1 files changed, 223 insertions, 0 deletions
diff --git a/packages/taler-util/src/http-client/bank-conversion.ts b/packages/taler-util/src/http-client/bank-conversion.ts
new file mode 100644
index 000000000..cb14d8b34
--- /dev/null
+++ b/packages/taler-util/src/http-client/bank-conversion.ts
@@ -0,0 +1,223 @@
+/*
+ This file is part of GNU Taler
+ (C) 2022-2024 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 { AmountJson, Amounts } from "../amounts.js";
+import { HttpRequestLibrary, readTalerErrorResponse } from "../http-common.js";
+import { HttpStatusCode } from "../http-status-codes.js";
+import { createPlatformHttpLib } from "../http.js";
+import { LibtoolVersion } from "../libtool-version.js";
+import {
+  FailCasesByMethod,
+  ResultByMethod,
+  opEmptySuccess,
+  opKnownHttpFailure,
+  opSuccessFromHttp,
+  opUnknownFailure,
+} from "../operation.js";
+import { TalerErrorCode } from "../taler-error-codes.js";
+import { codecForTalerErrorDetail } from "../wallet-types.js";
+import {
+  AccessToken,
+  TalerBankConversionApi,
+  codecForCashinConversionResponse,
+  codecForCashoutConversionResponse,
+  codecForConversionBankConfig,
+} from "./types.js";
+import {
+  CacheEvictor,
+  makeBearerTokenAuthHeader,
+  nullEvictor,
+} from "./utils.js";
+
+export type TalerBankConversionResultByMethod<
+  prop extends keyof TalerBankConversionHttpClient,
+> = ResultByMethod<TalerBankConversionHttpClient, prop>;
+export type TalerBankConversionErrorsByMethod<
+  prop extends keyof TalerBankConversionHttpClient,
+> = FailCasesByMethod<TalerBankConversionHttpClient, prop>;
+
+export enum TalerBankConversionCacheEviction {
+  UPDATE_RATE,
+}
+
+/**
+ * The API is used by the wallets.
+ */
+export class TalerBankConversionHttpClient {
+  public readonly PROTOCOL_VERSION = "0:0:0";
+
+  httpLib: HttpRequestLibrary;
+  cacheEvictor: CacheEvictor<TalerBankConversionCacheEviction>;
+
+  constructor(
+    readonly baseUrl: string,
+    httpClient?: HttpRequestLibrary,
+    cacheEvictor?: CacheEvictor<TalerBankConversionCacheEviction>,
+  ) {
+    this.httpLib = httpClient ?? createPlatformHttpLib();
+    this.cacheEvictor = cacheEvictor ?? nullEvictor;
+  }
+
+  isCompatible(version: string): boolean {
+    const compare = LibtoolVersion.compare(this.PROTOCOL_VERSION, version);
+    return compare?.compatible ?? false;
+  }
+
+  /**
+   * https://docs.taler.net/core/api-bank-conversion-info.html#get--config
+   *
+   */
+  async getConfig() {
+    const url = new URL(`config`, this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "GET",
+    });
+    switch (resp.status) {
+      case HttpStatusCode.Ok:
+        return opSuccessFromHttp(resp, codecForConversionBankConfig());
+      case HttpStatusCode.NotImplemented:
+        return opKnownHttpFailure(resp.status, resp);
+      default:
+        return opUnknownFailure(resp, await readTalerErrorResponse(resp));
+    }
+  }
+
+  /**
+   * https://docs.taler.net/core/api-bank-conversion-info.html#get--cashin-rate
+   *
+   */
+  async getCashinRate(conversion: { debit?: AmountJson; credit?: AmountJson }) {
+    const url = new URL(`cashin-rate`, this.baseUrl);
+    if (conversion.debit) {
+      url.searchParams.set("amount_debit", Amounts.stringify(conversion.debit));
+    }
+    if (conversion.credit) {
+      url.searchParams.set(
+        "amount_credit",
+        Amounts.stringify(conversion.credit),
+      );
+    }
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "GET",
+    });
+    switch (resp.status) {
+      case HttpStatusCode.Ok:
