Merge branch 'majestic_bank' into paynyms

lib/exceptions/exchange/exchange_exception.dart

@@ -0,0 +1,13 @@
+import 'package:stackwallet/exceptions/sw_exception.dart';
+
+enum ExchangeExceptionType { generic, serializeResponseError }
+
+class ExchangeException extends SWException {
+  ExchangeExceptionType type;
+  ExchangeException(super.message, this.type);
+
+  @override
+  String toString() {
+    return message;
+  }
+}

lib/exceptions/exchange/majestic_bank/mb_exception.dart

@@ -0,0 +1,5 @@
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
+
+class MBException extends ExchangeException {
+  MBException(super.message, super.type);
+}

lib/models/exchange/majestic_bank/mb_limit.dart

@@ -0,0 +1,19 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_object.dart';
+
+class MBLimit extends MBObject {
+  MBLimit({
+    required this.currency,
+    required this.min,
+    required this.max,
+  });
+
+  final String currency;
+  final Decimal min;
+  final Decimal max;
+
+  @override
+  String toString() {
+    return "MBLimit: { $currency: { min: $min, max: $max } }";
+  }
+}

lib/models/exchange/majestic_bank/mb_object.dart

@@ -0,0 +1 @@
+abstract class MBObject {}

lib/models/exchange/majestic_bank/mb_order.dart

@@ -0,0 +1,43 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_object.dart';
+
+enum MBOrderType {
+  fixed,
+  floating,
+}
+
+class MBOrder extends MBObject {
+  MBOrder({
+    required this.orderId,
+    required this.fromCurrency,
+    required this.fromAmount,
+    required this.receiveCurrency,
+    required this.receiveAmount,
+    required this.address,
+    required this.orderType,
+    required this.expiration,
+    required this.createdAt,
+  });
+
+  final String orderId;
+  final String fromCurrency;
+  final Decimal fromAmount;
+  final String receiveCurrency;
+  final String address;
+  final Decimal receiveAmount;
+  final MBOrderType orderType;
+
+  ///     minutes
+  final int expiration;
+
+  final DateTime createdAt;
+
+  bool isExpired() =>
+      (DateTime.now().difference(createdAt) >= Duration(minutes: expiration));
+
+  @override
+  String toString() {
+    // todo: full toString
+    return orderId;
+  }
+}

lib/models/exchange/majestic_bank/mb_order_calculation.dart

@@ -0,0 +1,21 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_object.dart';
+
+class MBOrderCalculation extends MBObject {
+  MBOrderCalculation({
+    required this.fromCurrency,
+    required this.fromAmount,
+    required this.receiveCurrency,
+    required this.receiveAmount,
+  });
+
+  final String fromCurrency;
+  final Decimal fromAmount;
+  final String receiveCurrency;
+  final Decimal receiveAmount;
+
+  @override
+  String toString() {
+    return "MBOrderCalculation: { $fromCurrency: $fromAmount, $receiveCurrency: $receiveAmount }";
+  }
+}

lib/models/exchange/majestic_bank/mb_order_status.dart

@@ -0,0 +1,32 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_object.dart';
+
+class MBOrderStatus extends MBObject {
+  MBOrderStatus({
+    required this.orderId,
+    required this.status,
+    required this.fromCurrency,
+    required this.fromAmount,
+    required this.receiveCurrency,
+    required this.receiveAmount,
+    required this.address,
+    required this.received,
+    required this.confirmed,
+  });
+
+  final String orderId;
+  final String status;
+  final String fromCurrency;
+  final Decimal fromAmount;
+  final String receiveCurrency;
+  final Decimal receiveAmount;
+  final String address;
+  final Decimal received;
+  final Decimal confirmed;
+
+  @override
+  String toString() {
+    // todo: full toString
+    return status;
+  }
+}

lib/models/exchange/majestic_bank/mb_rate.dart

@@ -0,0 +1,15 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_object.dart';
+
+class MBRate extends MBObject {
+  MBRate({required this.fromCurrency, required this.toCurrency, required this.rate,});
+
+  final String fromCurrency;
+  final String toCurrency;
+  final Decimal rate;
+
+  @override
+  String toString() {
+    return "MBRate: { $fromCurrency-$toCurrency: $rate }";
+  }
+}

lib/pages/settings_views/global_settings_view/hidden_settings.dart

@@ -11,6 +11,8 @@ import 'package:stackwallet/utilities/theme/stack_colors.dart';
 import 'package:stackwallet/widgets/background.dart';
 import 'package:stackwallet/widgets/rounded_white_container.dart';
 
