtxo)
+              ..add(persistedUtxo.copyWith(name: noteValue));
+          }
+        }
       }
 
       await isar.utxos.where().walletIdEqualTo(walletId).deleteAll();
@@ -381,14 +395,37 @@ class MainDB {
       isar.transactionNotes.where().walletIdEqualTo(walletId);
 
   Future<void> putTransactionNote(TransactionNote transactionNote) =>
-      isar.writeTxn(() async {
-        await isar.transactionNotes.put(transactionNote);
-      });
+      putTransactionNotes([transactionNote]);
 
+  /// Copies a note only to blank UTXO labels. The label is independent after
+  /// that first assignment, so later note edits cannot overwrite it.
   Future<void> putTransactionNotes(List<TransactionNote> transactionNotes) =>
-      isar.writeTxn(() async {
-        await isar.transactionNotes.putAll(transactionNotes);
-      });
+      transactionNotes.isEmpty
+      ? Future.value()
+      : isar.writeTxn(() async {
+          await isar.transactionNotes.putAll(transactionNotes);
+
+          final toUpdate = <UTXO>[];
+          for (final note in transactionNotes) {
+            if (note.value.isEmpty) {
+              continue;
+            }
+            final utxos = await isar.utxos
+                .where()
+                .walletIdEqualTo(note.walletId)
+                .filter()
+                .txidEqualTo(note.txid)
+                .findAll();
+            toUpdate.addAll(
+              utxos
+                  .where((utxo) => utxo.name.isEmpty)
+                  .map((utxo) => utxo.copyWith(name: note.value)),
+            );
+          }
+          if (toUpdate.isNotEmpty) {
+            await isar.utxos.putAll(toUpdate);
+          }
+        });
 
   Future<TransactionNote?> getTransactionNote(
     String walletId,

lib/pages/cakepay/cakepay_confirm_send_view.dart

@@ -8,6 +8,7 @@ import '../../notifications/show_flush_bar.dart';
 import '../../pages_desktop_specific/my_stack_view/wallet_view/sub_widgets/desktop_auth_send.dart';
 import '../../providers/providers.dart';
 import '../../route_generator.dart';
+import '../../services/transaction_note_service.dart';
 import '../../themes/stack_colors.dart';
 import '../../utilities/amount/amount_formatter.dart';
 import '../../utilities/constants.dart';
@@ -95,11 +96,10 @@ class _CakePayConfirmSendViewState
 
       txid = (results.first as TxData).txid!;
 
-      await ref
-          .read(mainDBProvider)
-          .putTransactionNote(
-            TransactionNote(walletId: walletId, txid: txid, value: note),
-          );
+      await saveTransactionNotesAfterSend(
+        notes: [TransactionNote(walletId: walletId, txid: txid, value: note)],
+        persist: ref.read(mainDBProvider).putTransactionNotes,
+      );
 
       if (context.mounted) {
         // pop sending dialog (pushed via showDialog which uses root navigator)

lib/pages/exchange_view/confirm_change_now_send.dart

@@ -21,6 +21,7 @@ import '../../notifications/show_flush_bar.dart';
 import '../../pages_desktop_specific/my_stack_view/wallet_view/sub_widgets/desktop_auth_send.dart';
 import '../../providers/providers.dart';
 import '../../route_generator.dart';
+import '../../services/transaction_note_service.dart';
 import '../../themes/stack_colors.dart';
 import '../../utilities/amount/amount.dart';
 import '../../utilities/amount/amount_formatter.dart';
@@ -135,12 +136,10 @@ class _ConfirmChangeNowSendViewState
 
       txid = (results.first as TxData).txid!;
 
-      // save note
-      await ref
-          .read(mainDBProvider)
-          .putTransactionNote(
-            TransactionNote(walletId: walletId, txid: txid, value: note),
-          );
+      await saveTransactionNotesAfterSend(
+        notes: [TransactionNote(walletId: walletId, txid: txid, value: note)],
+        persist: ref.read(mainDBProvider).putTransactionNotes,
+      );
 
       await ref
           .read(tradeSentFromStackLookupProvider)