CW-969-Add-DFX-s-Open-CryptoPay (#2122)

* feat: Add Open CryptoPay for sending

* bug: Fix sending Open CryptoPay for eth

* feat: add transaction dismissal

* style: remove print statements from OCP

* feat: add support for Monero over OCP

* bug: Hide "Add to Address Book" on OCP transactions

* style: revert code style in send_view_model.dart

* style: revert code style in send_view_model.dart

* feat: set failure state if it fails to create an OCP transaction

* Update lib/view_model/send/send_view_model.dart

---------

Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

cw_evm/lib/evm_chain_client.dart

@@ -190,7 +190,7 @@ abstract class EVMChainClient {
     _sendTransaction = () async => await sendTransaction(signedTransaction);
 
     return PendingEVMChainTransaction(
-      signedTransaction: signedTransaction,
+      signedTransaction: prepareSignedTransactionForSending(signedTransaction),
       amount: amount.toString(),
       fee: gasFee,
       sendTransaction: _sendTransaction,

cw_monero/lib/api/transaction_history.dart

@@ -185,13 +185,14 @@ Future<PendingTransactionDescription> createTransactionSync(
   final rAmt = monero.PendingTransaction_amount(pendingTx);
   final rFee = monero.PendingTransaction_fee(pendingTx);
   final rHash = monero.PendingTransaction_txid(pendingTx, '');
+  final rHex = monero.PendingTransaction_hex(pendingTx, '');
   final rTxKey = rHash;
 
   return PendingTransactionDescription(
       amount: rAmt,
       fee: rFee,
       hash: rHash,
-      hex: '',
+      hex: rHex,
       txKey: rTxKey,
       pointerAddress: pendingTx.address,
     );
@@ -234,7 +235,7 @@ Future<PendingTransactionDescription> createTransactionMultDest(
     amount: monero.PendingTransaction_amount(txptr),
     fee: monero.PendingTransaction_fee(txptr),
     hash: monero.PendingTransaction_txid(txptr, ''),
-    hex: monero.PendingTransaction_txid(txptr, ''),
+    hex: monero.PendingTransaction_hex(txptr, ''),
     txKey: monero.PendingTransaction_txid(txptr, ''),
     pointerAddress: txptr.address,
   );

lib/core/open_crypto_pay/exceptions.dart

@@ -0,0 +1,18 @@
+class OpenCryptoPayException implements Exception {
+  final String message;
+
+  OpenCryptoPayException([this.message = '']);
+
+  @override
+  String toString() =>
+      'OpenCryptoPayException${message.isNotEmpty ? ': $message' : ''}';
+}
+
+class OpenCryptoPayNotSupportedException extends OpenCryptoPayException {
+  final String provider;
+
+  OpenCryptoPayNotSupportedException(this.provider);
+
+  @override
+  String get message => "$provider does not support Open CryptoPay";
+}

