From 9f47d7beb1bcf797e13d3732463679dcf59678c3 Mon Sep 17 00:00:00 2001
From: Luc Mcgrady <lucmcgrady@gmail.com>
Date: Wed, 12 Nov 2025 21:45:00 +0000
Subject: [PATCH] Added: Undo state

---
 qt/aqt/mediasrv.py              |  1 +
 ts/routes/reviewer/+page.svelte |  6 +++++-
 ts/routes/reviewer/+page.ts     |  9 +++++++++
 ts/routes/reviewer/reviewer.ts  | 14 ++++++++++++--
 4 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 ts/routes/reviewer/+page.ts

diff --git a/qt/aqt/mediasrv.py b/qt/aqt/mediasrv.py
index 02a6c6796..91afb7a83 100644
--- a/qt/aqt/mediasrv.py
+++ b/qt/aqt/mediasrv.py
@@ -756,6 +756,7 @@ exposed_backend_list = [
     "get_custom_colours",
     "set_config_json",
     "get_config_json",
+    "get_undo_status",
     "undo",
     "redo",
     # DeckService
diff --git a/ts/routes/reviewer/+page.svelte b/ts/routes/reviewer/+page.svelte
index 517419267..3c20da131 100644
--- a/ts/routes/reviewer/+page.svelte
+++ b/ts/routes/reviewer/+page.svelte
@@ -2,7 +2,7 @@
 Copyright: Ankitects Pty Ltd and contributors
 License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 -->
-<script>
+<script lang="ts">
     import "./index.scss";
 
     import { onMount } from "svelte";
@@ -10,13 +10,17 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     import ReviewerBottom from "./reviewer-bottom/ReviewerBottom.svelte";
     import Reviewer from "./Reviewer.svelte";
     import { _blockDefaultDragDropBehavior } from "../../reviewer";
+    import type { PageData } from "./$types";
 
+    export let data: PageData;
     const state = new ReviewerState();
+
     onMount(() => {
         updateNightMode();
         globalThis.anki ??= {};
         globalThis.anki.changeReceived = () => state.showQuestion(null);
         _blockDefaultDragDropBehavior();
+        state.undoStatus = data.initialUndoStatus;
     });
     $: cardData = state.cardData;
     $: flag = $cardData?.queue?.cards[0].card?.flags;
diff --git a/ts/routes/reviewer/+page.ts b/ts/routes/reviewer/+page.ts
new file mode 100644
index 000000000..fc5d7d672
--- /dev/null
+++ b/ts/routes/reviewer/+page.ts
@@ -0,0 +1,9 @@
+// Copyright: Ankitects Pty Ltd and contributors
+// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+import { getUndoStatus } from "@generated/backend";
+import type { PageLoad } from "./$types";
+
+export const load = (async () => {
+    const initialUndoStatus = await getUndoStatus({});
+    return { initialUndoStatus };
+}) satisfies PageLoad;
diff --git a/ts/routes/reviewer/reviewer.ts b/ts/routes/reviewer/reviewer.ts
index 64112026e..decfbc8eb 100644
--- a/ts/routes/reviewer/reviewer.ts
+++ b/ts/routes/reviewer/reviewer.ts
@@ -1,5 +1,6 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+import type { UndoStatus } from "@generated/anki/collection_pb";
 import {
     BuryOrSuspendCardsRequest_Mode,
     CardAnswer,
@@ -59,6 +60,7 @@ export class ReviewerState {
     tooltipMessageTimeout: ReturnType<typeof setTimeout> | undefined;
     readonly tooltipMessage = writable("");
     readonly tooltipShown = writable(false);
+    undoStatus: UndoStatus | undefined = undefined;
 
     iframe: HTMLIFrameElement | undefined = undefined;
 
@@ -222,12 +224,16 @@ export class ReviewerState {
             }
             case "z": {
                 if (ctrl) {
-                    if (shift) {
+                    if (shift && this.undoStatus?.redo) {
                         const op = await redo({});
                         this.showTooltip(tr.undoActionRedone({ action: op.operation }));
-                    } else {
+                        this.undoStatus = op.newStatus;
+                    } else if (this.undoStatus?.undo) {
                         const op = await undo({});
                         this.showTooltip(tr.undoActionUndone({ action: op.operation }));
+                        this.undoStatus = op.newStatus;
+                    } else {
+                        this.showTooltip(shift ? tr.actionsNothingToRedo() : tr.actionsNothingToUndo());
                     }
                     this.refresh();
                 }
@@ -261,6 +267,10 @@ export class ReviewerState {
     }
 
     async showQuestion(answer: CardAnswer | null) {
+        if (answer !== null && this.undoStatus) {
+            this.undoStatus.undo = tr.actionsAnswerCard();
+        }
+
         const resp = await nextCardData({
             answer: answer || undefined,
         });