+import '../../../services/exchange/majestic_bank/majestic_bank_api.dart';
+
 class HiddenSettings extends StatelessWidget {
   const HiddenSettings({Key? key}) : super(key: key);
 
@@ -128,6 +130,48 @@ class HiddenSettings extends StatelessWidget {
                             ),
                           );
                         }),
+                        // const SizedBox(
+                        //   height: 12,
+                        // ),
+                        // Consumer(builder: (_, ref, __) {
+                        //   return GestureDetector(
+                        //     onTap: () async {
+                        //       final x =
+                        //           await MajesticBankAPI.instance.getRates();
+                        //       print(x);
+                        //     },
+                        //     child: RoundedWhiteContainer(
+                        //       child: Text(
+                        //         "Click me",
+                        //         style: STextStyles.button(context).copyWith(
+                        //             color: Theme.of(context)
+                        //                 .extension<StackColors>()!
+                        //                 .accentColorDark),
+                        //       ),
+                        //     ),
+                        //   );
+                        // }),
+                        const SizedBox(
+                          height: 12,
+                        ),
+                        Consumer(builder: (_, ref, __) {
+                          return GestureDetector(
+                            onTap: () async {
+                              final x =
+                                  await MajesticBankAPI.instance.getLimits();
+                              print(x);
+                            },
+                            child: RoundedWhiteContainer(
+                              child: Text(
+                                "Click me",
+                                style: STextStyles.button(context).copyWith(
+                                    color: Theme.of(context)
+                                        .extension<StackColors>()!
+                                        .accentColorDark),
+                              ),
+                            ),
+                          );
+                        }),
                         const SizedBox(
                           height: 12,
                         ),

lib/services/exchange/change_now/change_now_api.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 import 'package:decimal/decimal.dart';
 import 'package:flutter/foundation.dart';
 import 'package:http/http.dart' as http;
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
 import 'package:stackwallet/external_api_keys.dart';
 import 'package:stackwallet/models/exchange/change_now/cn_exchange_estimate.dart';
 import 'package:stackwallet/models/exchange/change_now/estimated_exchange_amount.dart';

lib/services/exchange/exchange_data_loading_service.dart

@@ -55,7 +55,7 @@ class ExchangeDataLoadingService {
       }
     } else {
       Logging.instance.log(
-          "Failed to load changeNOW fixed rate markets: ${response3.exception?.errorMessage}",
+          "Failed to load changeNOW fixed rate markets: ${response3.exception?.message}",
           level: LogLevel.Error);
 
       ref.read(changeNowFixedInitialLoadStatusStateProvider.state).state =
@@ -122,7 +122,7 @@ class ExchangeDataLoadingService {
         }
       } else {
         Logging.instance.log(
-            "Failed to load changeNOW available floating rate pairs: ${response2.exception?.errorMessage}",
+            "Failed to load changeNOW available floating rate pairs: ${response2.exception?.message}",
             level: LogLevel.Error);
         ref.read(changeNowEstimatedInitialLoadStatusStateProvider.state).state =
             ChangeNowLoadStatus.failed;
@@ -130,7 +130,7 @@ class ExchangeDataLoadingService {
       }
     } else {
       Logging.instance.log(
-          "Failed to load changeNOW currencies: ${response.exception?.errorMessage}",
+          "Failed to load changeNOW currencies: ${response.exception?.message}",
           level: LogLevel.Error);
       await Future<void>.delayed(const Duration(seconds: 3));
       ref.read(changeNowEstimatedInitialLoadStatusStateProvider.state).state =

lib/services/exchange/exchange_response.dart

@@ -1,15 +1,4 @@
-enum ExchangeExceptionType { generic, serializeResponseError }
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
-
-class ExchangeException implements Exception {
-  String errorMessage;
-  ExchangeExceptionType type;
-  ExchangeException(this.errorMessage, this.type);
-
-  @override
-  String toString() {
-    return errorMessage;
-  }
-}
 
 class ExchangeResponse<T> {
   late final T? value;

