wallet-core: draft qr content generation

5 files changed, 194 insertions, 0 deletions

diff --git a/packages/taler-util/src/index.ts b/packages/taler-util/src/index.ts
index 9f99f2f5a..287e03584 100644
--- a/packages/taler-util/src/index.ts
+++ b/packages/taler-util/src/index.ts
@@ -50,6 +50,7 @@ export * from "./observability.js";
 export * from "./operation.js";
 export * from "./payto.js";
 export * from "./promises.js";
+export * from "./qr.js";
 export * from "./rfc3548.js";
 export * from "./taler-crypto.js";
 export * from "./taler-types.js";
diff --git a/packages/taler-util/src/qr.ts b/packages/taler-util/src/qr.ts
new file mode 100644
index 000000000..2e8ffc652
--- /dev/null
+++ b/packages/taler-util/src/qr.ts
@@ -0,0 +1,161 @@
+/*
+ This file is part of GNU Taler
+ (C) 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 { Amounts } from "./index.node.js";
+import { parsePaytoUri } from "./payto.js";
+
+type EncodeResult = { type: "ok"; qrContent: string } | { type: "skip" };
+
+/**
+ * See "Schweizer Implementation Guidelines QR-Rechnung".
+ */
+function encodePaytoAsSwissQrBill(paytoUri: string): EncodeResult {
+  const parsedPayto = parsePaytoUri(paytoUri);
+  if (!parsedPayto) {
+    throw Error("invalid payto URI");
+  }
+  if (parsedPayto.targetType !== "iban") {
+    return { type: "skip" };
+  }
+  const amountStr = parsedPayto.params["amount"];
+  const iban = parsedPayto.targetPath;
+  const countryCode = iban.slice(0, 2);
+  const lines = [
+    "SPC", // QRType
+    "0200", // Version
+    "1", // Character set (1: UTF-8)
+    iban, // Beneficiary IBAN
+    // Group: Beneficiary
+    "S", // Address type (S: structured)
+    parsedPayto.params["receiver-name"], // Beneficiary name
+    "", // street
+    "", // apt. nr.
+    "", // postal code
+    "", // town
+    countryCode, // Country
+    // Group: Ultimate Debtor (not used in version 0200)
+    "", // Ultimate Debtor Address type (S: structured)
+    "", // Ultimate Debtor name
+    "", // Ultimate Debtor street
+    "", // Ultimate Debtor apt. nr
+    "", // Ultimate Debtor postal code
+    "", // Ultimate Debtor town
+    "", // Ultimate Debtor country
+    // Group: Amount
+    Amounts.stringifyValue(amountStr, 2), // Amount
+    Amounts.currencyOf(amountStr), // Currency
+    // Group: Debtor
+    "", // Address type (S: structured)
+    "", // Debtor name
+    "", // Debtor street
+    "", // Debtor apt. nr
+    "", // Debtor postal code
+    "", // Debtor town
+    "", // Debtor country
+    // Group: Reference
+    "NON", // reference type
+    "", // Reference
+    // Group: Additional Information
+    parsedPayto.params["message"], // Unstructured data
+    "EPD", // End of payment data
+  ];
+
+  return {
+    type: "ok",
+    qrContent: lines.join("\n"),
+  };
+}
+
+/**
+ * See "Quick Response Code - Guidelines to
+ * Enable the Data Capture for the
+ * Initiation of a SEPA Credit Transfer".
+ */
+function encodePaytoAsEpcQr(paytoUri: string): EncodeResult {
+  const parsedPayto = parsePaytoUri(paytoUri);
+  if (!parsedPayto) {
+    throw Error("invalid payto URI");
+  }
+  if (parsedPayto.targetType !== "iban") {
+    return { type: "skip" };
+  }
+  const amountStr = parsedPayto.params["amount"];
+  Amounts.stringifyValue;
+  const lines = [
+    "BCD", // service tag
+    "002", // version
+    "1", // character set (1: UTF-8)
+    "SCT", // Identification
+    "", // optional BIC
+    parsedPayto.params["receiver-name"], // Beneficiary name
+    parsedPayto.targetPath, // Beneficiary IBAN
+    `${Amounts.currencyOf(amountStr)}${Amounts.stringifyValue(amountStr, 2)}`, // Amount
+    "", // AT-44 Purpose
+    parsedPayto.params["message"], // AT-05 Unstructured remittance information
+  ];
+
+  return {
+    type: "ok",
+    qrContent: lines.join("\n"),
+  };
+}
+
+/**
+ * Specification of a QR code that includes payment information.
+ */
+export interface QrCodeSpec {
+  /**
+   * Type of the QR code.
+   *
+   * Depending on the type, different visual styles
+   * might be applied.
+   */
+  type: string;
+
+  /**
+   * Content of the QR code that should be rendered.
+   */
+  qrContent: string;
+}
+
+/**
+ * Get applicable QR code specifications for the given payto URI.
+ */
+export function getQrCodesForPayto(paytoUri: string): QrCodeSpec[] {
+  const res: QrCodeSpec[] = [];
+  {
+    const qr = encodePaytoAsEpcQr(paytoUri);
+    if (qr.type == "ok") {
+      res.push({
+        type: "epc-qr",
+        qrContent: qr.qrContent,
+      });
+    }
+  }
+  {
+    const qr = encodePaytoAsSwissQrBill(paytoUri);
+    if (qr.type == "ok") {
+      res.push({
+        type: "epc-qr",
+        qrContent: qr.qrContent,
+      });
+    }
+  }
+  return res;
+}
diff --git a/packages/taler-util/src/wallet-types.ts b/packages/taler-util/src/wallet-types.ts
index 360d8b183..2c92d9295 100644
--- a/packages/taler-util/src/wallet-types.ts
+++ b/packages/taler-util/src/wallet-types.ts
@@ -55,6 +55,7 @@ import {
 } from "./index.js";
 import { VersionMatchResult } from "./libtool-version.js";
 import { PaytoString, PaytoUri, codecForPaytoString } from "./payto.js";
+import { QrCodeSpec } from "./qr.js";
 import { AgeCommitmentProof } from "./taler-crypto.js";
 import { TalerErrorCode } from "./taler-error-codes.js";
 import {
@@ -3425,3 +3426,16 @@ export const codecForGetDepositWireTypesForCurrencyRequest =
 export interface GetDepositWireTypesForCurrencyResponse {
   wireTypes: string[];
 }
+
+export interface GetQrCodesForPaytoRequest {
+  paytoUri: string;
+}
+
+export const codecForGetQrCodesForPaytoRequest = () =>
+  buildCodecForObject<GetQrCodesForPaytoRequest>()
+    .property("paytoUri", codecForString())
+    .build("GetQrCodesForPaytoRequest");
+
+export interface GetQrCodesForPaytoResponse {
+  codes: QrCodeSpec[];
+}
diff --git a/packages/taler-wallet-core/src/wallet-api-types.ts b/packages/taler-wallet-core/src/wallet-api-types.ts
index c54ec1360..ce8be2927 100644
--- a/packages/taler-wallet-core/src/wallet-api-types.ts
+++ b/packages/taler-wallet-core/src/wallet-api-types.ts
@@ -81,6 +81,8 @@ import {
   GetExchangeTosResult,
   GetPlanForOperationRequest,
   GetPlanForOperationResponse,
+  GetQrCodesForPaytoRequest,
+  GetQrCodesForPaytoResponse,
   GetWithdrawalDetailsForAmountRequest,
   GetWithdrawalDetailsForUriRequest,
   HintNetworkAvailabilityRequest,
@@ -269,6 +271,7 @@ export enum WalletApiOperation {
   HintNetworkAvailability = "hintNetworkAvailability",
   CanonicalizeBaseUrl = "canonicalizeBaseUrl",
   GetDepositWireTypesForCurrency = "getDepositWireTypesForCurrency",
+  GetQrCodesForPayto = "getQrCodesForPayto",
   TestingWaitTransactionsFinal = "testingWaitTransactionsFinal",
   TestingWaitRefreshesFinal = "testingWaitRefreshesFinal",
   TestingWaitTransactionState = "testingWaitTransactionState",
@@ -999,6 +1002,12 @@ export type CanonicalizeBaseUrlOp = {
   response: CanonicalizeBaseUrlResponse;
 };
 
