@svelte-lean/query/live

import { live, rule } from '@svelte-lean/query/live';

// src/lib/api/live.ts
import { patch, tag, type } from '@svelte-lean/query';
import { live, rule, type LiveSource } from '@svelte-lean/query/live';
import { getMember } from '$api/members';
import type { Member } from '$api/types';

// An adapter: one EventSource per channel.
const source: LiveSource = {
	subscribe({ channel, event }, deliver, ready) {
		const events = new EventSource(`/events/${channel}`);
		events.addEventListener('open', ready, { once: true });
		events.addEventListener(event, (e) => deliver(JSON.parse((e as MessageEvent).data)));
		return () => events.close();
	}
};

export const realtime = live(source, [
	// Poke, then pull: the observed member lists refetch, coalesced.
	rule('Members', { channel: 'members', event: 'MemberCreated' }),
	// The event carries the row: every cached copy of it is patched, nothing is refetched.
	rule('Members', {
		channel: 'members',
		event: 'MemberUpdated',
		message: type<{ member: Member }>(),
		patch: (m) => patch(tag('Member', m.member.id), () => m.member)
	}),
	// Patch the one detail entry the message names.
	rule(getMember, {
		channel: 'members',
		event: 'MemberPinned',
		message: type<{ id: number; pinned: boolean }>(),
		patch: (m) => patch([getMember, { id: m.id }], (member) => ({ ...member, pinned: m.pinned }))
	})
]);