btcpayserver/BTCPayServer/Controllers/WalletsController.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using BTCPayServer.Abstractions.Constants;
using BTCPayServer.Abstractions.Extensions;
using BTCPayServer.Abstractions.Models;
using BTCPayServer.Client;
using BTCPayServer.Data;
using BTCPayServer.HostedServices;
using BTCPayServer.ModelBinders;
using BTCPayServer.Models;
using BTCPayServer.Models.StoreViewModels;
using BTCPayServer.Models.WalletViewModels;
using BTCPayServer.Payments;
using BTCPayServer.Security;
using BTCPayServer.Services;
using BTCPayServer.Services.Labels;
using BTCPayServer.Services.Rates;
using BTCPayServer.Services.Stores;
using BTCPayServer.Services.Wallets;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using NBitcoin;
using NBitcoin.DataEncoders;
using NBXplorer;
using NBXplorer.DerivationStrategy;
using NBXplorer.Models;
using Newtonsoft.Json;

namespace BTCPayServer.Controllers
{
    [Route("wallets")]
    [Authorize(Policy = Policies.CanModifyStoreSettings, AuthenticationSchemes = AuthenticationSchemes.Cookie)]
    [AutoValidateAntiforgeryToken]
    public partial class WalletsController : Controller
    {
        public StoreRepository Repository { get; }
        public WalletRepository WalletRepository { get; }
        public BTCPayNetworkProvider NetworkProvider { get; }
        public ExplorerClientProvider ExplorerClientProvider { get; }

        private readonly UserManager<ApplicationUser> _userManager;
        private readonly JsonSerializerSettings _serializerSettings;
        private readonly NBXplorerDashboard _dashboard;
        private readonly IAuthorizationService _authorizationService;
        private readonly IFeeProviderFactory _feeRateProvider;
        private readonly BTCPayWalletProvider _walletProvider;
        private readonly WalletReceiveStateService _WalletReceiveStateService;
        private readonly EventAggregator _EventAggregator;
        private readonly SettingsRepository _settingsRepository;
        private readonly DelayedTransactionBroadcaster _broadcaster;
        private readonly PayjoinClient _payjoinClient;
        private readonly LabelFactory _labelFactory;
        private readonly ApplicationDbContextFactory _dbContextFactory;
        private readonly BTCPayNetworkJsonSerializerSettings _jsonSerializerSettings;
        private readonly PullPaymentHostedService _pullPaymentService;

        public RateFetcher RateFetcher { get; }

        readonly CurrencyNameTable _currencyTable;
        public WalletsController(StoreRepository repo,
                                 WalletRepository walletRepository,
                                 CurrencyNameTable currencyTable,
                                 BTCPayNetworkProvider networkProvider,
                                 UserManager<ApplicationUser> userManager,
                                 MvcNewtonsoftJsonOptions mvcJsonOptions,
                                 NBXplorerDashboard dashboard,
                                 RateFetcher rateProvider,
                                 IAuthorizationService authorizationService,
                                 ExplorerClientProvider explorerProvider,
                                 IFeeProviderFactory feeRateProvider,
                                 BTCPayWalletProvider walletProvider,
                                 WalletReceiveStateService walletReceiveStateService,
                                 EventAggregator eventAggregator,
                                 SettingsRepository settingsRepository,
                                 DelayedTransactionBroadcaster broadcaster,
                                 PayjoinClient payjoinClient,
                                 LabelFactory labelFactory,
                                 ApplicationDbContextFactory dbContextFactory,
                                 BTCPayNetworkJsonSerializerSettings jsonSerializerSettings,
                                 HostedServices.PullPaymentHostedService pullPaymentService)
        {
            _currencyTable = currencyTable;
            Repository = repo;
            WalletRepository = walletRepository;
            RateFetcher = rateProvider;
            _authorizationService = authorizationService;
            NetworkProvider = networkProvider;
            _userManager = userManager;
            _serializerSettings = mvcJsonOptions.SerializerSettings;
            _dashboard = dashboard;
            ExplorerClientProvider = explorerProvider;
            _feeRateProvider = feeRateProvider;
            _walletProvider = walletProvider;
            _WalletReceiveStateService = walletReceiveStateService;
            _EventAggregator = eventAggregator;
            _settingsRepository = settingsRepository;
            _broadcaster = broadcaster;
            _payjoinClient = payjoinClient;
            _labelFactory = labelFactory;
            _dbContextFactory = dbContextFactory;
            _jsonSerializerSettings = jsonSerializerSettings;
            _pullPaymentService = pullPaymentService;
        }

        // Borrowed from https://github.com/ManageIQ/guides/blob/master/labels.md
        readonly string[] LabelColorScheme = new string[]
        {
            "#fbca04",
            "#0e8a16",
            "#ff7619",
            "#84b6eb",
            "#5319e7",
            "#cdcdcd",
            "#cc317c",
        };

        const int MaxLabelSize = 20;
        const int MaxCommentSize = 200;
        [HttpPost]
        [Route("{walletId}")]
        public async Task<IActionResult> ModifyTransaction(
            // We need addlabel and addlabelclick. addlabel is the + button if the label does not exists,
            // addlabelclick is if the user click on existing label. For some reason, reusing the same name attribute for both
            // does not work
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, string transactionId,
                                string addlabel = null,
                                string addlabelclick = null,
                                string addcomment = null,
                                string removelabel = null)
        {
            addlabel = addlabel ?? addlabelclick;
            // Hack necessary when the user enter a empty comment and submit.
            // For some reason asp.net consider addcomment null instead of empty string...
            try
            {
                if (addcomment == null && Request?.Form?.TryGetValue(nameof(addcomment), out _) is true)
                {
                    addcomment = string.Empty;
                }
            }
            catch { }
            /////////

