User token swap improvements (#2470)

* Handle null currency in trade

* Improve trade network handling and error reporting

* update Polygon network tag

* Update exchange_trade_view_model.dart

* handle nullable network fields

* Update lib/exchange/provider/letsexchange_exchange_provider.dart

---------

Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

lib/exchange/provider/chainflip_exchange_provider.dart

@@ -69,6 +69,8 @@ class ChainflipExchangeProvider extends ExchangeProvider {
       {required CryptoCurrency from,
       required CryptoCurrency to,
       required bool isFixedRateMode}) async {
+
+    try {
     final assetId = _normalizeCurrency(from);
 
     final assetsResponse = await _getAssets();
@@ -78,7 +80,13 @@ class ChainflipExchangeProvider extends ExchangeProvider {
             (asset) => asset['id'] == assetId,
             orElse: () => null)?['minimalAmountNative'] ?? '0';
 
+    if (minAmount == '0') throw Exception('No rates found for $from to $to');
+
     return Limits(min: _amountFromNative(minAmount.toString(), from));
+    } catch (e) {
+      printV(e.toString());
+      throw Exception('Chainflip failed to fetch limits');
+    }
   }
 
   @override

lib/exchange/provider/changenow_exchange_provider.dart

@@ -242,8 +242,10 @@ class ChangeNowExchangeProvider extends ExchangeProvider {
 
     final responseJSON = json.decode(response.body) as Map<String, dynamic>;
     final fromCurrency = responseJSON['fromCurrency'] as String;
+    final fromNetwork = responseJSON['fromNetwork'] as String?;
     final from = CryptoCurrency.safeParseCurrencyFromString(fromCurrency);
     final toCurrency = responseJSON['toCurrency'] as String;
+    final toNetwork = responseJSON['toNetwork'] as String?;
     final to = CryptoCurrency.safeParseCurrencyFromString(toCurrency);
     final inputAddress = responseJSON['payinAddress'] as String;
     final expectedSendAmount = responseJSON['expectedAmountFrom'].toString();
@@ -255,6 +257,9 @@ class ChangeNowExchangeProvider extends ExchangeProvider {
     final payoutAddress = responseJSON['payoutAddress'] as String;
     final expiredAt = DateTime.tryParse(expiredAtRaw ?? '')?.toLocal();
 
+    final _normalizedFromNetwork = _normalizeNetworkType(fromNetwork ?? '');
+    final _normalizedToNetwork = _normalizeNetworkType(toNetwork ?? '');
+
     return Trade(
       id: id,
       from: from,
@@ -267,8 +272,8 @@ class ChangeNowExchangeProvider extends ExchangeProvider {
       expiredAt: expiredAt,
       outputTransaction: outputTransaction,
       payoutAddress: payoutAddress,
-      userCurrencyFromRaw: '${fromCurrency.toUpperCase()}' + '_',
-      userCurrencyToRaw: '${toCurrency.toUpperCase()}' + '_',
+      userCurrencyFromRaw: '${fromCurrency.toUpperCase()}' + '_' + '${_normalizedFromNetwork.toUpperCase()}',
+      userCurrencyToRaw: '${toCurrency.toUpperCase()}' + '_' + '${_normalizedToNetwork.toUpperCase()}',
     );
   }
 
@@ -307,4 +312,14 @@ class ChangeNowExchangeProvider extends ExchangeProvider {
         return tag.toLowerCase();
     }
   }
+
+  String _normalizeNetworkType(String network) {
+    return switch (network.toUpperCase()) {
+      'POLY' => 'MATIC',
+      'AVAXC' => 'CCHAIN',
+      _ => network,
+    };
+  }
+
+
 }

