From 586d9fe601cc58577e3bab39f5c05c5235b018fc Mon Sep 17 00:00:00 2001
From: WardPearce <wardpearce@pm.me>
Date: Tue, 3 Mar 2026 23:27:41 +1300
Subject: [PATCH] More watch progress

---
 .../src/lib/components/WatchParty.svelte      | 139 ++++++++++--------
 materialious/src/lib/i18n/locales/en.json     |   5 +-
 2 files changed, 82 insertions(+), 62 deletions(-)

diff --git a/materialious/src/lib/components/WatchParty.svelte b/materialious/src/lib/components/WatchParty.svelte
index 5728511a..7650ab93 100644
--- a/materialious/src/lib/components/WatchParty.svelte
+++ b/materialious/src/lib/components/WatchParty.svelte
@@ -1,27 +1,36 @@
 <script lang="ts">
+	import { goto, pushState } from '$app/navigation';
+	import { page } from '$app/state';
 	import { _ } from '$lib/i18n';
 	import { playerState } from '$lib/store';
 	import sodium from 'libsodium-wrappers-sumo';
-	import { joinRoom, type ActionReceiver, type DataPayload, type Room } from 'trystero';
+	import { onDestroy, onMount } from 'svelte';
+	import { SvelteURLSearchParams } from 'svelte/reactivity';
+	import { joinRoom, type ActionReceiver, type DataPayload, type Room } from 'trystero/mqtt';
 	import z from 'zod';
 
 	const zWatchPartyEvent = z.object({
 		event: z.union([z.literal('pause'), z.literal('play'), z.literal('seek')]),
 		videoId: z.regex(/^[a-zA-Z0-9_-]{11}$/),
 		sent: z.date(),
-		currentTime: z.number()
+		currentTime: z.number().min(0)
 	});
 
 	type WatchPartyEvent = z.infer<typeof zWatchPartyEvent>;
 
 	let room: Room | undefined = $state();
+	let roomId: string | undefined = $state();
 
 	const appId = 'materialious_';
 
 	type SendEvent = (message: WatchPartyEvent) => void;
 
 	// If room not in use message just get sent nowhere.
-	let sendEvent: SendEvent = (message: WatchPartyEvent) => {};
+	let sendEvent: SendEvent = () => {};
+
+	onMount(() => initalRoom());
+
+	onDestroy(() => room?.leave());
 
 	function actionReceiver(receiver: ActionReceiver<DataPayload>) {
 		receiver((data) => {
@@ -33,27 +42,34 @@
 
 			const playerElement = player.playerElement;
 
+			const currentTime = playerElement.currentTime;
+			const sentTime = dataParsed.data.sent.getTime();
+			const timeDifference = Math.abs(currentTime - sentTime);
+
+			if (timeDifference > 5000) return;
+
+			const currentTimeWithDifference = Math.max(
+				0,
+				Math.min(dataParsed.data.currentTime + timeDifference, playerElement.duration)
+			);
+
 			switch (dataParsed.data.event) {
 				case 'play':
 					playerElement.play();
+					playerElement.currentTime = currentTimeWithDifference;
 					break;
 				case 'pause':
 					playerElement.pause();
+					playerElement.currentTime = currentTimeWithDifference;
 					break;
 				case 'seek':
-					playerElement.currentTime = dataParsed.data.currentTime;
+					playerElement.currentTime = currentTimeWithDifference;
 					break;
 			}
 		});
 	}
 
-	async function createRoom() {
-		await sodium.ready;
-
-		const roomId = sodium.to_base64(sodium.randombytes_buf(24));
-
-		room = joinRoom({ appId }, roomId);
-
+	function setupRoom(room: Room) {
 		const [sendAction, getAction] = room.makeAction('watchParty');
 
 		sendEvent = sendAction as unknown as SendEvent;
@@ -61,81 +77,82 @@
 		actionReceiver(getAction);
 	}
 
