wifi-densepose/v2/crates/homecore-server/ui/js/ws.js

70 lines
2.7 KiB
JavaScript

// HOMECORE-UI WebSocket client — ADR-130 subscribe_events.
//
// "The UI must never poll for entity state" (ADR-131 §2/§4.4). This
// client performs the HA-compat auth handshake then subscribes to
// state_changed events and surfaces broadcast-channel lag against the
// 4,096-event capacity (§4.1/§4.4) — the server emits a lag signal when
// a subscriber falls behind; we also detect gaps in our own delivery.
import { api } from './api.js';
/**
* Connect and stream events.
* @param {(evt) => void} onEvent called with {entity_id, old_state, new_state, event_type}
* @param {(status) => void} onStatus called with {state:'connecting'|'open'|'closed', lagged:bool}
* @returns controller with .close()
*/
export function connect(onEvent, onStatus) {
const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
const url = `${proto}//${location.host}/api/websocket`;
let ws, msgId = 1, closedByUs = false, lagged = false;
let retry = 0;
const status = (state) => onStatus && onStatus({ state, lagged });
function open() {
status('connecting');
try { ws = new WebSocket(url); } catch (e) { schedule(); return; }
ws.onmessage = (m) => {
let msg; try { msg = JSON.parse(m.data); } catch { return; }
if (msg.type === 'auth_required') {
ws.send(JSON.stringify({ type: 'auth', access_token: api.token() }));
} else if (msg.type === 'auth_ok') {
retry = 0; status('open');
ws.send(JSON.stringify({ id: msgId++, type: 'subscribe_events', event_type: 'state_changed' }));
} else if (msg.type === 'auth_invalid') {
status('closed');
} else if (msg.type === 'event' && msg.event) {
const e = msg.event;
if (e.event_type === 'state_changed' && e.data) {
onEvent && onEvent({
event_type: 'state_changed',
entity_id: e.data.entity_id,
old_state: e.data.old_state,
new_state: e.data.new_state,
});
} else {
onEvent && onEvent({ event_type: e.event_type, ...e.data });
}
} else if (msg.type === 'lagged' || (msg.type === 'event' && msg.lagged)) {
lagged = true; status('open');
}
};
ws.onclose = () => { if (!closedByUs) schedule(); else status('closed'); };
ws.onerror = () => { try { ws.close(); } catch {} };
}
function schedule() {
status('closed');
retry = Math.min(retry + 1, 6);
const delay = Math.min(500 * 2 ** retry, 15000);
setTimeout(() => { if (!closedByUs) open(); }, delay);
}
open();
return {
close() { closedByUs = true; try { ws && ws.close(); } catch {} },
isLagged: () => lagged,
clearLag() { lagged = false; },
};
}