wallet-core/packages/taler-wallet-core/src/operations/deposits.ts

/*
 This file is part of GNU Taler
 (C) 2021 Taler Systems S.A.

 GNU Taler is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

/**
 * Imports.
 */
import {
  AbsoluteTime,
  AmountJson,
  Amounts,
  CancellationToken,
  canonicalJson,
  codecForDepositSuccess,
  codecForTackTransactionAccepted,
  codecForTackTransactionWired,
  CoinDepositPermission,
  CreateDepositGroupRequest,
  CreateDepositGroupResponse,
  DepositGroupFees,
  durationFromSpec,
  encodeCrock,
  ExchangeDepositRequest,
  getRandomBytes,
  hashTruncate32,
  hashWire,
  HttpStatusCode,
  j2s,
  Logger,
  MerchantContractTerms,
  parsePaytoUri,
  PayCoinSelection,
  PrepareDepositRequest,
  PrepareDepositResponse,
  RefreshReason,
  stringToBytes,
  TalerErrorCode,
  TalerProtocolTimestamp,
  TrackTransaction,
  TransactionState,
  TransactionStateInfo,
  TransactionSubstate,
  TransactionType,
  URL,
  WireFee,
} from "@gnu-taler/taler-util";
import {
  DepositGroupRecord,
  OperationStatus,
  TransactionStatus,
} from "../db.js";
import { TalerError } from "@gnu-taler/taler-util";
import { KycPendingInfo, KycUserType } from "../index.js";
import { InternalWalletState } from "../internal-wallet-state.js";
import { readSuccessResponseJsonOrThrow } from "@gnu-taler/taler-util/http";
import { OperationAttemptResult } from "../util/retries.js";
import { makeTransactionId, spendCoins } from "./common.js";
import { getExchangeDetails } from "./exchanges.js";
import {
  extractContractData,
  generateDepositPermissions,
  getTotalPaymentCost,
} from "./pay-merchant.js";
import { selectPayCoinsNew } from "../util/coinSelection.js";

/**
 * Logger.
 */
const logger = new Logger("deposits.ts");

export async function computeDepositTransactionStatus(
  ws: InternalWalletState,
  dg: DepositGroupRecord,
): Promise<TransactionStateInfo> {
  switch (dg.operationStatus) {
    case OperationStatus.Finished: {
      return {
        txState: TransactionState.Done,
        txSubstate: TransactionSubstate.None,
      };
    }
    case OperationStatus.Pending: {
      const numTotal = dg.payCoinSelection.coinPubs.length;
      let numDeposited = 0;
      let numKycRequired = 0;
      let numWired = 0;
      for (let i = 0; i < numTotal; i++) {
        if (dg.depositedPerCoin[i]) {
          numDeposited++;
        }
        switch (dg.transactionPerCoin[i]) {
          case TransactionStatus.KycRequired:
            numKycRequired++;
            break;
          case TransactionStatus.Wired:
            numWired++;
            break;
        }
      }

      if (numKycRequired > 0) {
        return {
          txState: TransactionState.Pending,
          txSubstate: TransactionSubstate.DepositKycRequired,
        };
      }

      if (numDeposited == numTotal) {
        return {
          txState: TransactionState.Pending,
          txSubstate: TransactionSubstate.DepositPendingTrack,
        };
      }

      return {
        txState: TransactionState.Pending,
        txSubstate: TransactionSubstate.DepositPendingInitial,
      };
    }
    default:
      throw Error("unexpected deposit group state");
  }
}

export async function suspendDepositGroup(
  ws: InternalWalletState,
  depositGroupId: string,
): Promise<void> {
  throw Error("not implemented");
}

export async function abortDepositGroup(
  ws: InternalWalletState,
  depositGroupId: string,
): Promise<void> {
  throw Error("not implemented");
}

