db={"contracts":[{"_id":ObjectId("630c9e23fb146c4b3b801b9e"),"detention_id":[],"route_exclude":false,"trip_count":null,"fill_first":false,"is_dedicated":false,"truck_count":0,"running_trip_count":0,"is_round_trip_eligible":false,"is_synced":false,"bdr_label":"","bdr_charge":0,"is_migrated":false,"current_trip_count":0,"client_id":ObjectId("5e47c1f4a697c60195050059"),"updated_by":ObjectId("60a39adad079f9004d144cb8"),"user_id":ObjectId("60a39adad079f9004d144cb8"),"transporter_id":ObjectId("61d6d2227465c501d0915794"),"vehicle_type_id":ObjectId("61e1b3ad00516e004c893145"),"detention_group":"","delivery_type":2,"source":"amaravathi","destination":"Kozhikode","isDirect":false,"via":["6304804a9f90b8018844fc20","62fb93a711ea3f019ffe19e6"],"distance":100,"status":1,"contract_type":1,"current":{"minimum_rate":0,"multiplying_factor":null,"min_slab":0,"additional_charge_percentage":0,"hilly_region_addition_percentage":0,"return_freight_rate":0,"surge_threshold":0,"fixed_rate":null,"oda_rate":null,"oda_unit":3,"minimum_oda":0,"point_charges":0,"pickup_point_charges":0,"start":ISODate("2022-08-26T00:00:00.000+05:30"),"end":ISODate("2023-08-24T23:59:00.000+05:30"),"freight_unit":1,"freight_rate":5000,"transit_time":172800000},"next":[],"previous":[],"lookup_key":"f93187d8364fca313ab92c83ac39eafa","created_at":ISODate("2022-08-26T15:26:15.865+05:30"),"updated_at":ISODate("2022-08-29T13:20:39.058+05:30")}],"depots":[{"_id":ObjectId("6304804a9f90b8018844fc20"),"consignee_ref_ids":[],"status":1,"coordinates":[12.9039441,80.14567129999999],"unloading_capacity":0,"has_pit_stop":false,"type":1,"plant_type":1,"ports_associated":[],"overseas_customer":false,"sez":false,"timezone":"Asia/Kolkata","fax_number":"","is_optima_group_by_cluster":"","country":"India","name":"CTB","reference_id":"CTB","client_id":ObjectId("5e47c1f4a697c60195050059"),"address":"CTB","city":"Chennai","state":"Tamil Nadu","region":"South","pincode":"600126","phone":"","delivery_type":1,"short_code":"CTB","gstn_no":"HSKK309393k","gates":[{"coordinates":[12.9039441,80.14567129999999],"exclude_trucks":[],"_id":ObjectId("630480789f90b8018844fc21"),"country":"India","name":"CTG1","reference_id":"CTG1","status":1,"address":"CTB","city":"Chennai","state":"Tamil Nadu","region":"South","pincode":"600126","short_code":"CTG1","special_tax_rebate":false,"gstin":null,"is_virtual_gate":false,"category":"","delivery_do_not_combine":false,"combine":false,"loading_time":{"start":null,"end":null},"unloading_time":{"start":null,"end":null},"legal_entity":null,"display_reference_name":"","updated_at":ISODate("2022-08-23T12:53:46.233+05:30"),"created_at":ISODate("2022-08-23T12:53:36.046+05:30")}],"docks":[],"updated_by":ObjectId("5eaba6438a4895004916adbe"),"display_reference_name":"","receivers":[],"created_at":ISODate("2022-08-23T12:52:50.182+05:30"),"updated_at":ISODate("2022-08-23T13:09:18.468+05:30")},{"_id":ObjectId("62fb93a711ea3f019ffe19e6"),"consignee_ref_ids":[],"status":1,"coordinates":[20.593684,78.96288],"unloading_capacity":0,"has_pit_stop":false,"type":1,"plant_type":1,"ports_associated":[],"overseas_customer":false,"sez":false,"timezone":"Asia/Kolkata","fax_number":"","is_optima_group_by_cluster":"","country":"India","name":"Test","reference_id":"Test","client_id":ObjectId("5e47c1f4a697c60195050059"),"address":"test","city":"Test","state":"Test","region":"North","pincode":"0100301","phone":"","delivery_type":1,"short_code":"test","gstn_no":"1111","gates":[],"docks":[],"updated_by":ObjectId("62e7b04d91a9b50189b4319d"),"display_reference_name":"","receivers":[],"created_at":ISODate("2022-08-16T18:25:03.453+05:30"),"updated_at":ISODate("2022-08-16T18:25:03.913+05:30")},{"_id":ObjectId("630cc2ba38f87401899c35f1"),"consignee_ref_ids":[],"status":1,"coordinates":[20.593684,78.96288],"unloading_capacity":0,"has_pit_stop":false,"type":1,"plant_type":1,"ports_associated":[],"overseas_customer":false,"sez":false,"timezone":"Asia/Kolkata","fax_number":"","is_optima_group_by_cluster":"","country":"India","name":"B20220829191440","reference_id":"B20220829191440","client_id":ObjectId("62d8f30ce763689b942d5e12"),"address":"No 15,GST Street","city":"Blr20220829191440","state":"Karnataka","region":"South","pincode":"123456","phone":"5588","delivery_type":1,"short_code":"B214945","gstn_no":"123","gates":[{"coordinates":[10.9290666,78.7438114],"exclude_trucks":[],"_id":ObjectId("630cc2bb38f87401899c35f2"),"country":"India","name":"Gate 2","reference_id":"BG20220829191440","status":1,"address":"No 15 GST Road","city":"Blr20220829191440","state":"Karnataka","region":"South","pincode":"123456","short_code":"G1214945","special_tax_rebate":false,"is_virtual_gate":false,"category":"b","combine":true,"updated_at":ISODate("2022-08-29T19:14:27.912+05:30"),"created_at":ISODate("2022-08-29T19:14:27.551+05:30")}],"docks":[],"updated_by":ObjectId("62d8f30ce763689b942d5e15"),"display_reference_name":"","receivers":[],"created_at":ISODate("2022-08-29T19:14:26.892+05:30"),"updated_at":ISODate("2022-08-29T19:14:27.912+05:30")}]}

db.contracts.aggregate([{$match:{_id:ObjectId("630c9e23fb146c4b3b801b9e")}},{$set:{via:{$map:{input:"$via",in:{"$toObjectId":"$$this"}}}}},{$lookup:{from:"depots",localField:"via",as:"depots",foreignField:"_id"}},{$sort:{count:-1}}])