lib/services/exchange/majestic_bank/majestic_bank_api.dart

@@ -0,0 +1,339 @@
+import 'dart:convert';
+
+import 'package:decimal/decimal.dart';
+import 'package:http/http.dart' as http;
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_limit.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_order.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_order_calculation.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_order_status.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_rate.dart';
+import 'package:stackwallet/services/exchange/exchange_response.dart';
+import 'package:stackwallet/utilities/logger.dart';
+
+class MajesticBankAPI {
+  static const String scheme = "https";
+  static const String authority = "majesticbank.sc";
+  static const String version = "v1";
+  static const String refCode = "fixme";
+
+  MajesticBankAPI._();
+
+  static final MajesticBankAPI _instance = MajesticBankAPI._();
+
+  static MajesticBankAPI get instance => _instance;
+
+  /// set this to override using standard http client. Useful for testing
+  http.Client? client;
+
+  Uri _buildUri({required String endpoint, Map<String, String>? params}) {
+    return Uri.https(authority, "/api/$version/$endpoint", params);
+  }
+
+  Future<dynamic> _makeGetRequest(Uri uri) async {
+    final client = this.client ?? http.Client();
+    int code = -1;
+    try {
+      final response = await client.get(
+        uri,
+      );
+
+      code = response.statusCode;
+      print(response.body);
+
+      final parsed = jsonDecode(response.body);
+
+      return parsed;
+    } catch (e, s) {
+      Logging.instance.log(
+        "_makeRequest($uri) HTTP:$code threw: $e\n$s",
+        level: LogLevel.Error,
+      );
+      rethrow;
+    }
+  }
+
+  Future<ExchangeResponse<List<MBRate>>> getRates() async {
+    final uri = _buildUri(
+      endpoint: "rates",
+    );
+
+    try {
+      final jsonObject = await _makeGetRequest(uri);
+
+      final map = Map<String, dynamic>.from(jsonObject as Map);
+      final List<MBRate> rates = [];
+      for (final key in map.keys) {
+        final currencies = key.split("-");
+        if (currencies.length == 2) {
+          final rate = MBRate(
+            fromCurrency: currencies.first,
+            toCurrency: currencies.last,
+            rate: Decimal.parse(map[key].toString()),
+          );
+          rates.add(rate);
+        }
+      }
+      return ExchangeResponse(value: rates);
+    } catch (e, s) {
+      Logging.instance.log("getRates exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  Future<ExchangeResponse<MBLimit>> getLimit({
+    required String fromCurrency,
+  }) async {
+    final uri = _buildUri(
+      endpoint: "limits",
+      params: {
+        "from_currency": fromCurrency,
+      },
+    );
+
+    try {
+      final jsonObject = await _makeGetRequest(uri);
+
+      final map = Map<String, dynamic>.from(jsonObject as Map);
+
+      final limit = MBLimit(
+        currency: fromCurrency,
+        min: Decimal.parse(map["min"].toString()),
+        max: Decimal.parse(map["max"].toString()),
+      );
+
+      return ExchangeResponse(value: limit);
+    } catch (e, s) {
+      Logging.instance
+          .log("getLimits exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  Future<ExchangeResponse<List<MBLimit>>> getLimits() async {
+    final uri = _buildUri(
+      endpoint:
+          "rates", // limits are included in the rates call for some reason???
+    );
+
+    try {
+      final jsonObject = await _makeGetRequest(uri);
+
+      final map = Map<String, dynamic>.from(jsonObject as Map)["limits"] as Map;
+      final List<MBLimit> limits = [];
+      for (final key in map.keys) {
+        final limit = MBLimit(
+          currency: key as String,
+          min: Decimal.parse(map[key]["min"].toString()),
+          max: Decimal.parse(map[key]["max"].toString()),
+        );
+        limits.add(limit);
+      }
+
+      return ExchangeResponse(value: limits);
+    } catch (e, s) {
+      Logging.instance
+          .log("getLimits exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  /// If [reversed] then the amount is the expected receive_amount, otherwise
+  /// the amount is assumed to be the from_amount.
+  Future<ExchangeResponse<MBOrderCalculation>> calculateOrder({
+    required String amount,
+    required bool reversed,
+    required String fromCurrency,
+    required String receiveCurrency,
+  }) async {
+    final params = {
+      "from_currency": fromCurrency,
+      "receive_currency": receiveCurrency,
+    };
+
+    if (reversed) {
+      params["receive_amount"] = amount;
+    } else {
+      params["from_amount"] = amount;
+    }
+
+    final uri = _buildUri(
+      endpoint: "calculate",
+      params: params,
+    );
+
+    try {
