EventSnap/frontend/src/routes/diashow/+page.svelte

<script lang="ts">
	import { onMount, onDestroy } from 'svelte';
	import { goto } from '$app/navigation';
	import { api } from '$lib/api';
	import { getToken } from '$lib/auth';
	import { showBottomNav } from '$lib/ui-store';
	import { connectSse, disconnectSse, onSseEvent } from '$lib/sse';
	import { SlideQueue } from '$lib/diashow/queue';
	import { transitions, findTransition } from '$lib/diashow/transitions';
	import { acquireWakeLock, releaseWakeLock } from '$lib/diashow/wakelock';
	import type { FeedUpload, FeedResponse, DeltaResponse } from '$lib/types';

	const DWELL_OPTIONS = [3000, 6000, 10000];
	// Cap on how long we wait for the next image to decode before showing it anyway.
	const PRELOAD_TIMEOUT_MS = 4000;
	// How far inside the dwell the preload budget must finish.
	//
	// `advance()` starts the preload and `scheduleNext()` starts the dwell timer together, and
	// `commit()` is discarded if the slide token has moved on. So whenever the preload budget
	// is >= the dwell, a screen whose images consistently decode slowly (cold cache on a
	// congested venue uplink — the normal state for a projector on party wifi) can never land
	// a commit: at 3s dwell the 4s preload is discarded, the next one gets 4s and is discarded
	// at 6s, forever. The wall sticks on one photo for the rest of the night while the queue
	// drains silently behind it, and nothing on screen says anything is wrong.
	//
	// Bounding the budget strictly below the dwell means the timeout always fires first and
	// commits whatever it has — a possibly-undecoded image is a far better outcome than a
	// frozen wall that needs a human.
	const PRELOAD_HEADROOM_MS = 500;
	// If every source for a slide is unreadable we skip it — but bail out of skipping after
	// this many in a row so a total media outage can't hot-loop the show.
	const MAX_CONSECUTIVE_SKIPS = 5;
	// Feed pagination: the server caps `limit` at 100, so we page to cover larger events.
	const FEED_PAGE = 100;
	const MAX_PAGES = 100; // safety bound (~10k images) against a runaway pagination loop
	// Periodic full reconcile — the completeness backstop for anything a live event missed
	// (dropped SSE, rate-limited fetch, an add/remove that never arrived).
	const RECONCILE_INTERVAL_MS = 120_000;

	let queue = new SlideQueue();
	let current = $state<FeedUpload | null>(null);
	// Two-layer crossfade. Previously the diashow rendered only `current` inside a
	// `{#key current.id}` block, so on every advance Svelte destroyed the old slide the
	// instant the id changed and mounted the new one starting at opacity 0 over the black
	// backdrop — the old image vanished to black, then the new one faded up (and only
	// popped in once it decoded). That's the "black flash". Instead we keep the outgoing
	// slide fully opaque *underneath* the incoming one while it fades in, then drop it —
	// there's always an opaque frame on screen, so the black never shows through.
	type SlideLayer = { key: string; src: string; isVideo: boolean; phase: 'enter' | 'exit' };
	let layers = $state<SlideLayer[]>([]);
	let dropPrevTimer: ReturnType<typeof setTimeout> | null = null;
	let reconcileInterval: ReturnType<typeof setInterval> | null = null;
	// Guards the async (decode-gated) layer commit against a newer advance superseding it.
	let slideToken = 0;
	// Consecutive slides skipped because no source decoded — reset the moment one shows.
	let consecutiveSkips = 0;
	let dwellMs = $state(6000);
	// Set when the browser has no Screen Wake Lock API at all (Firefox, Safari < 16.4, most TV
	// browsers). The operator sets this screen up once and walks away, so a silent no-op meant
	// discovering the OS had dimmed the projector only by looking at it.
	let wakeLockUnsupported = $state(false);
	let transitionId = $state('crossfade');
	let paused = $state(false);
	let showOverlay = $state(false);
	let advanceTimer: ReturnType<typeof setTimeout> | null = null;
	const unsubs: Array<() => void> = [];

