handle failed best_orders RPC exception during login

assets/translations/en.json

@@ -507,6 +507,8 @@
   "orderBookNoAsks": "No asks found",
   "orderBookNoBids": "No bids found",
   "orderBookEmpty": "Orderbook is empty",
+  "dexNoSwapOffers": "No swap offers available for the selected asset.",
+  "bridgeNoCrossNetworkRoutes": "No cross-network routes found for this asset.",
   "freshAddress": "Fresh address",
   "userActionRequired": "User action required",
   "unknown": "Unknown",

lib/app_config/app_config.dart

@@ -44,6 +44,11 @@ const Duration kPerformanceLogInterval = Duration(minutes: 1);
 /// - Balance and price update polling
 const bool kDebugElectrumLogs = true;
 
+/// Temporary failure simulation toggles for testing UI/flows.
+/// Guarded by kDebugMode in calling sites.
+const bool kSimulateBestOrdersFailure = false;
+const double kSimulatedBestOrdersFailureRate = 0.5; // 50%
+
 // This information is here because it is not contextual and is branded.
 // Names of their own are not localized. Also, the application is initialized before
 // the localization package is initialized.

lib/bloc/bridge_form/bridge_bloc.dart

@@ -238,6 +238,17 @@ class BridgeBloc extends Bloc<BridgeEvent, BridgeState> {
       ),
     );
 
+    // Before login, show 0.00 instead of spinner
+    if (!_isLoggedIn) {
+      emit(
+        state.copyWith(
+          availableBalanceState: () => AvailableBalanceState.unavailable,
+          maxSellAmount: () => null,
+        ),
+      );
+      return;
+    }
+
     _autoActivateCoin(event.coin.abbr);
     _subscribeMaxSellAmount();
 
@@ -392,22 +403,27 @@ class BridgeBloc extends Bloc<BridgeEvent, BridgeState> {
       return;
     }
 
-    if (state.availableBalanceState == AvailableBalanceState.initial ||
-        event.setLoadingStatus) {
+    // If not logged in, show 0.00 (unavailable) and skip spinner
+    if (!_isLoggedIn) {
       emit(
         state.copyWith(
-          availableBalanceState: () => AvailableBalanceState.loading,
+          availableBalanceState: () => AvailableBalanceState.unavailable,
+          maxSellAmount: () => null,
         ),
       );
+      return;
     }
 
-    if (!_isLoggedIn) {
+    if (state.availableBalanceState == AvailableBalanceState.initial ||
+        event.setLoadingStatus) {
       emit(
         state.copyWith(
-          availableBalanceState: () => AvailableBalanceState.unavailable,
+          availableBalanceState: () => AvailableBalanceState.loading,
         ),
       );
-    } else {
+    }
+
+    {
       Rational? maxSellAmount = await _dexRepository.getMaxTakerVolume(
         state.sellCoin!.abbr,
       );

lib/bloc/dex_repository.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+import 'package:flutter/foundation.dart';
 import 'package:rational/rational.dart';
 import 'package:web_dex/app_config/app_config.dart';
 import 'package:web_dex/mm2/mm2_api/mm2_api.dart';
@@ -19,6 +21,8 @@ import 'package:web_dex/mm2/mm2_api/rpc/trade_preimage/trade_preimage_request.da
 import 'package:web_dex/mm2/mm2_api/rpc/trade_preimage/trade_preimage_response.dart';
 import 'package:web_dex/model/data_from_service.dart';
 import 'package:web_dex/model/swap.dart';
+import 'package:web_dex/router/state/routing_state.dart';
+import 'package:web_dex/model/main_menu_value.dart';
 import 'package:web_dex/model/text_error.dart';
 import 'package:web_dex/model/trade_preimage.dart';
 import 'package:web_dex/services/mappers/trade_preimage_mappers.dart';
@@ -54,9 +58,12 @@ class DexRepository {
       swapMethod: swapMethod,
       max: max,
     );
-    final ApiResponse<TradePreimageRequest, TradePreimageResponseResult,
-            Map<String, dynamic>> response =
-        await _mm2Api.getTradePreimage(request);
+    final ApiResponse<
+      TradePreimageRequest,
+      TradePreimageResponseResult,
+      Map<String, dynamic>
+    >
+    response = await _mm2Api.getTradePreimage(request);
 
     final Map<String, dynamic>? error = response.error;
     final TradePreimageResponseResult? result = response.result;
@@ -88,8 +95,9 @@ class DexRepository {
   }
 
   Future<Rational?> getMaxTakerVolume(String coinAbbr) async {
-    final MaxTakerVolResponse? response =
-        await _mm2Api.getMaxTakerVolume(MaxTakerVolRequest(coin: coinAbbr));
+    final MaxTakerVolResponse? response = await _mm2Api.getMaxTakerVolume(
+      MaxTakerVolRequest(coin: coinAbbr),
+    );
     if (response == null) {
       return null;
     }
@@ -98,8 +106,9 @@ class DexRepository {
   }
 
