Allow camera engines to signal events to the card.

src/camera-manager/camera.ts

@@ -1,22 +1,81 @@
+import { HomeAssistant } from '@dermotduffy/custom-card-helpers';
 import { CameraConfig } from '../config/types';
 import { localize } from '../localize/localize';
+import { allPromises } from '../utils/basic';
+import {
+  isTriggeredState,
+  parseStateChangeTrigger,
+  subscribeToTrigger,
+} from '../utils/ha';
+import { EntityRegistryManager } from '../utils/ha/entity-registry';
 import { CameraManagerEngine } from './engine';
 import { CameraNoIDError } from './error';
-import { CameraManagerCameraCapabilities } from './types';
+import { CameraEventCallback, CameraManagerCameraCapabilities } from './types';
+
+type DestroyCallback = () => Promise<void>;
 
 export class Camera {
   protected _config: CameraConfig;
   protected _engine: CameraManagerEngine;
-  protected _capabilities: CameraManagerCameraCapabilities;
+  protected _capabilities?: CameraManagerCameraCapabilities;
+  protected _eventCallback?: CameraEventCallback;
+  protected _destroyCallbacks: DestroyCallback[] = [];
 
   constructor(
     config: CameraConfig,
     engine: CameraManagerEngine,
-    capabilities: CameraManagerCameraCapabilities,
+    options?: {
+      capabilities?: CameraManagerCameraCapabilities;
+      eventCallback?: CameraEventCallback;
+    },
   ) {
     this._config = config;
     this._engine = engine;
-    this._capabilities = capabilities;
+    this._capabilities = options?.capabilities;
+    this._eventCallback = options?.eventCallback;
+  }
+
+  protected async _convertStateChangeToCameraEvent(data: unknown): Promise<void> {
+    const stateChange = parseStateChangeTrigger(data);
+    if (!stateChange) {
+      return;
+    }
+
+    this._eventCallback?.({
+      cameraID: this.getID(),
+      type: isTriggeredState(stateChange.to_state.state) ? 'new' : 'end',
+    });
+  }
+
+  protected async _subscribeToTriggerEntities(hass: HomeAssistant): Promise<void> {
+    if (!this._config.triggers.entities.length) {
+      return;
+    }
+
+    this._destroyCallbacks.push(
+      await subscribeToTrigger(
+        hass,
+        (data) => this._convertStateChangeToCameraEvent(data),
+        {
+          entityID: this._config.triggers.entities,
+          platform: 'state',
+          stateOnly: true,
+        },
+      ),
+    );
+  }
+
+  async initialize(
+    hass: HomeAssistant,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    _entityRegistryManager: EntityRegistryManager,
+  ): Promise<Camera> {
+    await this._subscribeToTriggerEntities(hass);
+    return this;
+  }
+
+  async destroy(): Promise<void> {
+    await allPromises(this._destroyCallbacks, (cb) => cb());
   }
 
   public getConfig(): CameraConfig {
@@ -38,7 +97,7 @@ export class Camera {
     return this._engine;
   }
 
-  public getCapabilities(): CameraManagerCameraCapabilities {
-    return this._capabilities;
+  public getCapabilities(): CameraManagerCameraCapabilities | null {
+    return this._capabilities ?? null;
   }
 }