cake_wallet/lib/src/screens/exchange/exchange_page.dart

import 'package:cake_wallet/di.dart';
import 'package:cake_wallet/src/screens/exchange/widgets/desktop_exchange_cards_section.dart';
import 'package:cake_wallet/src/screens/exchange/widgets/mobile_exchange_cards_section.dart';
import 'package:cake_wallet/src/widgets/add_template_button.dart';
import 'package:cake_wallet/themes/theme_base.dart';
import 'package:cake_wallet/utils/debounce.dart';
import 'package:cake_wallet/utils/responsive_layout_util.dart';
import 'package:cw_core/sync_status.dart';
import 'package:cw_core/wallet_type.dart';
import 'package:cake_wallet/entities/parse_address_from_domain.dart';
import 'package:cake_wallet/src/screens/send/widgets/extract_address_from_parsed.dart';
import 'package:cake_wallet/src/widgets/standard_checkbox.dart';
import 'package:flutter/material.dart';
import 'package:flutter_mobx/flutter_mobx.dart';
import 'package:keyboard_actions/keyboard_actions.dart';
import 'package:mobx/mobx.dart';
import 'package:cake_wallet/exchange/exchange_template.dart';
import 'package:cake_wallet/exchange/exchange_trade_state.dart';
import 'package:cake_wallet/exchange/limits_state.dart';
import 'package:cake_wallet/src/screens/base_page.dart';
import 'package:cake_wallet/src/widgets/alert_with_two_actions.dart';
import 'package:cake_wallet/src/widgets/keyboard_done_button.dart';
import 'package:cake_wallet/src/widgets/template_tile.dart';
import 'package:cake_wallet/src/widgets/trail_button.dart';
import 'package:cake_wallet/utils/show_pop_up.dart';
import 'package:cake_wallet/routes.dart';
import 'package:cake_wallet/generated/i18n.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:cake_wallet/src/screens/exchange/widgets/exchange_card.dart';
import 'package:cake_wallet/src/widgets/primary_button.dart';
import 'package:cake_wallet/src/widgets/scollable_with_bottom_section.dart';
import 'package:cake_wallet/src/widgets/alert_with_one_action.dart';
import 'package:cake_wallet/view_model/exchange/exchange_view_model.dart';
import 'package:cake_wallet/core/address_validator.dart';
import 'package:cake_wallet/core/amount_validator.dart';
import 'package:cake_wallet/src/screens/exchange/widgets/present_provider_picker.dart';
import 'package:cake_wallet/src/screens/dashboard/widgets/sync_indicator_icon.dart';

class ExchangePage extends BasePage {
  ExchangePage(this.exchangeViewModel) {
    depositWalletName = exchangeViewModel.depositCurrency == CryptoCurrency.xmr
        ? exchangeViewModel.wallet.name
        : null;
    receiveWalletName = exchangeViewModel.receiveCurrency == CryptoCurrency.xmr
        ? exchangeViewModel.wallet.name
        : null;
  }

  final ExchangeViewModel exchangeViewModel;
  final depositKey = GlobalKey<ExchangeCardState>();
  final receiveKey = GlobalKey<ExchangeCardState>();
  final _formKey = GlobalKey<FormState>();
  final _depositAmountFocus = FocusNode();
  final _depositAddressFocus = FocusNode();
  final _receiveAmountFocus = FocusNode();
  final _receiveAddressFocus = FocusNode();
  final _receiveAmountDebounce = Debounce(Duration(milliseconds: 500));
  final _depositAmountDebounce = Debounce(Duration(milliseconds: 500));
  var _isReactionsSet = false;

  final arrowBottomPurple = Image.asset(
    'assets/images/arrow_bottom_purple_icon.png',
    color: Colors.white,
    height: 8,
  );
  final arrowBottomCakeGreen = Image.asset(
    'assets/images/arrow_bottom_cake_green.png',
    color: Colors.white,
    height: 8,
  );

  late final String? depositWalletName;
  late final String? receiveWalletName;

  @override
  String get title => S.current.exchange;

  @override
  Color get titleColor => Colors.white;