lib/core/open_crypto_pay/lnurl.dart

@@ -0,0 +1,78 @@
+import 'dart:convert';
+
+import 'package:bech32/bech32.dart';
+
+Uri decodeLNURL(String encodedUrl) {
+  Uri decodedUri;
+
+  /// The URL doesn't have to be encoded at all as per LUD-17: Protocol schemes and raw (non bech32-encoded) URLs.
+  /// https://github.com/lnurl/luds/blob/luds/17.md
+  /// Handle non bech32-encoded LNURL
+  final lud17prefixes = ['lnurlw', 'lnurlc', 'lnurlp', 'keyauth'];
+  decodedUri = Uri.parse(encodedUrl);
+  for (final prefix in lud17prefixes) {
+    if (decodedUri.scheme.contains(prefix)) {
+      decodedUri = decodedUri.replace(scheme: prefix);
+    }
+  }
+  if (lud17prefixes.contains(decodedUri.scheme)) {
+    /// If the non-bech32 LNURL is a Tor address, the port has to be http instead of https for the clearnet LNURL so check if the host ends with '.onion' or '.onion.'
+    decodedUri = decodedUri.replace(
+        scheme: decodedUri.host.endsWith('onion') ||
+                decodedUri.host.endsWith('onion.')
+            ? 'http'
+            : 'https');
+  } else {
+    /// Try to parse the input as a lnUrl. Will throw an error if it fails.
+    final lnUrl = _findLnUrl(encodedUrl);
+
+    /// Decode the lnurl using bech32
+    final bech32 = const Bech32Codec().decode(lnUrl, lnUrl.length);
+    decodedUri = Uri.parse(utf8.decode(_convert(bech32.data, 5, 8, false)));
+  }
+  return decodedUri;
+}
+
+/// Parse and return a given lnurl string if it's valid. Will remove
+/// `lightning:` from the beginning of it if present.
+String _findLnUrl(String input) {
+  final res = RegExp(
+    r',*?((lnurl)([0-9]+[a-z0-9]+))',
+  ).allMatches(input.toLowerCase());
+
+  if (res.length == 1) {
+    return res.first.group(0)!;
+  } else {
+    throw ArgumentError('Not a valid lnurl string');
+  }
+}
+
+/// Taken from bech32 (bitcoinjs): https://github.com/bitcoinjs/bech32
+List<int> _convert(List<int> data, int inBits, int outBits, bool pad) {
+  var value = 0;
+  var bits = 0;
+  final maxV = (1 << outBits) - 1;
+
+  final result = <int>[];
+  for (final dataValue in data) {
+    value = (value << inBits) | dataValue;
+    bits += inBits;
+
+    while (bits >= outBits) {
+      bits -= outBits;
+      result.add((value >> bits) & maxV);
+    }
+  }
+
+  if (pad) {
+    if (bits > 0) result.add((value << (outBits - bits)) & maxV);
+  } else {
+    if (bits >= inBits) throw Exception('Excess padding');
+
+    if ((value << (outBits - bits)) & maxV > 0) {
+      throw Exception('Non-zero padding');
+    }
+  }
+
+  return result;
+}

lib/core/open_crypto_pay/models.dart

@@ -0,0 +1,26 @@
+class OpenCryptoPayRequest {
+  final String receiverName;
+  final int expiry;
+  final String callbackUrl;
+  final String quote;
+  final Map<String, List<OpenCryptoPayQuoteAsset>> methods;
+
+  OpenCryptoPayRequest({
+    required this.receiverName,
+    required this.expiry,
+    required this.callbackUrl,
+    required this.quote,
+    required this.methods,
+  });
+}
+
+class OpenCryptoPayQuoteAsset {
+  final String symbol;
+  final String amount;
+
+  const OpenCryptoPayQuoteAsset(this.symbol, this.amount);
+
+  OpenCryptoPayQuoteAsset.fromJson(Map<String, dynamic> json)
+      : symbol = json['asset'] as String,
+        amount = json['amount'] as String;
+}

