router/album.js

@@ -51,6 +51,12 @@ router.route("/filter/:term")
       res.json(result).status(200).end();
     });
   })
+router.route("/random/:count")
+  .get(passport.authenticate("jwt", { session: false }), (req, res) => {
+    database.albums.randomCovers(req.params.count, 64, (result) => {
+      res.json(result).status(200).end();
+    });
+  })
 
 router.route("/:id")
   .get(checkGuest, (req, res) => {

services/database/albums.js

@@ -310,4 +310,27 @@ exports.empty = function (callback) {
     .toArray((err, result) => {
       callback(result.filter(f => !f.tracks || f.tracks.length == 0));
     });
-};
+};
+
+exports.randomCovers = function (count, size, callback) {
+  dbo
+    .collection("albums")
+    .find({ "covers.cover64": { $exists: true } })
+    .project({ "covers.cover64": true })
+    .toArray((err, result) => {
+      if (result.length > count) {
+        let res = [];
+        while (count-- > 0) {
+          let rnd = randomNumber(0, result.length);
+          res.push(result[rnd]);
+        }
+        callback(res);
+      } else {
+        callback(result);
+      }
+    })
+}
+
+function randomNumber(min, max) {
+  return Math.floor(Math.random() * (max - min) + min);
+}