+      final jsonObject = await _makeGetRequest(uri);
+      final map = Map<String, dynamic>.from(jsonObject as Map);
+      final result = MBOrderCalculation(
+        fromCurrency: map["from_currency"] as String,
+        fromAmount: Decimal.parse(map["from_amount"].toString()),
+        receiveCurrency: map["receive_currency"] as String,
+        receiveAmount: Decimal.parse(map["receive_amount"].toString()),
+      );
+
+      return ExchangeResponse(value: result);
+    } catch (e, s) {
+      Logging.instance
+          .log("calculateOrder exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  Future<ExchangeResponse<MBOrder>> createOrder({
+    required String fromAmount,
+    required String fromCurrency,
+    required String receiveCurrency,
+    required String receiveAddress,
+  }) async {
+    final params = {
+      "from_amount": fromAmount,
+      "from_currency": fromCurrency,
+      "receive_currency": receiveCurrency,
+      "receive_address": receiveAddress,
+      "referral_code": refCode,
+    };
+
+    final uri = _buildUri(endpoint: "exchange", params: params);
+
+    try {
+      final now = DateTime.now();
+      final jsonObject = await _makeGetRequest(uri);
+      final json = Map<String, dynamic>.from(jsonObject as Map);
+
+      final order = MBOrder(
+        orderId: json["trx"] as String,
+        fromCurrency: json["from_currency"] as String,
+        fromAmount: Decimal.parse(json["from_amount"].toString()),
+        receiveCurrency: json["receive_currency"] as String,
+        receiveAmount: Decimal.parse(json["receive_amount"].toString()),
+        address: json["address"] as String,
+        orderType: MBOrderType.floating,
+        expiration: json["expiration"] as int,
+        createdAt: now,
+      );
+
+      return ExchangeResponse(value: order);
+    } catch (e, s) {
+      Logging.instance
+          .log("createOrder exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  /// Fixed rate for 10 minutes, useful for payments.
+  /// If [reversed] then the amount is the expected receive_amount, otherwise
+  /// the amount is assumed to be the from_amount.
+  Future<ExchangeResponse<MBOrder>> createFixedRateOrder({
+    required String amount,
+    required String fromCurrency,
+    required String receiveCurrency,
+    required String receiveAddress,
+    required bool reversed,
+  }) async {
+    final params = {
+      "from_currency": fromCurrency,
+      "receive_currency": receiveCurrency,
+      "receive_address": receiveAddress,
+      "referral_code": refCode,
+    };
+
+    if (reversed) {
+      params["receive_amount"] = amount;
+    } else {
+      params["from_amount"] = amount;
+    }
+
+    final uri = _buildUri(endpoint: "pay", params: params);
+
+    try {
+      final now = DateTime.now();
+      final jsonObject = await _makeGetRequest(uri);
+      final json = Map<String, dynamic>.from(jsonObject as Map);
+
+      final order = MBOrder(
+        orderId: json["trx"] as String,
+        fromCurrency: json["from_currency"] as String,
+        fromAmount: Decimal.parse(json["from_amount"].toString()),
+        receiveCurrency: json["receive_currency"] as String,
+        receiveAmount: Decimal.parse(json["receive_amount"].toString()),
+        address: json["address"] as String,
+        orderType: MBOrderType.fixed,
+        expiration: json["expiration"] as int,
+        createdAt: now,
+      );
+
+      return ExchangeResponse(value: order);
+    } catch (e, s) {
+      Logging.instance
+          .log("createFixedRateOrder exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+
+  Future<ExchangeResponse<MBOrderStatus>> trackOrder({
+    required String orderId,
+  }) async {
+    final uri = _buildUri(endpoint: "track", params: {
+      "trx": orderId,
+    });
+
+    try {
+      final jsonObject = await _makeGetRequest(uri);
+      final json = Map<String, dynamic>.from(jsonObject as Map);
+
+      final status = MBOrderStatus(
+        orderId: json["trx"] as String,
+        status: json["status"] as String,
+        fromCurrency: json["from_currency"] as String,
+        fromAmount: Decimal.parse(json["from_amount"].toString()),
+        receiveCurrency: json["receive_currency"] as String,
+        receiveAmount: Decimal.parse(json["receive_amount"].toString()),
+        address: json["address"] as String,
+        received: Decimal.parse(json["received"].toString()),
+        confirmed: Decimal.parse(json["confirmed"].toString()),
+      );
+
+      return ExchangeResponse(value: status);
+    } catch (e, s) {
+      Logging.instance
+          .log("createOrder exception: $e\n$s", level: LogLevel.Error);
+      return ExchangeResponse(
+        exception: ExchangeException(
+          e.toString(),
+          ExchangeExceptionType.generic,
+        ),
+      );
+    }
+  }
+}