	// Controls auto-hide: the top-right cluster shows on pointer/keyboard activity and fades
	// after a few seconds idle (the cursor hides with it) so a projector shows only photos.
	let controlsVisible = $state(true);
	let controlsHideTimer: ReturnType<typeof setTimeout> | null = null;
	// Fullscreen toggle via the Fullscreen API — an in-app button, independent of the
	// browser's own F11 chrome. `isFullscreen` mirrors the actual state via fullscreenchange.
	let isFullscreen = $state(false);
	let rootEl: HTMLDivElement | undefined = $state();

	const transitionDef = $derived(findTransition(transitionId));

	const isVideo = $derived(current?.mime_type.startsWith('video/') ?? false);

	function isEmpty(): boolean {
		return queue.stats().known === 0;
	}

	function scheduleNext() {
		clearTimer();
		if (paused) return;
		// Videos: advance on `ended` or after `max(dwell, 12s)` — whichever first.
		const ms = isVideo ? Math.max(dwellMs, 12000) : dwellMs;
		advanceTimer = setTimeout(advance, ms);
	}

	function clearTimer() {
		if (advanceTimer) {
			clearTimeout(advanceTimer);
			advanceTimer = null;
		}
	}

	// `immediate` = hard-cut with no exiting layer, used when the outgoing slide was just
	// removed (deleted / banned): it must vanish at once, not linger through the transition.
	function advance(immediate = false) {
		const next = queue.next();
		showSlide(next, immediate);
		if (current) scheduleNext();
	}

	// The diashow is a big screen (usually on good connectivity), so it ALWAYS prefers the
	// crisp ~2048px `display` derivative — decoupled from the per-device data-saver mode,
	// which is about a guest's phone data plan and irrelevant here. It falls back to the
	// original (uploads without a display yet) and then the 800px preview.
	function imageCandidates(u: FeedUpload): string[] {
		const displayOrOriginal = u.display_url ?? `/api/v1/upload/${u.id}/original`;
		const list = [displayOrOriginal];
		if (u.preview_url && u.preview_url !== displayOrOriginal) list.push(u.preview_url);
		return list;
	}

	// Swap in the next slide as the top layer while holding the outgoing one beneath it for
	// the length of the transition. Images are decode-gated (the fade reveals a painted
	// frame, not a blank one) and try each source in turn; the outgoing slide stays visible
	// until one commits, so there's never a black gap. Videos can't be pre-decoded, so they
	// swap in immediately.
	function showSlide(next: FeedUpload | null, immediate = false) {
		const token = ++slideToken;
		if (dropPrevTimer) {
			clearTimeout(dropPrevTimer);
			dropPrevTimer = null;
		}
		current = next;
		if (!next) {
			layers = [];
			return;
		}
		const isVid = next.mime_type.startsWith('video/');
		const prev = layers.length ? layers[layers.length - 1] : null;

		const commit = (src: string) => {
			if (token !== slideToken) return; // superseded by a newer advance — drop this frame
			consecutiveSkips = 0; // a slide actually reached the screen — reset the skip guard
			const slide: SlideLayer = { key: next.id, src, isVideo: isVid, phase: 'enter' };
			// Re-showing the same slide id (e.g. a re-fetch resolved to the current head) —
			// just replace it; never stack a slide on itself.
			if (prev && prev.key === slide.key) {
				layers = [slide];
				return;
			}
			// Removal-driven advance: drop the outgoing (removed) frame instantly — no exiting
			// layer. A brief blank over black beats showing a just-deleted/banned photo for
			// another second while it slides away.
			if (immediate) {
				layers = [slide];
				return;
			}
			// Mark the outgoing frame as exiting so slide transitions push it off in step with
			// the incoming one. Crossfade/Ken Burns ignore `phase` and just hold it opaque.
			const exiting = prev ? { ...prev, phase: 'exit' as const } : null;
			layers = exiting ? [exiting, slide] : [slide];
			if (exiting) {
				dropPrevTimer = setTimeout(() => {
					dropPrevTimer = null;
					layers = layers.filter((l) => l.key !== exiting.key);
				}, transitionDef.defaultDurationMs + 80);
			}
		};

