stack_wallet/lib/services/change_now/change_now.dart

717 lines
22 KiB
Dart

import 'dart:convert';
import 'package:decimal/decimal.dart';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'package:stackwallet/external_api_keys.dart';
import 'package:stackwallet/models/exchange/change_now/available_floating_rate_pair.dart';
import 'package:stackwallet/models/exchange/change_now/change_now_response.dart';
import 'package:stackwallet/models/exchange/change_now/cn_exchange_estimate.dart';
import 'package:stackwallet/models/exchange/change_now/currency.dart';
import 'package:stackwallet/models/exchange/change_now/estimated_exchange_amount.dart';
import 'package:stackwallet/models/exchange/change_now/exchange_transaction.dart';
import 'package:stackwallet/models/exchange/change_now/exchange_transaction_status.dart';
import 'package:stackwallet/models/exchange/change_now/fixed_rate_market.dart';
import 'package:stackwallet/utilities/logger.dart';
class ChangeNow {
static const String scheme = "https";
static const String authority = "api.changenow.io";
static const String apiVersion = "/v1";
static const String apiVersionV2 = "/v2";
ChangeNow._();
static final ChangeNow _instance = ChangeNow._();
static ChangeNow get instance => _instance;
/// set this to override using standard http client. Useful for testing
http.Client? client;
Uri _buildUri(String path, Map<String, dynamic>? params) {
return Uri.https(authority, apiVersion + path, params);
}
Uri _buildUriV2(String path, Map<String, dynamic>? params) {
return Uri.https(authority, apiVersionV2 + path, params);
}
Future<dynamic> _makeGetRequest(Uri uri) async {
final client = this.client ?? http.Client();
try {
final response = await client.get(
uri,
headers: {'Content-Type': 'application/json'},
);
final parsed = jsonDecode(response.body);
return parsed;
} catch (e, s) {
Logging.instance
.log("_makeRequest($uri) threw: $e\n$s", level: LogLevel.Error);
rethrow;
}
}
Future<dynamic> _makeGetRequestV2(Uri uri, String apiKey) async {
final client = this.client ?? http.Client();
try {
final response = await client.get(
uri,
headers: {
// 'Content-Type': 'application/json',
'x-changenow-api-key': apiKey,
},
);
final parsed = jsonDecode(response.body);
return parsed;
} catch (e, s) {
Logging.instance
.log("_makeRequestV2($uri) threw: $e\n$s", level: LogLevel.Error);
rethrow;
}
}
Future<dynamic> _makePostRequest(
Uri uri,
Map<String, String> body,
) async {
final client = this.client ?? http.Client();
try {
final response = await client.post(
uri,
headers: {'Content-Type': 'application/json'},
body: jsonEncode(body),
);
final parsed = jsonDecode(response.body);
return parsed;
} catch (e, s) {
Logging.instance
.log("_makeRequest($uri) threw: $e\n$s", level: LogLevel.Error);
rethrow;
}
}
/// This API endpoint returns the list of available currencies.
///
/// Set [active] to true to return only active currencies.
/// Set [fixedRate] to true to return only currencies available on a fixed-rate flow.
Future<ChangeNowResponse<List<Currency>>> getAvailableCurrencies({
bool? fixedRate,
bool? active,
}) async {
Map<String, dynamic>? params;
if (active != null || fixedRate != null) {
params = {};
if (fixedRate != null) {
params.addAll({"fixedRate": fixedRate.toString()});
}
if (active != null) {
params.addAll({"active": active.toString()});
}
}
final uri = _buildUri("/currencies", params);
try {
// json array is expected here
final jsonArray = await _makeGetRequest(uri);
try {
final result = await compute(
_parseAvailableCurrenciesJson, jsonArray as List<dynamic>);
return result;
} catch (e, s) {
Logging.instance.log("getAvailableCurrencies exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
"Error: $jsonArray",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getAvailableCurrencies exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
ChangeNowResponse<List<Currency>> _parseAvailableCurrenciesJson(
List<dynamic> jsonArray) {
try {
List<Currency> currencies = [];
for (final json in jsonArray) {
try {
currencies
.add(Currency.fromJson(Map<String, dynamic>.from(json as Map)));
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException("Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError));
}
}
return ChangeNowResponse(value: currencies);
} catch (_) {
rethrow;
}
}
/// This API endpoint returns the array of markets available for the specified currency be default.