   Future<Rational?> getMaxMakerVolume(String coinAbbr) async {
-    final MaxMakerVolResponse? response =
-        await _mm2Api.getMaxMakerVolume(MaxMakerVolRequest(coin: coinAbbr));
+    final MaxMakerVolResponse? response = await _mm2Api.getMaxMakerVolume(
+      MaxMakerVolRequest(coin: coinAbbr),
+    );
     if (response == null) {
       return null;
     }
@@ -108,8 +117,9 @@ class DexRepository {
   }
 
   Future<Rational?> getMinTradingVolume(String coinAbbr) async {
-    final MinTradingVolResponse? response =
-        await _mm2Api.getMinTradingVol(MinTradingVolRequest(coin: coinAbbr));
+    final MinTradingVolResponse? response = await _mm2Api.getMinTradingVol(
+      MinTradingVolRequest(coin: coinAbbr),
+    );
     if (response == null) {
       return null;
     }
@@ -122,28 +132,82 @@ class DexRepository {
   }
 
   Future<BestOrders> getBestOrders(BestOrdersRequest request) async {
+    // Only allow best_orders when user is on Swap (DEX) or Bridge pages
+    final MainMenuValue current = routingState.selectedMenu;
+    final bool isTradingPage =
+        current == MainMenuValue.dex || current == MainMenuValue.bridge;
+    if (!isTradingPage) {
+      // Not an error – we intentionally suppress best_orders away from trading pages
+      return BestOrders(result: <String, List<BestOrder>>{});
+    }
+
+    // Testing aid: opt-in random failure in debug mode
+    if (kDebugMode &&
+        kSimulateBestOrdersFailure &&
+        Random().nextDouble() < kSimulatedBestOrdersFailureRate) {
+      return BestOrders(
+        error: TextError(error: 'Simulated best_orders failure (debug)'),
+      );
+    }
+
     Map<String, dynamic>? response;
     try {
       response = await _mm2Api.getBestOrders(request);
-    } catch (e) {
+    } catch (e, s) {
+      log(
+        'best_orders request failed: $e',
+        trace: s,
+        path: 'api => getBestOrders',
+        isError: true,
+      ).ignore();
       return BestOrders(error: TextError.fromString(e.toString()));
     }
 
-    final isErrorResponse =
-        (response?['error'] as String?)?.isNotEmpty ?? false;
-    final hasResult =
-        (response?['result'] as Map<String, dynamic>?)?.isNotEmpty ?? false;
+    if (response == null) {
+      return BestOrders(
+        error: TextError(error: 'best_orders returned null response'),
+      );
+    }
+
+    final String? errorText = response['error'] as String?;
+    if (errorText != null && errorText.isNotEmpty) {
+      // Map known "no orders" network condition to empty result so UI shows a
+      // graceful "Nothing found" instead of an error panel.
+      final String? errorType = response['error_type'] as String?;
+      final String? errorPath = response['error_path'] as String?;
+      final bool isNoOrdersNetworkCondition =
+          errorPath == 'best_orders' &&
+          errorType == 'P2PError' &&
+          errorText.contains('No response from any peer');
 
-    if (isErrorResponse) {
-      return BestOrders(error: TextError(error: response!['error']!));
+      // Mm2Api.getBestOrders may wrap MM2 errors in an Exception() during
+      // retry handling, yielding text like: "Exception: No response from any peer"
+      // (without error_type/error_path). Treat these as "no orders" as well.
+      final bool isWrappedNoOrdersText = errorText.toLowerCase().contains(
+        'no response from any peer',
+      );
+
+      if (isNoOrdersNetworkCondition || isWrappedNoOrdersText) {
+        return BestOrders(result: <String, List<BestOrder>>{});
+      }
+
+      log(
+        'best_orders returned error: $errorText',
+        path: 'api => getBestOrders',
+        isError: true,
+      ).ignore();
+      return BestOrders(error: TextError(error: errorText));
     }
 
-    if (!hasResult) {
-      return BestOrders(error: TextError(error: 'Orders not found!'));
+    final Map<String, dynamic>? result =
+        response['result'] as Map<String, dynamic>?;
+    if (result == null || result.isEmpty) {
+      // No error and no result → no liquidity available
+      return BestOrders(result: <String, List<BestOrder>>{});
     }
 
     try {
-      return BestOrders.fromJson(response!);
+      return BestOrders.fromJson(response);
     } catch (e, s) {
       log('Error parsing best_orders response: $e', trace: s, isError: true);
 
@@ -156,8 +220,9 @@ class DexRepository {
   }
 
   Future<Swap> getSwapStatus(String swapUuid) async {
-    final response =
-        await _mm2Api.getSwapStatus(MySwapStatusReq(uuid: swapUuid));
+    final response = await _mm2Api.getSwapStatus(
+      MySwapStatusReq(uuid: swapUuid),
+    );
 
     if (response['error'] != null) {
       throw TextError(error: response['error']);

lib/bloc/taker_form/taker_bloc.dart

@@ -318,6 +318,17 @@ class TakerBloc extends Bloc<TakerEvent, TakerState> {
 
     add(TakerUpdateBestOrders(autoSelectOrderAbbr: event.autoSelectOrderAbbr));
 