		// Videos play the original file directly (can't be pre-decoded) — show immediately.
		if (isVid) {
			commit(`/api/v1/upload/${next.id}/original`);
			return;
		}

		// Try each image source in order. A decoded one is shown; a SLOW one is shown after
		// the timeout (don't stall the wall); a BROKEN one (fast decode reject) falls through
		// to the next source. If every source is unreadable, skip to a different slide rather
		// than parking a broken frame — guarded so a full media outage can't hot-loop.
		const candidates = imageCandidates(next);
		const tryCandidate = (i: number) => {
			if (token !== slideToken) return;
			if (i >= candidates.length) {
				if (consecutiveSkips < MAX_CONSECUTIVE_SKIPS) {
					consecutiveSkips++;
					advance();
				} else {
					consecutiveSkips = 0;
					commit(candidates[candidates.length - 1]); // give up skipping; show last try
				}
				return;
			}
			let settled = false;
			let timer: ReturnType<typeof setTimeout>;
			const done = (action: () => void) => {
				if (settled || token !== slideToken) return;
				settled = true;
				clearTimeout(timer);
				action();
			};
			// Always strictly less than the dwell — see PRELOAD_HEADROOM_MS.
			const preloadBudget = Math.max(
				250,
				Math.min(PRELOAD_TIMEOUT_MS, dwellMs - PRELOAD_HEADROOM_MS)
			);
			timer = setTimeout(() => done(() => commit(candidates[i])), preloadBudget);
			const pre = new Image();
			pre.src = candidates[i];
			pre.decode().then(
				() => done(() => commit(candidates[i])),
				() => done(() => tryCandidate(i + 1))
			);
		};
		tryCandidate(0);
	}

	// A video finished before its dwell/12s cap — advance immediately (unless paused).
	// `onended` is only wired to the layer whose key === current.id (see the template), so a
	// stale/exiting <video> that ends mid-transition can't trigger an advance.
	function handleVideoEnded() {
		if (!paused) advance();
	}

	// Full reconcile: page the ENTIRE eligible feed, merge everything, then evict anything
	// the server no longer returns. v_feed already excludes deleted/banned/hidden, so the
	// feed's id-set IS the eligible set — retaining exactly those ids converges the show to
	// the server truth in both directions, catching any add/remove a live event missed.
	// Runs on mount (initial fill), on reconnect deltas, and periodically as the backstop.
	// `initial` reshuffles once the whole set is in, so the first cycle isn't newest-first.
	async function reconcile(initial = false) {
		// Ids known BEFORE the scan — only these are eviction candidates, so an upload that
		// arrives mid-scan (not in this snapshot) is never wrongly pruned.
		const before = new Set(queue.knownIds());
		// eslint-disable-next-line svelte/prefer-svelte-reactivity -- local scan-bookkeeping set inside one reconcile() call; never stored in $state, so no reactivity is involved.
		const seen = new Set<string>();
		let cursor: string | null = null;
		let complete = false;
		try {
			for (let page = 0; page < MAX_PAGES; page++) {
				const qs: string = cursor ? `?limit=${FEED_PAGE}&cursor=${cursor}` : `?limit=${FEED_PAGE}`;
				const feed: FeedResponse = await api.get<FeedResponse>(`/feed${qs}`);
				for (const u of feed.uploads) seen.add(u.id);
				queue.merge(feed.uploads, { live: false });
				if (!current) advance(); // start the show the moment the first page lands
				if (feed.next_cursor == null) {
					complete = true;
					break;
				}
				cursor = feed.next_cursor;
			}
		} catch {
			// Partial fetch (network / rate-limit): keep what we merged but DON'T prune — a
			// truncated `seen` set must never evict valid slides. The next reconcile retries.
			complete = false;
		}
		if (complete) {
			if (initial) queue.reshuffle();
			// Evict only pre-existing slides the server no longer lists (deletions/bans/hides
			// we missed a live event for). Hard-cut if the current slide was one of them.
			let removedCurrent = false;
			for (const id of before) {
				if (!seen.has(id) && queue.remove(id, current?.id ?? null).wasCurrent) {
					removedCurrent = true;
				}
			}
			if (removedCurrent) advance(true);
		}
		if (!current) advance();
	}