            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();

            var walletBlobInfoAsync = WalletRepository.GetWalletInfo(walletId);
            var walletTransactionsInfoAsync = WalletRepository.GetWalletTransactionsInfo(walletId);
            var wallet = _walletProvider.GetWallet(paymentMethod.Network);
            var walletBlobInfo = await walletBlobInfoAsync;
            var walletTransactionsInfo = await walletTransactionsInfoAsync;
            if (addlabel != null)
            {
                addlabel = addlabel.Trim().TrimStart('{').ToLowerInvariant().Replace(',', ' ').Truncate(MaxLabelSize);
                var labels = _labelFactory.GetLabels(walletBlobInfo, Request);
                if (!walletTransactionsInfo.TryGetValue(transactionId, out var walletTransactionInfo))
                {
                    walletTransactionInfo = new WalletTransactionInfo();
                }
                if (!labels.Any(l => l.Value.Equals(addlabel, StringComparison.OrdinalIgnoreCase)))
                {
                    List<string> allColors = new List<string>();
                    allColors.AddRange(LabelColorScheme);
                    allColors.AddRange(labels.Select(l => l.Color));
                    var chosenColor =
                        allColors
                        .GroupBy(k => k)
                        .OrderBy(k => k.Count())
                        .ThenBy(k => {
                            var indexInColorScheme = Array.IndexOf(LabelColorScheme, k.Key);

                            // Ensures that any label color which may not be in our label color scheme is given the least priority
                            return indexInColorScheme == -1 ? double.PositiveInfinity : indexInColorScheme;
                        })
                        .First().Key;
                    walletBlobInfo.LabelColors.Add(addlabel, chosenColor);
                    await WalletRepository.SetWalletInfo(walletId, walletBlobInfo);
                }
                if (walletTransactionInfo.Labels.Add(addlabel))
                {
                    await WalletRepository.SetWalletTransactionInfo(walletId, transactionId, walletTransactionInfo);
                }
            }
            else if (removelabel != null)
            {
                removelabel = removelabel.Trim();
                if (walletTransactionsInfo.TryGetValue(transactionId, out var walletTransactionInfo))
                {
                    if (walletTransactionInfo.Labels.Remove(removelabel))
                    {
                        var canDelete = !walletTransactionsInfo.SelectMany(txi => txi.Value.Labels).Any(l => l == removelabel);
                        if (canDelete)
                        {
                            walletBlobInfo.LabelColors.Remove(removelabel);
                            await WalletRepository.SetWalletInfo(walletId, walletBlobInfo);
                        }
                        await WalletRepository.SetWalletTransactionInfo(walletId, transactionId, walletTransactionInfo);
                    }
                }
            }
            else if (addcomment != null)
            {
                addcomment = addcomment.Trim().Truncate(MaxCommentSize);
                if (!walletTransactionsInfo.TryGetValue(transactionId, out var walletTransactionInfo))
                {
                    walletTransactionInfo = new WalletTransactionInfo();
                }
                walletTransactionInfo.Comment = addcomment;
                await WalletRepository.SetWalletTransactionInfo(walletId, transactionId, walletTransactionInfo);
            }
            return RedirectToAction(nameof(WalletTransactions), new { walletId = walletId.ToString() });
        }

        [HttpGet]
        [AllowAnonymous]
        public async Task<IActionResult> ListWallets()
        {
            if (GetUserId() == null)
            {
                return Challenge(AuthenticationSchemes.Cookie);
            }
            var wallets = new ListWalletsViewModel();
            var stores = await Repository.GetStoresByUserId(GetUserId());

            var onChainWallets = stores
                                .SelectMany(s => s.GetSupportedPaymentMethods(NetworkProvider)
                                              .OfType<DerivationSchemeSettings>()
                                              .Select(d => ((Wallet: _walletProvider.GetWallet(d.Network),
                                                            DerivationStrategy: d.AccountDerivation,
                                                            Network: d.Network)))
                                              .Where(_ => _.Wallet != null && _.Network.WalletSupported)
                                              .Select(_ => (Wallet: _.Wallet,
                                                            Store: s,
                                                            Balance: GetBalanceString(_.Wallet, _.DerivationStrategy),
                                                            DerivationStrategy: _.DerivationStrategy,
                                                            Network: _.Network)))
                                              .ToList();

            foreach (var wallet in onChainWallets)
            {
                ListWalletsViewModel.WalletViewModel walletVm = new ListWalletsViewModel.WalletViewModel();
                wallets.Wallets.Add(walletVm);
                walletVm.Balance = await wallet.Balance + " " + wallet.Wallet.Network.CryptoCode;
                walletVm.IsOwner = wallet.Store.Role == StoreRoles.Owner;
                if (!walletVm.IsOwner)
                {
                    walletVm.Balance = "";
                }
                walletVm.CryptoCode = wallet.Network.CryptoCode;
                walletVm.StoreId = wallet.Store.Id;
                walletVm.Id = new WalletId(wallet.Store.Id, wallet.Network.CryptoCode);
                walletVm.StoreName = wallet.Store.StoreName;
            }

            return View(wallets);
        }

        [HttpGet]
        [Route("{walletId}")]
        [Route("{walletId}/transactions")]
        public async Task<IActionResult> WalletTransactions(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, 
            string labelFilter = null,
            int skip = 0, 
            int count = 50
        )
        {
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();