  @override
  bool get resizeToAvoidBottomInset => false;

  @override
  bool get extendBodyBehindAppBar => true;

  @override
  AppBarStyle get appBarStyle => AppBarStyle.transparent;

  @override
  Widget middle(BuildContext context) => Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Padding(
          padding: const EdgeInsets.only(right:6.0),
          child: Observer(builder: (_) => SyncIndicatorIcon(isSynced: exchangeViewModel.status is SyncedSyncStatus),)
        ),
        PresentProviderPicker(exchangeViewModel: exchangeViewModel)
      ],
    );


  @override
  Widget trailing(BuildContext context) => TrailButton(
      caption: S.of(context).reset,
      onPressed: () {
        _formKey.currentState?.reset();
        exchangeViewModel.reset();
      });

  @override
  Widget? leading(BuildContext context) {
    final _backButton = Icon(Icons.arrow_back_ios,
      color: titleColor,
      size: 16,
    );
    final _closeButton = currentTheme.type == ThemeType.dark
        ? closeButtonImageDarkTheme : closeButtonImage;

    bool isMobileView = ResponsiveLayoutUtil.instance.isMobile(context);

    return MergeSemantics(
      child: SizedBox(
        height: isMobileView ? 37 : 45,
        width: isMobileView ? 37 : 45,
        child: ButtonTheme(
          minWidth: double.minPositive,
          child: Semantics(
            label: !isMobileView ? 'Close' : 'Back',
            child: TextButton(
              style: ButtonStyle(
                overlayColor: MaterialStateColor.resolveWith(
                        (states) => Colors.transparent),
              ),
              onPressed: () => onClose(context),
              child: !isMobileView ? _closeButton : _backButton,
            ),
          ),
        ),
      ),
    );
  }

  @override
  Widget body(BuildContext context) {
    WidgetsBinding.instance
        .addPostFrameCallback((_) => _setReactions(context, exchangeViewModel));

    return KeyboardActions(
        disableScroll: true,
        config: KeyboardActionsConfig(
            keyboardActionsPlatform: KeyboardActionsPlatform.IOS,
            keyboardBarColor:
                Theme.of(context).accentTextTheme!.bodyText1!.backgroundColor!,
            nextFocus: false,
            actions: [
              KeyboardActionsItem(
                  focusNode: _depositAmountFocus,
                  toolbarButtons: [(_) => KeyboardDoneButton()]),
              KeyboardActionsItem(
                  focusNode: _receiveAmountFocus,
                  toolbarButtons: [(_) => KeyboardDoneButton()])
            ]),
        child: Container(
          color: Theme.of(context).backgroundColor,
          child: Form(
              key: _formKey,
              child: ScrollableWithBottomSection(
                contentPadding: EdgeInsets.only(bottom: 24),
                content: Observer(builder: (_) => Column(
                  children: <Widget>[
                    _exchangeCardsSection(context),
                    Padding(
                      padding: EdgeInsets.only(top: 12, left: 24),
                      child: Row(
                        mainAxisAlignment: MainAxisAlignment.start,
                        children: [
                          StandardCheckbox(
                            value: exchangeViewModel.isFixedRateMode,
                            caption: S.of(context).fixed_rate,
                            onChanged: (value) =>
                            exchangeViewModel.isFixedRateMode = value,
                          ),
                        ],
                      )
                    ),
                    SizedBox(height: 30),
                    _buildTemplateSection(context)
                    ],
                  ),
                ),
                bottomSectionPadding:
                    EdgeInsets.only(left: 24, right: 24, bottom: 24),
                bottomSection: Column(children: <Widget>[
                  Padding(
                    padding: EdgeInsets.only(bottom: 15),
                    child: Observer(builder: (_) {
                      final description = exchangeViewModel.isFixedRateMode
                          ? exchangeViewModel.isAvailableInSelected
                              ? S.of(context).amount_is_guaranteed
                              : S.of(context).fixed_pair_not_supported
                          : exchangeViewModel.isAvailableInSelected
                              ? S.of(context).amount_is_estimate
                              : S.of(context).variable_pair_not_supported;
                      return Center(
                        child: Text(
                          description,
                          textAlign: TextAlign.center,
                          style: TextStyle(
                              color: Theme.of(context)
                                  .primaryTextTheme!
                                  .headline1!
                                  .decorationColor!,
                              fontWeight: FontWeight.w500,
                              fontSize: 12),
                        ),
                      );
                    }),
                  ),
                  Observer(
                      builder: (_) => LoadingPrimaryButton(
                          text: S.of(context).exchange,
                          onPressed: () {
                            if (_formKey.currentState != null && _formKey.currentState!.validate()) {
                              if ((exchangeViewModel.depositCurrency ==
                                      CryptoCurrency.xmr) &&
                                  (!(exchangeViewModel.status
                                      is SyncedSyncStatus))) {
                                showPopUp<void>(
                                    context: context,
                                    builder: (BuildContext context) {
                                      return AlertWithOneAction(
                                          alertTitle: S.of(context).exchange,
                                          alertContent: S
                                              .of(context)
                                              .exchange_sync_alert_content,
                                          buttonText: S.of(context).ok,
                                          buttonAction: () =>
                                              Navigator.of(context).pop());
                                    });
                              } else {
                                exchangeViewModel.createTrade();
                              }
                            }
                          },
                          color: Theme.of(context).accentTextTheme!.bodyText1!.color!,
                          textColor: Colors.white,
                          isDisabled: exchangeViewModel.selectedProviders.isEmpty,
                          isLoading: exchangeViewModel.tradeState is TradeIsCreating)),
                ]),
              )),
        ));
  }

