db={"users":[{"_id":ObjectId("5da594c15324fec81d000027"),"password":"******","activation":"Active","userType":"Author","email":"something@gmail.com","name":"Something","profilePicture":"profile_pictures/5da594c15324fec81d0000271607094354423image.png","__v":0}],"userlogs":[{"_id":ObjectId("5fcb7bb4485c34a41900002b"),"duration":2.54,"page":1,"activityDetails":"Viewed Page for seconds","contentType":"article","activityType":"articlePageStayTime","label":3,"bookId":ObjectId("5f93e2cc74153f8c1800003f"),"ipAddress":"::1","creator":ObjectId("5da594c15324fec81d000027"),"created":ISODate("2020-12-05T12:23:16.867Z"),"__v":0}]}

db.users.aggregate([{$lookup:{from:"userlogs",localField:"_id",foreignField:"creator",as:"userlogs"}},{$project:{name:1,userlogs:{$filter:{input:"$userlogs",as:"u",cond:{$ne:["$$u.activityType","articleListeningTime"]}}}}},{$project:{name:1,totalCount:{$size:"$userlogs"},durationSum:{$sum:"$userlogs.duration"},labelAvg:{$avg:{$setUnion:"$userlogs.label"}},bookIdCount:{$size:{$setUnion:"$userlogs.bookId"}}}}])