lib/exchange/provider/exolix_exchange_provider.dart

@@ -241,7 +241,9 @@ class ExolixExchangeProvider extends ExchangeProvider {
 
     final responseJSON = json.decode(response.body) as Map<String, dynamic>;
     final coinFrom = responseJSON['coinFrom']['coinCode'] as String;
+    final coinFromNetwork = responseJSON['coinFrom']['network'] as String?;
     final coinTo = responseJSON['coinTo']['coinCode'] as String;
+    final coinToNetwork = responseJSON['coinTo']['network'] as String?;
     final inputAddress = responseJSON['depositAddress'] as String;
     final amount = responseJSON['amount'].toString();
     final status = responseJSON['status'] as String;
@@ -260,8 +262,8 @@ class ExolixExchangeProvider extends ExchangeProvider {
         extraId: extraId,
         outputTransaction: outputTransaction,
         payoutAddress: payoutAddress,
-      userCurrencyFromRaw: '${coinFrom.toUpperCase()}' + '_',
-      userCurrencyToRaw: '${coinTo.toUpperCase()}' + '_',
+      userCurrencyFromRaw: '${coinFrom.toUpperCase()}' + '_' + '${coinFromNetwork ?? ''}',
+      userCurrencyToRaw: '${coinTo.toUpperCase()}' + '_' + '${coinToNetwork ?? ''}',
     );
   }
 

lib/exchange/provider/letsexchange_exchange_provider.dart

@@ -237,9 +237,9 @@ class LetsExchangeExchangeProvider extends ExchangeProvider {
     }
     final responseJSON = json.decode(response.body) as Map<String, dynamic>;
     final from = responseJSON['coin_from'] as String;
-    final fromNetwork = responseJSON['coin_from_network'] as String;
+    final fromNetwork = responseJSON['coin_from_network'] as String?;
     final to = responseJSON['coin_to'] as String;
-    final toNetwork = responseJSON['coin_to_network'] as String;
+    final toNetwork = responseJSON['coin_to_network'] as String?;
     final payoutAddress = responseJSON['withdrawal'] as String;
     final depositAddress = responseJSON['deposit'] as String;
     final refundAddress = responseJSON['return'] as String;
@@ -253,6 +253,9 @@ class LetsExchangeExchangeProvider extends ExchangeProvider {
     final createdAt = DateTime.parse(createdAtString).toLocal();
     final expiredAt = DateTime.fromMillisecondsSinceEpoch(expiredAtTimestamp * 1000).toLocal();
 
+    final normalizedFromNetwork = _normalizeNetworkType(fromNetwork ?? '');
+    final normalizedToNetwork = _normalizeNetworkType(toNetwork ?? '');
+
     return Trade(
       id: id,
       from: CryptoCurrency.safeParseCurrencyFromString(from),
@@ -268,8 +271,8 @@ class LetsExchangeExchangeProvider extends ExchangeProvider {
       expiredAt: expiredAt,
       isRefund: status == 'refund',
       extraId: extraId,
-      userCurrencyFromRaw: '$from' + '_' + '$fromNetwork',
-      userCurrencyToRaw: '$to' + '_' + '$toNetwork',
+      userCurrencyFromRaw: '$from' + '_' + normalizedFromNetwork,
+      userCurrencyToRaw: '$to' + '_' + '$normalizedToNetwork',
     );
   }
 
@@ -313,6 +316,15 @@ class LetsExchangeExchangeProvider extends ExchangeProvider {
     return currency.title;
   }
 
+  String _normalizeNetworkType(String network) {
+    return switch (network.toUpperCase()) {
+      'ERC20' => 'ETH',
+      'TRC20' => 'TRX',
+      'BEP20' => 'BSC',
+      _ => network,
+    };
+  }
+
   String _normalizeBchAddress(String address) =>
       address.startsWith('bitcoincash:') ? address.substring(12) : address;
 }