  Widget _buildTemplateSection(BuildContext context) {
    return Container(
      height: 40,
      width: double.infinity,
      padding: EdgeInsets.only(left: 24),
      child: SingleChildScrollView(
        scrollDirection: Axis.horizontal,
        child: Observer(
          builder: (_) {
            final templates = exchangeViewModel.templates;
      
            return Row(
              children: <Widget>[
                AddTemplateButton(
                  onTap: () => Navigator.of(context).pushNamed(Routes.exchangeTemplate),
                  currentTemplatesLength: templates.length,
                ),
                ListView.builder(
                  scrollDirection: Axis.horizontal,
                  shrinkWrap: true,
                  physics: NeverScrollableScrollPhysics(),
                  itemCount: templates.length,
                  itemBuilder: (context, index) {
                    final template = templates[index];

                    return TemplateTile(
                      key: UniqueKey(),
                      amount: template.amount,
                      from: template.depositCurrency,
                      to: template.receiveCurrency,
                      onTap: () {
                        applyTemplate(context, exchangeViewModel, template);
                      },
                      onRemove: () {
                        showPopUp<void>(
                            context: context,
                            builder: (dialogContext) {
                              return AlertWithTwoActions(
                                  alertTitle: S.of(context).template,
                                  alertContent:
                                      S.of(context).confirm_delete_template,
                                  rightButtonText: S.of(context).delete,
                                  leftButtonText: S.of(context).cancel,
                                  actionRightButton: () {
                                    Navigator.of(dialogContext).pop();
                                    exchangeViewModel.removeTemplate(
                                        template: template);
                                    exchangeViewModel.updateTemplate();
                                  },
                                  actionLeftButton: () =>
                                      Navigator.of(dialogContext).pop());
                            });
                      },
                    );
                  },
                ),
              ],
            );
          },
        ),
      ),
    );
  }

  void applyTemplate(BuildContext context,
      ExchangeViewModel exchangeViewModel, ExchangeTemplate template) async {
    exchangeViewModel.changeDepositCurrency(
        currency: CryptoCurrency.fromString(template.depositCurrency));
    exchangeViewModel.changeReceiveCurrency(
        currency: CryptoCurrency.fromString(template.receiveCurrency));

    exchangeViewModel.changeDepositAmount(amount: template.amount);
    exchangeViewModel.depositAddress = template.depositAddress;
    exchangeViewModel.receiveAddress = template.receiveAddress;
    exchangeViewModel.isReceiveAmountEntered = false;
    exchangeViewModel.isFixedRateMode = false;