/**
 * Check KYC status with the exchange, throw an appropriate exception when KYC is required.
 *
 * FIXME: Why does this throw an exception when KYC is required?
 * Should we not return some proper result record here?
 */
async function checkDepositKycStatus(
  ws: InternalWalletState,
  exchangeUrl: string,
  kycInfo: KycPendingInfo,
  userType: KycUserType,
): Promise<void> {
  const url = new URL(
    `kyc-check/${kycInfo.requirementRow}/${kycInfo.paytoHash}/${userType}`,
    exchangeUrl,
  );
  logger.info(`kyc url ${url.href}`);
  const kycStatusReq = await ws.http.fetch(url.href, {
    method: "GET",
  });
  if (kycStatusReq.status === HttpStatusCode.Ok) {
    logger.warn("kyc requested, but already fulfilled");
    return;
  } else if (kycStatusReq.status === HttpStatusCode.Accepted) {
    const kycStatus = await kycStatusReq.json();
    logger.info(`kyc status: ${j2s(kycStatus)}`);
    // FIXME: This error code is totally wrong
    throw TalerError.fromDetail(
      TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED,
      {
        kycUrl: kycStatus.kyc_url,
      },
      `KYC check required for deposit`,
    );
  } else {
    throw Error(`unexpected response from kyc-check (${kycStatusReq.status})`);
  }
}

/**
 * Process a deposit group that is not in its final state yet.
 */
export async function processDepositGroup(
  ws: InternalWalletState,
  depositGroupId: string,
  options: {
    cancellationToken?: CancellationToken;
  } = {},
): Promise<OperationAttemptResult> {
  const depositGroup = await ws.db
    .mktx((x) => [x.depositGroups])
    .runReadOnly(async (tx) => {
      return tx.depositGroups.get(depositGroupId);
    });
  if (!depositGroup) {
    logger.warn(`deposit group ${depositGroupId} not found`);
    return OperationAttemptResult.finishedEmpty();
  }
  if (depositGroup.timestampFinished) {
    logger.trace(`deposit group ${depositGroupId} already finished`);
    return OperationAttemptResult.finishedEmpty();
  }

  const contractData = extractContractData(
    depositGroup.contractTermsRaw,
    depositGroup.contractTermsHash,
    "",
  );

  // Check for cancellation before expensive operations.
  options.cancellationToken?.throwIfCancelled();
  const depositPermissions = await generateDepositPermissions(
    ws,
    depositGroup.payCoinSelection,
    contractData,
  );

  for (let i = 0; i < depositPermissions.length; i++) {
    const perm = depositPermissions[i];

    let updatedDeposit: boolean | undefined = undefined;

    if (!depositGroup.depositedPerCoin[i]) {
      const requestBody: ExchangeDepositRequest = {
        contribution: Amounts.stringify(perm.contribution),
        merchant_payto_uri: depositGroup.wire.payto_uri,
        wire_salt: depositGroup.wire.salt,
        h_contract_terms: depositGroup.contractTermsHash,
        ub_sig: perm.ub_sig,
        timestamp: depositGroup.contractTermsRaw.timestamp,
        wire_transfer_deadline:
          depositGroup.contractTermsRaw.wire_transfer_deadline,
        refund_deadline: depositGroup.contractTermsRaw.refund_deadline,
        coin_sig: perm.coin_sig,
        denom_pub_hash: perm.h_denom,
        merchant_pub: depositGroup.merchantPub,
        h_age_commitment: perm.h_age_commitment,
      };
      // Check for cancellation before making network request.
      options.cancellationToken?.throwIfCancelled();
      const url = new URL(`coins/${perm.coin_pub}/deposit`, perm.exchange_url);
      logger.info(`depositing to ${url}`);
      const httpResp = await ws.http.fetch(url.href, {
        method: "POST",
        body: requestBody,
        cancellationToken: options.cancellationToken,
      });
      await readSuccessResponseJsonOrThrow(httpResp, codecForDepositSuccess());
      updatedDeposit = true;
    }

    let updatedTxStatus: TransactionStatus | undefined = undefined;
    type ValueOf<T> = T[keyof T];

    let newWiredTransaction:
      | {
          id: string;
          value: ValueOf<NonNullable<DepositGroupRecord["trackingState"]>>;
        }
      | undefined;

    if (depositGroup.transactionPerCoin[i] !== TransactionStatus.Wired) {
      const track = await trackDepositPermission(ws, depositGroup, perm);