lib/services/exchange/majestic_bank/majestic_bank_exchange.dart

@@ -0,0 +1,263 @@
+import 'package:decimal/decimal.dart';
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
+import 'package:stackwallet/exceptions/exchange/majestic_bank/mb_exception.dart';
+import 'package:stackwallet/models/exchange/majestic_bank/mb_order.dart';
+import 'package:stackwallet/models/exchange/response_objects/currency.dart';
+import 'package:stackwallet/models/exchange/response_objects/estimate.dart';
+import 'package:stackwallet/models/exchange/response_objects/pair.dart';
+import 'package:stackwallet/models/exchange/response_objects/range.dart';
+import 'package:stackwallet/models/exchange/response_objects/trade.dart';
+import 'package:stackwallet/services/exchange/exchange.dart';
+import 'package:stackwallet/services/exchange/exchange_response.dart';
+import 'package:stackwallet/services/exchange/majestic_bank/majestic_bank_api.dart';
+import 'package:uuid/uuid.dart';
+
+class MajesticBankExchange extends Exchange {
+  static const exchangeName = "MajesticBank";
+
+  @override
+  Future<ExchangeResponse<Trade>> createTrade({
+    required String from,
+    required String to,
+    required bool fixedRate,
+    required Decimal amount,
+    required String addressTo,
+    String? extraId,
+    required String addressRefund,
+    required String refundExtraId,
+    String? rateId,
+    required bool reversed,
+  }) async {
+    ExchangeResponse<MBOrder>? response;
+
+    if (fixedRate) {
+      response = await MajesticBankAPI.instance.createFixedRateOrder(
+        amount: amount.toString(),
+        fromCurrency: from,
+        receiveCurrency: to,
+        receiveAddress: addressTo,
+        reversed: reversed,
+      );
+    } else {
+      if (reversed) {
+        return ExchangeResponse(
+          exception: MBException(
+            "Reversed trade not available",
+            ExchangeExceptionType.generic,
+          ),
+        );
+      }
+      response = await MajesticBankAPI.instance.createOrder(
+        fromAmount: amount.toString(),
+        fromCurrency: from,
+        receiveCurrency: to,
+        receiveAddress: addressTo,
+      );
+    }
+
+    if (response.value != null) {
+      final order = response.value!;
+      final trade = Trade(
+        uuid: const Uuid().v1(),
+        tradeId: order.orderId,
+        rateType: fixedRate ? "fixed" : "floating",
+        direction: reversed ? "reversed" : "direct",
+        timestamp: order.createdAt,
+        updatedAt: order.createdAt,
+        payInCurrency: order.fromCurrency,
+        payInAmount: order.fromAmount.toString(),
+        payInAddress: order.address,
+        payInNetwork: "",
+        payInExtraId: "",
+        payInTxid: "",
+        payOutCurrency: order.receiveCurrency,
+        payOutAmount: order.receiveAmount.toString(),
+        payOutAddress: addressTo,
+        payOutNetwork: "",
+        payOutExtraId: "",
+        payOutTxid: "",
+        refundAddress: addressRefund,
+        refundExtraId: refundExtraId,
+        status: "Waiting",
+        exchangeName: exchangeName,
+      );
+
+      return ExchangeResponse(value: trade);
+    } else {
+      return ExchangeResponse(exception: response.exception!);
+    }
+  }
+
+  @override
+  Future<ExchangeResponse<List<Currency>>> getAllCurrencies(
+    bool fixedRate,
+  ) async {
+    final response = await MajesticBankAPI.instance.getLimits();
+    if (response.value == null) {
+      return ExchangeResponse(exception: response.exception);
+    }
+
+    final List<Currency> currencies = [];
+    final limits = response.value!;
+
+    for (final limit in limits) {
+      final currency = Currency(
+        ticker: limit.currency,
+        name: limit.currency,
+        network: "",
+        image: "",
+        hasExternalId: false,
+        isFiat: false,
+        featured: false,
+        isStable: false,
+        supportsFixedRate: true,
+      );
+      currencies.add(currency);
+    }
+
+    return ExchangeResponse(value: currencies);
+  }
+
+  @override
+  Future<ExchangeResponse<List<Pair>>> getAllPairs(bool fixedRate) async {
+    final response = await MajesticBankAPI.instance.getRates();
+    if (response.value == null) {
+      return ExchangeResponse(exception: response.exception);
+    }
+
