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diff --git a/packages/taler-util/src/bank-api-client.ts b/packages/taler-util/src/bank-api-client.ts
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+/*
+ This file is part of GNU Taler
+ (C) 2022 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/>
+ */
+
+/**
+ * Client for the Taler (demo-)bank.
+ */
+
+/**
+ * Imports.
+ */
+import {
+  AmountString,
+  base64FromArrayBuffer,
+  buildCodecForObject,
+  Codec,
+  codecForAny,
+  codecForString,
+  encodeCrock,
+  getRandomBytes,
+  HttpStatusCode,
+  j2s,
+  Logger,
+  opEmptySuccess,
+  opKnownHttpFailure,
+  opUnknownFailure,
+  stringToBytes,
+  TalerError,
+  TalerErrorCode,
+} from "@gnu-taler/taler-util";
+import {
+  checkSuccessResponseOrThrow,
+  createPlatformHttpLib,
+  HttpRequestLibrary,
+  readSuccessResponseJsonOrThrow,
+  readTalerErrorResponse,
+} from "@gnu-taler/taler-util/http";
+
+const logger = new Logger("bank-api-client.ts");
+
+export enum CreditDebitIndicator {
+  Credit = "credit",
+  Debit = "debit",
+}
+
+export interface BankAccountBalanceResponse {
+  balance: {
+    amount: AmountString;
+    credit_debit_indicator: CreditDebitIndicator;
+  };
+}
+
+export interface BankUser {
+  username: string;
+  password: string;
+  accountPaytoUri: string;
+}
+
+export interface WithdrawalOperationInfo {
+  withdrawal_id: string;
+  taler_withdraw_uri: string;
+}
+
+/**
+ * Helper function to generate the "Authorization" HTTP header.
+ */
+function makeBasicAuthHeader(username: string, password: string): string {
+  const auth = `${username}:${password}`;
+  const authEncoded: string = base64FromArrayBuffer(stringToBytes(auth));
+  return `Basic ${authEncoded}`;
+}
+
+const codecForWithdrawalOperationInfo = (): Codec<WithdrawalOperationInfo> =>
+  buildCodecForObject<WithdrawalOperationInfo>()
+    .property("withdrawal_id", codecForString())
+    .property("taler_withdraw_uri", codecForString())
+    .build("WithdrawalOperationInfo");
+
+export interface BankAccessApiClientArgs {
+  auth?: { username: string; password: string };
+  httpClient?: HttpRequestLibrary;
+}
+
+export interface BankAccessApiCreateTransactionRequest {
+  amount: AmountString;
+  paytoUri: string;
+}
+
+export class WireGatewayApiClientArgs {
+  auth?: {
+    username: string;
+    password: string;
+  };
+  httpClient?: HttpRequestLibrary;
+}
+
+/**
+ * This API look like it belongs to harness
+ * but it will be nice to have in utils to be used by others
+ */
+export class WireGatewayApiClient {
+  httpLib;
+
+  constructor(
+    private baseUrl: string,
+    private args: WireGatewayApiClientArgs = {},
+  ) {
+    this.httpLib = args.httpClient ?? createPlatformHttpLib();
+  }
+
+  private makeAuthHeader(): Record<string, string> {
+    const auth = this.args.auth;
+    if (auth) {
+      return {
+        Authorization: makeBasicAuthHeader(auth.username, auth.password),
+      };
+    }
+    return {};
+  }
+
+  async adminAddIncoming(params: {
+    amount: string;
+    reservePub: string;
+    debitAccountPayto: string;
+  }): Promise<void> {
+    let url = new URL(`admin/add-incoming`, this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: {
+        amount: params.amount,
+        reserve_pub: params.reservePub,
+        debit_account: params.debitAccountPayto,
+      },
+      headers: this.makeAuthHeader(),
+    });
+    logger.info(`add-incoming response status: ${resp.status}`);
+    await checkSuccessResponseOrThrow(resp);
+  }
+}
+
+export interface ChallengeContactData {
+  // E-Mail address
+  email?: string;
+
+  // Phone number.
