create unix timestamp and store it in db

WebApi/Controllers/PlayerController.cs

@@ -56,7 +56,7 @@ public PlayerController(IDatabase db, INearByFinder nearByFinder, IDirectionCalc
         [HttpPost("{id}/location")]
         public ActionResult<LocationUpdateResponseDTO> UpdateLocation(string id, [FromBody] LocationUpdateDTO pos)
         {
-            var newPosition = new Location { lat = pos.Lat, lon = pos.Long, tracked = pos.Tracked, at_home = pos.at_home };
+            Location newPosition = CreateLocationFromDTO(pos);
             if (db.Contains(id))
             {
                 db.Update(id, newPosition);
@@ -73,6 +73,18 @@ public ActionResult<LocationUpdateResponseDTO> UpdateLocation(string id, [FromBo
             };
         }
 
+        private static Location CreateLocationFromDTO(LocationUpdateDTO pos)
+        {
+            return new Location
+            {
+                lat = pos.Lat,
+                lon = pos.Long,
+                tracked = pos.Tracked,
+                at_home = pos.at_home,
+                timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
+            };
+        }
+
         private LocationUpdateResponseNearbyPlayerDTO CreateNearbyPlayerDTO(Location me, Location other)
         {
             var latDistance = me.lat - other.lat;

WebApi/Dependencies/MongoDatabase.cs

@@ -21,6 +21,8 @@ public class PlayerModel
         public bool currentTracked;
         public bool previousTracked;
         public bool atHome;
+        public long currentTimestamp;
+        public long previousTimestamp;
     }
 
     public class MongoDatabase : IDatabase, INearByFinder
@@ -66,6 +68,8 @@ public void Create(string id, Location location)
                 atHome = location.at_home,
                 currentTracked = location.tracked,
                 previousTracked = location.tracked,
+                currentTimestamp = location.timestamp,
+                previousTimestamp = location.timestamp,
             });
         }
 
@@ -85,10 +89,18 @@ public void Update(string id, Location location)
                         "$set",
                         new BsonDocument(new BsonElement("previousTracked", "$currentTracked"))
                 )),
+                new BsonDocument(new BsonElement(
+                        "$set",
+                        new BsonDocument(new BsonElement("previousTimestamp", "$currentTimestamp"))
+                )),
                 new BsonDocument(new BsonElement(
                     "$set",
                     new BsonDocument(new BsonElement("currentTracked", location.tracked))
                 )),
+                new BsonDocument(new BsonElement(
+                    "$set",
+                    new BsonDocument(new BsonElement("currentTimestamp", location.timestamp))
+                )),
                 new BsonDocument(new BsonElement(
                     "$set",
                     new BsonDocument(new BsonElement("currentLocation", GeoJson.Point(GeoJson.Geographic(location.lon, location.lat)).ToBsonDocument()))

WebApi/Entities/Location.cs

@@ -11,5 +11,10 @@ public class Location
         public double lon;
         public bool tracked;
         public bool at_home;
+
+        /// <summary>
+        /// represents the number of milliseconds that have elapsed since 1970-01-01T00:00:00.000Z
+        /// </summary>
+        public long timestamp;
     }
 }