lib/core/open_crypto_pay/open_cryptopay_service.dart

@@ -0,0 +1,184 @@
+import 'dart:convert';
+import 'dart:developer';
+
+import 'package:cake_wallet/core/open_crypto_pay/exceptions.dart';
+import 'package:cake_wallet/core/open_crypto_pay/lnurl.dart';
+import 'package:cake_wallet/core/open_crypto_pay/models.dart';
+import 'package:cw_core/crypto_currency.dart';
+import 'package:http/http.dart';
+
+class OpenCryptoPayService {
+  static bool isOpenCryptoPayQR(String value) =>
+      value.toLowerCase().contains("lightning=lnurl") ||
+      value.toLowerCase().startsWith("lnurl");
+
+  final Client _httpClient = Client();
+
+  Future<String> commitOpenCryptoPayRequest(
+    String txHex, {
+    required String txId,
+    required OpenCryptoPayRequest request,
+    required CryptoCurrency asset,
+  }) async {
+    final uri = Uri.parse(request.callbackUrl.replaceAll("/cb/", "/tx/"));
+
+    final queryParams = Map.of(uri.queryParameters);
+
+    queryParams['quote'] = request.quote;
+    queryParams['asset'] = asset.title;
+    queryParams['method'] = _getMethod(asset);
+    queryParams['hex'] = txHex;
+    queryParams['tx'] = txId;
+
+    final response =
+        await _httpClient.get(Uri.https(uri.authority, uri.path, queryParams));
+
+    if (response.statusCode == 200) {
+      final body = jsonDecode(response.body) as Map;
+
+      if (body.keys.contains("txId")) return body["txId"] as String;
+      throw OpenCryptoPayException(body.toString());
+    }
+    throw OpenCryptoPayException(
+        "Unexpected status code ${response.statusCode} ${response.body}");
+  }
+
+  Future<void> cancelOpenCryptoPayRequest(OpenCryptoPayRequest request) async {
+    final uri = Uri.parse(request.callbackUrl.replaceAll("/cb/", "/cancel/"));
+
+    await _httpClient.delete(uri);
+  }
+
+  Future<OpenCryptoPayRequest> getOpenCryptoPayInvoice(String lnUrl) async {
+    if (lnUrl.toLowerCase().startsWith("http")) {
+      final uri = Uri.parse(lnUrl);
+      final params = uri.queryParameters;
+      if (!params.containsKey("lightning")) {
+        throw OpenCryptoPayNotSupportedException(uri.authority);
+      }
+
+      lnUrl = params["lightning"] as String;
+    }
+    final url = decodeLNURL(lnUrl);
+    final params = await _getOpenCryptoPayParams(url);
+
+    return OpenCryptoPayRequest(
+      receiverName: params.$1.displayName ?? "Unknown",
+      expiry: params.$1.expiration.difference(DateTime.now()).inSeconds,
+      callbackUrl: params.$1.callbackUrl,
+      quote: params.$1.id,
+      methods: params.$2,
+    );
+  }
+
+  Future<(_OpenCryptoPayQuote, Map<String, List<OpenCryptoPayQuoteAsset>>)>
+      _getOpenCryptoPayParams(Uri uri) async {
+    final response = await _httpClient.get(uri);
+
+    if (response.statusCode == 200) {
+      final responseBody = jsonDecode(response.body) as Map;
+
+      for (final key in ['callback', 'transferAmounts', 'quote']) {
+        if (!responseBody.keys.contains(key)) {
+          throw OpenCryptoPayNotSupportedException(uri.authority);
+        }
+      }
+
+      final methods = <String, List<OpenCryptoPayQuoteAsset>>{};
+      for (final transferAmountRaw in responseBody['transferAmounts'] as List) {
+        final transferAmount = transferAmountRaw as Map;
+        final method = transferAmount['method'] as String;
+        methods[method] = [];
+        for (final assetJson in transferAmount['assets'] as List) {
+          final asset = OpenCryptoPayQuoteAsset.fromJson(
+              assetJson as Map<String, dynamic>);
+          methods[method]?.add(asset);
+        }
+      }
+
+      log(responseBody.toString());
+
+      final quote = _OpenCryptoPayQuote.fromJson(
+          responseBody['callback'] as String,
+          responseBody['displayName'] as String?,
+          responseBody['quote'] as Map<String, dynamic>);
+
+      return (quote, methods);
+    } else {
+      throw OpenCryptoPayException(
+          'Failed to get Open CryptoPay Request. Status: ${response.statusCode} ${response.body}');
+    }
+  }
+
+  Future<Uri> getOpenCryptoPayAddress(
+      OpenCryptoPayRequest request, CryptoCurrency asset) async {
+    final uri = Uri.parse(request.callbackUrl);
+    final queryParams = Map.of(uri.queryParameters);
+
+    queryParams['quote'] = request.quote;
+    queryParams['asset'] = asset.title;
+    queryParams['method'] = _getMethod(asset);
+
+    final response =
+        await _httpClient.get(Uri.https(uri.authority, uri.path, queryParams));
+
+    if (response.statusCode == 200) {
+      final responseBody = jsonDecode(response.body) as Map;
+
+      for (final key in ['expiryDate', 'uri']) {
+        if (!responseBody.keys.contains(key)) {
+          throw OpenCryptoPayNotSupportedException(uri.authority);
+        }
+      }
+
+      final result = Uri.parse(responseBody['uri'] as String);
+
+      if (result.queryParameters['amount'] != null) return result;
+
+      final newQueryParameters =
+          Map<String, dynamic>.from(result.queryParameters);
+
+      newQueryParameters['amount'] = _getAmountByAsset(request, asset);
+      return Uri(
+          scheme: result.scheme,
+          path: result.path.split("@").first,
+          queryParameters: newQueryParameters);
+    } else {
+      throw OpenCryptoPayException(
+          'Failed to create Open CryptoPay Request. Status: ${response.statusCode} ${response.body}');
+    }
+  }
+
+  String _getAmountByAsset(OpenCryptoPayRequest request, CryptoCurrency asset) {
+    final method = _getMethod(asset);
+    return request.methods[method]!
+        .firstWhere((e) => e.symbol == asset.title)
+        .amount;
+  }
+
+  String _getMethod(CryptoCurrency asset) {
+    switch (asset.tag) {
+      case "ETH":
+        return "Ethereum";
+      case "POL":
+        return "Polygon";
+      default:
+        return asset.fullName!;
+    }
+  }
+}
+
+class _OpenCryptoPayQuote {
+  final String callbackUrl;
+  final String? displayName;
+  final String id;
+  final DateTime expiration;
+
+  _OpenCryptoPayQuote(
+      this.callbackUrl, this.displayName, this.id, this.expiration);
+
+  _OpenCryptoPayQuote.fromJson(
+      this.callbackUrl, this.displayName, Map<String, dynamic> json)
+      : id = json['id'] as String,
+        expiration = DateTime.parse(json['expiration'] as String);
+}

