filter handler

Handler: func(db *gorm.DB, argument *admin.FilterArgument) *gorm.DB {
		
			startDate := argument.Value.Get("Start").Value
			endDate := argument.Value.Get("End").Value
			startDateTime, _ := time.Parse(C.DATE_YYYY_MM_DD_HH_MM, utils.ToString(startDate))
			endDateTime, _ := time.Parse(C.DATE_YYYY_MM_DD_HH_MM, utils.ToString(endDate))
		
			diffStartEnd := startDateTime.Sub(Date(endDateTime.Year(), endDateTime.Month(), endDateTime.Day(), endDateTime.Hour(), endDateTime.Minute())).Hours() / 24
			log.Printf("diffStartEnd: %f", diffStartEnd)
			if diffStartEnd < 0 {
		
				log.Printf("utils.Tostrng(): %s", utils.ToString(startDate))
				log.Printf("startDateTime: %v", startDateTime.Format(C.DATE_YYYY_MM_DD_HH_MM))
				log.Printf("endDateTime: %v", endDateTime.Format(C.DATE_YYYY_MM_DD_HH_MM))
		
				////the createdAt[it's in gorm.Model.createdAt] start-date should not be < 365 from current date
				diff := startDateTime.Sub(Date(time.Now().Year(), time.Now().Month(), time.Now().Day(), time.Now().Hour(), time.Now().Minute())).Hours() / 24
				log.Printf("diff days: %f", diff)
				if diff < -365 {
					logs.GetLogger().Error("Invalid CreatedAt filter!")
					errors.New("Invalid CreatedAt filter.")
					log.Printf("invalid start date: ")
					return db
				}
				//need to return the sql query with applied filters
				//return db.Raw("select * from se_bookings where created_at > '2019-04-18 00:00'")
				//generateConditionAndApplyFilter();
				return db;
			}
			return db
		},