+    final List<Pair> pairs = [];
+    final rates = response.value!;
+
+    for (final rate in rates) {
+      final pair = Pair(
+        from: rate.fromCurrency,
+        fromNetwork: "",
+        to: rate.toCurrency,
+        toNetwork: "",
+        fixedRate: true,
+        floatingRate: true,
+      );
+      pairs.add(pair);
+    }
+
+    return ExchangeResponse(value: pairs);
+  }
+
+  @override
+  Future<ExchangeResponse<Estimate>> getEstimate(
+    String from,
+    String to,
+    Decimal amount,
+    bool fixedRate,
+    bool reversed,
+  ) async {
+    final response = await MajesticBankAPI.instance.calculateOrder(
+      amount: amount.toString(),
+      reversed: reversed,
+      fromCurrency: from,
+      receiveCurrency: to,
+    );
+    if (response.value == null) {
+      return ExchangeResponse(exception: response.exception);
+    }
+
+    final calc = response.value!;
+    final estimate = Estimate(
+      estimatedAmount: reversed ? calc.fromAmount : calc.receiveAmount,
+      fixedRate: fixedRate,
+      reversed: reversed,
+    );
+    return ExchangeResponse(value: estimate);
+  }
+
+  @override
+  Future<ExchangeResponse<List<Pair>>> getPairsFor(
+    String currency,
+    bool fixedRate,
+  ) async {
+    final response = await getAllPairs(fixedRate);
+    if (response.value == null) {
+      return ExchangeResponse(exception: response.exception);
+    }
+
+    final pairs = response.value!.where(
+      (e) =>
+          e.from.toUpperCase() == currency.toUpperCase() ||
+          e.to.toUpperCase() == currency.toUpperCase(),
+    );
+
+    return ExchangeResponse(value: pairs.toList());
+  }
+
+  @override
+  Future<ExchangeResponse<Range>> getRange(
+    String from,
+    String to,
+    bool fixedRate,
+  ) async {
+    final response =
+        await MajesticBankAPI.instance.getLimit(fromCurrency: from);
+    if (response.value == null) {
+      return ExchangeResponse(exception: response.exception);
+    }
+
+    final limit = response.value!;
+    final range = Range(min: limit.min, max: limit.max);
+
+    return ExchangeResponse(value: range);
+  }
+
+  @override
+  Future<ExchangeResponse<Trade>> getTrade(String tradeId) async {
+    // TODO: implement getTrade
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<ExchangeResponse<List<Trade>>> getTrades() async {
+    // TODO: implement getTrades
+    throw UnimplementedError();
+  }
+
+  @override
+  String get name => exchangeName;
+
+  @override
+  Future<ExchangeResponse<Trade>> updateTrade(Trade trade) async {
+    final response = await MajesticBankAPI.instance.trackOrder(
+      orderId: trade.tradeId,
+    );
+
+    if (response.value != null) {
+      final status = response.value!;
+      final updatedTrade = Trade(
+        uuid: trade.uuid,
+        tradeId: status.orderId,
+        rateType: trade.rateType,
+        direction: trade.direction,
+        timestamp: trade.timestamp,
+        updatedAt: DateTime.now(),
+        payInCurrency: status.fromCurrency,
+        payInAmount: status.fromAmount.toString(),
+        payInAddress: status.address,
+        payInNetwork: trade.payInNetwork,
+        payInExtraId: trade.payInExtraId,
+        payInTxid: trade.payInTxid,
+        payOutCurrency: status.receiveCurrency,
+        payOutAmount: status.receiveAmount.toString(),
+        payOutAddress: trade.payOutAddress,
+        payOutNetwork: trade.payOutNetwork,
+        payOutExtraId: trade.payOutExtraId,
+        payOutTxid: trade.payOutTxid,
+        refundAddress: trade.refundAddress,
+        refundExtraId: trade.refundExtraId,
+        status: status.status,
+        exchangeName: exchangeName,
+      );
+
+      return ExchangeResponse(value: updatedTrade);
+    } else {
+      return ExchangeResponse(exception: response.exception);
+    }
+  }
+}

lib/services/exchange/simpleswap/simpleswap_api.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 import 'package:decimal/decimal.dart';
 import 'package:flutter/foundation.dart';
 import 'package:http/http.dart' as http;
+import 'package:stackwallet/exceptions/exchange/exchange_exception.dart';
 import 'package:stackwallet/external_api_keys.dart';
 import 'package:stackwallet/models/exchange/response_objects/fixed_rate_market.dart';
 import 'package:stackwallet/models/exchange/response_objects/pair.dart';