            var wallet = _walletProvider.GetWallet(paymentMethod.Network);
            var walletBlobAsync = WalletRepository.GetWalletInfo(walletId);
            var walletTransactionsInfoAsync = WalletRepository.GetWalletTransactionsInfo(walletId);
            var transactions = await wallet.FetchTransactions(paymentMethod.AccountDerivation);
            var walletBlob = await walletBlobAsync;
            var walletTransactionsInfo = await walletTransactionsInfoAsync;
            var model = new ListTransactionsViewModel
            {
                Skip = skip,
                Count = count,
                Total = 0
            };
            if (transactions == null)
            {
                TempData.SetStatusMessageModel(new StatusMessageModel()
                {
                    Severity = StatusMessageModel.StatusSeverity.Error,
                    Message =
                        "There was an error retrieving the transactions list. Is NBXplorer configured correctly?"
                });
                model.Transactions = new List<ListTransactionsViewModel.TransactionViewModel>();
            }
            else
            {
                foreach (var tx in transactions.UnconfirmedTransactions.Transactions
                    .Concat(transactions.ConfirmedTransactions.Transactions).ToArray())
                {
                    var vm = new ListTransactionsViewModel.TransactionViewModel();
                    vm.Id = tx.TransactionId.ToString();
                    vm.Link = string.Format(CultureInfo.InvariantCulture, paymentMethod.Network.BlockExplorerLink,
                        vm.Id);
                    vm.Timestamp = tx.Timestamp;
                    vm.Positive = tx.BalanceChange.GetValue(wallet.Network) >= 0;
                    vm.Balance = tx.BalanceChange.ShowMoney(wallet.Network);
                    vm.IsConfirmed = tx.Confirmations != 0;

                    if (walletTransactionsInfo.TryGetValue(tx.TransactionId.ToString(), out var transactionInfo))
                    {
                        var labels = _labelFactory.GetLabels(walletBlob, transactionInfo, Request);
                        vm.Labels.AddRange(labels);
                        model.Labels.AddRange(labels);
                        vm.Comment = transactionInfo.Comment;
                    }

                    if (labelFilter == null ||
                        vm.Labels.Any(l => l.Value.Equals(labelFilter, StringComparison.OrdinalIgnoreCase)))
                        model.Transactions.Add(vm);
                }

                model.Total = model.Transactions.Count;
                model.Transactions = model.Transactions.OrderByDescending(t => t.Timestamp).Skip(skip).Take(count).ToList();
            }

            return View(model);
        }

        private static string GetLabelTarget(WalletId walletId, uint256 txId)
        {
            return $"{walletId}:{txId}";
        }

        [HttpGet]
        [Route("{walletId}/receive")]
        public IActionResult WalletReceive([ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId)
        {
            if (walletId?.StoreId == null)
                return NotFound();
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();
            var network = NetworkProvider.GetNetwork<BTCPayNetwork>(walletId?.CryptoCode);
            if (network == null)
                return NotFound();

            var address = _WalletReceiveStateService.Get(walletId)?.Address;
            return View(new WalletReceiveViewModel()
            {
                CryptoCode = walletId.CryptoCode,
                Address = address?.ToString(),
                CryptoImage = GetImage(paymentMethod.PaymentId, network)
            });
        }

        [HttpPost]
        [Route("{walletId}/receive")]
        public async Task<IActionResult> WalletReceive([ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, WalletReceiveViewModel viewModel, string command)
        {
            if (walletId?.StoreId == null)
                return NotFound();
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();
            var network = this.NetworkProvider.GetNetwork<BTCPayNetwork>(walletId?.CryptoCode);
            if (network == null)
                return NotFound();
            var wallet = _walletProvider.GetWallet(network);
            switch (command)
            {
                case "unreserve-current-address":
                    KeyPathInformation cachedAddress = _WalletReceiveStateService.Get(walletId);
                    if (cachedAddress == null)
                    {
                        break;
                    }
                    var address = cachedAddress.ScriptPubKey.GetDestinationAddress(network.NBitcoinNetwork);
                    ExplorerClientProvider.GetExplorerClient(network)
                        .CancelReservation(cachedAddress.DerivationStrategy, new[] { cachedAddress.KeyPath });
                    this.TempData.SetStatusMessageModel(new StatusMessageModel()
                    {
                        AllowDismiss = true,
                        Message = $"Address {address} was unreserved.",
                        Severity = StatusMessageModel.StatusSeverity.Success,
                    });
                    _WalletReceiveStateService.Remove(walletId);
                    break;
                case "generate-new-address":
                    var reserve = (await wallet.ReserveAddressAsync(paymentMethod.AccountDerivation));
                    _WalletReceiveStateService.Set(walletId, reserve);
                    break;
            }
            return RedirectToAction(nameof(WalletReceive), new { walletId });
        }

        private async Task<bool> CanUseHotWallet()
        {
            var isAdmin = (await _authorizationService.AuthorizeAsync(User, Policies.CanModifyServerSettings)).Succeeded;
            if (isAdmin)
                return true;
            var policies = await _settingsRepository.GetSettingAsync<PoliciesSettings>();
            return policies?.AllowHotWalletForAll is true;
        }

        [HttpGet]
        [Route("{walletId}/send")]
        public async Task<IActionResult> WalletSend(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, string defaultDestination = null, string defaultAmount = null, string bip21 = null)
        {
            if (walletId?.StoreId == null)
                return NotFound();
            var store = await Repository.FindStore(walletId.StoreId, GetUserId());
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();
            var network = this.NetworkProvider.GetNetwork<BTCPayNetwork>(walletId?.CryptoCode);
            if (network == null || network.ReadonlyWallet)
                return NotFound();
            var storeData = store.GetStoreBlob();
            var rateRules = store.GetStoreBlob().GetRateRules(NetworkProvider);
            rateRules.Spread = 0.0m;
            var currencyPair = new Rating.CurrencyPair(paymentMethod.PaymentId.CryptoCode, GetCurrencyCode(storeData.DefaultLang) ?? "USD");
            double.TryParse(defaultAmount, out var amount);
            var model = new WalletSendModel()
            {
                Outputs = new List<WalletSendModel.TransactionOutput>()
                {
                    new WalletSendModel.TransactionOutput()
                    {
                        Amount = Convert.ToDecimal(amount),
                        DestinationAddress = defaultDestination
                    }
                },
                CryptoCode = walletId.CryptoCode
            };
            if (!string.IsNullOrEmpty(bip21))
            {
                LoadFromBIP21(model, bip21, network);
            }
            var feeProvider = _feeRateProvider.CreateFeeProvider(network);
            var recommendedFees =
                new[]
                    {
                        TimeSpan.FromMinutes(10.0), TimeSpan.FromMinutes(60.0), TimeSpan.FromHours(6.0),
                        TimeSpan.FromHours(24.0),
                    }.Select(async time =>
                    {
                        try
                        {
                            var result = await feeProvider.GetFeeRateAsync(
                                (int)network.NBitcoinNetwork.Consensus.GetExpectedBlocksFor(time));
                            return new WalletSendModel.FeeRateOption() { Target = time, FeeRate = result.SatoshiPerByte };
                        }
                        catch (Exception)
                        {
                            return null;
                        }
                    })
                    .ToArray();
            var balance = _walletProvider.GetWallet(network).GetBalance(paymentMethod.AccountDerivation);
            model.NBXSeedAvailable = await CanUseHotWallet() && !string.IsNullOrEmpty(await ExplorerClientProvider.GetExplorerClient(network)
                .GetMetadataAsync<string>(GetDerivationSchemeSettings(walletId).AccountDerivation,
                    WellknownMetadataKeys.MasterHDKey));
            model.CurrentBalance = await balance;