/// The availability of a particular pair is determined by the 'isAvailable' field.
///
/// Required [ticker] to fetch paired currencies for.
/// Set [fixedRate] to true to return only currencies available on a fixed-rate flow.
Future<ChangeNowResponse<List<Currency>>> getPairedCurrencies({
required String ticker,
bool? fixedRate,
}) async {
Map<String, dynamic>? params;
if (fixedRate != null) {
params = {};
params.addAll({"fixedRate": fixedRate.toString()});
}
final uri = _buildUri("/currencies-to/$ticker", params);
try {
// json array is expected here
final jsonArray = (await _makeGetRequest(uri)) as List;
List<Currency> currencies = [];
try {
for (final json in jsonArray) {
try {
currencies
.add(Currency.fromJson(Map<String, dynamic>.from(json as Map)));
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
}
} catch (e, s) {
Logging.instance.log("getPairedCurrencies exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException("Error: $jsonArray",
ChangeNowExceptionType.serializeResponseError));
}
return ChangeNowResponse(value: currencies);
} catch (e, s) {
Logging.instance
.log("getPairedCurrencies exception: $e\n$s", level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
/// The API endpoint returns minimal payment amount required to make
/// an exchange of [fromTicker] to [toTicker].
/// If you try to exchange less, the transaction will most likely fail.
Future<ChangeNowResponse<Decimal>> getMinimalExchangeAmount({
required String fromTicker,
required String toTicker,
String? apiKey,
}) async {
Map<String, dynamic>? params = {"api_key": apiKey ?? kChangeNowApiKey};
final uri = _buildUri("/min-amount/${fromTicker}_$toTicker", params);
try {
// simple json object is expected here
final json = await _makeGetRequest(uri);
try {
final value = Decimal.parse(json["minAmount"].toString());
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getMinimalExchangeAmount exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
/// Get estimated amount of [toTicker] cryptocurrency to receive
/// for [fromAmount] of [fromTicker]
Future<ChangeNowResponse<EstimatedExchangeAmount>>
getEstimatedExchangeAmount({
required String fromTicker,
required String toTicker,
required Decimal fromAmount,
String? apiKey,
}) async {
Map<String, dynamic> params = {"api_key": apiKey ?? kChangeNowApiKey};
final uri = _buildUri(
"/exchange-amount/${fromAmount.toString()}/${fromTicker}_$toTicker",
params,
);
try {
// simple json object is expected here
final json = await _makeGetRequest(uri);
try {
final value = EstimatedExchangeAmount.fromJson(
Map<String, dynamic>.from(json as Map));
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getEstimatedExchangeAmount exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
// old v1 version
/// This API endpoint returns fixed-rate estimated exchange amount of
/// [toTicker] cryptocurrency to receive for [fromAmount] of [fromTicker]
// Future<ChangeNowResponse<EstimatedExchangeAmount>>
// getEstimatedFixedRateExchangeAmount({
// required String fromTicker,
// required String toTicker,
// required Decimal fromAmount,
// // (Optional) Use rateId for fixed-rate flow. If this field is true, you
// // could use returned field "rateId" in next method for creating transaction
// // to freeze estimated amount that you got in this method. Current estimated
// // amount would be valid until time in field "validUntil"
// bool useRateId = true,
// String? apiKey,
// }) async {
// Map<String, dynamic> params = {
// "api_key": apiKey ?? kChangeNowApiKey,
// "useRateId": useRateId.toString(),
// };
//
// final uri = _buildUri(
