cake_wallet/lib/view_model/dashboard/balance_view_model.dart

import 'package:cake_wallet/bitcoin/bitcoin_wallet.dart';
import 'package:cake_wallet/core/wallet_base.dart';
import 'package:cake_wallet/entities/crypto_currency.dart';
import 'package:cake_wallet/monero/monero_balance.dart';
import 'package:cake_wallet/monero/monero_wallet.dart';
import 'package:cake_wallet/entities/balance_display_mode.dart';
import 'package:cake_wallet/entities/calculate_fiat_amount.dart';
import 'package:cake_wallet/store/app_store.dart';
import 'package:cake_wallet/view_model/dashboard/wallet_balance.dart';
import 'package:cake_wallet/store/settings_store.dart';
import 'package:cake_wallet/store/dashboard/fiat_conversion_store.dart';
import 'package:flutter/cupertino.dart';
import 'package:mobx/mobx.dart';

part 'balance_view_model.g.dart';

class BalanceViewModel = BalanceViewModelBase with _$BalanceViewModel;

abstract class BalanceViewModelBase with Store {
  BalanceViewModelBase({
    @required this.appStore,
    @required this.settingsStore,
    @required this.fiatConvertationStore
  }) {
    isReversing = false;

    wallet ??= appStore.wallet;

    _reaction = reaction((_) => appStore.wallet, _onWalletChange);

    final _wallet = wallet;

    if (_wallet is MoneroWallet) {
      moneroBalance = _wallet.balance;

      _onMoneroBalanceChangeReaction = reaction((_) => _wallet.balance,
              (MoneroBalance balance) => moneroBalance = balance);
    }
  }

  final AppStore appStore;
  final SettingsStore settingsStore;
  final FiatConversionStore fiatConvertationStore;

  @observable
  bool isReversing;

  @observable
  MoneroBalance moneroBalance;

  @observable
  WalletBase wallet;

  @computed
  BalanceDisplayMode get savedDisplayMode => settingsStore.balanceDisplayMode;

  @computed
  BalanceDisplayMode get displayMode => isReversing
  ? (savedDisplayMode == BalanceDisplayMode.availableBalance
    ? BalanceDisplayMode.fullBalance
    : BalanceDisplayMode.availableBalance)
  : savedDisplayMode;

  @computed
  double get price => fiatConvertationStore.price;

  @computed
  String get cryptoBalance {
    final walletBalance = _walletBalance;
    var balance = '---';

    if (displayMode == BalanceDisplayMode.availableBalance) {
      balance = walletBalance.unlockedBalance ?? '0.0';
    }

    if (displayMode == BalanceDisplayMode.fullBalance) {
      balance = walletBalance.totalBalance ?? '0.0';
    }

    return balance;
  }

  @computed
  String get fiatBalance {
    final walletBalance = _walletBalance;
    final fiatCurrency = settingsStore.fiatCurrency;
    var balance = '---';

    final totalBalance = _getFiatBalance(
        price: price,
        cryptoAmount: walletBalance.totalBalance
    );

    final unlockedBalance = _getFiatBalance(
        price: price,
        cryptoAmount: walletBalance.unlockedBalance
    );

    if (displayMode == BalanceDisplayMode.availableBalance) {
      balance = fiatCurrency.toString() + ' ' + unlockedBalance ?? '0.00';
    }

    if (displayMode == BalanceDisplayMode.fullBalance) {
      balance = fiatCurrency.toString() + ' ' + totalBalance ?? '0.00';
    }

    return balance;
  }

  @computed
  WalletBalance get _walletBalance {
    final _wallet = wallet;

    if (_wallet is MoneroWallet) {
      return  WalletBalance(
          unlockedBalance: moneroBalance.formattedUnlockedBalance,
          totalBalance: moneroBalance.formattedFullBalance);
    }

    if (_wallet is BitcoinWallet) {
      return WalletBalance(
          unlockedBalance: _wallet.balance.totalFormatted,
          totalBalance: _wallet.balance.totalFormatted);
    }

    return null;
  }

  @computed
  CryptoCurrency get currency => appStore.wallet.currency;

  @action
  void _onWalletChange(WalletBase wallet) {
    this.wallet = wallet;

    if (wallet is MoneroWallet) {
      moneroBalance = wallet.balance;

      _onMoneroBalanceChangeReaction?.reaction?.dispose();

      _onMoneroBalanceChangeReaction = reaction((_) => wallet.balance,
              (MoneroBalance balance) => moneroBalance = balance);
    }
  }

  ReactionDisposer _onMoneroBalanceChangeReaction;

  ReactionDisposer _reaction;

  String _getFiatBalance({double price, String cryptoAmount}) {
    if (cryptoAmount == null) {
      return '0.00';
    }

    return calculateFiatAmount(price: price, cryptoAmount: cryptoAmount);
  }
}