	// Live catch-up after `upload-processed`. Pages from the newest downward, merging onto
	// the live queue (shown soon), and stops at the first page overlapping what we already
	// know — so a burst larger than one 100-item page is fully captured, while a steady
	// trickle costs a single request. We deliberately ignore `new-upload` (fires before
	// compression, so preview_url is still null and the item isn't displayable yet).
	async function catchUpNew() {
		let cursor: string | null = null;
		try {
			for (let page = 0; page < MAX_PAGES; page++) {
				const qs: string = cursor ? `?limit=${FEED_PAGE}&cursor=${cursor}` : `?limit=${FEED_PAGE}`;
				const feed: FeedResponse = await api.get<FeedResponse>(`/feed${qs}`);
				// A known id marks the boundary: everything below it we already have.
				const reachedKnown = feed.uploads.some((u) => queue.has(u.id));
				queue.merge(feed.uploads, { live: true });
				if (!current) advance();
				if (feed.next_cursor == null || reachedKnown) break;
				cursor = feed.next_cursor;
			}
		} catch {
			// transient — the max-wait debounce re-fires and the periodic reconcile backstops
		}
	}

	// Debounce `upload-processed` into a single catch-up, BUT with a max-wait: a sustained
	// burst (every guest uploading at once) would otherwise keep resetting a plain trailing
	// debounce and never fire. The max-wait forces a catch-up at least every 2s mid-burst.
	let processedDebounce: ReturnType<typeof setTimeout> | null = null;
	let processedMaxWait: ReturnType<typeof setTimeout> | null = null;
	function fireCatchUp() {
		if (processedDebounce) {
			clearTimeout(processedDebounce);
			processedDebounce = null;
		}
		if (processedMaxWait) {
			clearTimeout(processedMaxWait);
			processedMaxWait = null;
		}
		void catchUpNew();
	}
	function handleUploadProcessed(data: string) {
		try {
			const { upload_id } = JSON.parse(data) as { upload_id: string };
			if (!upload_id) return;
		} catch {
			return;
		}
		if (processedDebounce) clearTimeout(processedDebounce);
		processedDebounce = setTimeout(fireCatchUp, 500);
		if (!processedMaxWait) processedMaxWait = setTimeout(fireCatchUp, 2000);
	}

	function handleUploadDeleted(data: string) {
		try {
			const { upload_id } = JSON.parse(data) as { upload_id: string };
			// Hard-cut: a just-deleted photo must not linger through the exit transition.
			if (queue.remove(upload_id, current?.id ?? null).wasCurrent) advance(true);
		} catch {
			// ignore
		}
	}

	function handleUserHidden(data: string) {
		try {
			const { user_id } = JSON.parse(data) as { user_id: string };
			if (queue.removeByUser(user_id, current?.id ?? null).wasCurrent) advance(true);
		} catch {
			// ignore
		}
	}

	// Reconnect after an SSE drop: the client fans out a delta of everything since the last
	// seen timestamp. Apply removals first (hard-cut off the current slide if affected),
	// then merge additions; a truncated delta means the gap overflowed the cap, so fall back
	// to a full catch-up scan.
	function handleFeedDelta(data: string) {
		try {
			const delta = JSON.parse(data) as DeltaResponse;
			let removedCurrent = false;
			for (const id of delta.deleted_ids) {
				if (queue.remove(id, current?.id ?? null).wasCurrent) removedCurrent = true;
			}
			for (const userId of delta.hidden_user_ids) {
				if (queue.removeByUser(userId, current?.id ?? null).wasCurrent) removedCurrent = true;
			}
			if (removedCurrent) advance(true); // one advance regardless of how many were removed
			if (delta.truncated) {
				void catchUpNew();
				return;
			}
			queue.merge(delta.uploads, { live: true });
			if (!current) advance();
		} catch {
			// ignore — non-fatal; the periodic reconcile backstops anything dropped here
		}
	}