lib/src/screens/send/send_page.dart

@@ -547,9 +547,9 @@ class SendPage extends BasePage {
       }
 
       if (state is ExecutedSuccessfullyState) {
-        WidgetsBinding.instance.addPostFrameCallback((_) {
+        WidgetsBinding.instance.addPostFrameCallback((_) async {
           if (context.mounted) {
-            showModalBottomSheet<void>(
+            final result = await showModalBottomSheet<bool>(
               context: context,
               isDismissible: false,
               isScrollControlled: true,
@@ -570,13 +570,16 @@ class SendPage extends BasePage {
                   feeFiatAmount: sendViewModel.pendingTransactionFeeFiatAmountFormatted,
                   outputs: sendViewModel.outputs,
                   onSlideComplete: () async {
-                    Navigator.of(bottomSheetContext).pop();
+                    Navigator.of(bottomSheetContext).pop(true);
                     sendViewModel.commitTransaction(context);
                   },
                   change: sendViewModel.pendingTransaction!.change,
+                  isOpenCryptoPay: sendViewModel.ocpRequest != null,
                 );
               },
             );
+
+            if (result == null) sendViewModel.dismissTransaction();
           }
         });
       }
@@ -600,7 +603,8 @@ class SendPage extends BasePage {
             context: context,
             isDismissible: false,
             builder: (BuildContext bottomSheetContext) {
-              return showContactSheet
+              return showContactSheet &&
+                      sendViewModel.ocpRequest == null
                   ? InfoBottomSheet(
                       currentTheme: currentTheme,
                       showDontAskMeCheckbox: true,

lib/src/screens/send/widgets/send_card.dart

@@ -1,16 +1,17 @@
+import 'package:cake_wallet/core/open_crypto_pay/open_cryptopay_service.dart';
 import 'package:cake_wallet/entities/priority_for_wallet_type.dart';
 import 'package:cake_wallet/src/screens/receive/widgets/currency_input_field.dart';
 import 'package:cake_wallet/src/widgets/picker.dart';
 import 'package:cake_wallet/src/widgets/standard_checkbox.dart';
-import 'package:cake_wallet/themes/extensions/keyboard_theme.dart';
 import 'package:cake_wallet/src/screens/exchange/widgets/currency_picker.dart';
 import 'package:cake_wallet/src/widgets/alert_with_one_action.dart';
+import 'package:cake_wallet/themes/extensions/cake_text_theme.dart';
+import 'package:cake_wallet/themes/theme_base.dart';
 import 'package:cake_wallet/utils/payment_request.dart';
 import 'package:cake_wallet/utils/responsive_layout_util.dart';
 import 'package:cw_core/crypto_currency.dart';
 import 'package:cw_core/currency.dart';
 import 'package:cake_wallet/routes.dart';
-import 'package:cake_wallet/src/widgets/keyboard_done_button.dart';
 import 'package:cake_wallet/view_model/send/output.dart';
 import 'package:cw_core/transaction_priority.dart';
 import 'package:cw_core/unspent_coin_type.dart';
@@ -18,7 +19,6 @@ import 'package:cw_core/wallet_type.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:mobx/mobx.dart';
-import 'package:keyboard_actions/keyboard_actions.dart';
 import 'package:cake_wallet/view_model/send/send_view_model.dart';
 import 'package:cake_wallet/utils/show_pop_up.dart';
 import 'package:cake_wallet/src/widgets/address_text_field.dart';
@@ -26,9 +26,6 @@ import 'package:cake_wallet/generated/i18n.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/themes/extensions/send_page_theme.dart';
 
