fix: zcash address for exchange (#3491)

* fix: zcash address for exchange

* fix: honour the restore height the user entered

- Make Zcash rescan work in both directions by resetting sync from the new birth height
- Keep the entered height when restoring a wallet from keys
- Tolerate grouping separators in typed restore heights

---------

Co-authored-by: Vik Sharma <vik@cakewallet.com>

cw_zcash/lib/src/zcash_wallet.dart

@@ -1021,7 +1021,50 @@ abstract class ZcashWalletBase
   @override
   @action
   Future<void> rescan({required final int height}) async {
-    await zkool_sync.rewindSync(height: height, account: accountId, c: c);
+    syncStatus = StartingScanSyncStatus(height);
+    try {
+      await zkool_sync.cancelSync();
+      isSyncing = false;
+
+      await runWithCoin(
+        accountId: accountId,
+        func: (final coin) async {
+          await zkool_account.updateAccount(
+            update: zkool_account.AccountUpdate(
+              coin: coin.coin,
+              id: accountId,
+              birth: height,
+              folder: 0,
+            ),
+            c: coin,
+          );
+
+          final accounts = await zkool_account.listAccounts(c: coin);
+          final updated =
+              accounts.where((final a) => a.id == accountId).firstOrNull;
+          if (updated == null) {
+            throw Exception('account $accountId not found after update');
+          }
+          if (updated.birth != height) {
+            throw Exception(
+              'birth height did not persist: wanted $height, '
+              'database still has ${updated.birth}',
+            );
+          }
+
+          await zkool_account.resetSync(id: accountId, c: coin);
+        },
+      );
+
+      lastKnownRestoreHeight = height;
+      await save();
+
+      syncStatus = ConnectedSyncStatus();
+      unawaited(startSync());
+    } catch (e) {
+      printV('Zcash rescan failed: $e');
+      syncStatus = FailedSyncStatus(error: e.toString());
+    }
     // try {
     //   syncStatus = StartingScanSyncStatus(height);
     //   printV("rescanning from: $height");

cw_zcash/lib/src/zcash_wallet_addresses.dart

@@ -220,6 +220,13 @@ abstract class ZcashWalletAddressesBase extends WalletAddresses with Store {
     };
     await _syncRotationHiddenAddresses();
     await _applyAddressForCurrentType();
+    await _persistAddressForExchange();
+  }
+
+  Future<void> _persistAddressForExchange() async {
+    final addr = addressForExchange;
+    if (isPlaceholderAddress(addr)) return;
+    await walletInfo.setAddresses({addr: 'transparent'});
   }
 
   Future<void> _applyAddressForCurrentType() async {
@@ -253,6 +260,7 @@ abstract class ZcashWalletAddressesBase extends WalletAddresses with Store {
         walletInfo.address = address;
       }
       await walletInfo.setAddresses({});
+      await _persistAddressForExchange();
       await walletInfo.setAddressInfos(addressInfos);
       await walletInfo.setUsedAddresses(usedAddresses.toList());
       await walletInfo.setHiddenAddresses(hiddenAddresses.toList());

lib/src/screens/restore/wallet_restore_page.dart

@@ -215,6 +215,10 @@ class WalletRestorePage extends BasePage {
             walletRestoreFromKeysFormKey.currentState!.privateKeyController.text;
         credentials['name'] =
             walletRestoreFromKeysFormKey.currentState!.nameTextEditingController.text;
+        if (walletRestoreViewModel.hasBlockchainHeightSelector) {
+          credentials['height'] =
+              walletRestoreFromKeysFormKey.currentState!.blockchainHeightKey.currentState?.height;
+        }
       } else {
         credentials['name'] =
             walletRestoreFromKeysFormKey.currentState!.nameTextEditingController.text;

lib/src/widgets/blockchain_height_widget.dart

@@ -65,7 +65,8 @@ class BlockchainHeightState extends State<BlockchainHeightWidget> {
       try {
         final int _height;
         if (restoreHeightController.text.isNotEmpty) {
-          _height = int.tryParse(restoreHeightController.text) ?? 0;
+          final digits = restoreHeightController.text.replaceAll(RegExp(r'[^0-9]'), '');
+          _height = int.tryParse(digits) ?? 0;
         } else {
           _height = 0;
         }

lib/view_model/exchange/exchange_view_model.dart

@@ -1185,6 +1185,19 @@ abstract class ExchangeViewModelBase extends WalletChangeListenerViewModel with
         }
       }
 
+      if (receiveCurrency == CryptoCurrency.zec &&
+          selectedAddressBookWallet?.type == WalletType.zcash) {
+        if (wallet.type == WalletType.zcash && wallet.name == selectedAddressBookWallet!.name) {
+          receiveAddress = wallet.walletAddresses.addressForExchange;
+        } else {
+          receiveAddress = (await selectedAddressBookWallet!.getAddresses())
+                  .entries
+                  .firstWhereOrNull((e) => e.value == 'transparent')
+                  ?.key ??
+              receiveAddress;
+        }
+      }
+
       // parse Lightning address to bolt11 invoice
       if (receiveAddress.contains("@")) {
         receiveAddress = await getBolt11FromLightingAddress(receiveAddress) ?? receiveAddress;