	// Reveal the control cluster on any pointer/keyboard activity and re-arm the idle timer.
	// Controls stay up while the settings panel is open so it can't vanish mid-interaction.
	function showControls() {
		controlsVisible = true;
		if (controlsHideTimer) clearTimeout(controlsHideTimer);
		controlsHideTimer = setTimeout(() => {
			if (!showOverlay) controlsVisible = false;
		}, 3000);
	}

	// Manual toggle from the control button — stays open (no auto-hide) so keyboard users
	// can tab through the settings without them vanishing mid-interaction.
	function toggleOverlay() {
		showOverlay = !showOverlay;
		showControls();
	}

	async function toggleFullscreen() {
		try {
			if (document.fullscreenElement) {
				await document.exitFullscreen();
			} else {
				await (rootEl ?? document.documentElement).requestFullscreen();
			}
		} catch {
			// Fullscreen can be refused (missing user gesture, unsupported) — non-fatal.
		}
	}

	function handleFullscreenChange() {
		isFullscreen = document.fullscreenElement !== null;
	}

	function togglePause() {
		paused = !paused;
		if (paused) {
			clearTimer();
		} else {
			scheduleNext();
		}
	}

	function exit() {
		void goto('/feed');
	}

	function handleKeydown(e: KeyboardEvent) {
		showControls();
		if (e.key === 'Escape') {
			// In fullscreen the browser exits on Escape — don't ALSO navigate away.
			if (isFullscreen) return;
			if (showOverlay) {
				showOverlay = false;
			} else {
				exit();
			}
		}
		if (e.key === ' ') {
			e.preventDefault();
			togglePause();
		}
		if (e.key === 'f' || e.key === 'F') {
			e.preventDefault();
			void toggleFullscreen();
		}
	}

	onMount(() => {
		// Auth guard — mirror the other protected routes. Without this an
		// unauthenticated visitor lands on a permanently-loading empty slideshow
		// instead of being sent to /join.
		if (!getToken()) {
			goto('/join');
			return;
		}
		showBottomNav.set(false);
		void acquireWakeLock().then((supported) => {
			wakeLockUnsupported = !supported;
		});
		document.addEventListener('fullscreenchange', handleFullscreenChange);
		showControls(); // show briefly on entry, then fade after the idle timeout
		unsubs.push(onSseEvent('upload-processed', handleUploadProcessed));
		unsubs.push(onSseEvent('upload-deleted', handleUploadDeleted));
		unsubs.push(onSseEvent('user-hidden', handleUserHidden));
		// An unban restores that guest's photos to the eligible set. The periodic `reconcile`
		// below would pick this up on its own, but this is the projector nobody is standing at —
		// waiting a whole interval to un-hide photos the host has just decided are fine again is
		// needlessly visible. A full reconcile is the only correct response anyway: the hidden
		// cards were dropped from local state, so there is nothing to restore in place.
		unsubs.push(onSseEvent('user-shown', () => void reconcile()));
		unsubs.push(onSseEvent('feed-delta', handleFeedDelta));
		// Open the stream ourselves — a kiosk/projector loads /diashow directly (never
		// via /feed), so we can't rely on another page having opened the singleton
		// EventSource. Without this the show only ever gets its one-time /feed snapshot
		// and never receives live `upload-processed` events. connectSse() is idempotent
		// (no-ops if the feed page already opened it). Subscriptions are registered above
		// first so no early event is missed.
		connectSse();
		void reconcile(true); // initial full load
		// Completeness backstop: periodically re-sync the whole eligible set, so a dropped
		// SSE event, a rate-limited catch-up, or any missed add/remove self-heals.
		reconcileInterval = setInterval(() => void reconcile(), RECONCILE_INTERVAL_MS);
	});

	onDestroy(() => {
		showBottomNav.set(true);
		clearTimer();
		if (controlsHideTimer) clearTimeout(controlsHideTimer);
		if (processedDebounce) clearTimeout(processedDebounce);
		if (processedMaxWait) clearTimeout(processedMaxWait);
		if (reconcileInterval) clearInterval(reconcileInterval);
		if (dropPrevTimer) clearTimeout(dropPrevTimer);
		document.removeEventListener('fullscreenchange', handleFullscreenChange);
		// Leave fullscreen when exiting the show, so /feed isn't stuck fullscreen.
		if (document.fullscreenElement) void document.exitFullscreen().catch(() => {});
		void releaseWakeLock();
		for (const unsub of unsubs) unsub();
		disconnectSse();
	});
</script>