            await Task.WhenAll(recommendedFees);
            model.RecommendedSatoshiPerByte =
                recommendedFees.Select(tuple => tuple.Result).Where(option => option != null).ToList();

            model.FeeSatoshiPerByte = model.RecommendedSatoshiPerByte.LastOrDefault()?.FeeRate;
            model.SupportRBF = network.SupportRBF;

            model.CryptoDivisibility = network.Divisibility;
            using (CancellationTokenSource cts = new CancellationTokenSource())
            {
                try
                {
                    cts.CancelAfter(TimeSpan.FromSeconds(5));
                    var result = await RateFetcher.FetchRate(currencyPair, rateRules, cts.Token).WithCancellation(cts.Token);
                    if (result.BidAsk != null)
                    {
                        model.Rate = result.BidAsk.Center;
                        model.FiatDivisibility = _currencyTable.GetNumberFormatInfo(currencyPair.Right, true).CurrencyDecimalDigits;
                        model.Fiat = currencyPair.Right;
                    }
                    else
                    {
                        model.RateError = $"{result.EvaluatedRule} ({string.Join(", ", result.Errors.OfType<object>().ToArray())})";
                    }
                }
                catch (Exception ex) { model.RateError = ex.Message; }
            }
            return View(model);
        }


        [HttpPost]
        [Route("{walletId}/send")]
        public async Task<IActionResult> WalletSend(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, WalletSendModel vm, string command = "", CancellationToken cancellation = default, string bip21 = "")
        {
            if (walletId?.StoreId == null)
                return NotFound();
            var store = await Repository.FindStore(walletId.StoreId, GetUserId());
            if (store == null)
                return NotFound();
            var network = this.NetworkProvider.GetNetwork<BTCPayNetwork>(walletId?.CryptoCode);
            if (network == null || network.ReadonlyWallet)
                return NotFound();
            vm.SupportRBF = network.SupportRBF;
            vm.NBXSeedAvailable = await CanUseHotWallet() && !string.IsNullOrEmpty(await ExplorerClientProvider.GetExplorerClient(network)
                .GetMetadataAsync<string>(GetDerivationSchemeSettings(walletId).AccountDerivation,
                    WellknownMetadataKeys.MasterHDKey, cancellation));
            if (!string.IsNullOrEmpty(bip21))
            {
                LoadFromBIP21(vm, bip21, network);
            }

            decimal transactionAmountSum = 0;
            if (command == "toggle-input-selection")
            {
                vm.InputSelection = !vm.InputSelection;
            }
            if (vm.InputSelection)
            {
                var schemeSettings = GetDerivationSchemeSettings(walletId);
                var walletBlobAsync = await WalletRepository.GetWalletInfo(walletId);
                var walletTransactionsInfoAsync = await WalletRepository.GetWalletTransactionsInfo(walletId);

                var utxos = await _walletProvider.GetWallet(network).GetUnspentCoins(schemeSettings.AccountDerivation, cancellation);
                vm.InputsAvailable = utxos.Select(coin =>
                {
                    walletTransactionsInfoAsync.TryGetValue(coin.OutPoint.Hash.ToString(), out var info);
                    return new WalletSendModel.InputSelectionOption()
                    {
                        Outpoint = coin.OutPoint.ToString(),
                        Amount = coin.Value.GetValue(network),
                        Comment = info?.Comment,
                        Labels = info == null ? null : _labelFactory.GetLabels(walletBlobAsync, info, Request),
                        Link = string.Format(CultureInfo.InvariantCulture, network.BlockExplorerLink, coin.OutPoint.Hash.ToString())
                    };
                }).ToArray();
            }

            if (command == "toggle-input-selection")
            {
                ModelState.Clear();
                return View(vm);
            }

            if (!string.IsNullOrEmpty(bip21))
            {
                return View(vm);
            }
            if (command == "add-output")
            {
                ModelState.Clear();
                vm.Outputs.Add(new WalletSendModel.TransactionOutput());
                return View(vm);
            }
            if (command.StartsWith("remove-output", StringComparison.InvariantCultureIgnoreCase))
            {
                ModelState.Clear();
                var index = int.Parse(command.Substring(command.IndexOf(":", StringComparison.InvariantCultureIgnoreCase) + 1), CultureInfo.InvariantCulture);
                vm.Outputs.RemoveAt(index);
                return View(vm);
            }

            if (!vm.Outputs.Any())
            {
                ModelState.AddModelError(string.Empty,
                    "Please add at least one transaction output");
                return View(vm);
            }

            var subtractFeesOutputsCount = new List<int>();
            var substractFees = vm.Outputs.Any(o => o.SubtractFeesFromOutput);
            for (var i = 0; i < vm.Outputs.Count; i++)
            {
                var transactionOutput = vm.Outputs[i];
                if (transactionOutput.SubtractFeesFromOutput)
                {
                    subtractFeesOutputsCount.Add(i);
                }
                transactionOutput.DestinationAddress = transactionOutput.DestinationAddress?.Trim() ?? string.Empty;

                try
                {
                    BitcoinAddress.Create(transactionOutput.DestinationAddress, network.NBitcoinNetwork);
                }
                catch
                {
                    var inputName =
                        string.Format(CultureInfo.InvariantCulture, "Outputs[{0}].", i.ToString(CultureInfo.InvariantCulture)) +
                        nameof(transactionOutput.DestinationAddress);