+	async function createRoom() {
+		await sodium.ready;
+
+		roomId = sodium.to_base64(sodium.randombytes_buf(24));
+		room = joinRoom({ appId }, roomId);
+
+		setupRoom(room);
+
+		const currentSearchParams = new SvelteURLSearchParams(window.location.search);
+
+		currentSearchParams.set('room', roomId);
+
+		pushState(`?${currentSearchParams.toString()}`, { replaceState: false }); // eslint-disable-line svelte/no-navigation-without-resolve
+	}
+
+	function initalRoom() {
+		const givenRoomId = page.url.searchParams.get('room');
+
+		if (!givenRoomId) return;
+
+		room = joinRoom({ appId }, givenRoomId);
+
+		setupRoom(room);
+	}
+
 	playerState.subscribe((player) => {
 		if (!player?.playerElement) return;
 
 		const playerElement = player.playerElement;
 
-		playerElement.addEventListener('play', () => {
-			if (!room) return;
+		function sendPlayerEvent(event: 'play' | 'pause' | 'seek') {
+			if (!room || !player) return;
 
 			sendEvent({
-				event: 'play',
+				event,
 				videoId: player.data.video.videoId,
 				sent: new Date(),
 				currentTime: playerElement.currentTime
 			});
-		});
+		}
 
+		let initalPlaying = true;
+
+		playerElement.addEventListener('play', () => sendPlayerEvent('play'));
 		playerElement.addEventListener('playing', () => {
-			if (!room) return;
+			if (!initalPlaying) return;
+			initalPlaying = true;
 
-			sendEvent({
-				event: 'play',
-				videoId: player.data.video.videoId,
-				sent: new Date(),
-				currentTime: playerElement.currentTime
-			});
-		});
-
-		playerElement.addEventListener('seeked', () => {
-			sendEvent({
-				event: 'seek',
-				videoId: player.data.video.videoId,
-				sent: new Date(),
-				currentTime: playerElement.currentTime
-			});
-		});
-
-		playerElement.addEventListener('pause', () => {
-			sendEvent({
-				event: 'pause',
-				videoId: player.data.video.videoId,
-				sent: new Date(),
-				currentTime: playerElement.currentTime
-			});
-		});
-
-		playerElement.addEventListener('waiting', () => {
-			sendEvent({
-				event: 'pause',
-				videoId: player.data.video.videoId,
-				sent: new Date(),
-				currentTime: playerElement.currentTime
-			});
-		});
-
-		playerElement.addEventListener('error', () => {
-			sendEvent({
-				event: 'pause',
-				videoId: player.data.video.videoId,
-				sent: new Date(),
-				currentTime: playerElement.currentTime
-			});
+			sendPlayerEvent('play');
 		});
+		playerElement.addEventListener('seeked', () => sendPlayerEvent('seek'));
+		playerElement.addEventListener('pause', () => sendPlayerEvent('pause'));
+		playerElement.addEventListener('waiting', () => sendPlayerEvent('pause'));
+		playerElement.addEventListener('error', () => sendPlayerEvent('pause'));
 	});
 </script>
 
 <article>
 	<h4>{$_('watchParty.header')}</h4>
-	<div class="space"></div>
 
 	{#if !room}
+		<div class="space"></div>
+
 		<button onclick={createRoom} class="surface-container-highest">
 			<span>{$_('watchParty.createRoom')}</span>
 		</button>
-		<button class="surface-container-high">
-			<span>{$_('watchParty.joinRoom')}</span>
+	{:else}
+		<div class="space"></div>
+		<button
+			onclick={() => {
+				room?.leave();
+				room = undefined;
+			}}
+			class="surface-container-highest"
+		>
+			{$_('watchParty.leaveRoom')}
 		</button>
 	{/if}
 </article>
diff --git a/materialious/src/lib/i18n/locales/en.json b/materialious/src/lib/i18n/locales/en.json
index 63002191..689f2675 100644
--- a/materialious/src/lib/i18n/locales/en.json
+++ b/materialious/src/lib/i18n/locales/en.json
@@ -89,7 +89,10 @@
 		"start": "Start a watch party",
 		"header": "Watch party",
 		"createRoom": "Create room",
-		"joinRoom": "Join room"
+		"joinRoom": "Join room",
+		"roomID": "Room ID",
+		"shareRoom": "Share room",
+		"leaveRoom": "Leave room"
 	},
 	"subscriptions": {
 		"manageSubscriptions": "Manage subscriptions"