feat: amount formatter and associated providers + prefs

lib/utilities/amount/amount_formatter.dart

@@ -0,0 +1,55 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:stackwallet/providers/global/locale_provider.dart';
+import 'package:stackwallet/providers/global/prefs_provider.dart';
+import 'package:stackwallet/utilities/amount/amount.dart';
+import 'package:stackwallet/utilities/amount/amount_unit.dart';
+import 'package:stackwallet/utilities/enums/coin_enum.dart';
+
+final pAmountUnit = Provider.family<AmountUnit, Coin>(
+  (ref, coin) => ref.watch(
+    prefsChangeNotifierProvider.select(
+      (value) => value.amountUnit(coin),
+    ),
+  ),
+);
+final pMaxDecimals = Provider.family<int, Coin>(
+  (ref, coin) => ref.watch(
+    prefsChangeNotifierProvider.select(
+      (value) => value.maxDecimals(coin),
+    ),
+  ),
+);
+
+final pAmountFormatter = Provider.family<AmountFormatter, Coin>((ref, coin) {
+  return AmountFormatter(
+    unit: ref.watch(pAmountUnit(coin)),
+    locale: ref.watch(
+      localeServiceChangeNotifierProvider.select((value) => value.locale),
+    ),
+    coin: coin,
+    maxDecimals: ref.watch(pMaxDecimals(coin)),
+  );
+});
+
+class AmountFormatter {
+  final AmountUnit unit;
+  final String locale;
+  final Coin coin;
+  final int maxDecimals;
+
+  AmountFormatter({
+    required this.unit,
+    required this.locale,
+    required this.coin,
+    required this.maxDecimals,
+  });
+
+  String format(Amount amount) {
+    return unit.displayAmount(
+      amount: amount,
+      locale: locale,
+      coin: coin,
+      maxDecimalPlaces: maxDecimals,
+    );
+  }
+}

lib/utilities/amount/amount_unit.dart

@@ -6,6 +6,7 @@ import 'package:intl/number_symbols_data.dart';
 import 'package:stackwallet/utilities/amount/amount.dart';
 import 'package:stackwallet/utilities/enums/coin_enum.dart';
 
+// preserve index order as index is used to store value in preferences
 enum AmountUnit {
   normal(0),
   milli(3),

lib/utilities/prefs.dart

@@ -1,7 +1,9 @@
 import 'package:flutter/cupertino.dart';
 import 'package:stackwallet/db/hive/db.dart';
+import 'package:stackwallet/utilities/amount/amount_unit.dart';
 import 'package:stackwallet/utilities/constants.dart';
 import 'package:stackwallet/utilities/enums/backup_frequency_type.dart';
+import 'package:stackwallet/utilities/enums/coin_enum.dart';
 import 'package:stackwallet/utilities/enums/languages_enum.dart';
 import 'package:stackwallet/utilities/enums/sync_type_enum.dart';
 import 'package:uuid/uuid.dart';
@@ -46,6 +48,8 @@ class Prefs extends ChangeNotifier {
       _themeId = await _getThemeId();
       _systemBrightnessLightThemeId = await _getSystemBrightnessLightThemeId();
       _systemBrightnessDarkThemeId = await _getSystemBrightnessDarkTheme();
+      await _setAmountUnits();
+      await _setMaxDecimals();
 
       _initialized = true;
     }
@@ -796,4 +800,62 @@ class Prefs extends ChangeNotifier {
         ) as String? ??
         "dark";
   }
+
+  // coin amount unit settings
+
+  final Map<Coin, AmountUnit> _amountUnits = {};
+
+  AmountUnit amountUnit(Coin coin) => _amountUnits[coin] ?? AmountUnit.normal;
+
+  void updateAmountUnit({required Coin coin, required AmountUnit amountUnit}) {
+    if (this.amountUnit(coin) != amountUnit) {
+      DB.instance.put<dynamic>(
+        boxName: DB.boxNamePrefs,
+        key: "amountUnitFor${coin.name}",
+        value: amountUnit.index,
+      );
+      _amountUnits[coin] = amountUnit;
+      notifyListeners();
+    }
+  }
+
+  Future<void> _setAmountUnits() async {
+    for (final coin in Coin.values) {
+      final unitIndex = await DB.instance.get<dynamic>(
+            boxName: DB.boxNamePrefs,
+            key: "amountUnitFor${coin.name}",
+          ) as int? ??
+          0; // 0 is "normal"
+      _amountUnits[coin] = AmountUnit.values[unitIndex];
+    }
+  }
+
+  // coin precision setting (max decimal places to show)
+
+  final Map<Coin, int> _amountDecimals = {};
+
+  int maxDecimals(Coin coin) => _amountDecimals[coin] ?? coin.decimals;
+
+  void updateMaxDecimals({required Coin coin, required int maxDecimals}) {
+    if (this.maxDecimals(coin) != maxDecimals) {
+      DB.instance.put<dynamic>(
+        boxName: DB.boxNamePrefs,
+        key: "maxDecimalsFor${coin.name}",
+        value: maxDecimals,
+      );
+      _amountDecimals[coin] = maxDecimals;
+      notifyListeners();
+    }
+  }
+
+  Future<void> _setMaxDecimals() async {
+    for (final coin in Coin.values) {
+      final decimals = await DB.instance.get<dynamic>(
+            boxName: DB.boxNamePrefs,
+            key: "maxDecimalsFor${coin.name}",
+          ) as int? ??
+          coin.decimals;
+      _amountDecimals[coin] = decimals;
+    }
+  }
 }