-import '../../../../themes/extensions/cake_text_theme.dart';
-import '../../../../themes/theme_base.dart';
-
 class SendCard extends StatefulWidget {
   SendCard({
     Key? key,
@@ -185,11 +182,16 @@ class SendCardState extends State<SendCard> with AutomaticKeepAliveClientMixin<S
                   addressKey: ValueKey('send_page_address_textfield_key'),
                   focusNode: addressFocusNode,
                   controller: addressController,
-                  onURIScanned: (uri) {
+                  onURIScanned: (uri) async {
-                    final paymentRequest = PaymentRequest.fromUri(uri);
+                    if (OpenCryptoPayService.isOpenCryptoPayQR(
-                    addressController.text = paymentRequest.address;
+                        uri.toString())) {
-                    cryptoAmountController.text = paymentRequest.amount;
+                      sendViewModel.createOpenCryptoPayTransaction(uri.toString());
-                    noteController.text = paymentRequest.note;
+                    } else {
+                      final paymentRequest = PaymentRequest.fromUri(uri);
+                      addressController.text = paymentRequest.address;
+                      cryptoAmountController.text = paymentRequest.amount;
+                      noteController.text = paymentRequest.note;
+                    }
                   },
                   options: [
                     AddressTextFieldOption.paste,

lib/src/widgets/bottom_sheet/confirm_sending_bottom_sheet_widget.dart

@@ -28,6 +28,7 @@ class ConfirmSendingBottomSheet extends BaseBottomSheet {
   final List<Output> outputs;
   final VoidCallback onSlideComplete;
   final PendingChange? change;
+  final bool isOpenCryptoPay;
 
   ConfirmSendingBottomSheet({
     required String titleText,
@@ -46,6 +47,7 @@ class ConfirmSendingBottomSheet extends BaseBottomSheet {
     required this.outputs,
     required this.onSlideComplete,
     this.change,
+    this.isOpenCryptoPay = false,
     Key? key,
   })  : showScrollbar = outputs.length > 3,
         super(titleText: titleText, titleIconPath: titleIconPath);
@@ -132,7 +134,7 @@ class ConfirmSendingBottomSheet extends BaseBottomSheet {
                   final _amount = item.cryptoAmount.replaceAll(',', '.') + ' ${currency.title}';
                   return isBatchSending || contactName.isNotEmpty
                       ? AddressExpansionTile(
-                          contactType: 'Contact',
+                          contactType: isOpenCryptoPay ? 'Open CryptoPay' : S.of(context).contact,
                           currentTheme: currentTheme,
                           name: isBatchSending ? batchContactTitle : contactName,
                           address: _address,
@@ -143,7 +145,7 @@ class ConfirmSendingBottomSheet extends BaseBottomSheet {
                           tileBackgroundColor: tileBackgroundColor,
                         )
                       : AddressTile(
-                          itemTitle: 'Address',
+                          itemTitle: S.of(context).address,
                           currentTheme: currentTheme,
                           itemTitleTextStyle: itemTitleTextStyle,
                           isBatchSending: isBatchSending,

