cleanup unused cached images

backend/src/managers/image/image.module.ts

@@ -1,6 +1,11 @@
-import { Module } from '@nestjs/common';
+import { Logger, Module, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
+import ms from 'ms';
+import { SysPreference } from 'picsur-shared/dist/dto/sys-preferences.dto';
+import { HasFailed } from 'picsur-shared/dist/types';
 import { ImageDBModule } from '../../collections/image-db/image-db.module';
+import { ImageFileDBService } from '../../collections/image-db/image-file-db.service';
 import { PreferenceModule } from '../../collections/preference-db/preference-db.module';
+import { SysPreferenceService } from '../../collections/preference-db/sys-preference-db.service';
 import { ImageConverterService } from './image-converter.service';
 import { ImageProcessorService } from './image-processor.service';
 import { ImageManagerService } from './image.service';
@@ -14,4 +19,48 @@ import { ImageManagerService } from './image.service';
   ],
   exports: [ImageManagerService],
 })
-export class ImageManagerModule {}
+export class ImageManagerModule implements OnModuleInit, OnModuleDestroy {
+  private readonly logger = new Logger('ImageManagerModule');
+  private interval: NodeJS.Timeout;
+
+  constructor(
+    private prefManager: SysPreferenceService,
+    private imageFileDB: ImageFileDBService,
+  ) {}
+
+  async onModuleInit() {
+    this.interval = setInterval(
+      // Run demoManagerService.execute() every interval
+      this.imageManagerCron.bind(this),
+      1000 * 60 * 60,
+    );
+    await this.imageManagerCron();
+  }
+
+  private async imageManagerCron() {
+    const remove_derivatives_after = await this.prefManager.getStringPreference(
+      SysPreference.RemoveDerivativesAfter,
+    );
+    if (HasFailed(remove_derivatives_after)) {
+      this.logger.warn('Failed to get remove_derivatives_after preference');
+      return;
+    }
+
+    const after_ms = ms(remove_derivatives_after);
+    if (after_ms === 0) {
+      this.logger.log('remove_derivatives_after is 0, skipping cron');
+      return;
+    }
+
+    const result = await this.imageFileDB.cleanupDerivatives(after_ms / 1000);
+    if (HasFailed(result)) {
+      this.logger.warn(`Failed to cleanup derivatives`);
+    }
+
+    this.logger.log(`Cleaned up ${result} derivatives`);
+  }
+
+  onModuleDestroy() {
+    if (this.interval) clearInterval(this.interval);
+  }
+}