      if (track.type === "accepted") {
        if (!track.kyc_ok && track.requirement_row !== undefined) {
          updatedTxStatus = TransactionStatus.KycRequired;
          const { requirement_row: requirementRow } = track;
          const paytoHash = encodeCrock(
            hashTruncate32(stringToBytes(depositGroup.wire.payto_uri + "\0")),
          );
          await checkDepositKycStatus(
            ws,
            perm.exchange_url,
            { paytoHash, requirementRow },
            "individual",
          );
        } else {
          updatedTxStatus = TransactionStatus.Accepted;
        }
      } else if (track.type === "wired") {
        updatedTxStatus = TransactionStatus.Wired;

        const payto = parsePaytoUri(depositGroup.wire.payto_uri);
        if (!payto) {
          throw Error(`unparsable payto: ${depositGroup.wire.payto_uri}`);
        }

        const fee = await getExchangeWireFee(
          ws,
          payto.targetType,
          perm.exchange_url,
          track.execution_time,
        );
        const raw = Amounts.parseOrThrow(track.coin_contribution);
        const wireFee = Amounts.parseOrThrow(fee.wireFee);

        newWiredTransaction = {
          value: {
            amountRaw: Amounts.stringify(raw),
            wireFee: Amounts.stringify(wireFee),
            exchangePub: track.exchange_pub,
            timestampExecuted: track.execution_time,
            wireTransferId: track.wtid,
          },
          id: track.exchange_sig,
        };
      } else {
        updatedTxStatus = TransactionStatus.Unknown;
      }
    }

    if (updatedTxStatus !== undefined || updatedDeposit !== undefined) {
      await ws.db
        .mktx((x) => [x.depositGroups])
        .runReadWrite(async (tx) => {
          const dg = await tx.depositGroups.get(depositGroupId);
          if (!dg) {
            return;
          }
          if (updatedDeposit !== undefined) {
            dg.depositedPerCoin[i] = updatedDeposit;
          }
          if (updatedTxStatus !== undefined) {
            dg.transactionPerCoin[i] = updatedTxStatus;
          }
          if (newWiredTransaction) {
            if (!dg.trackingState) {
              dg.trackingState = {};
            }

            dg.trackingState[newWiredTransaction.id] =
              newWiredTransaction.value;
          }
          await tx.depositGroups.put(dg);
        });
    }
  }

  await ws.db
    .mktx((x) => [x.depositGroups])
    .runReadWrite(async (tx) => {
      const dg = await tx.depositGroups.get(depositGroupId);
      if (!dg) {
        return;
      }
      let allDepositedAndWired = true;
      for (let i = 0; i < depositGroup.depositedPerCoin.length; i++) {
        if (
          !depositGroup.depositedPerCoin[i] ||
          depositGroup.transactionPerCoin[i] !== TransactionStatus.Wired
        ) {
          allDepositedAndWired = false;
          break;
        }
      }
      if (allDepositedAndWired) {
        dg.timestampFinished = TalerProtocolTimestamp.now();
        dg.operationStatus = OperationStatus.Finished;
        await tx.depositGroups.put(dg);
      }
    });
  return OperationAttemptResult.finishedEmpty();
}

async function getExchangeWireFee(
  ws: InternalWalletState,
  wireType: string,
  baseUrl: string,
  time: TalerProtocolTimestamp,
): Promise<WireFee> {
  const exchangeDetails = await ws.db
    .mktx((x) => [x.exchanges, x.exchangeDetails])
    .runReadOnly(async (tx) => {
      const ex = await tx.exchanges.get(baseUrl);
      if (!ex || !ex.detailsPointer) return undefined;
      return await tx.exchangeDetails.indexes.byPointer.get([
        baseUrl,
        ex.detailsPointer.currency,
        ex.detailsPointer.masterPublicKey,
      ]);
    });

  if (!exchangeDetails) {
    throw Error(`exchange missing: ${baseUrl}`);
  }

  const fees = exchangeDetails.wireInfo.feesForType[wireType];
  if (!fees || fees.length === 0) {
    throw Error(
      `exchange ${baseUrl} doesn't have fees for wire type ${wireType}`,
    );
  }
  const fee = fees.find((x) => {
    return AbsoluteTime.isBetween(
      AbsoluteTime.fromTimestamp(time),
      AbsoluteTime.fromTimestamp(x.startStamp),
      AbsoluteTime.fromTimestamp(x.endStamp),
    );
  });
  if (!fee) {
    throw Error(
      `exchange ${exchangeDetails.exchangeBaseUrl} doesn't have fees for wire type ${wireType} at ${time.t_s}`,
    );
  }