lib/view_model/send/send_view_model.dart

@@ -1,53 +1,57 @@
+import 'package:cake_wallet/bitcoin/bitcoin.dart';
+import 'package:cake_wallet/core/address_validator.dart';
+import 'package:cake_wallet/core/amount_validator.dart';
+import 'package:cake_wallet/core/execution_state.dart';
+import 'package:cake_wallet/core/open_crypto_pay/models.dart';
+import 'package:cake_wallet/core/open_crypto_pay/open_cryptopay_service.dart';
+import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_change_listener_view_model.dart';
+import 'package:cake_wallet/decred/decred.dart';
+import 'package:cake_wallet/entities/calculate_fiat_amount.dart';
 import 'package:cake_wallet/entities/contact.dart';
+import 'package:cake_wallet/entities/contact_record.dart';
 import 'package:cake_wallet/entities/evm_transaction_error_fees_handler.dart';
+import 'package:cake_wallet/entities/fiat_currency.dart';
+import 'package:cake_wallet/entities/parsed_address.dart';
+import 'package:cake_wallet/entities/template.dart';
 import 'package:cake_wallet/entities/transaction_description.dart';
+import 'package:cake_wallet/entities/wallet_contact.dart';
 import 'package:cake_wallet/ethereum/ethereum.dart';
 import 'package:cake_wallet/exchange/provider/exchange_provider.dart';
 import 'package:cake_wallet/exchange/provider/thorchain_exchange.provider.dart';
+import 'package:cake_wallet/generated/i18n.dart';
+import 'package:cake_wallet/monero/monero.dart';
 import 'package:cake_wallet/nano/nano.dart';
-import 'package:cake_wallet/decred/decred.dart';
-import 'package:cake_wallet/core/wallet_change_listener_view_model.dart';
-import 'package:cake_wallet/entities/contact_record.dart';
-import 'package:cake_wallet/entities/wallet_contact.dart';
 import 'package:cake_wallet/polygon/polygon.dart';
 import 'package:cake_wallet/reactions/wallet_connect.dart';
 import 'package:cake_wallet/routes.dart';
 import 'package:cake_wallet/solana/solana.dart';
 import 'package:cake_wallet/store/app_store.dart';
+import 'package:cake_wallet/store/dashboard/fiat_conversion_store.dart';
+import 'package:cake_wallet/store/settings_store.dart';
 import 'package:cake_wallet/tron/tron.dart';
+import 'package:cake_wallet/utils/payment_request.dart';
 import 'package:cake_wallet/view_model/contact_list/contact_list_view_model.dart';
 import 'package:cake_wallet/view_model/dashboard/balance_view_model.dart';
 import 'package:cake_wallet/view_model/hardware_wallet/ledger_view_model.dart';
 import 'package:cake_wallet/view_model/send/fees_view_model.dart';
+import 'package:cake_wallet/view_model/send/output.dart';
+import 'package:cake_wallet/view_model/send/send_template_view_model.dart';
+import 'package:cake_wallet/view_model/send/send_view_model_state.dart';
 import 'package:cake_wallet/view_model/unspent_coins/unspent_coins_list_view_model.dart';
 import 'package:cake_wallet/wownero/wownero.dart';
 import 'package:cake_wallet/zano/zano.dart';
+import 'package:cw_core/crypto_currency.dart';
 import 'package:cw_core/exceptions.dart';
+import 'package:cw_core/pending_transaction.dart';
+import 'package:cw_core/sync_status.dart';
 import 'package:cw_core/transaction_info.dart';
 import 'package:cw_core/unspent_coin_type.dart';
-import 'package:cake_wallet/view_model/send/output.dart';
+import 'package:cw_core/utils/print_verbose.dart';
-import 'package:cake_wallet/view_model/send/send_template_view_model.dart';
+import 'package:cw_core/wallet_type.dart';
 import 'package:flutter/material.dart';
 import 'package:hive/hive.dart';
 import 'package:mobx/mobx.dart';
-import 'package:cake_wallet/entities/template.dart';
-import 'package:cake_wallet/core/address_validator.dart';
-import 'package:cake_wallet/core/amount_validator.dart';
-import 'package:cw_core/pending_transaction.dart';
-import 'package:cake_wallet/core/validator.dart';
-import 'package:cake_wallet/core/execution_state.dart';
-import 'package:cake_wallet/monero/monero.dart';
-import 'package:cw_core/sync_status.dart';
-import 'package:cw_core/crypto_currency.dart';
-import 'package:cake_wallet/entities/fiat_currency.dart';
-import 'package:cake_wallet/entities/calculate_fiat_amount.dart';
-import 'package:cw_core/wallet_type.dart';
-import 'package:cake_wallet/store/dashboard/fiat_conversion_store.dart';
-import 'package:cake_wallet/store/settings_store.dart';
-import 'package:cake_wallet/view_model/send/send_view_model_state.dart';
-import 'package:cake_wallet/entities/parsed_address.dart';
-import 'package:cake_wallet/bitcoin/bitcoin.dart';
-import 'package:cake_wallet/generated/i18n.dart';
 
