decred: Add rescan.

cw_decred/lib/api/libdcrwallet.dart

@@ -206,3 +206,13 @@ String listUnspents(String walletName) {
   );
   return res.payload;
 }
+
+String rescanFromHeight(String walletName, String height) {
+  final cName = walletName.toCString();
+  final cHeight = height.toCString();
+  final res = executePayloadFn(
+    fn: () => dcrwalletApi.rescanFromHeight(cName, cHeight),
+    ptrsToFree: [cName, cHeight],
+  );
+  return res.payload;
+}

cw_decred/lib/wallet.dart

@@ -401,7 +401,10 @@ abstract class DecredWalletBase extends WalletBase<DecredBalance,
 
   @override
   Future<void> rescan({required int height}) async {
-    // TODO.
+    if (height > this.bestHeight) {
+      return;
+    }
+    libdcrwallet.rescanFromHeight(walletInfo.name, height.toString());
   }
 
   @override

lib/decred/cw_decred.dart

@@ -103,5 +103,17 @@ class CWDecred extends Decred {
     return decredWallet.unspents();
   }
 
+  @override
   void updateUnspents(Object wallet) async {}
+
+  @override
+  int heightByDate(DateTime date) {
+    final genesisBlocktime =
+        DateTime.fromMillisecondsSinceEpoch(1454954400 * 1000);
+    final minutesDiff = date.difference(genesisBlocktime).inMinutes;
+    // Decred has five minute blocks on mainnet.
+    // NOTE: This is off by about a day.
+    // TODO: Remove this and just rescan from the wallet birthday.
+    return (minutesDiff / 5).toInt();
+  }
 }

lib/di.dart

@@ -1113,7 +1113,7 @@ Future<void> setup({
 
   getIt.registerFactory(() => RescanViewModel(getIt.get<AppStore>().wallet!));
 
-  getIt.registerFactory(() => RescanPage(getIt.get<RescanViewModel>()));
+  getIt.registerFactory(() => RescanPage(getIt.get<RescanViewModel>(), getIt.get<AppStore>().wallet!.type));
 
   getIt.registerFactory(() => FaqPage(getIt.get<SettingsStore>()));
 

lib/src/screens/rescan/rescan_page.dart

@@ -9,9 +9,10 @@ import 'package:cake_wallet/src/screens/base_page.dart';
 import 'package:cake_wallet/src/widgets/blockchain_height_widget.dart';
 import 'package:cake_wallet/src/widgets/primary_button.dart';
 import 'package:cake_wallet/generated/i18n.dart';
+import 'package:cw_core/wallet_type.dart';
 
 class RescanPage extends BasePage {
-  RescanPage(this._rescanViewModel)
+  RescanPage(this._rescanViewModel, this.type)
       : _blockchainHeightWidgetKey = GlobalKey<BlockchainHeightState>();
 
   @override
@@ -19,6 +20,7 @@ class RescanPage extends BasePage {
       _rescanViewModel.isSilentPaymentsScan ? S.current.silent_payments_scanning : S.current.rescan;
   final GlobalKey<BlockchainHeightState> _blockchainHeightWidgetKey;
   final RescanViewModel _rescanViewModel;
+  final WalletType type;
 
   @override
   Widget body(BuildContext context) {
@@ -30,6 +32,7 @@ class RescanPage extends BasePage {
         child: Column(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [
           Observer(
               builder: (_) => BlockchainHeightWidget(
+                    type: this.type,
                     key: _blockchainHeightWidgetKey,
                     onHeightOrDateEntered: (value) => _rescanViewModel.isButtonEnabled = value,
                     isSilentPaymentsScan: _rescanViewModel.isSilentPaymentsScan,

lib/src/widgets/blockchain_height_widget.dart

@@ -9,10 +9,14 @@ import 'package:intl/intl.dart';
 import 'package:cake_wallet/generated/i18n.dart';
 import 'package:cake_wallet/monero/monero.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
+import 'package:cake_wallet/decred/decred.dart';
+import 'package:cw_core/wallet_type.dart';
+
 
 class BlockchainHeightWidget extends StatefulWidget {
   BlockchainHeightWidget({
     GlobalKey? key,
+    this.type,
     this.onHeightChange,
     this.focusNode,
     this.onHeightOrDateEntered,
@@ -26,6 +30,7 @@ class BlockchainHeightWidget extends StatefulWidget {
     this.blockHeightTextFieldKey,
   }) : super(key: key);
 