// "/exchange-amount/fixed-rate/${fromAmount.toString()}/${fromTicker}_$toTicker",
// params,
// );
//
// try {
// // simple json object is expected here
// final json = await _makeGetRequest(uri);
//
// try {
// final value = EstimatedExchangeAmount.fromJson(
// Map<String, dynamic>.from(json as Map));
// return ChangeNowResponse(value: value);
// } catch (_) {
// return ChangeNowResponse(
// exception: ChangeNowException(
// "Failed to serialize $json",
// ChangeNowExceptionType.serializeResponseError,
// ),
// );
// }
// } catch (e, s) {
// Logging.instance.log(
// "getEstimatedFixedRateExchangeAmount exception: $e\n$s",
// level: LogLevel.Error);
// return ChangeNowResponse(
// exception: ChangeNowException(
// e.toString(),
// ChangeNowExceptionType.generic,
// ),
// );
// }
// }
/// Get estimated amount of [toTicker] cryptocurrency to receive
/// for [fromAmount] of [fromTicker]
Future<ChangeNowResponse<CNExchangeEstimate>> getEstimatedExchangeAmountV2({
required String fromTicker,
required String toTicker,
required CNEstimateType fromOrTo,
required Decimal amount,
String? fromNetwork,
String? toNetwork,
CNFlowType flow = CNFlowType.standard,
String? apiKey,
}) async {
Map<String, dynamic>? params = {
"fromCurrency": fromTicker,
"toCurrency": toTicker,
"flow": flow.value,
"type": fromOrTo.name,
};
switch (fromOrTo) {
case CNEstimateType.direct:
params["fromAmount"] = amount.toString();
break;
case CNEstimateType.reverse:
params["toAmount"] = amount.toString();
break;
}
if (fromNetwork != null) {
params["fromNetwork"] = fromNetwork;
}
if (toNetwork != null) {
params["toNetwork"] = toNetwork;
}
if (flow == CNFlowType.fixedRate) {
params["useRateId"] = "true";
}
final uri = _buildUriV2("/exchange/estimated-amount", params);
try {
// simple json object is expected here
final json = await _makeGetRequestV2(uri, apiKey ?? kChangeNowApiKey);
try {
final value =
CNExchangeEstimate.fromJson(Map<String, dynamic>.from(json as Map));
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getEstimatedExchangeAmountV2 exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
/// This API endpoint returns the list of all the pairs available on a
/// fixed-rate flow. Some currencies get enabled or disabled from time to
/// time and the market info gets updates, so make sure to refresh the list
/// occasionally. One time per minute is sufficient.
Future<ChangeNowResponse<List<FixedRateMarket>>>
getAvailableFixedRateMarkets({
String? apiKey,
}) async {
final uri = _buildUri(
"/market-info/fixed-rate/${apiKey ?? kChangeNowApiKey}", null);
try {
// json array is expected here
final jsonArray = await _makeGetRequest(uri);
try {
final result =
await compute(_parseFixedRateMarketsJson, jsonArray as List);
return result;
} catch (e, s) {
Logging.instance.log("getAvailableFixedRateMarkets exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
"Error: $jsonArray",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getAvailableFixedRateMarkets exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
ChangeNowResponse<List<FixedRateMarket>> _parseFixedRateMarketsJson(
List<dynamic> jsonArray) {
try {
List<FixedRateMarket> markets = [];
for (final json in jsonArray) {
try {
markets.add(
FixedRateMarket.fromJson(Map<String, dynamic>.from(json as Map)));
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException("Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError));
}
}
return ChangeNowResponse(value: markets);
} catch (_) {
rethrow;
}
}
/// The API endpoint creates a transaction, generates an address for
/// sending funds and returns transaction attributes.