  return fee;
}

async function trackDepositPermission(
  ws: InternalWalletState,
  depositGroup: DepositGroupRecord,
  dp: CoinDepositPermission,
): Promise<TrackTransaction> {
  const wireHash = depositGroup.contractTermsRaw.h_wire;

  const url = new URL(
    `deposits/${wireHash}/${depositGroup.merchantPub}/${depositGroup.contractTermsHash}/${dp.coin_pub}`,
    dp.exchange_url,
  );
  const sigResp = await ws.cryptoApi.signTrackTransaction({
    coinPub: dp.coin_pub,
    contractTermsHash: depositGroup.contractTermsHash,
    merchantPriv: depositGroup.merchantPriv,
    merchantPub: depositGroup.merchantPub,
    wireHash,
  });
  url.searchParams.set("merchant_sig", sigResp.sig);
  const httpResp = await ws.http.get(url.href);
  switch (httpResp.status) {
    case HttpStatusCode.Accepted: {
      const accepted = await readSuccessResponseJsonOrThrow(
        httpResp,
        codecForTackTransactionAccepted(),
      );
      return { type: "accepted", ...accepted };
    }
    case HttpStatusCode.Ok: {
      const wired = await readSuccessResponseJsonOrThrow(
        httpResp,
        codecForTackTransactionWired(),
      );
      return { type: "wired", ...wired };
    }
    default: {
      throw Error(
        `unexpected response from track-transaction (${httpResp.status})`,
      );
    }
  }
}

/**
 * FIXME: This should be renamed to checkDepositGroup,
 * as it doesn't prepare anything
 */
export async function prepareDepositGroup(
  ws: InternalWalletState,
  req: PrepareDepositRequest,
): Promise<PrepareDepositResponse> {
  const p = parsePaytoUri(req.depositPaytoUri);
  if (!p) {
    throw Error("invalid payto URI");
  }
  const amount = Amounts.parseOrThrow(req.amount);

  const exchangeInfos: { url: string; master_pub: string }[] = [];

  await ws.db
    .mktx((x) => [x.exchanges, x.exchangeDetails])
    .runReadOnly(async (tx) => {
      const allExchanges = await tx.exchanges.iter().toArray();
      for (const e of allExchanges) {
        const details = await getExchangeDetails(tx, e.baseUrl);
        if (!details || amount.currency !== details.currency) {
          continue;
        }
        exchangeInfos.push({
          master_pub: details.masterPublicKey,
          url: e.baseUrl,
        });
      }
    });

  const now = AbsoluteTime.now();
  const nowRounded = AbsoluteTime.toTimestamp(now);
  const contractTerms: MerchantContractTerms = {
    auditors: [],
    exchanges: exchangeInfos,
    amount: req.amount,
    max_fee: Amounts.stringify(amount),
    max_wire_fee: Amounts.stringify(amount),
    wire_method: p.targetType,
    timestamp: nowRounded,
    merchant_base_url: "",
    summary: "",
    nonce: "",
    wire_transfer_deadline: nowRounded,
    order_id: "",
    h_wire: "",
    pay_deadline: AbsoluteTime.toTimestamp(
      AbsoluteTime.addDuration(now, durationFromSpec({ hours: 1 })),
    ),
    merchant: {
      name: "(wallet)",
    },
    merchant_pub: "",
    refund_deadline: TalerProtocolTimestamp.zero(),
  };

  const { h: contractTermsHash } = await ws.cryptoApi.hashString({
    str: canonicalJson(contractTerms),
  });

  const contractData = extractContractData(
    contractTerms,
    contractTermsHash,
    "",
  );

  const payCoinSel = await selectPayCoinsNew(ws, {
    auditors: contractData.allowedAuditors,
    exchanges: contractData.allowedExchanges,
    wireMethod: contractData.wireMethod,
    contractTermsAmount: Amounts.parseOrThrow(contractData.amount),
    depositFeeLimit: Amounts.parseOrThrow(contractData.maxDepositFee),
    wireFeeAmortization: contractData.wireFeeAmortization ?? 1,
    wireFeeLimit: Amounts.parseOrThrow(contractData.maxWireFee),
    prevPayCoins: [],
  });

