feat(core): bettery save mode (#12996)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
* Introduced a battery save mode that can pause background sync and
processing to conserve energy.
* Battery save mode is automatically enabled when the app window loses
focus and disabled when the window regains focus or is interacted with.
  * Available in both web and desktop (Electron) versions.

* **Improvements**
* Added user activity detection to optimize background operations for
better battery efficiency.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/common/nbstore/src/sync/indexer/index.ts

@@ -159,6 +159,14 @@ export class IndexerSyncImpl implements IndexerSync {
     this.remote = Object.values(this.peers.remotes).find(remote => !!remote);
   }
 
+  enableBatterySaveMode() {
+    this.status.enableBatterySaveMode();
+  }
+
+  disableBatterySaveMode() {
+    this.status.disableBatterySaveMode();
+  }
+
   start() {
     if (this.abort) {
       this.abort.abort(MANUALLY_STOP);
@@ -611,6 +619,10 @@ class IndexerSyncStatus {
   currentJob: string | null = null;
   errorMessage: string | null = null;
   statusUpdatedSubject$ = new Subject<string | true>();
+  batterySaveMode: {
+    promise: Promise<void>;
+    resolve: () => void;
+  } | null = null;
 
   state$ = new Observable<IndexerSyncState>(subscribe => {
     const next = () => {
@@ -685,6 +697,9 @@ class IndexerSyncStatus {
   }
 
   async acceptJob(abort?: AbortSignal) {
+    if (this.batterySaveMode) {
+      await this.batterySaveMode.promise;
+    }
     const job = await this.jobs.asyncPop(abort);
     this.currentJob = job;
     this.statusUpdatedSubject$.next(job);
@@ -709,6 +724,18 @@ class IndexerSyncStatus {
     };
   }
 
+  enableBatterySaveMode() {
+    if (this.batterySaveMode) {
+      return;
+    }
+    this.batterySaveMode = Promise.withResolvers();
+  }
+
+  disableBatterySaveMode() {
+    this.batterySaveMode?.resolve();
+    this.batterySaveMode = null;
+  }
+
   reset() {
     // reset all state, except prioritySettings
     this.isReadonly = false;

packages/common/nbstore/src/worker/client.ts

@@ -86,6 +86,21 @@ export class StoreManagerClient {
       connection.dispose();
     });
   }
+
+  enableBatterySaveMode() {
+    this.connections.forEach(connection => {
+      connection.store.enableBatterySaveMode().catch(err => {
+        console.error('error enabling battery save mode', err);
+      });
+    });
+  }
+  disableBatterySaveMode() {
+    this.connections.forEach(connection => {
+      connection.store.disableBatterySaveMode().catch(err => {
+        console.error('error disabling battery save mode', err);
+      });
+    });
+  }
 }
 
 export class StoreClient {
@@ -113,6 +128,13 @@ export class StoreClient {
   readonly blobFrontend: BlobFrontend;
   readonly awarenessFrontend: AwarenessFrontend;
   readonly indexerFrontend: IndexerFrontend;
+
+  enableBatterySaveMode(): Promise<void> {
+    return this.client.call('sync.enableBatterySaveMode');
+  }
+  disableBatterySaveMode(): Promise<void> {
+    return this.client.call('sync.disableBatterySaveMode');
+  }
 }
 
 class WorkerDocStorage implements DocStorage {

packages/common/nbstore/src/worker/consumer.ts

@@ -134,6 +134,35 @@ class StoreConsumer {
     }
   }
 
+  private readonly ENABLE_BATTERY_SAVE_MODE_DELAY = 1000;
+  private enableBatterySaveModeTimeout: NodeJS.Timeout | null = null;
+  private enabledBatterySaveMode = false;
+
+  enableBatterySaveMode() {
+    if (this.enableBatterySaveModeTimeout || this.enabledBatterySaveMode) {
+      return;
+    }
+    this.enableBatterySaveModeTimeout = setTimeout(() => {
+      if (!this.enabledBatterySaveMode) {
+        this.indexerSync.enableBatterySaveMode();
+        this.enabledBatterySaveMode = true;
+        console.log('[BatterySaveMode] enabled');
+      }
+    }, this.ENABLE_BATTERY_SAVE_MODE_DELAY);
+  }
+
+  disableBatterySaveMode() {
+    if (this.enableBatterySaveModeTimeout) {
+      clearTimeout(this.enableBatterySaveModeTimeout);
+      this.enableBatterySaveModeTimeout = null;
+    }
+    if (this.enabledBatterySaveMode) {
+      this.indexerSync.disableBatterySaveMode();
+      this.enabledBatterySaveMode = false;
+      console.log('[BatterySaveMode] disabled');
+    }
+  }
+
   private registerHandlers(consumer: OpConsumer<WorkerOps>) {
     const collectJobs = new Map<
       string,
@@ -285,6 +314,8 @@ class StoreConsumer {
         this.indexerSync.search$(table, query, options),
       'indexerSync.subscribeAggregate': ({ table, query, field, options }) =>
         this.indexerSync.aggregate$(table, query, field, options),
+      'sync.enableBatterySaveMode': () => this.enableBatterySaveMode(),
+      'sync.disableBatterySaveMode': () => this.disableBatterySaveMode(),
     });
   }
 }

packages/common/nbstore/src/worker/ops.ts

@@ -140,6 +140,10 @@ interface GroupedWorkerOps {
       AggregateResult<any, any>,
     ];
   };
+  sync: {
+    enableBatterySaveMode: [void, void];
+    disableBatterySaveMode: [void, void];
+  };
 }
 
 type Values<T> = T extends { [k in keyof T]: any } ? T[keyof T] : never;