+  phone?: string;
+}
+
+export interface AccountBalance {
+  amount: AmountString;
+  credit_debit_indicator: "credit" | "debit";
+}
+
+export interface RegisterAccountRequest {
+  // Username
+  username: string;
+
+  // Password.
+  password: string;
+
+  // Legal name of the account owner
+  name: string;
+
+  // Defaults to false.
+  is_public?: boolean;
+
+  // Is this a taler exchange account?
+  // If true:
+  // - incoming transactions to the account that do not
+  //   have a valid reserve public key are automatically
+  // - the account provides the taler-wire-gateway-api endpoints
+  // Defaults to false.
+  is_taler_exchange?: boolean;
+
+  // Addresses where to send the TAN for transactions.
+  // Currently only used for cashouts.
+  // If missing, cashouts will fail.
+  // In the future, might be used for other transactions
+  // as well.
+  challenge_contact_data?: ChallengeContactData;
+
+  // 'payto' address pointing a bank account
+  // external to the libeufin-bank.
+  // Payments will be sent to this bank account
+  // when the user wants to convert the local currency
+  // back to fiat currency outside libeufin-bank.
+  cashout_payto_uri?: string;
+
+  // Internal payto URI of this bank account.
+  // Used mostly for testing.
+  payto_uri?: string;
+}
+
+export interface AccountData {
+  // Legal name of the account owner.
+  name: string;
+
+  // Available balance on the account.
+  balance: AccountBalance;
+
+  // payto://-URI of the account.
+  payto_uri: string;
+
+  // Number indicating the max debit allowed for the requesting user.
+  debit_threshold: AmountString;
+
+  contact_data?: ChallengeContactData;
+
+  // 'payto' address pointing the bank account
+  // where to send cashouts.  This field is optional
+  // because not all the accounts are required to participate
+  // in the merchants' circuit.  One example is the exchange:
+  // that never cashouts.  Registering these accounts can
+  // be done via the access API.
+  cashout_payto_uri?: string;
+}
+
+export interface ConfirmWithdrawalArgs {
+  withdrawalOperationId: string;
+}
+
+/**
+ * Client for the Taler corebank API.
+ */
+export class TalerCorebankApiClient {
+  httpLib: HttpRequestLibrary;
+
+  constructor(
+    private baseUrl: string,
+    private args: BankAccessApiClientArgs = {},
+  ) {
+    this.httpLib = args.httpClient ?? createPlatformHttpLib();
+  }
+
+  setAuth(auth: { username: string; password: string }) {
+    this.args.auth = auth;
+  }
+
+  private makeAuthHeader(): Record<string, string> {
+    if (!this.args.auth) {
+      return {};
+    }
+    const authHeaderValue = makeBasicAuthHeader(
+      this.args.auth.username,
+      this.args.auth.password,
+    );
+    return {
+      Authorization: authHeaderValue,
+    };
+  }
+
+  async getAccountBalance(
+    username: string,
+  ): Promise<BankAccountBalanceResponse> {
+    const url = new URL(`accounts/${username}`, this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      headers: this.makeAuthHeader(),
+    });
+    return readSuccessResponseJsonOrThrow(resp, codecForAny());
+  }
+
+  async getTransactions(username: string): Promise<void> {
+    const reqUrl = new URL(`accounts/${username}/transactions`, this.baseUrl);
+    const resp = await this.httpLib.fetch(reqUrl.href, {
+      method: "GET",
+      headers: {
+        ...this.makeAuthHeader(),
+      },
+    });
+
+    const res = await readSuccessResponseJsonOrThrow(resp, codecForAny());
+    logger.info(`result: ${j2s(res)}`);
+  }
+
+  async createTransaction(
+    username: string,
+    req: BankAccessApiCreateTransactionRequest,
+  ): Promise<any> {
+    const reqUrl = new URL(`accounts/${username}/transactions`, this.baseUrl);
+
+    const resp = await this.httpLib.fetch(reqUrl.href, {
+      method: "POST",
+      body: req,
+      headers: this.makeAuthHeader(),
+    });
+
+    return await readSuccessResponseJsonOrThrow(resp, codecForAny());
+  }
+
+  async registerAccountExtended(req: RegisterAccountRequest): Promise<void> {
+    const url = new URL("accounts", this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: req,
+      headers: this.makeAuthHeader(),
+    });
+
+    if (
+      resp.status !== 200 &&
+      resp.status !== 201 &&
+      resp.status !== 202 &&
+      resp.status !== 204
+    ) {
+      logger.error(`unexpected status ${resp.status} from POST ${url.href}`);
+      logger.error(`${j2s(await resp.json())}`);
+      throw TalerError.fromDetail(
+        TalerErrorCode.GENERIC_UNEXPECTED_REQUEST_ERROR,
+        {
+          httpStatusCode: resp.status,
+        },
+      );
+    }
+  }
+
+  /**
+   * Register a new account and return information about it.