lib/exchange/provider/sideshift_exchange_provider.dart

@@ -254,7 +254,9 @@ class SideShiftExchangeProvider extends ExchangeProvider {
 
     final responseJSON = json.decode(response.body) as Map<String, dynamic>;
     final fromCurrency = responseJSON['depositCoin'] as String;
+    final fromNetwork = responseJSON['depositNetwork'] as String?;
     final toCurrency = responseJSON['settleCoin'] as String;
+    final toNetwork = responseJSON['settleNetwork'] as String?;
     final inputAddress = responseJSON['depositAddress'] as String;
     final expectedSendAmount = responseJSON['depositAmount'] as String?;
     final status = responseJSON['status'] as String?;
@@ -275,8 +277,8 @@ class SideShiftExchangeProvider extends ExchangeProvider {
         expiredAt: expiredAt,
         payoutAddress: settleAddress,
         extraId: depositMemo,
-      userCurrencyFromRaw: '${fromCurrency.toUpperCase()}' + '_',
-      userCurrencyToRaw: '${toCurrency.toUpperCase()}' + '_',
+      userCurrencyFromRaw: '${fromCurrency.toUpperCase()}' + '_' + _normalizeNetworkType(fromNetwork ?? ''),
+      userCurrencyToRaw: '${toCurrency.toUpperCase()}' + '_' + _normalizeNetworkType(toNetwork ?? ''),
     );
   }
 
@@ -335,7 +337,7 @@ class SideShiftExchangeProvider extends ExchangeProvider {
         return 'tron';
       case 'LN':
         return 'lightning';
-      case 'POLY':
+      case 'POL':
         return 'polygon';
       case 'ZEC':
         return 'zcash';
@@ -345,4 +347,16 @@ class SideShiftExchangeProvider extends ExchangeProvider {
         return tag.toLowerCase();
     }
   }
+
+  String _normalizeNetworkType(String network) {
+    return switch (network) {
+      'ethereum' => 'ETH',
+      'tron' => 'TRX',
+      'lightning' => 'LN',
+      'polygon' => 'POL',
+      'zcash' => 'ZEC',
+      'avax' => 'AVAXC',
+      _ => network,
+    };
+  }
 }

lib/exchange/provider/stealth_ex_exchange_provider.dart

@@ -224,7 +224,9 @@ class StealthExExchangeProvider extends ExchangeProvider {
 
     final respId = responseJSON['id'] as String;
     final from = deposit['symbol'] as String;
+    final fromNetwork = deposit['network'] as String?;
     final to = withdrawal['symbol'] as String;
+    final toNetwork = withdrawal['network'] as String?;
     final payoutAddress = withdrawal['address'] as String;
     final depositAddress = deposit['address'] as String;
     final refundAddress = responseJSON['refund_address'] as String;
@@ -249,8 +251,8 @@ class StealthExExchangeProvider extends ExchangeProvider {
       createdAt: createdAt,
       isRefund: status == 'refunded',
       extraId: extraId,
-      userCurrencyFromRaw: '${from.toUpperCase()}' + '_',
-      userCurrencyToRaw: '${to.toUpperCase()}' + '_',
+      userCurrencyFromRaw: '${from.toUpperCase()}' + '_' + '${fromNetwork?.toUpperCase() ?? ''}',
+      userCurrencyToRaw: '${to.toUpperCase()}' + '_' + '${toNetwork?.toUpperCase() ?? ''}',
     );
   }
 

lib/exchange/provider/swaptrade_exchange_provider.dart

@@ -81,20 +81,20 @@ class SwapTradeExchangeProvider extends ExchangeProvider {
 
       final coinsInfo = responseJSON['data'] as List<dynamic>;
 
-      for (var coin in coinsInfo) {
-        if (coin['id'].toString().toUpperCase() == _normalizeCurrency(from)) {
-          return Limits(
-            min: double.parse(coin['min'].toString()),
-            max: double.parse(coin['max'].toString()),
-          );
-        }
-      }
+      final coin = coinsInfo.firstWhere(
+            (coin) => coin['id'].toString().toUpperCase() == _normalizeCurrency(from),
+        orElse: () => null,
+      );
 