+  final WalletType? type;
   final Function(int)? onHeightChange;
   final Function(bool)? onHeightOrDateEntered;
   final FocusNode? focusNode;
@@ -183,7 +188,9 @@ class BlockchainHeightState extends State<BlockchainHeightWidget> {
           bitcoinMempoolAPIEnabled: await widget.bitcoinMempoolAPIEnabled,
         );
       } else {
-        if (widget.walletType == WalletType.monero) {
+        if (widget.type == WalletType.decred) {
+          height = decred!.heightByDate(date);
+        } else if (widget.walletType == WalletType.monero) {
           height = monero!.getHeightByDate(date: date);
         } else {
           assert(widget.walletType == WalletType.wownero,

lib/view_model/dashboard/dashboard_view_model.dart

@@ -388,6 +388,7 @@ abstract class DashboardViewModelBase with Store {
       wallet.type == WalletType.monero ||
       wallet.type == WalletType.litecoin ||
       wallet.type == WalletType.wownero ||
+      wallet.type == WalletType.decred ||
       wallet.type == WalletType.haven;
 
   @computed

scripts/android/build_decred.sh

@@ -3,14 +3,16 @@
 . ./config.sh
 CW_DECRED_DIR=${WORKDIR}/cake_wallet/cw_decred
 LIBWALLET_PATH="${WORKDIR}/decred/libwallet"
-LIBWALLET_URL="https://github.com/itswisdomagain/libwallet.git"
+LIBWALLET_URL="https://github.com/decred/libwallet.git"
+LIBWALLET_COMMIT="9f39f38b460e2dece5704cbc4aee293c741ee710"
 
 if [ -e $LIBWALLET_PATH ]; then
        rm -fr $LIBWALLET_PATH
 fi
 mkdir -p $LIBWALLET_PATH
-git clone $LIBWALLET_URL $LIBWALLET_PATH --branch cgo
+git clone $LIBWALLET_URL $LIBWALLET_PATH
 cd $LIBWALLET_PATH
+git checkout $LIBWALLET_COMMIT
 
 export CPATH="$(clang -v 2>&1 | grep "Selected GCC installation" | rev | cut -d' ' -f1 | rev)/include"
 

scripts/ios/build_decred.sh

@@ -2,14 +2,16 @@
 
 . ./config.sh
 LIBWALLET_PATH="${EXTERNAL_IOS_SOURCE_DIR}/libwallet"
-LIBWALLET_URL="https://github.com/itswisdomagain/libwallet.git"
+LIBWALLET_URL="https://github.com/decred/libwallet.git"
+LIBWALLET_COMMIT="9f39f38b460e2dece5704cbc4aee293c741ee710"
 
 if [ -e $LIBWALLET_PATH ]; then
        rm -fr $LIBWALLET_PATH
 fi
 mkdir -p $LIBWALLET_PATH
-git clone $LIBWALLET_URL $LIBWALLET_PATH --branch cgo
+git clone $LIBWALLET_URL $LIBWALLET_PATH
 cd $LIBWALLET_PATH
+git checkout $LIBWALLET_COMMIT
 
 SYSROOT=`xcrun --sdk iphoneos --show-sdk-path`
 CLANG="clang -isysroot ${SYSROOT}"

tool/configure.dart

@@ -1461,6 +1461,8 @@ abstract class Decred {
 
   List<Unspent> getUnspents(Object wallet);
   void updateUnspents(Object wallet);
+
+  int heightByDate(DateTime date);
 }
 """;