CW-1155: Mask fiat amounts to be more readable (#2420)

* feat: Mask fiat amounts to be more readable, with comma formating for large numbers

* fix: Add fiat masking to buy and sell

lib/buy/buy_quote.dart

@@ -1,6 +1,7 @@
 import 'package:cake_wallet/buy/buy_provider.dart';
 import 'package:cake_wallet/buy/payment_method.dart';
 import 'package:cake_wallet/core/selectable_option.dart';
+import 'package:cake_wallet/entities/calculate_fiat_amount.dart';
 import 'package:cake_wallet/entities/fiat_currency.dart';
 import 'package:cake_wallet/entities/provider_types.dart';
 import 'package:cake_wallet/exchange/limits.dart';
@@ -96,7 +97,7 @@ class Quote extends SelectableOption {
 
   @override
   String get topLeftSubTitle =>
-      this.rate > 0 ? '1 $cryptoName = ${rate.toStringAsFixed(2)} $fiatName' : '';
+      this.rate > 0 ? '1 $cryptoName = ${formatWithCommas(rate.toStringAsFixed(2))} $fiatName' : '';
 
   @override
   String get bottomLeftSubTitle {

lib/entities/calculate_fiat_amount.dart

@@ -4,7 +4,7 @@ String calculateFiatAmount({double? price, String? cryptoAmount}) {
   }
 
   cryptoAmount = cryptoAmount.replaceAll(',', '.');
-  
+
   final _amount = double.parse(cryptoAmount);
   final _result = price * _amount;
   final result = _result < 0 ? _result * -1 : _result;
@@ -15,14 +15,31 @@ String calculateFiatAmount({double? price, String? cryptoAmount}) {
 
   var formatted = '';
   final parts = result.toString().split('.');
-  
+
   if (parts.length >= 2) {
     if (parts[1].length > 2) {
-      formatted = parts[0] + '.' + parts[1].substring(0, 2);
+      formatted = formatWithCommas(parts[0] + '.' + parts[1].substring(0, 2));
     } else {
-      formatted = parts[0] + '.' + parts[1];
+      formatted = formatWithCommas(parts[0] + '.' + parts[1]);
     }
+  } else {
+    formatted = formatWithCommas(parts[0]);
   }
 
   return result > 0.01 ? formatted : '< 0.01';
 }
+
+String formatWithCommas(String number) {
+  if (number.isEmpty) return number;
+
+  final parts = number.split('.');
+  final integerPart = parts[0];
+  final decimalPart = parts.length > 1 ? parts[1] : '';
+
+  final formattedInteger = integerPart.replaceAllMapped(
+    RegExp(r'\B(?=(\d{3})+(?!\d))'),
+    (Match match) => ',',
+  );
+
+  return decimalPart.isNotEmpty ? '$formattedInteger.$decimalPart' : formattedInteger;
+}

lib/entities/calculate_fiat_amount_raw.dart

@@ -1,3 +1,5 @@
+import 'calculate_fiat_amount.dart';
+
 String calculateFiatAmountRaw({required double cryptoAmount, double? price}) {
   if (price == null) {
     return '0.00';
@@ -9,5 +11,5 @@ String calculateFiatAmountRaw({required double cryptoAmount, double? price}) {
     return '0.00';
   }
 
-  return result > 0.01 ? result.toStringAsFixed(2) : '< 0.01';
+  return result > 0.01 ? formatWithCommas(result.toStringAsFixed(2)) : '< 0.01';
 }

lib/entities/format_amount.dart

@@ -1,8 +1,10 @@
+import 'calculate_fiat_amount.dart';
+
 String formatAmount(String amount) {
   if ((!amount.contains('.'))&&(!amount.contains(','))) {
-    return amount + '.00';
+    return formatWithCommas(amount + '.00');
   } else if ((amount.endsWith('.'))||(amount.endsWith(','))) {
-    return amount + '00';
+    return formatWithCommas(amount + '00');
   }
-  return amount;
+  return formatWithCommas(amount);
 }