+    // Before login, show 0.00 instead of spinner
+    if (!_isLoggedIn) {
+      emit(
+        state.copyWith(
+          availableBalanceState: () => AvailableBalanceState.unavailable,
+          maxSellAmount: () => null,
+        ),
+      );
+      return;
+    }
+
     await _autoActivateCoin(state.sellCoin?.abbr);
     _subscribeMaxSellAmount();
     add(TakerGetMinSellAmount());
@@ -440,6 +451,17 @@ class TakerBloc extends Bloc<TakerEvent, TakerState> {
       _maxSellAmountTimer?.cancel();
       return;
     }
+    // If not logged in, show 0.00 (unavailable) and skip spinner
+    if (!_isLoggedIn) {
+      emitter(
+        state.copyWith(
+          availableBalanceState: () => AvailableBalanceState.unavailable,
+          maxSellAmount: () => null,
+        ),
+      );
+      return;
+    }
+
     if (state.availableBalanceState == AvailableBalanceState.initial ||
         event.setLoadingStatus) {
       emitter(
@@ -469,34 +491,26 @@ class TakerBloc extends Bloc<TakerEvent, TakerState> {
         return;
       }
 
-      if (!_isLoggedIn) {
+      Rational? maxSellAmount = await _dexRepo.getMaxTakerVolume(
+        state.sellCoin!.abbr,
+      );
+      if (maxSellAmount != null) {
         emitter(
           state.copyWith(
-            availableBalanceState: () => AvailableBalanceState.unavailable,
+            maxSellAmount: () => maxSellAmount,
+            availableBalanceState: () => AvailableBalanceState.success,
           ),
         );
       } else {
-        Rational? maxSellAmount = await _dexRepo.getMaxTakerVolume(
-          state.sellCoin!.abbr,
+        maxSellAmount = await _frequentlyGetMaxTakerVolume();
+        emitter(
+          state.copyWith(
+            maxSellAmount: () => maxSellAmount,
+            availableBalanceState: maxSellAmount == null
+                ? () => AvailableBalanceState.failure
+                : () => AvailableBalanceState.success,
+          ),
         );
-        if (maxSellAmount != null) {
-          emitter(
-            state.copyWith(
-              maxSellAmount: () => maxSellAmount,
-              availableBalanceState: () => AvailableBalanceState.success,
-            ),
-          );
-        } else {
-          maxSellAmount = await _frequentlyGetMaxTakerVolume();
-          emitter(
-            state.copyWith(
-              maxSellAmount: () => maxSellAmount,
-              availableBalanceState: maxSellAmount == null
-                  ? () => AvailableBalanceState.failure
-                  : () => AvailableBalanceState.success,
-            ),
-          );
-        }
       }
     } catch (e, s) {
       _log.severe('Failed to update max sell amount', e, s);

lib/blocs/maker_form_bloc.dart

@@ -246,7 +246,10 @@ class MakerFormBloc implements BlocBase {
   Future<void> _updateMaxSellAmountListener() async {
     _maxSellAmountTimer?.cancel();
     maxSellAmount = null;
-    availableBalanceState = AvailableBalanceState.loading;
+    // Only show loading spinner when signed in
+    final bool isSignedIn = await kdfSdk.auth.isSignedIn();
+    availableBalanceState =
+        isSignedIn ? AvailableBalanceState.loading : AvailableBalanceState.unavailable;
     isMaxActive = false;
 
     await _updateMaxSellAmount();
@@ -259,17 +262,17 @@ class MakerFormBloc implements BlocBase {
 
   Future<void> _updateMaxSellAmount() async {
     final Coin? coin = sellCoin;
-    if (availableBalanceState == AvailableBalanceState.initial) {
-      availableBalanceState = AvailableBalanceState.loading;
-    }
-
     final bool isSignedIn = await kdfSdk.auth.isSignedIn();
     if (!isSignedIn) {
       maxSellAmount = null;
       availableBalanceState = AvailableBalanceState.unavailable;
       return;
     }
 
+    if (availableBalanceState == AvailableBalanceState.initial) {
+      availableBalanceState = AvailableBalanceState.loading;
+    }
+
     if (coin == null) {
       maxSellAmount = null;
       availableBalanceState = AvailableBalanceState.unavailable;

lib/generated/codegen_loader.g.dart

@@ -503,6 +503,8 @@ abstract class  LocaleKeys {
   static const orderBookNoAsks = 'orderBookNoAsks';
   static const orderBookNoBids = 'orderBookNoBids';
   static const orderBookEmpty = 'orderBookEmpty';
+  static const dexNoSwapOffers = 'dexNoSwapOffers';
+  static const bridgeNoCrossNetworkRoutes = 'bridgeNoCrossNetworkRoutes';
   static const freshAddress = 'freshAddress';
   static const userActionRequired = 'userActionRequired';
   static const unknown = 'unknown';