1 files changed, 81 insertions, 23 deletions

diff --git a/packages/taler-wallet-core/src/pay-merchant.ts b/packages/taler-wallet-core/src/pay-merchant.ts
index 49ebc282e..090a11cf0 100644
--- a/packages/taler-wallet-core/src/pay-merchant.ts
+++ b/packages/taler-wallet-core/src/pay-merchant.ts
@@ -34,13 +34,17 @@ import {
   assertUnreachable,
   AsyncFlag,
   checkDbInvariant,
+  CheckPaymentResponse,
+  CheckPayTemplateReponse,
+  CheckPayTemplateRequest,
   codecForAbortResponse,
   codecForMerchantContractTerms,
   codecForMerchantOrderStatusPaid,
   codecForMerchantPayResponse,
-  codecForMerchantPostOrderResponse,
+  codecForPostOrderResponse,
   codecForProposal,
   codecForWalletRefundResponse,
+  codecForWalletTemplateDetails,
   CoinDepositPermission,
   CoinRefreshRequest,
   ConfirmPayResult,
@@ -76,6 +80,8 @@ import {
   TalerError,
   TalerErrorCode,
   TalerErrorDetail,
+  TalerMerchantApi,
+  TalerMerchantInstanceHttpClient,
   TalerPreciseTimestamp,
   TalerProtocolViolationError,
   TalerUriAction,
@@ -1578,39 +1584,92 @@ async function internalWaitProposalDownloaded(
   }
 }
 
+async function downloadTemplate(
+  wex: WalletExecutionContext,
+  merchantBaseUrl: string,
+  templateId: string,
+): Promise<TalerMerchantApi.WalletTemplateDetails> {
+  const reqUrl = new URL(`templates/${templateId}`, merchantBaseUrl);
+  const httpReq = await wex.http.fetch(reqUrl.href, {
+    method: "GET",
+    cancellationToken: wex.cancellationToken,
+  });
+  const resp = await readSuccessResponseJsonOrThrow(
+    httpReq,
+    codecForWalletTemplateDetails(),
+  );
+  return resp;
+}
+
+export async function checkPayForTemplate(
+  wex: WalletExecutionContext,
+  req: CheckPayTemplateRequest,
+): Promise<CheckPayTemplateReponse> {
+  const parsedUri = parsePayTemplateUri(req.talerPayTemplateUri);
+  if (!parsedUri) {
+    throw Error("invalid taler-template URI");
+  }
+  const templateDetails = await downloadTemplate(
+    wex,
+    parsedUri.merchantBaseUrl,
+    parsedUri.templateId,
+  );
+
+  const merchantApi = new TalerMerchantInstanceHttpClient(
+    parsedUri.merchantBaseUrl,
+    wex.http,
+  );
+
+  const cfg = await merchantApi.getConfig();
+  if (cfg.type === "fail") {
+    throw TalerError.fromUncheckedDetail(cfg.detail);
+  }
+
+  return {
+    templateDetails,
+    supportedCurrencies: Object.keys(cfg.body.currencies),
+  };
+}
+
 export async function preparePayForTemplate(
   wex: WalletExecutionContext,
   req: PreparePayTemplateRequest,
 ): Promise<PreparePayResult> {
   const parsedUri = parsePayTemplateUri(req.talerPayTemplateUri);
-  const templateDetails: MerchantUsingTemplateDetails = {};
   if (!parsedUri) {
     throw Error("invalid taler-template URI");
   }
   logger.trace(`parsed URI: ${j2s(parsedUri)}`);
+  const templateDetails: MerchantUsingTemplateDetails = {};
 
-  const amountFromUri = parsedUri.templateParams.amount;
-  if (amountFromUri != null) {
-    const templateParamsAmount = req.templateParams?.amount;
-    if (templateParamsAmount != null) {
-      templateDetails.amount = templateParamsAmount as AmountString;
-    } else {
-      if (Amounts.isCurrency(amountFromUri)) {
-        throw Error(
-          "Amount from template URI only has a currency without value. The value must be provided in the templateParams.",
-        );
-      } else {
-        templateDetails.amount = amountFromUri as AmountString;
-      }
+  const templateInfo = await downloadTemplate(
+    wex,
+    parsedUri.merchantBaseUrl,
+    parsedUri.templateId,
+  );
+
+  const templateParamsAmount = req.templateParams?.amount as
+    | AmountString
+    | undefined;
+  if (templateParamsAmount === null) {
+    const amountFromUri = templateInfo.editable_defaults?.amount;
+    if (amountFromUri != null) {
+      templateDetails.amount = amountFromUri as AmountString;
     }
+  } else {
+    templateDetails.amount = templateParamsAmount;
   }
-  if (
-    parsedUri.templateParams.summary !== undefined &&
-    typeof parsedUri.templateParams.summary === "string"
-  ) {
-    templateDetails.summary =
-      req.templateParams?.summary ?? parsedUri.templateParams.summary;
+
+  const templateParamsSummary = req.templateParams?.summary;
+  if (templateParamsSummary === null) {
+    const summaryFromUri = templateInfo.editable_defaults?.summary;
+    if (summaryFromUri != null) {
+      templateDetails.summary = summaryFromUri;
+    }
+  } else {
+    templateDetails.summary = templateParamsSummary;
   }
+
   const reqUrl = new URL(
     `templates/${parsedUri.templateId}`,
     parsedUri.merchantBaseUrl,
@@ -1621,7 +1680,7 @@ export async function preparePayForTemplate(
   });
   const resp = await readSuccessResponseJsonOrThrow(
     httpReq,
-    codecForMerchantPostOrderResponse(),
+    codecForPostOrderResponse(),
   );
 
   const payUri = stringifyPayUri({
@@ -2875,7 +2934,6 @@ async function processPurchaseAutoRefund(
   );
 
   requestUrl.searchParams.set("timeout_ms", "10000");
-  requestUrl.searchParams.set("await_refund_obtained", "yes");
   requestUrl.searchParams.set("refund", Amounts.stringify(totalKnownRefund));
 
   const resp = await wex.http.fetch(requestUrl.href, {