                    ModelState.AddModelError(inputName, "Invalid address");
                }

                if (transactionOutput.Amount.HasValue)
                {
                    transactionAmountSum += transactionOutput.Amount.Value;

                    if (vm.CurrentBalance == transactionOutput.Amount.Value &&
                        !transactionOutput.SubtractFeesFromOutput)
                        vm.AddModelError(model => model.Outputs[i].SubtractFeesFromOutput,
                            "You are sending your entire balance to the same destination, you should subtract the fees",
                            this);
                }
            }

            if (subtractFeesOutputsCount.Count > 1)
            {
                foreach (var subtractFeesOutput in subtractFeesOutputsCount)
                {
                    vm.AddModelError(model => model.Outputs[subtractFeesOutput].SubtractFeesFromOutput,
                        "You can only subtract fees from one output", this);
                }
            }
            else if (vm.CurrentBalance == transactionAmountSum && !substractFees)
            {
                ModelState.AddModelError(string.Empty,
                    "You are sending your entire balance, you should subtract the fees from an output");
            }

            if (vm.CurrentBalance < transactionAmountSum)
            {
                for (var i = 0; i < vm.Outputs.Count; i++)
                {
                    vm.AddModelError(model => model.Outputs[i].Amount,
                        "You are sending more than what you own", this);
                }
            }
            if (vm.FeeSatoshiPerByte is decimal fee)
            {
                if (fee < 0)
                {
                    vm.AddModelError(model => model.FeeSatoshiPerByte,
                            "The fee rate should be above 0", this);
                }
            }

            if (!ModelState.IsValid)
                return View(vm);

            DerivationSchemeSettings derivationScheme = GetDerivationSchemeSettings(walletId);

            CreatePSBTResponse psbt = null;
            try
            {
                psbt = await CreatePSBT(network, derivationScheme, vm, cancellation);
            }
            catch (NBXplorerException ex)
            {
                ModelState.AddModelError(string.Empty, ex.Error.Message);
                return View(vm);
            }
            catch (NotSupportedException)
            {
                ModelState.AddModelError(string.Empty, "You need to update your version of NBXplorer");
                return View(vm);
            }
            derivationScheme.RebaseKeyPaths(psbt.PSBT);

            var signingContext = new SigningContextModel()
            {
                PayJoinBIP21 = vm.PayJoinBIP21,
                EnforceLowR = psbt.Suggestions?.ShouldEnforceLowR,
                ChangeAddress = psbt.ChangeAddress?.ToString()
            };

            var res = await TryHandleSigningCommands(walletId, psbt.PSBT, command, signingContext);
            if (res != null)
            {
                return res;
            }

            switch (command)
            {
                case "analyze-psbt":
                    var name =
                        $"Send-{string.Join('_', vm.Outputs.Select(output => $"{output.Amount}->{output.DestinationAddress}{(output.SubtractFeesFromOutput ? "-Fees" : string.Empty)}"))}.psbt";
                    return RedirectToWalletPSBT(new WalletPSBTViewModel()
                    {
                        PSBT = psbt.PSBT.ToBase64(),
                        FileName = name
                    });
                default:
                    return View(vm);
            }

        }

        private void LoadFromBIP21(WalletSendModel vm, string bip21, BTCPayNetwork network)
        {
            try
            {
                if (bip21.StartsWith(network.UriScheme, StringComparison.InvariantCultureIgnoreCase))
                {
                    bip21 = $"bitcoin{bip21.Substring(network.UriScheme.Length)}";
                }

                var uriBuilder = new NBitcoin.Payment.BitcoinUrlBuilder(bip21, network.NBitcoinNetwork);
                vm.Outputs = new List<WalletSendModel.TransactionOutput>()
                {
                    new WalletSendModel.TransactionOutput()
                    {
                        Amount = uriBuilder.Amount.ToDecimal(MoneyUnit.BTC),
                        DestinationAddress = uriBuilder.Address.ToString(),
                        SubtractFeesFromOutput = false
                    }
                };
                if (!string.IsNullOrEmpty(uriBuilder.Label) || !string.IsNullOrEmpty(uriBuilder.Message))
                {
                    TempData.SetStatusMessageModel(new StatusMessageModel()
                    {
                        Severity = StatusMessageModel.StatusSeverity.Info,
                        Html =
                            $"Payment {(string.IsNullOrEmpty(uriBuilder.Label) ? string.Empty : $" to {uriBuilder.Label}")} {(string.IsNullOrEmpty(uriBuilder.Message) ? string.Empty : $" for {uriBuilder.Message}")}"
                    });
                }

                if (uriBuilder.TryGetPayjoinEndpoint(out _))
                    vm.PayJoinBIP21 = uriBuilder.ToString();
            }
            catch
            {
                try
                {
                    vm.Outputs = new List<WalletSendModel.TransactionOutput>()
                    {
                        new WalletSendModel.TransactionOutput()
                        {
                            DestinationAddress = BitcoinAddress.Create(bip21, network.NBitcoinNetwork).ToString()
                        }
                    };
                }
                catch
                {
                    TempData.SetStatusMessageModel(new StatusMessageModel()
                    {
                        Severity = StatusMessageModel.StatusSeverity.Error,
                        Message = "The provided BIP21 payment URI was malformed"
                    });
                }
            }