    var domain = template.depositAddress;
    var ticker = template.depositCurrency.toLowerCase();
    exchangeViewModel.depositAddress =
      await fetchParsedAddress(context, domain, ticker);

    domain = template.receiveAddress;
    ticker = template.receiveCurrency.toLowerCase();
    exchangeViewModel.receiveAddress =
      await fetchParsedAddress(context, domain, ticker);
  }

  void _setReactions(
      BuildContext context, ExchangeViewModel exchangeViewModel) {
    if (_isReactionsSet) {
      return;
    }

     if (exchangeViewModel.isLowFee) {
      _showFeeAlert(context);
    }

    final depositAddressController = depositKey.currentState!.addressController;
    final depositAmountController = depositKey.currentState!.amountController;
    final receiveAddressController = receiveKey.currentState!.addressController;
    final receiveAmountController = receiveKey.currentState!.amountController;
    final limitsState = exchangeViewModel.limitsState;

    if (limitsState is LimitsLoadedSuccessfully) {
      final min = limitsState.limits.min != null
          ? limitsState.limits.min.toString()
          : null;
      final max = limitsState.limits.max != null
          ? limitsState.limits.max.toString()
          : null;
      final key = exchangeViewModel.isFixedRateMode
        ? receiveKey
        : depositKey;
      key.currentState!.changeLimits(min: min, max: max);
    }

    _onCurrencyChange(
        exchangeViewModel.receiveCurrency, exchangeViewModel, receiveKey);
    _onCurrencyChange(
        exchangeViewModel.depositCurrency, exchangeViewModel, depositKey);

    reaction(
        (_) => exchangeViewModel.wallet.name,
        (String _) => _onWalletNameChange(
            exchangeViewModel, exchangeViewModel.receiveCurrency, receiveKey));

    reaction(
        (_) => exchangeViewModel.wallet.name,
        (String _) => _onWalletNameChange(
            exchangeViewModel, exchangeViewModel.depositCurrency, depositKey));

    reaction(
        (_) => exchangeViewModel.receiveCurrency,
        (CryptoCurrency currency) =>
            _onCurrencyChange(currency, exchangeViewModel, receiveKey));

    reaction(
        (_) => exchangeViewModel.depositCurrency,
        (CryptoCurrency currency) =>
            _onCurrencyChange(currency, exchangeViewModel, depositKey));

    reaction((_) => exchangeViewModel.depositAmount, (String amount) {
      if (depositKey.currentState!.amountController.text != amount) {
        depositKey.currentState!.amountController.text = amount;
      }
    });

    reaction((_) => exchangeViewModel.depositAddress, (String address) {
      if (depositKey.currentState!.addressController.text != address) {
        depositKey.currentState!.addressController.text = address;
      }
    });

    reaction((_) => exchangeViewModel.isDepositAddressEnabled,
        (bool isEnabled) {
      depositKey.currentState!.isAddressEditable(isEditable: isEnabled);
    });

    reaction((_) => exchangeViewModel.receiveAmount, (String amount) {
      if (receiveKey.currentState!.amountController.text != amount) {
        receiveKey.currentState!.amountController.text = amount;
      }
    });

    reaction((_) => exchangeViewModel.receiveAddress, (String address) {
      if (receiveKey.currentState!.addressController.text != address) {
        receiveKey.currentState!.addressController.text = address;
      }
    });

    reaction((_) => exchangeViewModel.isReceiveAddressEnabled,
        (bool isEnabled) {
      receiveKey.currentState!.isAddressEditable(isEditable: isEnabled);
    });

    reaction((_) => exchangeViewModel.isReceiveAmountEditable,
        (bool isReceiveAmountEditable) {
      receiveKey.currentState!.isAmountEditable(isEditable: isReceiveAmountEditable);
    });

