fix: Fix initialization race condition that occurs in certain circumstances (#1545)

* fix: Fix initialization race condition in certain circumstances

* Minor improvements and camera iris logo

src/camera-manager/manager.ts

@@ -111,7 +111,6 @@ export class CameraManager {
   protected _api: CardCameraAPI;
   protected _engineFactory: CameraManagerEngineFactory;
   protected _store: CameraManagerStore;
-  protected _initializationLimit = new PQueue({ concurrency: 1 });
   protected _requestLimit = new PQueue();
 
   constructor(
@@ -147,16 +146,8 @@ export class CameraManager {
       recursivelyMergeObjectsNotArrays({}, cloneDeep(config?.cameras_global), camera),
     );
 
-    const resetAndInitialize = async () => {
-      await this._reset();
-      await this._initializeCameras(cameras);
-    };
-
     try {
-      // This concurrency limit prevents multiple rapidly arriving configs from
-      // generating reset-n-initialize race conditions (e.g. changing values
-      // rapidly in the config editor).
-      await this._initializationLimit.add(resetAndInitialize);
+      await this._initializeCameras(cameras);
     } catch (e: unknown) {
       this._api
         .getMessageManager()
@@ -166,7 +157,7 @@ export class CameraManager {
     return true;
   }
 
-  protected async _reset(): Promise<void> {
+  public async reset(): Promise<void> {
     await this._store.reset();
   }
 
@@ -246,6 +237,8 @@ export class CameraManager {
       async ([cameraConfig, engine]) => await engine.createCamera(hass, cameraConfig),
     );
 
+    const cameraIDs: Set<string> = new Set();
+
     // Do the additions based off the result-order, to ensure the map order is
     // preserved.
     cameras.forEach((camera) => {
@@ -258,7 +251,7 @@ export class CameraManager {
         );
       }
 
-      if (this._store.hasCameraID(cameraID)) {
+      if (cameraIDs.has(cameraID)) {
         throw new CameraInitializationError(
           localize('error.duplicate_camera_id'),
           camera.getConfig(),
@@ -267,9 +260,11 @@ export class CameraManager {
 
       // Always ensure the actual ID used in the card is in the configuration itself.
       camera.setID(cameraID);
-      this._store.addCamera(camera);
+      cameraIDs.add(cameraID);
     });
 
+    await this._store.setCameras(cameras);
+
     log(
       this._api.getConfigManager().getCardWideConfig(),
       'Frigate Card CameraManager initialized (Cameras: ',

src/camera-manager/store.ts

@@ -44,6 +44,30 @@ export class CameraManagerStore implements CameraManagerReadOnlyConfigStore {
     this._enginesByType.set(camera.getEngine().getEngineType(), camera.getEngine());
   }
 
+  public async setCameras(cameras: Camera[]): Promise<void> {
+    // In setting the store cameras, take great care to replace/add first before
+    // remove. Otherwise, there may be race conditions where the card attempts
+    // to render a view with (momentarily) no camera.
+    // See: https://github.com/dermotduffy/frigate-hass-card/issues/1533
+
+    // Replace/Add the new cameras.
+    for (const camera of cameras) {
+      const oldCamera = this._cameras.get(camera.getID());
+      if (oldCamera !== camera) {
+        this.addCamera(camera);
+        await oldCamera?.destroy();
+      }
+    }
+
+    // Remove the old cameras.
+    for (const camera of this._cameras.values()) {
+      if (!cameras.includes(camera)) {
+        await camera.destroy();
+        this._cameras.delete(camera.getID());
+      }
+    }
+  }
+
   public async reset(): Promise<void> {
     await allPromises(this._cameras.values(), (camera) => camera.destroy());
     this._cameras.clear();