Future<ChangeNowResponse<ExchangeTransaction>>
createStandardExchangeTransaction({
required String fromTicker,
required String toTicker,
required String receivingAddress,
required Decimal amount,
String extraId = "",
String userId = "",
String contactEmail = "",
String refundAddress = "",
String refundExtraId = "",
String? apiKey,
}) async {
final Map<String, String> map = {
"from": fromTicker,
"to": toTicker,
"address": receivingAddress,
"amount": amount.toString(),
"flow": "standard",
"extraId": extraId,
"userId": userId,
"contactEmail": contactEmail,
"refundAddress": refundAddress,
"refundExtraId": refundExtraId,
};
final uri = _buildUri("/transactions/${apiKey ?? kChangeNowApiKey}", null);
try {
// simple json object is expected here
final json = await _makePostRequest(uri, map);
// pass in date to prevent using default 1970 date
json["date"] = DateTime.now().toString();
try {
final value = ExchangeTransaction.fromJson(
Map<String, dynamic>.from(json as Map));
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log(
"createStandardExchangeTransaction exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
/// The API endpoint creates a transaction, generates an address for
/// sending funds and returns transaction attributes.
Future<ChangeNowResponse<ExchangeTransaction>>
createFixedRateExchangeTransaction({
required String fromTicker,
required String toTicker,
required String receivingAddress,
required Decimal amount,
required String rateId,
String extraId = "",
String userId = "",
String contactEmail = "",
String refundAddress = "",
String refundExtraId = "",
String? apiKey,
}) async {
final Map<String, String> map = {
"from": fromTicker,
"to": toTicker,
"address": receivingAddress,
"amount": amount.toString(),
"flow": "fixed-rate",
"extraId": extraId,
"userId": userId,
"contactEmail": contactEmail,
"refundAddress": refundAddress,
"refundExtraId": refundExtraId,
"rateId": rateId,
};
final uri = _buildUri(
"/transactions/fixed-rate/${apiKey ?? kChangeNowApiKey}", null);
try {
// simple json object is expected here
final json = await _makePostRequest(uri, map);
// pass in date to prevent using default 1970 date
json["date"] = DateTime.now().toString();
try {
final value = ExchangeTransaction.fromJson(
Map<String, dynamic>.from(json as Map));
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log(
"createFixedRateExchangeTransaction exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
Future<ChangeNowResponse<ExchangeTransactionStatus>> getTransactionStatus({
required String id,
String? apiKey,
}) async {
final uri =
_buildUri("/transactions/$id/${apiKey ?? kChangeNowApiKey}", null);
try {
// simple json object is expected here
final json = await _makeGetRequest(uri);
try {
final value = ExchangeTransactionStatus.fromJson(
Map<String, dynamic>.from(json as Map));
return ChangeNowResponse(value: value);
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException(
"Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance
.log("getTransactionStatus exception: $e\n$s", level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
Future<ChangeNowResponse<List<AvailableFloatingRatePair>>>
getAvailableFloatingRatePairs({
bool includePartners = false,
}) async {
final uri = _buildUri("/market-info/available-pairs",
{"includePartners": includePartners.toString()});
try {
// json array is expected here
final jsonArray = await _makeGetRequest(uri);
try {
final result = await compute(
_parseAvailableFloatingRatePairsJson, jsonArray as List);
return result;
} catch (e, s) {
Logging.instance.log("getAvailableFloatingRatePairs exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
"Error: $jsonArray",
ChangeNowExceptionType.serializeResponseError,
),
);
}
} catch (e, s) {
Logging.instance.log("getAvailableFloatingRatePairs exception: $e\n$s",
level: LogLevel.Error);
return ChangeNowResponse(
exception: ChangeNowException(
e.toString(),
ChangeNowExceptionType.generic,
),
);
}
}
ChangeNowResponse<List<AvailableFloatingRatePair>>
_parseAvailableFloatingRatePairsJson(List<dynamic> jsonArray) {
try {
List<AvailableFloatingRatePair> pairs = [];
for (final json in jsonArray) {
try {
final List<String> stringPair = (json as String).split("_");
pairs.add(AvailableFloatingRatePair(
fromTicker: stringPair[0], toTicker: stringPair[1]));
} catch (_) {
return ChangeNowResponse(
exception: ChangeNowException("Failed to serialize $json",
ChangeNowExceptionType.serializeResponseError));
}
}
return ChangeNowResponse(value: pairs);
} catch (_) {
rethrow;
}
}
}