exchange view amount string provider fix

lib/pages/exchange_view/exchange_form.dart

@@ -35,6 +35,7 @@ import 'package:stackwallet/services/exchange/exchange_data_loading_service.dart
 import 'package:stackwallet/services/exchange/majestic_bank/majestic_bank_exchange.dart';
 import 'package:stackwallet/services/exchange/trocador/trocador_exchange.dart';
 import 'package:stackwallet/themes/stack_colors.dart';
+import 'package:stackwallet/utilities/amount/amount_unit.dart';
 import 'package:stackwallet/utilities/assets.dart';
 import 'package:stackwallet/utilities/constants.dart';
 import 'package:stackwallet/utilities/enums/coin_enum.dart';
@@ -160,26 +161,15 @@ class _ExchangeFormState extends ConsumerState<ExchangeForm> {
     if (value == null) {
       return null;
     }
-    try {
-      // wtf Dart?????
-      // This turns "99999999999999999999" into 100000000000000000000.0
-      // final numFromLocalised = NumberFormat.decimalPattern(
-      //         ref.read(localeServiceChangeNotifierProvider).locale)
-      //     .parse(value);
-      // return Decimal.tryParse(numFromLocalised.toString());
 
-      try {
+    return AmountUnit.normal
-        return Decimal.parse(value);
+        .tryParse(
-      } catch (_) {
+          value,
-        try {
+          locale: ref.read(localeServiceChangeNotifierProvider).locale,
-          return Decimal.parse(value.replaceAll(",", "."));
+          coin: Coin.bitcoin, // dummy value (not used due to override)
-        } catch (_) {
+          overrideWithDecimalPlacesFromString: true,
-          rethrow;
+        )
-        }
+        ?.decimal;
-      }
-    } catch (_) {
-      return null;
-    }
   }
 
   Future<AggregateCurrency> _getAggregateCurrency(Currency currency) async {
@@ -824,7 +814,7 @@ class _ExchangeFormState extends ConsumerState<ExchangeForm> {
     });
 
     ref.listen(efEstimateProvider.notifier, (previous, next) {
-      final estimate = (next as StateController<Estimate?>).state;
+      final estimate = (next).state;
       if (ref.read(efReversedProvider)) {
         updateSend(estimate);
       } else {

lib/providers/exchange/exchange_form_state_provider.dart

@@ -13,8 +13,12 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:stackwallet/models/exchange/active_pair.dart';
 import 'package:stackwallet/models/exchange/response_objects/estimate.dart';
 import 'package:stackwallet/models/exchange/response_objects/range.dart';
+import 'package:stackwallet/providers/global/locale_provider.dart';
 import 'package:stackwallet/services/exchange/exchange.dart';
 import 'package:stackwallet/services/exchange/exchange_response.dart';
+import 'package:stackwallet/utilities/amount/amount.dart';
+import 'package:stackwallet/utilities/amount/amount_unit.dart';
+import 'package:stackwallet/utilities/enums/coin_enum.dart';
 import 'package:stackwallet/utilities/enums/exchange_rate_type_enum.dart';
 import 'package:tuple/tuple.dart';
 
@@ -44,7 +48,22 @@ final efSendAmountStringProvider = StateProvider<String>((ref) {
   if (refreshing && reversed) {
     return "-";
   } else {
-    return ref.watch(efSendAmountProvider)?.toString() ?? "";
+    final decimal = ref.watch(efSendAmountProvider);
+    String string = "";
+    if (decimal != null) {
+      final amount = Amount.fromDecimal(decimal, fractionDigits: decimal.scale);
+      final locale = ref.watch(localeServiceChangeNotifierProvider).locale;
+      string = AmountUnit.normal.displayAmount(
+        amount: amount,
+        locale: locale,
+        coin: Coin
+            .nano, // use nano just to ensure decimal.scale < Coin.value.decimals
+        withUnitName: false,
+        maxDecimalPlaces: decimal.scale,
+      );
+    }
+
+    return string;
   }
 });
 final efReceiveAmountStringProvider = StateProvider<String>((ref) {
@@ -54,7 +73,22 @@ final efReceiveAmountStringProvider = StateProvider<String>((ref) {
   if (refreshing && reversed == false) {
     return "-";
   } else {
-    return ref.watch(efReceiveAmountProvider)?.toString() ?? "";
+    final decimal = ref.watch(efReceiveAmountProvider);
+    String string = "";
+    if (decimal != null) {
+      final amount = Amount.fromDecimal(decimal, fractionDigits: decimal.scale);
+      final locale = ref.watch(localeServiceChangeNotifierProvider).locale;
+      string = AmountUnit.normal.displayAmount(
+        amount: amount,
+        locale: locale,
+        coin: Coin
+            .nano, // use nano just to ensure decimal.scale < Coin.value.decimals
+        withUnitName: false,
+        maxDecimalPlaces: decimal.scale,
+      );
+    }
+
+    return string;
   }
 });
 

lib/utilities/amount/amount_unit.dart

@@ -168,6 +168,7 @@ extension AmountUnitExt on AmountUnit {
     required String locale,
     required Coin coin,
     EthContract? tokenContract,
+    bool overrideWithDecimalPlacesFromString = false,
   }) {
     final precisionLost = value.startsWith("~");
 
@@ -201,7 +202,9 @@ extension AmountUnitExt on AmountUnit {
       return null;
     }
 
-    final decimalPlaces = tokenContract?.decimals ?? coin.decimals;
+    final decimalPlaces = overrideWithDecimalPlacesFromString
+        ? decimal.scale
+        : tokenContract?.decimals ?? coin.decimals;
     final realShift = math.min(shift, decimalPlaces);
 
     return decimal.shift(0 - realShift).toAmount(fractionDigits: decimalPlaces);