            ModelState.Clear();
        }

        private IActionResult ViewVault(WalletId walletId, SigningContextModel signingContext)
        {
            return View(nameof(WalletSendVault), new WalletSendVaultModel()
            {
                SigningContext = signingContext,
                WalletId = walletId.ToString(),
                WebsocketPath = this.Url.Action(nameof(VaultController.VaultBridgeConnection), "Vault", new { walletId = walletId.ToString() })
            });
        }

        [HttpPost]
        [Route("{walletId}/vault")]
        public IActionResult WalletSendVault([ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, WalletSendVaultModel model)
        {
            return RedirectToWalletPSBTReady(new WalletPSBTReadyViewModel()
            {
                SigningContext = model.SigningContext
            });
        }
        private IActionResult RedirectToWalletPSBTReady(WalletPSBTReadyViewModel vm)
        {
            var redirectVm = new PostRedirectViewModel()
            {
                AspController = "Wallets",
                AspAction = nameof(WalletPSBTReady),
                Parameters =
                {
                    new KeyValuePair<string, string>("SigningKey", vm.SigningKey),
                    new KeyValuePair<string, string>("SigningKeyPath", vm.SigningKeyPath)
                }
            };
            AddSigningContext(redirectVm, vm.SigningContext);
            if (!string.IsNullOrEmpty(vm.SigningContext.OriginalPSBT) &&
                !string.IsNullOrEmpty(vm.SigningContext.PSBT))
            {
                //if a hw device signed a payjoin, we want it broadcast instantly
                redirectVm.Parameters.Add(new KeyValuePair<string, string>("command", "broadcast"));  
            }
            return View("PostRedirect", redirectVm);
        }

        private void AddSigningContext(PostRedirectViewModel redirectVm, SigningContextModel signingContext)
        {
            if (signingContext is null)
                return;
            redirectVm.Parameters.Add(new KeyValuePair<string, string>("SigningContext.PSBT", signingContext.PSBT));
            redirectVm.Parameters.Add(new KeyValuePair<string, string>("SigningContext.OriginalPSBT", signingContext.OriginalPSBT));
            redirectVm.Parameters.Add(new KeyValuePair<string, string>("SigningContext.PayJoinBIP21", signingContext.PayJoinBIP21));
            redirectVm.Parameters.Add(new KeyValuePair<string, string>("SigningContext.EnforceLowR", signingContext.EnforceLowR?.ToString(CultureInfo.InvariantCulture)));
            redirectVm.Parameters.Add(new KeyValuePair<string, string>("SigningContext.ChangeAddress", signingContext.ChangeAddress));
        }

        private IActionResult RedirectToWalletPSBT(WalletPSBTViewModel vm)
        {
            var redirectVm = new PostRedirectViewModel()
            {
                AspController = "Wallets",
                AspAction = nameof(WalletPSBT),
                Parameters =
                {
                    new KeyValuePair<string, string>("psbt", vm.PSBT),
                    new KeyValuePair<string, string>("fileName", vm.FileName)
                }
            };
            return View("PostRedirect", redirectVm);
        }

        [HttpGet("{walletId}/psbt/seed")]
        public IActionResult SignWithSeed([ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, SigningContextModel signingContext)
        {
            return View(nameof(SignWithSeed), new SignWithSeedViewModel()
            {
                SigningContext = signingContext,
            });
        }

        [HttpPost("{walletId}/psbt/seed")]
        public IActionResult SignWithSeed([ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, SignWithSeedViewModel viewModel)
        {
            if (!ModelState.IsValid)
            {
                return View("SignWithSeed", viewModel);
            }
            var network = NetworkProvider.GetNetwork<BTCPayNetwork>(walletId.CryptoCode);
            if (network == null)
                throw new FormatException("Invalid value for crypto code");

            ExtKey extKey = viewModel.GetExtKey(network.NBitcoinNetwork);

            if (extKey == null)
            {
                ModelState.AddModelError(nameof(viewModel.SeedOrKey),
                    "Seed or Key was not in a valid format. It is either the 12/24 words or starts with xprv");
            }

            var psbt = PSBT.Parse(viewModel.SigningContext.PSBT, network.NBitcoinNetwork);

            if (!psbt.IsReadyToSign())
            {
                ModelState.AddModelError(nameof(viewModel.SigningContext.PSBT), "PSBT is not ready to be signed");
            }

            if (!ModelState.IsValid)
            {
                return View("SignWithSeed", viewModel);
            }

            ExtKey signingKey = null;
            var settings = GetDerivationSchemeSettings(walletId);
            var signingKeySettings = settings.GetSigningAccountKeySettings();
            if (signingKeySettings.RootFingerprint is null)
                signingKeySettings.RootFingerprint = extKey.GetPublicKey().GetHDFingerPrint();

            RootedKeyPath rootedKeyPath = signingKeySettings.GetRootedKeyPath();
            if (rootedKeyPath == null)
            {
                ModelState.AddModelError(nameof(viewModel.SeedOrKey), "The master fingerprint and/or account key path of your seed are not set in the wallet settings.");
                return View(nameof(SignWithSeed), viewModel);
            }
            // The user gave the root key, let's try to rebase the PSBT, and derive the account private key
            if (rootedKeyPath.MasterFingerprint == extKey.GetPublicKey().GetHDFingerPrint())
            {
                psbt.RebaseKeyPaths(signingKeySettings.AccountKey, rootedKeyPath);
                signingKey = extKey.Derive(rootedKeyPath.KeyPath);
            }
            else
            {
                ModelState.AddModelError(nameof(viewModel.SeedOrKey), "The master fingerprint does not match the one set in your wallet settings. Probable cause are: wrong seed, wrong passphrase or wrong fingerprint in your wallet settings.");
                return View(nameof(SignWithSeed), viewModel);
            }

