From 99b4e72b7d370e610e2b85f79c21c8c0877df7d2 Mon Sep 17 00:00:00 2001
From: oppiliappan <me@oppi.li>
Date: Sun, 12 Apr 2026 04:45:43 +0100
Subject: [PATCH] feat: implement queue snapshotting

before queue mutations, store the state of the queue into the queue
history manager.

Signed-off-by: oppiliappan <me@oppi.li>
---
 src/js/queue.js | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/js/queue.js b/src/js/queue.js
index b9a76cc..e3766b6 100644
--- a/src/js/queue.js
+++ b/src/js/queue.js
@@ -1,8 +1,36 @@
 // queue management, sorting, virtual scrolling, and track display
 
+class QueueSnapshot {
+	static create(queue, queueIndex) {
+		return {
+			queue: structuredClone(queue),
+			queueIndex,
+			timestamp: Date.now(),
+		};
+	}
+
+	static apply(snapshot, state) {
+		state.queue = structuredClone(snapshot.queue);
+		state.queueIndex = snapshot.queueIndex;
+	}
+}
+
+// create snapshot of current queue state
+function snapshotQueue() {
+	return QueueSnapshot.create(state.queue, state.queueIndex);
+}
+
+// restore queue state from snapshot and update UI
+function restoreQueue(snapshot) {
+	if (!snapshot) return;
+	QueueSnapshot.apply(snapshot, state);
+	updateQueue();
+}
+
 // sort or shuffle queue, preserving current track position
 // if items are selected, only sorts selected items, otherwise sorts entire queue
 function sortQueue(field, ascending) {
+	history.saveState(snapshotQueue());
 	const currentTrack =
 		state.queueIndex >= 0 ? state.queue[state.queueIndex] : null;
 	const selectedIndices = queueSelection?.getSelected() ?? [];
@@ -144,6 +172,7 @@ function getQueueCallbacks() {
 
 // move items within queue
 function moveQueueItems(queue, selectedIndices, insertPos, callbacks = {}) {
+	history.saveState(snapshotQueue());
 	const { onSelectionChange, onQueueChange } = callbacks;
 	const sortedIndices = Array.from(selectedIndices).sort((a, b) => a - b);
 	const movedItems = sortedIndices.map((i) => queue[i]);
@@ -221,6 +250,7 @@ const SONG_EXTRACTORS = {
 
 // add songs to queue
 async function addToQueue(fetcher, songExtractor, insertNext = false) {
+	history.saveState(snapshotQueue());
 	const songs = await songExtractor(await fetcher());
 	songs.forEach((song) => {
 		if (song.userRating && song.userRating > 0) {
@@ -293,6 +323,7 @@ function updateQueueDisplay() {
 
 // clear selected rows
 function clearSelectedRows() {
+	history.saveState(snapshotQueue());
 	const toRemove = queueSelection.getSelected();
 	if (toRemove.length === 0) return;
 
@@ -328,6 +359,7 @@ function clearSelectedRows() {
 
 // remove a song by index, adjusting queue index if necessary
 function removeFromQueue(idx) {
+	history.saveState(snapshotQueue());
 	const isCurrentTrack = idx === state.queueIndex;
 
 	state.queue.splice(idx, 1);
@@ -375,6 +407,7 @@ function handleCurrentTrackDeleted() {
 
 // remove all items from queue
 function clearQueue() {
+	history.saveState(snapshotQueue());
 	state.queue = [];
 	state.queueIndex = -1;
 	saveQueue();
-- 
2.51.2