    reaction((_) => exchangeViewModel.tradeState, (ExchangeTradeState state) {
      if (state is TradeIsCreatedFailure) {
        WidgetsBinding.instance.addPostFrameCallback((_) {
          showPopUp<void>(
              context: context,
              builder: (BuildContext context) {
                return AlertWithOneAction(
                    alertTitle: S.of(context).provider_error(state.title),
                    alertContent: state.error,
                    buttonText: S.of(context).ok,
                    buttonAction: () => Navigator.of(context).pop());
              });
        });
      }
      if (state is TradeIsCreatedSuccessfully) {
        exchangeViewModel.reset();
        Navigator.of(context).pushNamed(Routes.exchangeConfirm);
      }
    });

    reaction((_) => exchangeViewModel.limitsState, (LimitsState state) {
      String? min;
      String? max;

      if (state is LimitsLoadedSuccessfully) {
        min = state.limits.min != null ? state.limits.min.toString() : null;
        max = state.limits.max != null ? state.limits.max.toString() : null;
      }

      if (state is LimitsLoadedFailure) {
        min = '0';
        max = '0';
      }

      if (state is LimitsIsLoading) {
        min = '...';
        max = '...';
      }

      if (exchangeViewModel.isFixedRateMode) {
        depositKey.currentState!.changeLimits(min: null, max: null);
        receiveKey.currentState!.changeLimits(min: min, max: max);
      } else {
        depositKey.currentState!.changeLimits(min: min, max: max);
        receiveKey.currentState!.changeLimits(min: null, max: null);
      }
    });

    depositAddressController.addListener(
        () => exchangeViewModel.depositAddress = depositAddressController.text);

    depositAmountController.addListener(() {
      if (depositAmountController.text != exchangeViewModel.depositAmount) {
        _depositAmountDebounce.run(() { 
          exchangeViewModel.changeDepositAmount(amount: depositAmountController.text);
          exchangeViewModel.isReceiveAmountEntered = false;
        });
      }
    });

    receiveAddressController.addListener(
        () => exchangeViewModel.receiveAddress = receiveAddressController.text);

    receiveAmountController.addListener(() {
      if (receiveAmountController.text != exchangeViewModel.receiveAmount) {
        _receiveAmountDebounce.run(() {
          exchangeViewModel.changeReceiveAmount(amount: receiveAmountController.text);
          exchangeViewModel.isReceiveAmountEntered = true;
        });
      }
    });

    reaction((_) => exchangeViewModel.wallet.walletAddresses.address,
            (String address) {
      if (exchangeViewModel.depositCurrency == CryptoCurrency.xmr) {
        depositKey.currentState!.changeAddress(address: address);
      }

      if (exchangeViewModel.receiveCurrency == CryptoCurrency.xmr) {
        receiveKey.currentState!.changeAddress(address: address);
      }
    });

    _depositAddressFocus.addListener(() async {
      if (!_depositAddressFocus.hasFocus &&
          depositAddressController.text.isNotEmpty) {
        final domain = depositAddressController.text;
        final ticker = exchangeViewModel.depositCurrency.title.toLowerCase();
        exchangeViewModel.depositAddress =
          await fetchParsedAddress(context, domain, ticker);
      }
    });

    _receiveAddressFocus.addListener(() async {
      if (!_receiveAddressFocus.hasFocus &&
          receiveAddressController.text.isNotEmpty) {
        final domain = receiveAddressController.text;
        final ticker = exchangeViewModel.receiveCurrency.title.toLowerCase();
        exchangeViewModel.receiveAddress =
          await fetchParsedAddress(context, domain, ticker);
      }
    });

    _receiveAmountFocus.addListener(() {
      if (_receiveAmountFocus.hasFocus) {
        exchangeViewModel.isFixedRateMode = true;
      }
      // exchangeViewModel.changeReceiveAmount(amount: receiveAmountController.text);
    });

    _depositAmountFocus.addListener(() {
      exchangeViewModel.isFixedRateMode = false;
      // exchangeViewModel.changeDepositAmount(
      //   amount: depositAmountController.text);
    });