 part 'send_view_model.g.dart';
 
@@ -390,15 +394,62 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
     return conditionsList.contains(true);
   }
 
-  @action
+  final _ocpService = OpenCryptoPayService();
-  Future<PendingTransaction?> createTransaction({ExchangeProvider? provider}) async {
-    try {
-      if (wallet.isHardwareWallet)
-        state = IsAwaitingDeviceResponseState();
-      else
-        state = IsExecutingState();
 
-      pendingTransaction = await wallet.createTransaction(_credentials(provider));
+  @observable
+  OpenCryptoPayRequest? ocpRequest;
+
+  @action
+  Future<void> dismissTransaction() async {
+    state = InitialExecutionState();
+    if (ocpRequest != null) {
+      clearOutputs();
+      _ocpService.cancelOpenCryptoPayRequest(ocpRequest!);
+      ocpRequest = null;
+    }
+  }
+
+  @action
+  Future<PendingTransaction?> createOpenCryptoPayTransaction(String uri) async {
+    state = IsExecutingState();
+
+    try {
+      final originalOCPRequest =
+          await _ocpService.getOpenCryptoPayInvoice(uri.toString());
+      final paymentUri = await _ocpService.getOpenCryptoPayAddress(
+        originalOCPRequest,
+        selectedCryptoCurrency,
+      );
+
+      ocpRequest = originalOCPRequest;
+
+      final paymentRequest = PaymentRequest.fromUri(paymentUri);
+      clearOutputs();
+
+      outputs.first.address = paymentRequest.address;
+      outputs.first.parsedAddress = ParsedAddress(
+          addresses: [paymentRequest.address], name: ocpRequest!.receiverName);
+      outputs.first.setCryptoAmount(paymentRequest.amount);
+      outputs.first.note = ocpRequest!.receiverName;
+
+      return createTransaction();
+    } catch (e) {
+      printV(e);
+      state = FailureState(translateErrorMessage(e, walletType, currency));
+      return null;
+    }
+  }
+
+  @action
+  Future<PendingTransaction?> createTransaction(
+      {ExchangeProvider? provider}) async {
+    try {
+      if (!(state is IsExecutingState)) state = IsExecutingState();
+
+      if (wallet.isHardwareWallet) state = IsAwaitingDeviceResponseState();
+
+      pendingTransaction =
+          await wallet.createTransaction(_credentials(provider));
 
       if (provider is ThorChainExchangeProvider) {
         final outputCount = pendingTransaction?.outputCount ?? 0;
@@ -412,7 +463,8 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
       }
 
       if (wallet.type == WalletType.bitcoin) {
-        final updatedOutputs = bitcoin!.updateOutputs(pendingTransaction!, outputs);
+        final updatedOutputs =
+            bitcoin!.updateOutputs(pendingTransaction!, outputs);
 
         if (outputs.length == updatedOutputs.length) {
           outputs.replaceRange(0, outputs.length, updatedOutputs);
@@ -473,7 +525,26 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
   @action
   Future<void> commitTransaction(BuildContext context) async {
     if (pendingTransaction == null) {
-      throw Exception("Pending transaction doesn't exist. It should not be happened.");
+      throw Exception(
+          "Pending transaction doesn't exist. It should not be happened.");
+    }
+
+    if (ocpRequest != null) {
+      state = TransactionCommitting();
+      if (selectedCryptoCurrency == CryptoCurrency.xmr) {
+        await pendingTransaction!.commit();
+      }
+
+      await _ocpService.commitOpenCryptoPayRequest(
+        pendingTransaction!.hex,
+        txId: pendingTransaction!.id,
+        request: ocpRequest!,
+        asset: selectedCryptoCurrency,
+      );
+
+      state = TransactionCommitted();
+
+      return;
     }
 
