fix: better handle exchange url launching

lib/buy/sell_buy_states.dart

@@ -17,4 +17,8 @@ class BuySellQuotLoading extends BuySellQuotLoadingState {}
 
 class BuySellQuotLoaded extends BuySellQuotLoadingState {}
 
-class BuySellQuotFailed extends BuySellQuotLoadingState {}
+class BuySellQuotFailed extends BuySellQuotLoadingState {
+  final String? errorMessage;
+
+  BuySellQuotFailed({this.errorMessage});
+}

lib/core/wallet_loading_service.dart

@@ -131,7 +131,11 @@ class WalletLoadingService {
               alertContent: S.of(context).corrupted_seed_notice,
               leftButtonText: S.of(context).cancel,
               rightButtonText: S.of(context).show_seed,
-              actionLeftButton: () => Navigator.of(context).pop(),
+              actionLeftButton: () {
+                if (context.mounted && Navigator.of(context).canPop()) {
+                  Navigator.of(context).pop();
+                }
+              },
               actionRightButton: () => showSeedsPopup(context, msg),
             );
         });

lib/src/screens/buy/buy_sell_page.dart

@@ -148,7 +148,7 @@ class BuySellPage extends BasePage {
             bottomSection: Observer(
               builder: (_) => Column(
                 children: [
-                  if (buySellViewModel.isBuySellQuotFailed)
+                  if (buySellViewModel.isBuySellQuoteFailed)
                     Padding(
                       padding: EdgeInsets.only(bottom: 15),
                       child: Row(
@@ -166,7 +166,8 @@ class BuySellPage extends BasePage {
                           Expanded(
                             flex: 8,
                             child: Text(
-                              S.of(context).buy_sell_pair_is_not_supported_warning,
+                              buySellViewModel.buySellQuoteFailedError ??
+                                  S.of(context).buy_sell_pair_is_not_supported_warning,
                               textAlign: TextAlign.center,
                               softWrap: true,
                               overflow: TextOverflow.ellipsis,
@@ -188,9 +189,9 @@ class BuySellPage extends BasePage {
                     },
                     color: Theme.of(context).colorScheme.primary,
                     textColor: Theme.of(context).colorScheme.onPrimary,
-                    isDisabled: buySellViewModel.isBuySellQuotFailed,
+                    isDisabled: buySellViewModel.isBuySellQuoteFailed,
                     isLoading:
-                        !buySellViewModel.isReadyToTrade && !buySellViewModel.isBuySellQuotFailed,
+                        !buySellViewModel.isReadyToTrade && !buySellViewModel.isBuySellQuoteFailed,
                   ),
                 ],
               ),

lib/view_model/buy/buy_sell_view_model.dart

@@ -157,7 +157,12 @@ abstract class BuySellViewModelBase extends WalletChangeListenerViewModel with S
   }
 
   @computed
-  bool get isBuySellQuotFailed => buySellQuotState is BuySellQuotFailed;
+  bool get isBuySellQuoteFailed => buySellQuotState is BuySellQuotFailed;
+
+  @computed
+  String? get buySellQuoteFailedError => buySellQuotState is BuySellQuotFailed
+      ? (buySellQuotState as BuySellQuotFailed).errorMessage
+      : null;
 
   @action
   void reset() {
@@ -201,10 +206,10 @@ abstract class BuySellViewModelBase extends WalletChangeListenerViewModel with S
 
     final enteredAmount = double.tryParse(amount.replaceAll(',', '.')) ?? 0;
 
-    if (!isReadyToTrade && !isBuySellQuotFailed) {
+    if (!isReadyToTrade && !isBuySellQuoteFailed) {
       cryptoAmount = S.current.fetching;
       return;
-    } else if (isBuySellQuotFailed) {
+    } else if (isBuySellQuoteFailed) {
       cryptoAmount = '';
       return;
     }
@@ -232,10 +237,10 @@ abstract class BuySellViewModelBase extends WalletChangeListenerViewModel with S
 
     final enteredAmount = double.tryParse(amount.replaceAll(',', '.')) ?? 0;
 
-    if (!isReadyToTrade && !isBuySellQuotFailed) {
+    if (!isReadyToTrade && !isBuySellQuoteFailed) {
       fiatAmount = S.current.fetching;
       return;
-    } else if (isBuySellQuotFailed) {
+    } else if (isBuySellQuoteFailed) {
       fiatAmount = '';
       return;
     }
@@ -478,12 +483,20 @@ abstract class BuySellViewModelBase extends WalletChangeListenerViewModel with S
   @action
   Future<void> launchTrade(BuildContext context) async {
     final provider = selectedQuote!.provider;
-    await provider.launchProvider(
-      context: context,
-      quote: selectedQuote!,
-      amount: amount,
-      isBuyAction: isBuyAction,
-      cryptoCurrencyAddress: cryptoCurrencyAddress,
-    );
+    try {
+      await provider.launchProvider(
+        context: context,
+        quote: selectedQuote!,
+        amount: amount,
+        isBuyAction: isBuyAction,
+        cryptoCurrencyAddress: cryptoCurrencyAddress,
+      );
+    } catch (e) {
+      if (e.toString().contains("403")) {
+        buySellQuotState = BuySellQuotFailed(errorMessage: "Using Tor is not supported");
+      } else {
+        buySellQuotState = BuySellQuotFailed(errorMessage: "Something went wrong please try again later");
+      }
+    }
   }
 }