-      // coin not found:
-      return Limits(min: 0, max: 0);
+      if (coin == null) throw Exception('Coin not found: ${_normalizeCurrency(from)}');
+
+      return Limits(
+        min: double.parse(coin['min'].toString()),
+        max: double.parse(coin['max'].toString()),
+      );
     } catch (e) {
       printV(e.toString());
-      return Limits(min: 0, max: 0);
+      throw Exception('Error fetching limits: ${e.toString()}');
     }
   }
 

lib/exchange/provider/trocador_exchange_provider.dart

@@ -277,7 +277,9 @@ class TrocadorExchangeProvider extends ExchangeProvider {
       final addressProviderMemo = responseJSON['address_provider_memo'] as String?;
 
       final from = responseJSON['ticker_from'] as String;
+      final networkFrom = responseJSON['network_from'] as String?;
       final to = responseJSON['ticker_to'] as String;
+      final networkTo = responseJSON['network_to'] as String?;
 
       return Trade(
         id: id,
@@ -294,8 +296,8 @@ class TrocadorExchangeProvider extends ExchangeProvider {
         providerId: providerId,
         providerName: providerName,
         extraId: addressProviderMemo,
-        userCurrencyFromRaw: '${from.toUpperCase()}' + '_',
-        userCurrencyToRaw: '${to.toUpperCase()}' + '_',
+        userCurrencyFromRaw: '${from.toUpperCase()}' + '_' + _normalizeNetworkType(networkFrom ?? ''),
+        userCurrencyToRaw: '${to.toUpperCase()}' + '_' + _normalizeNetworkType(networkTo ?? ''), // Handle null network
       );
     });
   }
@@ -362,6 +364,18 @@ class TrocadorExchangeProvider extends ExchangeProvider {
     }
   }
 
+  String _normalizeNetworkType(String network) {
+    return switch (network.toUpperCase()) {
+      'ERC20' => 'ETH',
+      'TRC20' => 'TRX',
+      'BEP20' => 'BSC',
+      'LIGHTNING' => 'LN',
+      _ => network,
+    };
+  }
+
+
+
   Future<Uri> _getUri(String path, Map<String, String> queryParams) async {
     final uri = Uri.http(onionApiAuthority, path, queryParams);
 

lib/exchange/trade.dart

@@ -36,9 +36,8 @@ class Trade extends HiveObject {
   }) {
     if (provider != null) providerRaw = provider.raw;
 
-    if (from != null) fromRaw = from.raw;
-
-    if (to != null) toRaw = to.raw;
+    fromRaw = from?.raw ?? -1;
+    toRaw   = to?.raw   ?? -1;
 
     if (state != null) stateRaw = state.raw;
   }
@@ -56,15 +55,15 @@ class Trade extends HiveObject {
   ExchangeProviderDescription get provider =>
       ExchangeProviderDescription.deserialize(raw: providerRaw);
 
-  @HiveField(2, defaultValue: 0)
-  late int fromRaw;
+  @HiveField(2, defaultValue: -1)
+  int fromRaw = -1;
 
-  CryptoCurrency get from => CryptoCurrency.deserialize(raw: fromRaw);
+  CryptoCurrency? get from => CryptoCurrency.safeDeserialize(raw: fromRaw);
 
-  @HiveField(3, defaultValue: 0)
-  late int toRaw;
+  @HiveField(3, defaultValue: -1)
+  int toRaw = -1;
 
-  CryptoCurrency get to => CryptoCurrency.deserialize(raw: toRaw);
+  CryptoCurrency? get to => CryptoCurrency.safeDeserialize(raw: toRaw);
 