+   *
+   * This is a helper, as it does both the registration and the
+   * account info query.
+   */
+  async registerAccount(username: string, password: string): Promise<BankUser> {
+    const url = new URL("accounts", this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: {
+        username,
+        password,
+        name: username,
+      },
+      headers: this.makeAuthHeader(),
+    });
+    if (
+      resp.status !== 200 &&
+      resp.status !== 201 &&
+      resp.status !== 202 &&
+      resp.status !== 204
+    ) {
+      logger.error(`unexpected status ${resp.status} from POST ${url.href}`);
+      logger.error(`${j2s(await resp.json())}`);
+      throw TalerError.fromDetail(
+        TalerErrorCode.GENERIC_UNEXPECTED_REQUEST_ERROR,
+        {
+          httpStatusCode: resp.status,
+        },
+      );
+    }
+    // FIXME: Corebank should directly return this info!
+    const infoUrl = new URL(`accounts/${username}`, this.baseUrl);
+    const infoResp = await this.httpLib.fetch(infoUrl.href, {
+      headers: {
+        Authorization: makeBasicAuthHeader(username, password),
+      },
+    });
+    // FIXME: Validate!
+    const acctInfo: AccountData = await readSuccessResponseJsonOrThrow(
+      infoResp,
+      codecForAny(),
+    );
+    return {
+      password,
+      username,
+      accountPaytoUri: acctInfo.payto_uri,
+    };
+  }
+
+  async createRandomBankUser(): Promise<BankUser> {
+    const username = "user-" + encodeCrock(getRandomBytes(10)).toLowerCase();
+    const password = "pw-" + encodeCrock(getRandomBytes(10)).toLowerCase();
+    return await this.registerAccount(username, password);
+  }
+
+  async createWithdrawalOperation(
+    user: string,
+    amount: string,
+  ): Promise<WithdrawalOperationInfo> {
+    const url = new URL(`accounts/${user}/withdrawals`, this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: {
+        amount,
+      },
+      headers: this.makeAuthHeader(),
+    });
+    return readSuccessResponseJsonOrThrow(
+      resp,
+      codecForWithdrawalOperationInfo(),
+    );
+  }
+
+  async confirmWithdrawalOperation(
+    username: string,
+    wopi: ConfirmWithdrawalArgs,
+  ) {
+    const url = new URL(
+      `accounts/${username}/withdrawals/${wopi.withdrawalOperationId}/confirm`,
+      this.baseUrl,
+    );
+    logger.info(`confirming withdrawal operation via ${url.href}`);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: {},
+      headers: this.makeAuthHeader(),
+    });
+
+    switch (resp.status) {
+      case HttpStatusCode.Ok:
+      case HttpStatusCode.NoContent:
+        return opEmptySuccess(resp);
+      case HttpStatusCode.NotFound:
+        return opKnownHttpFailure(resp.status, resp);
+      default:
+        return opUnknownFailure(resp, await readTalerErrorResponse(resp));
+    }
+  }
+
+  async abortWithdrawalOperation(wopi: WithdrawalOperationInfo): Promise<void> {
+    const url = new URL(
+      `withdrawals/${wopi.withdrawal_id}/abort`,
+      this.baseUrl,
+    );
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      body: {},
+      headers: this.makeAuthHeader(),
+    });
+    await readSuccessResponseJsonOrThrow(resp, codecForAny());
+  }
+}