cake_wallet/lib/exchange/provider/exolix_exchange_provider.dart

import 'dart:convert';

import 'package:cake_wallet/.secrets.g.dart' as secrets;
import 'package:cake_wallet/exchange/exchange_provider_description.dart';
import 'package:cake_wallet/exchange/limits.dart';
import 'package:cake_wallet/exchange/provider/exchange_provider.dart';
import 'package:cake_wallet/exchange/trade.dart';
import 'package:cake_wallet/exchange/trade_not_found_exception.dart';
import 'package:cake_wallet/exchange/trade_request.dart';
import 'package:cake_wallet/exchange/trade_state.dart';
import 'package:cake_wallet/exchange/utils/currency_pairs_utils.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:cw_core/utils/print_verbose.dart';
import 'package:http/http.dart';

class ExolixExchangeProvider extends ExchangeProvider {
  ExolixExchangeProvider() : super(pairList: supportedPairs(_notSupported));

  static final apiKey = secrets.exolixApiKey;
  static const apiBaseUrl = 'exolix.com';
  static const transactionsPath = '/api/v2/transactions';
  static const ratePath = '/api/v2/rate';

  static const List<CryptoCurrency> _notSupported = [
    CryptoCurrency.usdt,
    CryptoCurrency.xhv,
    CryptoCurrency.btt,
    CryptoCurrency.firo,
    CryptoCurrency.zaddr,
    CryptoCurrency.xvg,
    CryptoCurrency.kmd,
    CryptoCurrency.paxg,
    CryptoCurrency.rune,
    CryptoCurrency.scrt,
    CryptoCurrency.btcln,
    CryptoCurrency.cro,
    CryptoCurrency.ftm,
    CryptoCurrency.frax,
    CryptoCurrency.gusd,
    CryptoCurrency.gtc,
    CryptoCurrency.weth,
  ];

  @override
  String get title => 'Exolix';

  @override
  bool get isAvailable => true;

  @override
  bool get isEnabled => true;

  @override
  bool get supportsFixedRate => true;

  @override
  ExchangeProviderDescription get description => ExchangeProviderDescription.exolix;

  @override
  Future<bool> checkIsAvailable() async => true;

  @override
  Future<Limits> fetchLimits({
    required CryptoCurrency from,
    required CryptoCurrency to,
    required bool isFixedRateMode,
  }) async {
    final params = <String, String>{
      'rateType': _getRateType(isFixedRateMode),
      'amount': '1',
      'apiToken': apiKey,
    };

    if (isFixedRateMode) {
      params['coinFrom'] = _normalizeCurrency(to);
      params['coinTo'] = _normalizeCurrency(from);
      params['networkFrom'] = _networkFor(to);
      params['networkTo'] = _networkFor(from);
    } else {
      params['coinFrom'] = _normalizeCurrency(from);
      params['coinTo'] = _normalizeCurrency(to);
      params['networkFrom'] = _networkFor(from);
      params['networkTo'] = _networkFor(to);
    }

    // Maximum of 2 attempts to fetch limits
    for (int i = 0; i < 2; i++) {
      final uri = Uri.https(apiBaseUrl, ratePath, params);
      final response = await get(uri);

      if (response.statusCode == 200) {
        final responseJSON = json.decode(response.body) as Map<String, dynamic>;
        final minAmount = responseJSON['minAmount'];
        final maxAmount = responseJSON['maxAmount'];
        return Limits(min: _toDouble(minAmount), max: _toDouble(maxAmount));
      } else if (response.statusCode == 422) {
        final errorResponse = json.decode(response.body) as Map<String, dynamic>;
        if (errorResponse.containsKey('minAmount')) {
          params['amount'] = errorResponse['minAmount'].toString();
          continue;
        }
        throw Exception('Error 422: ${errorResponse['message'] ?? 'Unknown error'}');
      } else {
        throw Exception('Unexpected HTTP status: ${response.statusCode}');
      }
    }

    throw Exception('Failed to fetch limits after retrying.');
  }

  @override
  Future<double> fetchRate(
      {required CryptoCurrency from,
      required CryptoCurrency to,
      required double amount,
      required bool isFixedRateMode,
      required bool isReceiveAmount}) async {
    try {
      if (amount == 0) return 0.0;

      final params = {
        'coinFrom': _normalizeCurrency(from),
        'coinTo': _normalizeCurrency(to),
        'networkFrom': _networkFor(from),
        'networkTo': _networkFor(to),
        'rateType': _getRateType(isFixedRateMode),
        'apiToken': apiKey,
      };

      if (isReceiveAmount)
        params['withdrawalAmount'] = amount.toString();
      else
        params['amount'] = amount.toString();

      final uri = Uri.https(apiBaseUrl, ratePath, params);
      final response = await get(uri);
      final responseJSON = json.decode(response.body) as Map<String, dynamic>;

      if (response.statusCode != 200) {
        final message = responseJSON['message'] as String?;
        throw Exception(message);
      }

      return responseJSON['rate'] as double;
    } catch (e) {
      printV(e.toString());
      return 0.0;
    }
  }

