From 0a2540d676904e804544b95959bae223e42bc0c1 Mon Sep 17 00:00:00 2001
From: Florian Dold <florian@dold.me>
Date: Fri, 8 Mar 2024 10:30:23 +0100
Subject: wallet-core: notification-based waiting for dependent transactions
 instead of long-polling

---
 packages/taler-wallet-core/src/withdraw.ts | 86 ++++++++++++++++++++++++++++--
 1 file changed, 81 insertions(+), 5 deletions(-)

(limited to 'packages/taler-wallet-core/src/withdraw.ts')

diff --git a/packages/taler-wallet-core/src/withdraw.ts b/packages/taler-wallet-core/src/withdraw.ts
index 0f70479a5..f27e9e132 100644
--- a/packages/taler-wallet-core/src/withdraw.ts
+++ b/packages/taler-wallet-core/src/withdraw.ts
@@ -94,10 +94,6 @@ import {
   readSuccessResponseJsonOrThrow,
   throwUnexpectedRequestError,
 } from "@gnu-taler/taler-util/http";
-import {
-  selectForcedWithdrawalDenominations,
-  selectWithdrawalDenominations,
-} from "./denomSelection.js";
 import {
   PendingTaskType,
   TaskIdStr,
@@ -127,6 +123,10 @@ import {
   WithdrawalRecordType,
   timestampPreciseToDb,
 } from "./db.js";
+import {
+  selectForcedWithdrawalDenominations,
+  selectWithdrawalDenominations,
+} from "./denomSelection.js";
 import { isWithdrawableDenom } from "./denominations.js";
 import {
   ReadyExchangeSummary,
@@ -1935,7 +1935,8 @@ export async function getWithdrawalDetailsForUri(
             uri: talerWithdrawUri,
           });
         }
-      }).finally(() => {
+      })
+      .finally(() => {
         ongoingChecks[talerWithdrawUri] = false;
       });
   }
@@ -2703,6 +2704,7 @@ async function waitWithdrawalRegistered(
   wex: WalletExecutionContext,
   ctx: WithdrawTransactionContext,
 ): Promise<void> {
+  // FIXME: Doesn't support cancellation yet
   // FIXME: We should use Symbol.dispose magic here for cleanup!
 
   const withdrawalNotifFlag = new AsyncFlag();
@@ -2914,3 +2916,77 @@ export async function createManualWithdrawal(
     transactionId: ctx.transactionId,
   };
 }
+
+/**
+ * Wait until a refresh operation is final.
+ */
+export async function waitWithdrawalFinal(
+  wex: WalletExecutionContext,
+  withdrawalGroupId: string,
+): Promise<void> {
+  const ctx = new WithdrawTransactionContext(wex, withdrawalGroupId);
+  wex.taskScheduler.startShepherdTask(ctx.taskId);
+
+  // FIXME: Clean up using the new JS "using" / Symbol.dispose syntax.
+  const withdrawalNotifFlag = new AsyncFlag();
+  // Raise purchaseNotifFlag whenever we get a notification
+  // about our refresh.
+  const cancelNotif = wex.ws.addNotificationListener((notif) => {
+    if (
+      notif.type === NotificationType.TransactionStateTransition &&
+      notif.transactionId === ctx.transactionId
+    ) {
+      withdrawalNotifFlag.raise();
+    }
+  });
+  const unregisterOnCancelled = wex.cancellationToken.onCancelled(() => {
+    cancelNotif();
+    withdrawalNotifFlag.raise();
+  });
+
+  try {
+    await internalWaitWithdrawalFinal(ctx, withdrawalNotifFlag);
+  } catch (e) {
+    unregisterOnCancelled();
+    cancelNotif();
+  }
+}
+
+async function internalWaitWithdrawalFinal(
+  ctx: WithdrawTransactionContext,
+  flag: AsyncFlag,
+): Promise<void> {
+  while (true) {
+    if (ctx.wex.cancellationToken.isCancelled) {
+      throw Error("cancelled");
+    }
+
+    // Check if refresh is final
+    const res = await ctx.wex.db.runReadOnlyTx(
+      ["withdrawalGroups", "operationRetries"],
+      async (tx) => {
+        return {
+          wg: await tx.withdrawalGroups.get(ctx.withdrawalGroupId),
+        };
+      },
+    );
+    const { wg } = res;
+    if (!wg) {
+      // Must've been deleted, we consider that final.
+      return;
+    }
+    switch (wg.status) {
+      case WithdrawalGroupStatus.AbortedBank:
+      case WithdrawalGroupStatus.AbortedExchange:
+      case WithdrawalGroupStatus.Done:
+      case WithdrawalGroupStatus.FailedAbortingBank:
+      case WithdrawalGroupStatus.FailedBankAborted:
+        // Transaction is final
+        return;
+    }
+
+    // Wait for the next transition
+    await flag.wait();
+    flag.reset();
+  }
+}
-- 
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