            var changed = PSBTChanged(psbt, () => psbt.SignAll(settings.AccountDerivation, signingKey, rootedKeyPath, new SigningOptions()
            {
                EnforceLowR = !(viewModel.SigningContext?.EnforceLowR is false)
            }));
            if (!changed)
            {
                ModelState.AddModelError(nameof(viewModel.SeedOrKey), "Impossible to sign the transaction. Probable cause: Incorrect account key path in wallet settings, PSBT already signed.");
                return View(nameof(SignWithSeed), viewModel);
            }
            ModelState.Remove(nameof(viewModel.SigningContext.PSBT));
            viewModel.SigningContext.PSBT = psbt.ToBase64();
            return RedirectToWalletPSBTReady(new WalletPSBTReadyViewModel()
            {
                SigningKey = signingKey.GetWif(network.NBitcoinNetwork).ToString(),
                SigningKeyPath = rootedKeyPath?.ToString(),
                SigningContext = viewModel.SigningContext
            });
        }


        private bool PSBTChanged(PSBT psbt, Action act)
        {
            var before = psbt.ToBase64();
            act();
            var after = psbt.ToBase64();
            return before != after;
        }

        private string ValueToString(Money v, BTCPayNetworkBase network)
        {
            return v.ToString() + " " + network.CryptoCode;
        }

        private IActionResult RedirectToWalletTransaction(WalletId walletId, Transaction transaction)
        {
            var network = NetworkProvider.GetNetwork<BTCPayNetwork>(walletId.CryptoCode);
            if (transaction != null)
            {
                var wallet = _walletProvider.GetWallet(network);
                var derivationSettings = GetDerivationSchemeSettings(walletId);
                wallet.InvalidateCache(derivationSettings.AccountDerivation);
            }
            return RedirectToAction(nameof(WalletTransactions), new { walletId = walletId.ToString() });
        }

        [HttpGet]
        [Route("{walletId}/rescan")]
        public async Task<IActionResult> WalletRescan(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId)
        {
            if (walletId?.StoreId == null)
                return NotFound();
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();

            var vm = new RescanWalletModel();
            vm.IsFullySync = _dashboard.IsFullySynched(walletId.CryptoCode, out var unused);
            vm.IsServerAdmin = (await _authorizationService.AuthorizeAsync(User, Policies.CanModifyServerSettings)).Succeeded;
            vm.IsSupportedByCurrency = _dashboard.Get(walletId.CryptoCode)?.Status?.BitcoinStatus?.Capabilities?.CanScanTxoutSet == true;
            var explorer = ExplorerClientProvider.GetExplorerClient(walletId.CryptoCode);
            var scanProgress = await explorer.GetScanUTXOSetInformationAsync(paymentMethod.AccountDerivation);
            if (scanProgress != null)
            {
                vm.PreviousError = scanProgress.Error;
                if (scanProgress.Status == ScanUTXOStatus.Queued || scanProgress.Status == ScanUTXOStatus.Pending)
                {
                    if (scanProgress.Progress == null)
                    {
                        vm.Progress = 0;
                    }
                    else
                    {
                        vm.Progress = scanProgress.Progress.OverallProgress;
                        vm.RemainingTime = TimeSpan.FromSeconds(scanProgress.Progress.RemainingSeconds).PrettyPrint();
                    }
                }
                if (scanProgress.Status == ScanUTXOStatus.Complete)
                {
                    vm.LastSuccess = scanProgress.Progress;
                    vm.TimeOfScan = (scanProgress.Progress.CompletedAt.Value - scanProgress.Progress.StartedAt).PrettyPrint();
                }
            }
            return View(vm);
        }

        [HttpPost]
        [Route("{walletId}/rescan")]
        [Authorize(Policy = Policies.CanModifyServerSettings, AuthenticationSchemes = AuthenticationSchemes.Cookie)]
        public async Task<IActionResult> WalletRescan(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, RescanWalletModel vm)
        {
            if (walletId?.StoreId == null)
                return NotFound();
            DerivationSchemeSettings paymentMethod = GetDerivationSchemeSettings(walletId);
            if (paymentMethod == null)
                return NotFound();
            var explorer = ExplorerClientProvider.GetExplorerClient(walletId.CryptoCode);
            try
            {
                await explorer.ScanUTXOSetAsync(paymentMethod.AccountDerivation, vm.BatchSize, vm.GapLimit, vm.StartingIndex);
            }
            catch (NBXplorerException ex) when (ex.Error.Code == "scanutxoset-in-progress")
            {

            }
            return RedirectToAction();
        }

        private string GetCurrencyCode(string defaultLang)
        {
            if (defaultLang == null)
                return null;
            try
            {
                var ri = new RegionInfo(defaultLang);
                return ri.ISOCurrencySymbol;
            }
            catch (ArgumentException) { }
            return null;
        }

        public StoreData CurrentStore
        {
            get
            {
                return HttpContext.GetStoreData();
            }
        }

        internal DerivationSchemeSettings GetDerivationSchemeSettings(WalletId walletId)
        {
            var paymentMethod = CurrentStore
                            .GetSupportedPaymentMethods(NetworkProvider)
                            .OfType<DerivationSchemeSettings>()
                            .FirstOrDefault(p => p.PaymentId.PaymentType == Payments.PaymentTypes.BTCLike && p.PaymentId.CryptoCode == walletId.CryptoCode);
            return paymentMethod;
        }

        private static async Task<string> GetBalanceString(BTCPayWallet wallet, DerivationStrategyBase derivationStrategy)
        {
            using (CancellationTokenSource cts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
            {
                try
                {
                    return (await wallet.GetBalance(derivationStrategy, cts.Token)).ShowMoney(wallet.Network
                        .Divisibility);
                }
                catch
                {
                    return "--";
                }
            }
        }

        private string GetUserId()
        {
            return _userManager.GetUserId(User);
        }