     String address = outputs.fold('', (acc, value) {
@@ -493,8 +564,8 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
 
       if (pendingTransaction!.shouldCommitUR()) {
         final urstr = await pendingTransaction!.commitUR();
-        final result =
+        final result = await Navigator.of(context)
-            await Navigator.of(context).pushNamed(Routes.urqrAnimatedPage, arguments: urstr);
+            .pushNamed(Routes.urqrAnimatedPage, arguments: urstr);
         if (result == null) {
           state = FailureState("Canceled by user");
           return;
@@ -508,12 +579,18 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
       }
 
       if (pendingTransaction!.id.isNotEmpty) {
-        final descriptionKey = '${pendingTransaction!.id}_${wallet.walletAddresses.primaryAddress}';
+        final descriptionKey =
+            '${pendingTransaction!.id}_${wallet.walletAddresses.primaryAddress}';
         _settingsStore.shouldSaveRecipientAddress
             ? await transactionDescriptionBox.add(TransactionDescription(
-                id: descriptionKey, recipientAddress: address, transactionNote: note))
+                id: descriptionKey,
-            : await transactionDescriptionBox
+                recipientAddress: address,
-                .add(TransactionDescription(id: descriptionKey, transactionNote: note));
+                transactionNote: note,
+              ))
+            : await transactionDescriptionBox.add(TransactionDescription(
+                id: descriptionKey,
+                transactionNote: note,
+              ));
       }
 
       state = TransactionCommitted();
@@ -552,12 +629,10 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
         );
 
       case WalletType.monero:
-        return monero!
+        return monero!.createMoneroTransactionCreationCredentials(outputs: outputs, priority: priority!);
-            .createMoneroTransactionCreationCredentials(outputs: outputs, priority: priority!);
 
       case WalletType.wownero:
-        return wownero!
+        return wownero!.createWowneroTransactionCreationCredentials(outputs: outputs, priority: priority!);
-            .createWowneroTransactionCreationCredentials(outputs: outputs, priority: priority!);
 
       case WalletType.ethereum:
         return ethereum!.createEthereumTransactionCredentials(outputs,
@@ -568,8 +643,7 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
         return polygon!.createPolygonTransactionCredentials(outputs,
             priority: priority!, currency: selectedCryptoCurrency);
       case WalletType.solana:
-        return solana!
+        return solana!.createSolanaTransactionCredentials(outputs, currency: selectedCryptoCurrency);
-            .createSolanaTransactionCredentials(outputs, currency: selectedCryptoCurrency);
       case WalletType.tron:
         return tron!.createTronTransactionCredentials(outputs, currency: selectedCryptoCurrency);
       case WalletType.zano:
@@ -603,8 +677,8 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
 
   ContactRecord? newContactAddress() {
     final Set<String> contactAddresses =
-        Set.from(contactListViewModel.contacts.map((contact) => contact.address))
+    Set.from(contactListViewModel.contacts.map((contact) => contact.address))
-          ..addAll(contactListViewModel.walletContacts.map((contact) => contact.address));
+      ..addAll(contactListViewModel.walletContacts.map((contact) => contact.address));
 
     for (var output in outputs) {
       String address;

res/values/strings_de.arb

@@ -697,7 +697,7 @@
   "send": "Senden",
   "send_address": "${cryptoCurrency}-Adresse",
   "send_amount": "Betrag:",
-  "send_change_to_you": "Verändere dich zu dir:",
+  "send_change_to_you": "Rückgeld:",
   "send_creating_transaction": "Erstelle Transaktion",
   "send_error_currency": "Die Währung darf nur Zahlen enthalten",
   "send_error_minimum_value": "Der Mindestbetrag ist 0,01",