<svelte:window onkeydown={handleKeydown} />

<div
	bind:this={rootEl}
	class="fixed inset-0 z-[60] flex items-center justify-center bg-black text-white"
	class:cursor-none={!controlsVisible}
	role="presentation"
	onpointermove={showControls}
	onpointerdown={showControls}
>
	{#if layers.length}
		{#each layers as layer (layer.key)}
			<transitionDef.component
				src={layer.src}
				isVideo={layer.isVideo}
				durationMs={transitionDef.defaultDurationMs}
				phase={layer.phase}
				onended={layer.key === current?.id ? handleVideoEnded : undefined}
				{...transitionDef.props ?? {}}
			/>
		{/each}
	{:else if isEmpty()}
		<div class="text-center">
			<p class="text-2xl font-semibold">Noch keine Beiträge</p>
			<p class="mt-2 text-white/60">Neue Beiträge erscheinen hier automatisch.</p>
		</div>
	{:else}
		<div class="text-white/60">Lade…</div>
	{/if}

	<!-- The one thing the operator must know before walking away. This browser cannot hold a
	     screen wake lock at all, so the OS will dim or lock the display on its own schedule and
	     somebody will have to walk over and tap it. Placed bottom-left, out of the controls'
	     corner, and deliberately not auto-hidden with them — it is setup information, and it is
	     only ever shown when it is actionable. -->
	{#if wakeLockUnsupported}
		<div
			class="pointer-events-none absolute bottom-4 left-4 max-w-xs rounded-md bg-black/60 px-3 py-2 text-left text-xs text-white/70 backdrop-blur"
		>
			Dieser Browser kann den Bildschirm nicht wachhalten. Bitte die automatische Bildschirmsperre
			am Gerät deaktivieren.
		</div>
	{/if}

	<!-- Controls appear on pointer/keyboard activity and fade when idle. Still fully
	     keyboard-reachable (any key reveals them), so the show is never a trap. Notch-safe. -->
	<div
		class="absolute right-0 top-0 z-10 flex gap-2 p-3 transition-opacity duration-300"
		class:opacity-0={!controlsVisible}
		class:pointer-events-none={!controlsVisible}
		style="padding-top: calc(env(safe-area-inset-top) + 0.75rem)"
	>
		<button
			type="button"
			onclick={(e) => {
				e.stopPropagation();
				toggleOverlay();
			}}
			aria-label="Steuerung anzeigen"
			aria-expanded={showOverlay}
			class="inline-flex h-11 w-11 items-center justify-center rounded-full bg-white/10 text-white hover:bg-white/20"
		>
			<svg class="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="1.8">
				<path
					stroke-linecap="round"
					stroke-linejoin="round"
					d="M10.5 6h9.75M10.5 6a1.5 1.5 0 1 1-3 0m3 0a1.5 1.5 0 1 0-3 0M3.75 6H7.5m3 12h9.75m-9.75 0a1.5 1.5 0 0 1-3 0m3 0a1.5 1.5 0 0 0-3 0m-3.75 0H7.5m9-6h3.75m-3.75 0a1.5 1.5 0 0 1-3 0m3 0a1.5 1.5 0 0 0-3 0m-9.75 0h9.75"
				/>
			</svg>
		</button>
		<button
			type="button"
			onclick={(e) => {
				e.stopPropagation();
				void toggleFullscreen();
			}}
			aria-label={isFullscreen ? 'Vollbild beenden' : 'Vollbild'}
			aria-pressed={isFullscreen}
			class="inline-flex h-11 w-11 items-center justify-center rounded-full bg-white/10 text-white hover:bg-white/20"
		>
			{#if isFullscreen}
				<!-- arrows pointing in -->
				<svg
					class="h-5 w-5"
					fill="none"
					viewBox="0 0 24 24"
					stroke="currentColor"
					stroke-width="1.8"
				>
					<path
						stroke-linecap="round"
						stroke-linejoin="round"
						d="M9 9V4.5M9 9H4.5M9 9 3.75 3.75M9 15v4.5M9 15H4.5M9 15l-5.25 5.25M15 9h4.5M15 9V4.5M15 9l5.25-5.25M15 15h4.5M15 15v4.5m0-4.5 5.25 5.25"
					/>
				</svg>
			{:else}
				<!-- arrows pointing out -->
				<svg
					class="h-5 w-5"
					fill="none"
					viewBox="0 0 24 24"
					stroke="currentColor"
					stroke-width="1.8"
				>
					<path
						stroke-linecap="round"
						stroke-linejoin="round"
						d="M3.75 3.75v4.5m0-4.5h4.5m-4.5 0L9 9M3.75 20.25v-4.5m0 4.5h4.5m-4.5 0L9 15M20.25 3.75h-4.5m4.5 0v4.5m0-4.5L15 9m5.25 11.25h-4.5m4.5 0v-4.5m0 4.5L15 15"
					/>
				</svg>
			{/if}
		</button>
		<button
			type="button"
			onclick={(e) => {
				e.stopPropagation();
				exit();
			}}
			aria-label="Diashow beenden"
			class="inline-flex h-11 w-11 items-center justify-center rounded-full bg-white/10 text-white hover:bg-white/20"
		>
			<svg class="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="2">
				<path stroke-linecap="round" stroke-linejoin="round" d="M6 18 18 6M6 6l12 12" />
			</svg>
		</button>
	</div>