        [Route("{walletId}/settings")]
        public async Task<IActionResult> WalletSettings(
             [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId)
        {
            var derivationSchemeSettings = GetDerivationSchemeSettings(walletId);
            if (derivationSchemeSettings == null || derivationSchemeSettings.Network.ReadonlyWallet)
                return NotFound();
            var store = (await Repository.FindStore(walletId.StoreId, GetUserId()));
            var vm = new WalletSettingsViewModel()
            {
                StoreName = store.StoreName,
                UriScheme = derivationSchemeSettings.Network.UriScheme,
                Label = derivationSchemeSettings.Label,
                DerivationScheme = derivationSchemeSettings.AccountDerivation.ToString(),
                DerivationSchemeInput = derivationSchemeSettings.AccountOriginal,
                SelectedSigningKey = derivationSchemeSettings.SigningKey.ToString(),
                NBXSeedAvailable = await CanUseHotWallet() && !string.IsNullOrEmpty(await ExplorerClientProvider.GetExplorerClient(walletId.CryptoCode)
                    .GetMetadataAsync<string>(GetDerivationSchemeSettings(walletId).AccountDerivation,
                        WellknownMetadataKeys.MasterHDKey))
            };
            vm.AccountKeys = derivationSchemeSettings.AccountKeySettings
                            .Select(e => new WalletSettingsAccountKeyViewModel()
                            {
                                AccountKey = e.AccountKey.ToString(),
                                MasterFingerprint = e.RootFingerprint is HDFingerprint fp ? fp.ToString() : null,
                                AccountKeyPath = e.AccountKeyPath == null ? "" : $"m/{e.AccountKeyPath}"
                            }).ToList();
            return View(vm);
        }

        [Route("{walletId}/settings")]
        [HttpPost]
        public async Task<IActionResult> WalletSettings(
            [ModelBinder(typeof(WalletIdModelBinder))]
            WalletId walletId, WalletSettingsViewModel vm, string command = "save",
            CancellationToken cancellationToken = default)
        {
            if (!ModelState.IsValid)
                return View(vm);
            var derivationScheme = GetDerivationSchemeSettings(walletId);
            if (derivationScheme == null || derivationScheme.Network.ReadonlyWallet)
                return NotFound();

            if (command == "save")
            {
                derivationScheme.Label = vm.Label;
                derivationScheme.SigningKey = string.IsNullOrEmpty(vm.SelectedSigningKey)
                    ? null
                    : new BitcoinExtPubKey(vm.SelectedSigningKey, derivationScheme.Network.NBitcoinNetwork);
                for (int i = 0; i < derivationScheme.AccountKeySettings.Length; i++)
                {
                    derivationScheme.AccountKeySettings[i].AccountKeyPath =
                        string.IsNullOrWhiteSpace(vm.AccountKeys[i].AccountKeyPath)
                            ? null
                            : new KeyPath(vm.AccountKeys[i].AccountKeyPath);
                    derivationScheme.AccountKeySettings[i].RootFingerprint =
                        string.IsNullOrWhiteSpace(vm.AccountKeys[i].MasterFingerprint)
                            ? (HDFingerprint?)null
                            : new HDFingerprint(Encoders.Hex.DecodeData(vm.AccountKeys[i].MasterFingerprint));
                }

                var store = (await Repository.FindStore(walletId.StoreId, GetUserId()));
                store.SetSupportedPaymentMethod(derivationScheme);
                await Repository.UpdateStore(store);
                TempData[WellKnownTempData.SuccessMessage] = "Wallet settings updated";
                return RedirectToAction(nameof(WalletSettings));
            }
            else if (command == "prune")
            {
                var result = await ExplorerClientProvider.GetExplorerClient(walletId.CryptoCode)
                    .PruneAsync(derivationScheme.AccountDerivation, new PruneRequest(), cancellationToken);
                if (result.TotalPruned == 0)
                {
                    TempData[WellKnownTempData.SuccessMessage] = $"The wallet is already pruned";
                }
                else
                {
                    TempData[WellKnownTempData.SuccessMessage] =
                        $"The wallet has been successfully pruned ({result.TotalPruned} transactions have been removed from the history)";
                }

                return RedirectToAction(nameof(WalletSettings));
            }
            else if (command == "view-seed" && await CanUseHotWallet())
            {
                var seed = await ExplorerClientProvider.GetExplorerClient(walletId.CryptoCode)
                    .GetMetadataAsync<string>(derivationScheme.AccountDerivation,
                        WellknownMetadataKeys.Mnemonic, cancellationToken);
                if (string.IsNullOrEmpty(seed))
                {
                    TempData.SetStatusMessageModel(new StatusMessageModel()
                    {
                        Severity = StatusMessageModel.StatusSeverity.Error,
                        Message = "The seed was not found"
                    });
                }
                else
                {
                    var recoveryVm = new RecoverySeedBackupViewModel()
                    {
                        CryptoCode = walletId.CryptoCode,
                        Mnemonic = seed,
                        IsStored = true,
                        RequireConfirm = false,
                        ReturnUrl = Url.Action(nameof(WalletSettings), new { walletId })
                    };
                    return this.RedirectToRecoverySeedBackup(recoveryVm);
                }

                return RedirectToAction(nameof(WalletSettings));
            }
            else
            {
                return NotFound();
            }
        }

        private string GetImage(PaymentMethodId paymentMethodId, BTCPayNetwork network)
        {
            var res = paymentMethodId.PaymentType == PaymentTypes.BTCLike
                ? Url.Content(network.CryptoImagePath)
                : Url.Content(network.LightningImagePath);
            return "/" + res;
        }
    }

    public class WalletReceiveViewModel
    {
        public string CryptoImage { get; set; }
        public string CryptoCode { get; set; }
        public string Address { get; set; }
    }


    public class GetInfoResult
    {
    }

    public class SendToAddressResult
    {
        [JsonProperty("psbt")]
        public string PSBT { get; set; }
    }
}