  @override
  Future<Trade> createTrade({
    required TradeRequest request,
    required bool isFixedRateMode,
    required bool isSendAll,
  }) async {
    final headers = {'Content-Type': 'application/json'};
    final body = {
      'coinFrom': _normalizeCurrency(request.fromCurrency),
      'coinTo': _normalizeCurrency(request.toCurrency),
      'networkFrom': _networkFor(request.fromCurrency),
      'networkTo': _networkFor(request.toCurrency),
      'withdrawalAddress': _normalizeAddress(request.toAddress),
      'refundAddress': _normalizeAddress(request.refundAddress),
      'rateType': _getRateType(isFixedRateMode),
      'apiToken': apiKey,
    };

    if (isFixedRateMode)
      body['withdrawalAmount'] = request.toAmount;
    else
      body['amount'] = request.fromAmount;

    final uri = Uri.https(apiBaseUrl, transactionsPath);
    final response = await post(uri, headers: headers, body: json.encode(body));

    if (response.statusCode == 400) {
      final responseJSON = json.decode(response.body) as Map<String, dynamic>;
      final errors = responseJSON['errors'] as Map<String, String>;
      final errorMessage = errors.values.join(', ');
      throw Exception(errorMessage);
    }

    if (response.statusCode != 200 && response.statusCode != 201)
      throw Exception('Unexpected http status: ${response.statusCode}');

    final responseJSON = json.decode(response.body) as Map<String, dynamic>;
    final id = responseJSON['id'] as String;
    final inputAddress = responseJSON['depositAddress'] as String;
    final refundAddress = responseJSON['refundAddress'] as String?;
    final extraId = responseJSON['depositExtraId'] as String?;
    final payoutAddress = responseJSON['withdrawalAddress'] as String;
    final amount = responseJSON['amount'].toString();
    final receiveAmount = responseJSON['amountTo']?.toString();

    return Trade(
      id: id,
      from: request.fromCurrency,
      to: request.toCurrency,
      provider: description,
      inputAddress: inputAddress,
      refundAddress: refundAddress,
      extraId: extraId,
      createdAt: DateTime.now(),
      amount: amount,
      receiveAmount:receiveAmount ?? request.toAmount,
      state: TradeState.created,
      payoutAddress: payoutAddress,
      isSendAll: isSendAll,
    );
  }

  @override
  Future<Trade> findTradeById({required String id}) async {
    final findTradeByIdPath = '$transactionsPath/$id';
    final uri = Uri.https(apiBaseUrl, findTradeByIdPath);
    final response = await get(uri);

    if (response.statusCode == 404) throw TradeNotFoundException(id, provider: description);

    if (response.statusCode == 400) {
      final responseJSON = json.decode(response.body) as Map<String, dynamic>;
      final errors = responseJSON['errors'] as Map<String, String>;
      final errorMessage = errors.values.join(', ');

      throw TradeNotFoundException(id, provider: description, description: errorMessage);
    }

    if (response.statusCode != 200)
      throw Exception('Unexpected http status: ${response.statusCode}');

    final responseJSON = json.decode(response.body) as Map<String, dynamic>;
    final coinFrom = responseJSON['coinFrom']['coinCode'] as String;
    final coinTo = responseJSON['coinTo']['coinCode'] as String;
    final inputAddress = responseJSON['depositAddress'] as String;
    final amount = responseJSON['amount'].toString();
    final status = responseJSON['status'] as String;
    final extraId = responseJSON['depositExtraId'] as String?;
    final outputTransaction = responseJSON['hashOut']['hash'] as String?;
    final payoutAddress = responseJSON['withdrawalAddress'] as String;

    return Trade(
        id: id,
        from: CryptoCurrency.fromString(coinFrom),
        to: CryptoCurrency.fromString(coinTo),
        provider: description,
        inputAddress: inputAddress,
        amount: amount,
        state: TradeState.deserialize(raw: _prepareStatus(status)),
        extraId: extraId,
        outputTransaction: outputTransaction,
        payoutAddress: payoutAddress);
  }

  String _getRateType(bool isFixedRate) => isFixedRate ? 'fixed' : 'float';

  String _prepareStatus(String status) {
    switch (status) {
      case 'deleted':
      case 'error':
        return 'overdue';
      default:
        return status;
    }
  }

  String _networkFor(CryptoCurrency currency) {
    switch (currency) {
      case CryptoCurrency.arb:
        return 'ARBITRUM';
      default:
        return currency.tag != null ? _normalizeTag(currency.tag!) : currency.title;
    }
  }

  String _normalizeCurrency(CryptoCurrency currency) {
    switch (currency) {
      case CryptoCurrency.nano:
        return 'XNO';
      case CryptoCurrency.bttc:
        return 'BTT';
      case CryptoCurrency.zec:
        return 'ZEC';
      default:
        return currency.title;
    }
  }

  String _normalizeTag(String tag) {
    switch (tag) {
      case 'POLY':
        return 'Polygon';
      default:
        return tag;
    }
  }

  String _normalizeAddress(String address) =>
      address.startsWith('bitcoincash:') ? address.replaceFirst('bitcoincash:', '') : address;

  static double? _toDouble(dynamic value) {
    if (value is int) {
      return value.toDouble();
    } else if (value is double) {
      return value;
    } else if (value is String) {
      return double.tryParse(value);
    }
    return null;
  }
}