Started some reducing of callback in different files

server/handlers/dbFunctions/advancedFunctions/changeSong.js

@@ -0,0 +1,195 @@
+var path = require("path");
+var db = require(pathThumbnails + "/handlers/db.js");
+var aggregate = require(pathThumbnails + "/handlers/dbFunctions/aggregate.js");
+var remove = require(pathThumbnails + "/handlers/dbFunctions/remove.js");
+var frontpage = require(pathThumbnails +
+  "/handlers/dbFunctions/frontpageUpdates.js");
+var findAggregate = [
+  {
+    $match: {
+      views: {
+        $exists: false
+      },
+      type: {
+        $ne: "suggested"
+      }
+    }
+  },
+  {
+    $sort: {
+      now_playing: -1,
+      votes: -1,
+      added: 1,
+      title: 1
+    }
+  },
+  {
+    $limit: 2
+  }
+];
+
+var verifyAggregate = [
+  {
+    $match: {
+      now_playing: false,
+      type: {
+        $ne: "suggested"
+      }
+    }
+  },
+  {
+    $sort: {
+      votes: -1,
+      added: 1,
+      title: 1
+    }
+  },
+  {
+    $limit: 2
+  }
+];
+
+async function changeSong(coll, error, id, conf, socket) {
+  return pre(coll, error, id, conf, socket);
+}
+
+async function pre(coll, error, id, conf, socket) {
+  return new Promise((resolve, reject) => {
+    var startTime = conf[0].startTime;
+    if (conf === null || conf.length == 0) {
+      return;
+    }
+
+    var now_playing_doc = await aggregate(coll, findAggregate);
+    if (
+      now_playing_doc.length > 0 &&
+      ((id && id == now_playing_doc[0].id) || !id)
+    ) {
+      if (error) {
+        var docs = await remove(coll, { now_playing: true, id: id });
+        var next_song;
+        if (now_playing_doc.length == 2) {
+          next_song = now_playing_doc[1].id;
+        }
+        await post(coll, next_song, conf, socket, error);
+        /*if (!callback) {
+          io.to(coll).emit("channel", {
+            type: "deleted",
+            value: now_playing_doc[0].id,
+            removed: true
+          });
+        }*/
+        if (docs.deletedCount == 1) {
+          frontpage.incrementList("frontpage_lists", -1);
+        }
+        resolve();
+        return;
+      } else if (conf[0].removeplay === true) {
+        var docs = await remove(coll, { now_playing: true, id: id });
+        var next_song;
+        if (now_playing_doc.length == 2) next_song = now_playing_doc[1].id;
+        await post(coll, next_song, conf, socket, error);
+        if (docs.deletedCount == 1) {
+          frontpage.incrementList("frontpage_lists", -1);
+        }
+        resolve();
+        return;
+      } else {
+        if (
+          (conf[0].skipped_time != undefined &&
+            conf[0].skipped_time != Functions.get_time()) ||
+          conf[0].skipped_time == undefined
+        ) {
+          var docs = await update(
+            coll,
+            { now_playing: true, id: id },
+            {
+              $set: {
+                now_playing: false,
+                votes: 0,
+                guids: []
+              }
+            },
+            { multi: true }
+          );
+          var next_song;
+          if (now_playing_doc.length == 2) next_song = now_playing_doc[1].id;
+          await post(coll, next_song, conf, socket, error);
+
+          resolve();
+          return;
+        }
+      }
+    }
+    if (
+      now_playing_doc.length > 0 &&
+      now_playing_doc[0].now_playing == true &&
+      now_playing_doc.length > 1 &&
+      now_playing_doc[1].id == id
+    ) {
+      var docs = await update(
+        coll,
+        { id: now_playing_doc[0].id },
+        { $set: { now_playing: false } },
+        {}
+      );
+      return await pre(coll, error, id, conf, socket, error);
+    }
+    resolve();
+  });
+}
+
+async function post(coll, next_song, conf, socket, removed) {
+  return new Promise((resolve, reject) => {
+    var docs = await aggregate(coll, verifyAggregate);
+    if (docs === null || docs.length == 0) {
+      reject();
+      return;
+    }
+    var id = docs[0].id;
+    if (next_song && next_song != id) {
+      if (docs.length == 2 && next_song == docs[1].id) {
+        id = docs[1].id;
+      } else {
+        reject();
+        return;
+      }
+    }
+    var returnDocs = await update(
+      coll,
+      { id: id, now_playing: false },
+      {
+        $set: {
+          now_playing: true,
+          votes: 0,
+          guids: [],
+          added: Functions.get_time()
+        }
+      },
+      {}
+    );
+    if (
+      (returnDocs.hasOwnProperty("nModified") && returnDocs.nModified == 0) ||
+      (returnDocs.hasOwnProperty("n") && returnDocs.n == 0)
+    ) {
+      resolve();
+      return;
+    }
+    returnDocs = await update(
+      coll + "_settings",
+      { id: "config" },
+      {
+        $set: {
+          startTime: Functions.get_time(),
+          skips: []
+        }
+      },
+      {}
+    );
+    resolve();
+  });
+}
+
+module.exports.changeSong = changeSong;
+module.exports.pre = pre;
+module.exports.post = post;