  if (payCoinSel.type !== "success") {
    throw TalerError.fromDetail(
      TalerErrorCode.WALLET_DEPOSIT_GROUP_INSUFFICIENT_BALANCE,
      {
        insufficientBalanceDetails: payCoinSel.insufficientBalanceDetails,
      },
    );
  }

  const totalDepositCost = await getTotalPaymentCost(ws, payCoinSel.coinSel);

  const effectiveDepositAmount = await getCounterpartyEffectiveDepositAmount(
    ws,
    p.targetType,
    payCoinSel.coinSel,
  );

  return {
    totalDepositCost: Amounts.stringify(totalDepositCost),
    effectiveDepositAmount: Amounts.stringify(effectiveDepositAmount),
  };
}

export async function createDepositGroup(
  ws: InternalWalletState,
  req: CreateDepositGroupRequest,
): Promise<CreateDepositGroupResponse> {
  const p = parsePaytoUri(req.depositPaytoUri);
  if (!p) {
    throw Error("invalid payto URI");
  }

  const amount = Amounts.parseOrThrow(req.amount);

  const exchangeInfos: { url: string; master_pub: string }[] = [];

  await ws.db
    .mktx((x) => [x.exchanges, x.exchangeDetails])
    .runReadOnly(async (tx) => {
      const allExchanges = await tx.exchanges.iter().toArray();
      for (const e of allExchanges) {
        const details = await getExchangeDetails(tx, e.baseUrl);
        if (!details || amount.currency !== details.currency) {
          continue;
        }
        exchangeInfos.push({
          master_pub: details.masterPublicKey,
          url: e.baseUrl,
        });
      }
    });

  const now = AbsoluteTime.now();
  const nowRounded = AbsoluteTime.toTimestamp(now);
  const noncePair = await ws.cryptoApi.createEddsaKeypair({});
  const merchantPair = await ws.cryptoApi.createEddsaKeypair({});
  const wireSalt = encodeCrock(getRandomBytes(16));
  const wireHash = hashWire(req.depositPaytoUri, wireSalt);
  const contractTerms: MerchantContractTerms = {
    auditors: [],
    exchanges: exchangeInfos,
    amount: req.amount,
    max_fee: Amounts.stringify(amount),
    max_wire_fee: Amounts.stringify(amount),
    wire_method: p.targetType,
    timestamp: nowRounded,
    merchant_base_url: "",
    summary: "",
    nonce: noncePair.pub,
    wire_transfer_deadline: nowRounded,
    order_id: "",
    h_wire: wireHash,
    pay_deadline: AbsoluteTime.toTimestamp(
      AbsoluteTime.addDuration(now, durationFromSpec({ hours: 1 })),
    ),
    merchant: {
      name: "(wallet)",
    },
    merchant_pub: merchantPair.pub,
    refund_deadline: TalerProtocolTimestamp.zero(),
  };

  const { h: contractTermsHash } = await ws.cryptoApi.hashString({
    str: canonicalJson(contractTerms),
  });

  const contractData = extractContractData(
    contractTerms,
    contractTermsHash,
    "",
  );

  const payCoinSel = await selectPayCoinsNew(ws, {
    auditors: contractData.allowedAuditors,
    exchanges: contractData.allowedExchanges,
    wireMethod: contractData.wireMethod,
    contractTermsAmount: Amounts.parseOrThrow(contractData.amount),
    depositFeeLimit: Amounts.parseOrThrow(contractData.maxDepositFee),
    wireFeeAmortization: contractData.wireFeeAmortization ?? 1,
    wireFeeLimit: Amounts.parseOrThrow(contractData.maxWireFee),
    prevPayCoins: [],
  });

  if (payCoinSel.type !== "success") {
    throw TalerError.fromDetail(
      TalerErrorCode.WALLET_DEPOSIT_GROUP_INSUFFICIENT_BALANCE,
      {
        insufficientBalanceDetails: payCoinSel.insufficientBalanceDetails,
      },
    );
  }

  const totalDepositCost = await getTotalPaymentCost(ws, payCoinSel.coinSel);

  const depositGroupId = encodeCrock(getRandomBytes(32));

