sync.ts

Blame: the commit that last changed each line · file · history

`4e701dc7` 2026-03-16 Pavel Safronov	1	import { ref, onValue } from 'firebase/database';
`b4e7f682` 2026-03-16 Pavel Safronov	2	import type { Database } from 'firebase/database';
`f32f5e95` 2026-03-16 Pavel Safronov	3	import { decryptJson } from '../../core/crypto';
`92f24c4e` 2026-03-16 Pavel Safronov	4
`e790982a` 2026-03-16 Pavel Safronov	5	type FriendRecord = {
`92f24c4e` 2026-03-16 Pavel Safronov	6	id?: string;
`b4e7f682` 2026-03-16 Pavel Safronov	7	name?: string;
	8	color?: string;
	9	position?: { lat: number; lon: number };
	10	timestamp?: number;
	11	lastSeen?: number;
`92f24c4e` 2026-03-16 Pavel Safronov	12	encryptedState?: string;
	13	encryptedPosition?: string;
	14	[key: string]: unknown;
	15	};
`36d64b37` 2026-03-15 Pavel Safronov	16
	17	/**
`e790982a` 2026-03-16 Pavel Safronov	18	* Subscribes to the friends node for a room, decrypting each record
	19	* as needed. Calls onUpdate(friends) after every snapshot resolves.
`36d64b37` 2026-03-15 Pavel Safronov	20	*
	21	* @param {object} opts
	22	* @param {object} opts.db - Firebase Database instance
	23	* @param {string} opts.roomId
	24	* @param {CryptoKey\|null} opts.roomKey - AES-GCM key, or null for unencrypted rooms
`e790982a` 2026-03-16 Pavel Safronov	25	* @param {function} opts.onUpdate - (friends: object[]) => void
	26	* @returns {{ friends: object[] }} Shared array reference, mutated in place on each update
`36d64b37` 2026-03-15 Pavel Safronov	27	*/
`b4e7f682` 2026-03-16 Pavel Safronov	28	export function subscribeToFriends({
	29	db,
	30	roomId,
	31	roomKey,
	32	onUpdate
	33	}: {
	34	db: Database;
	35	roomId: string;
	36	roomKey: CryptoKey \| null;
	37	onUpdate: (friends: FriendRecord[]) => void;
	38	}) {
`e790982a` 2026-03-16 Pavel Safronov	39	const friendsRef = ref(db, `rooms/${roomId}/friends`);
`b4e7f682` 2026-03-16 Pavel Safronov	40	const friends: FriendRecord[] = [];
`36d64b37` 2026-03-15 Pavel Safronov	41	let snapshotVersion = 0;
	42
`e790982a` 2026-03-16 Pavel Safronov	43	onValue(friendsRef, async (snapshot) => {
`36d64b37` 2026-03-15 Pavel Safronov	44	const version = ++snapshotVersion;
	45
`e790982a` 2026-03-16 Pavel Safronov	46	const friendsData = snapshot.val();
	47	if (friendsData) {
	48	const rawFriends = Object.values(friendsData as Record<string, FriendRecord>);
`b4e7f682` 2026-03-16 Pavel Safronov	49	const decrypted = await Promise.all(rawFriends.map(async (p): Promise<FriendRecord \| null> => {
`36d64b37` 2026-03-15 Pavel Safronov	50	if (p.encryptedState && roomKey) {
	51	try {
`b4e7f682` 2026-03-16 Pavel Safronov	52	const decryptedState = await decryptJson(roomKey, p.encryptedState) as Record<string, unknown>;
`cf7471ca` 2026-03-16 Pavel Safronov	53	return { ...decryptedState, lastSeen: p.lastSeen };
`36d64b37` 2026-03-15 Pavel Safronov	54	} catch (err) {
`e790982a` 2026-03-16 Pavel Safronov	55	console.error('Failed to decrypt friend state', p.id, err);
`36d64b37` 2026-03-15 Pavel Safronov	56	return null;
	57	}
	58	}
	59	if (p.encryptedPosition && roomKey) {
	60	try {
`b4e7f682` 2026-03-16 Pavel Safronov	61	const position = await decryptJson(roomKey, p.encryptedPosition) as { lat: number; lon: number };
`36d64b37` 2026-03-15 Pavel Safronov	62	const { encryptedPosition: _stripped, ...rest } = p;
	63	return { ...rest, position };
	64	} catch (err) {
`e790982a` 2026-03-16 Pavel Safronov	65	console.error('Failed to decrypt legacy friend position', p.id, err);
`36d64b37` 2026-03-15 Pavel Safronov	66	return null;
	67	}
	68	}
	69	return p;
	70	}));
	71	if (version !== snapshotVersion) return;
`e790982a` 2026-03-16 Pavel Safronov	72	friends.length = 0;
`b4e7f682` 2026-03-16 Pavel Safronov	73	friends.push(...decrypted.filter((item): item is FriendRecord => item !== null));
`36d64b37` 2026-03-15 Pavel Safronov	74	} else {
	75	if (version !== snapshotVersion) return;
`e790982a` 2026-03-16 Pavel Safronov	76	friends.length = 0;
`36d64b37` 2026-03-15 Pavel Safronov	77	}
	78
`e790982a` 2026-03-16 Pavel Safronov	79	onUpdate(friends);
`36d64b37` 2026-03-15 Pavel Safronov	80	});
	81
`e790982a` 2026-03-16 Pavel Safronov	82	return { friends };
`36d64b37` 2026-03-15 Pavel Safronov	83	}