global player pt. 10 fix displaying shuffled queue

src/lib/components/GlobalPlayer.svelte

@@ -2,6 +2,12 @@
 	import type { Track } from "$lib/player/types";
 
 	export type GlobalPlayerNowPlaying = Track | null;
+
+	export type QueueDisplayItem = {
+		track: Track;
+		queueIndex: number;
+		isCurrent: boolean;
+	};
 </script>
 
 <script lang="ts">
@@ -233,6 +239,70 @@
 		return `${title} — ${artist}`;
 	}
 
+	function computeQueueDisplay(): QueueDisplayItem[] {
+		const q = snap.queue;
+
+		if (q.length === 0) return [];
+
+		const current = snap.currentIndex;
+
+		// Non-shuffle: display stable queue order.
+		if (!snap.shuffleEnabled) {
+			return q.map((track, queueIndex) => ({
+				track,
+				queueIndex,
+				isCurrent: current === queueIndex,
+			}));
+		}
+
+		// Shuffle: display play order (history up to cursor + future order).
+		// This prevents the UI's "current position" from appearing to jump around.
+		//
+		// Invariants we try to preserve:
+		// - Past (history[0..cursor]) stays in the same order.
+		// - Current item is history[cursor] when available, otherwise currentIndex.
+		// - Future comes from `order` (already excludes visited indices).
+		const out: QueueDisplayItem[] = [];
+		const seen = new Set<number>();
+
+		const pushIndex = (queueIndex: number) => {
+			if (!Number.isInteger(queueIndex)) return;
+			if (queueIndex < 0 || queueIndex >= q.length) return;
+			if (seen.has(queueIndex)) return;
+			seen.add(queueIndex);
+
+			out.push({
+				track: q[queueIndex]!,
+				queueIndex,
+				isCurrent: current === queueIndex,
+			});
+		};
+
+		// Past + current
+		const hist = snap.history;
+		const cursor = snap.cursor;
+
+		for (let i = 0; i < hist.length; i += 1) {
+			// Only show "past" up through current cursor; the rest would be "future via history"
+			// and is confusing to duplicate (future is represented by `order`).
+			if (i > cursor) break;
+			pushIndex(hist[i]!);
+		}
+
+		// If history is empty or cursor doesn't match currentIndex, ensure currentIndex is shown.
+		if (current != null) pushIndex(current);
+
+		// Future
+		for (const i of snap.order) pushIndex(i);
+
+		// Any remaining items (not yet visited nor scheduled) go at the end (rare but possible after edits).
+		for (let i = 0; i < q.length; i += 1) pushIndex(i);
+
+		return out;
+	}
+
+	const queueDisplay = $derived(computeQueueDisplay());
+
 	const canPrev = $derived(
 		snap.queue.length > 0 &&
 			snap.currentIndex != null &&
@@ -417,7 +487,7 @@
 							<p class="text-sm text-muted-foreground">Queue is empty.</p>
 						{:else}
 							<ul class="max-h-64 overflow-auto rounded border">
-								{#each snap.queue as t, i (t.id)}
+								{#each queueDisplay as item (item.track.id)}
 									<li
 										class="flex items-center gap-2 border-b px-2 py-2 last:border-b-0"
 									>
@@ -425,20 +495,20 @@
 											class="min-w-0 flex-1 truncate text-left text-sm hover:underline"
 											type="button"
 											onclick={() => {
-												jumpToTrack(t.id);
+												jumpToTrack(item.track.id);
 												void syncAndAutoplay();
 											}}
 										>
-											{#if snap.currentIndex === i}
+											{#if item.isCurrent}
 												<span class="text-muted-foreground">▶ </span>
 											{/if}
-											{titleForTrack(t)}
+											{titleForTrack(item.track)}
 										</button>
 
 										<button
 											class="rounded border px-2 py-1 text-xs"
 											type="button"
-											onclick={() => removeTrack(t.id)}
+											onclick={() => removeTrack(item.track.id)}
 										>
 											Remove
 										</button>
@@ -562,7 +632,7 @@
 						<p class="text-sm text-muted-foreground">Queue is empty.</p>
 					{:else}
 						<ul class="rounded border">
-							{#each snap.queue as t, i (t.id)}
+							{#each queueDisplay as item (item.track.id)}
 								<li
 									class="flex items-center gap-2 border-b px-2 py-2 last:border-b-0"
 								>
@@ -570,20 +640,20 @@
 										class="min-w-0 flex-1 truncate text-left text-sm hover:underline"
 										type="button"
 										onclick={() => {
-											jumpToTrack(t.id);
+											jumpToTrack(item.track.id);
 											void syncAndAutoplay();
 										}}
 									>
-										{#if snap.currentIndex === i}
+										{#if item.isCurrent}
 											<span class="text-muted-foreground">▶ </span>
 										{/if}
-										{titleForTrack(t)}
+										{titleForTrack(item.track)}
 									</button>
 
 									<button
 										class="rounded border px-2 py-1 text-xs"
 										type="button"
-										onclick={() => removeTrack(t.id)}
+										onclick={() => removeTrack(item.track.id)}
 									>
 										Remove
 									</button>