    _isReactionsSet = true;
  }

  void _onCurrencyChange(CryptoCurrency currency,
      ExchangeViewModel exchangeViewModel, GlobalKey<ExchangeCardState> key) {
    final isCurrentTypeWallet = currency == exchangeViewModel.wallet.currency;

    key.currentState!.changeSelectedCurrency(currency);
    key.currentState!.changeWalletName(
        isCurrentTypeWallet ? exchangeViewModel.wallet.name : '');

    key.currentState!.changeAddress(
        address: isCurrentTypeWallet
            ? exchangeViewModel.wallet.walletAddresses.address : '');

    key.currentState!.changeAmount(amount: '');
  }

  void _onWalletNameChange(ExchangeViewModel exchangeViewModel,
      CryptoCurrency currency, GlobalKey<ExchangeCardState> key) {
    final isCurrentTypeWallet = currency == exchangeViewModel.wallet.currency;

    if (isCurrentTypeWallet) {
      key.currentState!.changeWalletName(exchangeViewModel.wallet.name);
      key.currentState!.addressController.text =
          exchangeViewModel.wallet.walletAddresses.address;
    } else if (key.currentState!.addressController.text ==
        exchangeViewModel.wallet.walletAddresses.address) {
      key.currentState!.changeWalletName('');
      key.currentState!.addressController.text = '';
    }
  }

  Future<String> fetchParsedAddress(
      BuildContext context, String domain, String ticker) async {
    final parsedAddress = await getIt.get<AddressResolver>().resolve(domain, ticker);
    final address = await extractAddressFromParsed(context, parsedAddress);
    return address;
  }

  void _showFeeAlert(BuildContext context) async {
    await Future<void>.delayed(Duration(seconds: 1));
    final confirmed = await showPopUp<bool>(
        context: context,
        builder: (dialogContext) {
          return AlertWithTwoActions(
              alertTitle: S.of(context).low_fee,
              alertContent: S.of(context).low_fee_alert,
              leftButtonText: S.of(context).ignor,
              rightButtonText: S.of(context).use_suggested,
              actionLeftButton: () => Navigator.of(context).pop(false),
              actionRightButton: () => Navigator.of(context).pop(true));
        }) ?? false;
    if (confirmed) {
      exchangeViewModel.setDefaultTransactionPriority();
    }
  }

  void disposeBestRateSync() => exchangeViewModel.bestRateSync.cancel();

  Widget _exchangeCardsSection(BuildContext context) {
    final firstExchangeCard = Observer(builder: (_) => ExchangeCard(
      onDispose: disposeBestRateSync,
      hasAllAmount: exchangeViewModel.hasAllAmount,
      allAmount: exchangeViewModel.hasAllAmount
          ? () => exchangeViewModel.calculateDepositAllAmount()
          : null,
      amountFocusNode: _depositAmountFocus,
      addressFocusNode: _depositAddressFocus,
      key: depositKey,
      title: S.of(context).you_will_send,
      initialCurrency: exchangeViewModel.depositCurrency,
      initialWalletName: depositWalletName ?? '',
      initialAddress:
      exchangeViewModel.depositCurrency == exchangeViewModel.wallet.currency
          ? exchangeViewModel.wallet.walletAddresses.address
          : exchangeViewModel.depositAddress,
      initialIsAmountEditable: true,
      initialIsAddressEditable: exchangeViewModel.isDepositAddressEnabled,
      isAmountEstimated: false,
      hasRefundAddress: true,
      isMoneroWallet: exchangeViewModel.isMoneroWallet,
      currencies: exchangeViewModel.depositCurrencies,
      onCurrencySelected: (currency) {
        // FIXME: need to move it into view model
        if (currency == CryptoCurrency.xmr &&
            exchangeViewModel.wallet.type != WalletType.monero) {
          showPopUp<void>(
              context: context,
              builder: (dialogContext) {
                return AlertWithOneAction(
                    alertTitle: S.of(context).error,
                    alertContent:
                    S.of(context).exchange_incorrect_current_wallet_for_xmr,
                    buttonText: S.of(context).ok,
                    buttonAction: () => Navigator.of(dialogContext).pop());
              });
          return;
        }