  const countarpartyEffectiveDepositAmount =
    await getCounterpartyEffectiveDepositAmount(
      ws,
      p.targetType,
      payCoinSel.coinSel,
    );

  const depositGroup: DepositGroupRecord = {
    contractTermsHash,
    contractTermsRaw: contractTerms,
    depositGroupId,
    noncePriv: noncePair.priv,
    noncePub: noncePair.pub,
    timestampCreated: AbsoluteTime.toTimestamp(now),
    timestampFinished: undefined,
    transactionPerCoin: payCoinSel.coinSel.coinPubs.map(
      () => TransactionStatus.Unknown,
    ),
    payCoinSelection: payCoinSel.coinSel,
    payCoinSelectionUid: encodeCrock(getRandomBytes(32)),
    depositedPerCoin: payCoinSel.coinSel.coinPubs.map(() => false),
    merchantPriv: merchantPair.priv,
    merchantPub: merchantPair.pub,
    totalPayCost: Amounts.stringify(totalDepositCost),
    effectiveDepositAmount: Amounts.stringify(
      countarpartyEffectiveDepositAmount,
    ),
    wire: {
      payto_uri: req.depositPaytoUri,
      salt: wireSalt,
    },
    operationStatus: OperationStatus.Pending,
  };

  await ws.db
    .mktx((x) => [
      x.depositGroups,
      x.coins,
      x.recoupGroups,
      x.denominations,
      x.refreshGroups,
      x.coinAvailability,
    ])
    .runReadWrite(async (tx) => {
      await spendCoins(ws, tx, {
        allocationId: `txn:deposit:${depositGroup.depositGroupId}`,
        coinPubs: payCoinSel.coinSel.coinPubs,
        contributions: payCoinSel.coinSel.coinContributions.map((x) =>
          Amounts.parseOrThrow(x),
        ),
        refreshReason: RefreshReason.PayDeposit,
      });
      await tx.depositGroups.put(depositGroup);
    });

  return {
    depositGroupId: depositGroupId,
    transactionId: makeTransactionId(TransactionType.Deposit, depositGroupId),
  };
}

/**
 * Get the amount that will be deposited on the users bank
 * account after depositing, not considering aggregation.
 */
export async function getCounterpartyEffectiveDepositAmount(
  ws: InternalWalletState,
  wireType: string,
  pcs: PayCoinSelection,
): Promise<AmountJson> {
  const amt: AmountJson[] = [];
  const fees: AmountJson[] = [];
  const exchangeSet: Set<string> = new Set();

  await ws.db
    .mktx((x) => [x.coins, x.denominations, x.exchanges, x.exchangeDetails])
    .runReadOnly(async (tx) => {
      for (let i = 0; i < pcs.coinPubs.length; i++) {
        const coin = await tx.coins.get(pcs.coinPubs[i]);
        if (!coin) {
          throw Error("can't calculate deposit amount, coin not found");
        }
        const denom = await ws.getDenomInfo(
          ws,
          tx,
          coin.exchangeBaseUrl,
          coin.denomPubHash,
        );
        if (!denom) {
          throw Error("can't find denomination to calculate deposit amount");
        }
        amt.push(Amounts.parseOrThrow(pcs.coinContributions[i]));
        fees.push(Amounts.parseOrThrow(denom.feeDeposit));
        exchangeSet.add(coin.exchangeBaseUrl);
      }

      for (const exchangeUrl of exchangeSet.values()) {
        const exchangeDetails = await getExchangeDetails(tx, exchangeUrl);
        if (!exchangeDetails) {
          continue;
        }

        // FIXME/NOTE: the line below _likely_ throws exception
        // about "find method not found on undefined" when the wireType
        // is not supported by the Exchange.
        const fee = exchangeDetails.wireInfo.feesForType[wireType].find((x) => {
          return AbsoluteTime.isBetween(
            AbsoluteTime.now(),
            AbsoluteTime.fromTimestamp(x.startStamp),
            AbsoluteTime.fromTimestamp(x.endStamp),
          );
        })?.wireFee;
        if (fee) {
          fees.push(Amounts.parseOrThrow(fee));
        }
      }
    });
  return Amounts.sub(Amounts.sum(amt).amount, Amounts.sum(fees).amount).amount;
}