+export type GetQrCodesForPaytoOp = {
+  op: WalletApiOperation.GetQrCodesForPayto;
+  request: GetQrCodesForPaytoRequest;
+  response: GetQrCodesForPaytoResponse;
+};
+
 // group: Database Management
 
 /**
@@ -1382,6 +1391,7 @@ export type WalletOperations = {
   [WalletApiOperation.TestingResetAllRetries]: TestingResetAllRetriesOp;
   [WalletApiOperation.HintNetworkAvailability]: HintNetworkAvailabilityOp;
   [WalletApiOperation.GetDepositWireTypesForCurrency]: GetDepositWireTypesForCurrencyOp;
+  [WalletApiOperation.GetQrCodesForPayto]: GetQrCodesForPaytoOp;
 };
 
 export type WalletCoreRequestType<
diff --git a/packages/taler-wallet-core/src/wallet.ts b/packages/taler-wallet-core/src/wallet.ts
index a58e3aff0..69f0e5f0b 100644
--- a/packages/taler-wallet-core/src/wallet.ts
+++ b/packages/taler-wallet-core/src/wallet.ts
@@ -107,6 +107,7 @@ import {
   codecForGetExchangeEntryByUrlRequest,
   codecForGetExchangeResourcesRequest,
   codecForGetExchangeTosRequest,
+  codecForGetQrCodesForPaytoRequest,
   codecForGetWithdrawalDetailsForAmountRequest,
   codecForGetWithdrawalDetailsForUri,
   codecForHintNetworkAvailabilityRequest,
@@ -149,6 +150,7 @@ import {
   codecForValidateIbanRequest,
   codecForWithdrawTestBalance,
   getErrorDetailFromException,
+  getQrCodesForPayto,
   j2s,
   openPromise,
   parsePaytoUri,
@@ -1061,6 +1063,12 @@ async function dispatchRequestInternal(
       const req = codecForPreparePayTemplateRequest().decode(payload);
       return preparePayForTemplate(wex, req);
     }
+    case WalletApiOperation.GetQrCodesForPayto: {
+      const req = codecForGetQrCodesForPaytoRequest().decode(payload);
+      return {
+        codes: getQrCodesForPayto(req.paytoUri),
+      };
+    }
     case WalletApiOperation.ConfirmPay: {
       const req = codecForConfirmPayRequest().decode(payload);
       let transactionId;