	{#if showOverlay}
		<div
			class="absolute inset-x-0 bottom-0 flex flex-col gap-3 bg-gradient-to-t from-black/90 via-black/60 to-transparent p-6 pb-10"
		>
			<div class="flex flex-wrap items-center gap-2">
				<button
					type="button"
					onclick={togglePause}
					class="inline-flex items-center gap-1.5 rounded-full bg-white/10 px-4 py-2 text-sm font-medium hover:bg-white/20"
				>
					{#if paused}
						<svg class="h-4 w-4" fill="currentColor" viewBox="0 0 24 24"
							><path d="M8 5v14l11-7z" /></svg
						>
						Fortsetzen
					{:else}
						<svg class="h-4 w-4" fill="currentColor" viewBox="0 0 24 24"
							><path d="M6 5h4v14H6zM14 5h4v14h-4z" /></svg
						>
						Pause
					{/if}
				</button>

				<label class="flex items-center gap-2 rounded-full bg-white/10 px-3 py-2 text-sm">
					Dauer
					<select
						bind:value={dwellMs}
						onchange={scheduleNext}
						class="bg-transparent text-sm font-medium focus:outline-none"
					>
						{#each DWELL_OPTIONS as ms (ms)}
							<option value={ms} class="bg-black">{ms / 1000} s</option>
						{/each}
					</select>
				</label>

				<label class="flex items-center gap-2 rounded-full bg-white/10 px-3 py-2 text-sm">
					Übergang
					<select
						bind:value={transitionId}
						class="bg-transparent text-sm font-medium focus:outline-none"
					>
						{#each transitions as t (t.id)}
							<option value={t.id} class="bg-black">{t.label}</option>
						{/each}
					</select>
				</label>

				<button
					type="button"
					onclick={exit}
					class="ml-auto inline-flex items-center gap-1.5 rounded-full bg-white/10 px-4 py-2 text-sm font-medium hover:bg-white/20"
				>
					<svg
						class="h-4 w-4"
						fill="none"
						viewBox="0 0 24 24"
						stroke="currentColor"
						stroke-width="2"
						><path stroke-linecap="round" stroke-linejoin="round" d="M6 18 18 6M6 6l12 12" /></svg
					>
					Beenden
				</button>
			</div>

			{#if current}
				<p class="text-xs text-white/70">
					{current.uploader_name}
					{#if current.caption}· {current.caption}{/if}
				</p>
			{/if}
		</div>
	{/if}
</div>