+        return opSuccessFromHttp(resp, codecForCashinConversionResponse());
+      case HttpStatusCode.BadRequest: {
+        const body = await resp.json();
+        const details = codecForTalerErrorDetail().decode(body);
+        switch (details.code) {
+          case TalerErrorCode.GENERIC_PARAMETER_MISSING:
+            return opKnownHttpFailure(resp.status, resp);
+          case TalerErrorCode.GENERIC_PARAMETER_MALFORMED:
+            return opKnownHttpFailure(resp.status, resp);
+          case TalerErrorCode.GENERIC_CURRENCY_MISMATCH:
+            return opKnownHttpFailure(resp.status, resp);
+          default:
+            return opUnknownFailure(resp, body);
+        }
+      }
+      case HttpStatusCode.Conflict:
+        return opKnownHttpFailure(resp.status, resp);
+      case HttpStatusCode.NotImplemented:
+        return opKnownHttpFailure(resp.status, resp);
+      default:
+        return opUnknownFailure(resp, await readTalerErrorResponse(resp));
+    }
+  }
+
+  /**
+   * https://docs.taler.net/core/api-bank-conversion-info.html#get--cashout-rate
+   *
+   */
+  async getCashoutRate(conversion: {
+    debit?: AmountJson;
+    credit?: AmountJson;
+  }) {
+    const url = new URL(`cashout-rate`, this.baseUrl);
+    if (conversion.debit) {
+      url.searchParams.set("amount_debit", Amounts.stringify(conversion.debit));
+    }
+    if (conversion.credit) {
+      url.searchParams.set(
+        "amount_credit",
+        Amounts.stringify(conversion.credit),
+      );
+    }
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "GET",
+    });
+    switch (resp.status) {
+      case HttpStatusCode.Ok:
+        return opSuccessFromHttp(resp, codecForCashoutConversionResponse());
+      case HttpStatusCode.BadRequest: {
+        const body = await resp.json();
+        const details = codecForTalerErrorDetail().decode(body);
+        switch (details.code) {
+          case TalerErrorCode.GENERIC_PARAMETER_MISSING:
+            return opKnownHttpFailure(resp.status, resp);
+          case TalerErrorCode.GENERIC_PARAMETER_MALFORMED:
+            return opKnownHttpFailure(resp.status, resp);
+          case TalerErrorCode.GENERIC_CURRENCY_MISMATCH:
+            return opKnownHttpFailure(resp.status, resp);
+          default:
+            return opUnknownFailure(resp, body);
+        }
+      }
+      case HttpStatusCode.Conflict:
+        return opKnownHttpFailure(resp.status, resp);
+      case HttpStatusCode.NotImplemented:
+        return opKnownHttpFailure(resp.status, resp);
+      default:
+        return opUnknownFailure(resp, await readTalerErrorResponse(resp));
+    }
+  }
+
+  /**
+   * https://docs.taler.net/core/api-bank-conversion-info.html#post--conversion-rate
+   *
+   */
+  async updateConversionRate(
+    auth: AccessToken,
+    body: TalerBankConversionApi.ConversionRate,
+  ) {
+    const url = new URL(`conversion-rate`, this.baseUrl);
+    const resp = await this.httpLib.fetch(url.href, {
+      method: "POST",
+      headers: {
+        Authorization: makeBearerTokenAuthHeader(auth),
+      },
+      body,
+    });
+    switch (resp.status) {
+      case HttpStatusCode.NoContent: {
+        this.cacheEvictor.notifySuccess(
+          TalerBankConversionCacheEviction.UPDATE_RATE,
+        );
+        return opEmptySuccess(resp);
+      }
+      case HttpStatusCode.Unauthorized:
+        return opKnownHttpFailure(resp.status, resp);
+      case HttpStatusCode.NotImplemented:
+        return opKnownHttpFailure(resp.status, resp);
+      default:
+        return opUnknownFailure(resp, await readTalerErrorResponse(resp));
+    }
+  }
+}