feat(server): random assets API (#4184)

* feat(server): get random assets API

* Fix tests

* Use correct validation annotation

* Fix offset use in query

* Update API specs

* Fix typo

* Random assets e2e tests

* Improve e2e tests

server/src/infra/repositories/asset.repository.ts

@@ -429,6 +429,17 @@ export class AssetRepository implements IAssetRepository {
     return result;
   }
 
+  getRandom(ownerId: string, count: number): Promise<AssetEntity[]> {
+    // can't use queryBuilder because of custom OFFSET clause
+    return this.repository.query(
+      `SELECT *
+       FROM assets
+       WHERE "ownerId" = $1
+       OFFSET FLOOR(RANDOM() * (SELECT GREATEST(COUNT(*) - 1, 0) FROM ASSETS)) LIMIT $2`,
+      [ownerId, count],
+    );
+  }
+
   getTimeBuckets(options: TimeBucketOptions): Promise<TimeBucketItem[]> {
     const truncateValue = truncateMap[options.size];