        exchangeViewModel.changeDepositCurrency(currency: currency);
      },
      imageArrow: arrowBottomPurple,
      currencyButtonColor: Colors.transparent,
      addressButtonsColor: Theme.of(context).focusColor!,
      borderColor: Theme.of(context).primaryTextTheme!.bodyText1!.color!,
      currencyValueValidator: (value) {
        return !exchangeViewModel.isFixedRateMode
            ? AmountValidator(
                isAutovalidate: true,
                currency: exchangeViewModel.depositCurrency,
                minValue: exchangeViewModel.limits.min.toString(),
                maxValue: exchangeViewModel.limits.max.toString(),
              ).call(value)
            : null;
      },
      addressTextFieldValidator:
      AddressValidator(type: exchangeViewModel.depositCurrency),
      onPushPasteButton: (context) async {
        final domain = exchangeViewModel.depositAddress;
        final ticker = exchangeViewModel.depositCurrency.title.toLowerCase();
        exchangeViewModel.depositAddress =
        await fetchParsedAddress(context, domain, ticker);
      },
      onPushAddressBookButton: (context) async {
        final domain = exchangeViewModel.depositAddress;
        final ticker = exchangeViewModel.depositCurrency.title.toLowerCase();
        exchangeViewModel.depositAddress =
        await fetchParsedAddress(context, domain, ticker);
      },
    ));

    final secondExchangeCard = Observer(builder: (_) => ExchangeCard(
      onDispose: disposeBestRateSync,
      amountFocusNode: _receiveAmountFocus,
      addressFocusNode: _receiveAddressFocus,
      key: receiveKey,
      title: S.of(context).you_will_get,
      initialCurrency: exchangeViewModel.receiveCurrency,
      initialWalletName: receiveWalletName ?? '',
      initialAddress:
      exchangeViewModel.receiveCurrency == exchangeViewModel.wallet.currency
          ? exchangeViewModel.wallet.walletAddresses.address
          : exchangeViewModel.receiveAddress,
      initialIsAmountEditable: exchangeViewModel.isReceiveAmountEditable,
      initialIsAddressEditable: exchangeViewModel.isReceiveAddressEnabled,
      isAmountEstimated: true,
      isMoneroWallet: exchangeViewModel.isMoneroWallet,
      currencies: exchangeViewModel.receiveCurrencies,
      onCurrencySelected: (currency) =>
          exchangeViewModel.changeReceiveCurrency(currency: currency),
      imageArrow: arrowBottomCakeGreen,
      currencyButtonColor: Colors.transparent,
      addressButtonsColor: Theme.of(context).focusColor!,
      borderColor:
      Theme.of(context).primaryTextTheme!.bodyText1!.decorationColor!,
      currencyValueValidator: (value) {
        return exchangeViewModel.isFixedRateMode
            ? AmountValidator(
                isAutovalidate: true,
                currency: exchangeViewModel.receiveCurrency,
                minValue: exchangeViewModel.limits.min.toString(),
                maxValue: exchangeViewModel.limits.max.toString(),
              ).call(value)
            : null;
      },
      addressTextFieldValidator:
      AddressValidator(type: exchangeViewModel.receiveCurrency),
      onPushPasteButton: (context) async {
        final domain = exchangeViewModel.receiveAddress;
        final ticker = exchangeViewModel.receiveCurrency.title.toLowerCase();
        exchangeViewModel.receiveAddress =
        await fetchParsedAddress(context, domain, ticker);
      },
      onPushAddressBookButton: (context) async {
        final domain = exchangeViewModel.receiveAddress;
        final ticker = exchangeViewModel.receiveCurrency.title.toLowerCase();
        exchangeViewModel.receiveAddress =
        await fetchParsedAddress(context, domain, ticker);
      },
    ));

    if (ResponsiveLayoutUtil.instance.isMobile(context)) {
      return MobileExchangeCardsSection(
        firstExchangeCard: firstExchangeCard,
        secondExchangeCard: secondExchangeCard,
      );
    }

    return DesktopExchangeCardsSection(
      firstExchangeCard: firstExchangeCard,
      secondExchangeCard: secondExchangeCard,
    );
  }
}