Files
advanced-camera-card/src/camera-manager/frigate/event-watcher.ts
T
2026-02-07 20:32:05 -08:00

82 lines
2.7 KiB
TypeScript

import { HomeAssistant } from '../../ha/types';
import { FrigateEventChange, frigateEventChangeSchema } from './types';
export interface FrigateEventWatcherRequest {
instanceID: string;
matcher?(event: FrigateEventChange): boolean;
callback(event: FrigateEventChange): void;
}
export interface FrigateEventWatcherSubscriptionInterface {
subscribe(hass: HomeAssistant, request: FrigateEventWatcherRequest): Promise<void>;
unsubscribe(callback: FrigateEventWatcherRequest): void;
}
type SubscriptionUnsubscribe = () => Promise<void>;
export class FrigateEventWatcher implements FrigateEventWatcherSubscriptionInterface {
protected _requests: FrigateEventWatcherRequest[] = [];
protected _unsubscribeCallback: Record<string, SubscriptionUnsubscribe> = {};
public async subscribe(
hass: HomeAssistant,
request: FrigateEventWatcherRequest,
): Promise<void> {
const shouldSubscribe = !this._hasSubscribers(request.instanceID);
this._requests.push(request);
if (shouldSubscribe) {
this._unsubscribeCallback[request.instanceID] =
await hass.connection.subscribeMessage<string>(
(data) => this._receiveHandler(request.instanceID, data),
{ type: 'frigate/events/subscribe', instance_id: request.instanceID },
);
}
}
public async unsubscribe(request: FrigateEventWatcherRequest): Promise<void> {
this._requests = this._requests.filter(
(existingRequest) => existingRequest !== request,
);
if (!this._hasSubscribers(request.instanceID)) {
const callback = this._unsubscribeCallback[request.instanceID];
delete this._unsubscribeCallback[request.instanceID];
// Callback may be undefined if unsubscribe is called while subscribe is
// still awaiting the Home Assistant connection.
await callback?.();
}
}
protected _hasSubscribers(instanceID: string): boolean {
return !!this._requests.filter((request) => request.instanceID === instanceID)
.length;
}
protected _receiveHandler(instanceID: string, data: string): void {
let json: unknown;
try {
json = JSON.parse(data);
// eslint-disable-next-line @typescript-eslint/no-unused-vars
} catch (e) {
console.warn('Received non-JSON payload as Frigate event', data);
return;
}
const parsedEvent = frigateEventChangeSchema.safeParse(json);
if (!parsedEvent.success) {
console.warn('Received malformed Frigate event from Home Assistant', data);
return;
}
for (const request of this._requests) {
if (
request.instanceID === instanceID &&
(!request.matcher || request.matcher(parsedEvent.data))
) {
request.callback(parsedEvent.data);
}
}
}
}