   @HiveField(4, defaultValue: '')
   late String stateRaw;
@@ -193,8 +192,8 @@ class Trade extends HiveObject {
     return <String, dynamic>{
       'id': id,
       'provider': provider.serialize(),
-      'input': from.serialize(),
-      'output': to.serialize(),
+      'input': fromRaw,
+      'output': toRaw,
       'date': createdAt != null ? createdAt!.millisecondsSinceEpoch : null,
       'amount': amount,
       'receive_amount': receiveAmount,
@@ -252,8 +251,8 @@ class TradeAdapter extends TypeAdapter<Trade> {
       userCurrencyToRaw: fields[25] as String?,
     )
       ..providerRaw = fields[1] == null ? 0 : fields[1] as int
-      ..fromRaw = fields[2] == null ? 0 : fields[2] as int
-      ..toRaw = fields[3] == null ? 0 : fields[3] as int
+      ..fromRaw = (fields[2] as int?) ?? -1
+      ..toRaw = (fields[3] as int?) ?? -1
       ..stateRaw = fields[4] == null ? '' : fields[4] as String;
   }
 

lib/src/screens/exchange/exchange_page.dart

@@ -368,8 +368,12 @@ class ExchangePage extends BasePage {
 
   void applyTemplate(
       BuildContext context, ExchangeViewModel exchangeViewModel, ExchangeTemplate template) async {
-    final depositCryptoCurrency = CryptoCurrency.fromString(template.depositCurrency);
-    final receiveCryptoCurrency = CryptoCurrency.fromString(template.receiveCurrency);
+    final depositCryptoCurrency = CryptoCurrency.safeParseCurrencyFromString(template.depositCurrency);
+    final receiveCryptoCurrency = CryptoCurrency.safeParseCurrencyFromString(template.receiveCurrency);
+
+    if (depositCryptoCurrency == null || receiveCryptoCurrency == null) { ///TO DO: add support for user tokens
+      return;
+    }
 
     exchangeViewModel.changeDepositCurrency(currency: depositCryptoCurrency);
     exchangeViewModel.changeReceiveCurrency(currency: receiveCryptoCurrency);

lib/src/screens/exchange_trade/exchange_trade_page.dart

@@ -28,10 +28,12 @@ void showInformation(ExchangeTradeViewModel exchangeTradeViewModel, BuildContext
   final trade = exchangeTradeViewModel.trade;
   final walletName = exchangeTradeViewModel.wallet.name;
 
+  final from = trade.from?.toString() ?? trade.userCurrencyFrom.toString();
+
   final information = exchangeTradeViewModel.isSendable
-      ? S.current.exchange_trade_result_confirm(trade.amount, trade.from.toString(), walletName) +
+      ? S.current.exchange_trade_result_confirm(trade.amount, from, walletName) +
           exchangeTradeViewModel.extraInfo
-      : S.current.exchange_result_description(trade.amount, trade.from.toString()) +
+      : S.current.exchange_result_description(trade.amount, from) +
           exchangeTradeViewModel.extraInfo;
 
   showPopUp<void>(

lib/view_model/exchange/exchange_trade_view_model.dart

@@ -128,7 +128,15 @@ abstract class ExchangeTradeViewModelBase with Store {
   @action
   Future<void> confirmSending() async {
     if (!isSendable) return;
-    sendViewModel.selectedCryptoCurrency = trade.from;
+
+    final selected = trade.from ?? trade.userCurrencyFrom;
+    if (selected == null) {
+      printV('No selectable currency for trade ${trade.id}');
+      return;
+    }
+
+    sendViewModel.selectedCryptoCurrency = selected;
+
     final pendingTransaction = await sendViewModel.createTransaction(provider: _provider);
     if (_provider is ThorChainExchangeProvider) {
       trade.id = pendingTransaction?.id ?? '';
@@ -251,7 +259,7 @@ abstract class ExchangeTradeViewModelBase with Store {
 
     bool _isEthToken() =>
         wallet.currency == CryptoCurrency.eth &&
-        tradesStore.trade!.from.tag == CryptoCurrency.eth.title;
+            tradeFrom?.tag == CryptoCurrency.eth.title;
 
     bool _isPolygonToken() =>
         wallet.currency == CryptoCurrency.maticpoly &&