package uniquegenerator

import (
   "errors"
   "math/rand"

   "github.com/oklog/ulid/v2"

   "time"
)

var (
   t       = time.Unix(1000000, 0)
   entropy = ulid.Monotonic(rand.New(rand.NewSource(t.UnixNano())), 0)
)

//generateUlid ex. output: 0000XSNJG0MQJHBF4QX1EFD6Y3
func generateUlid() ulid.ULID {
   return ulid.MustNew(ulid.Timestamp(t), entropy)
}

//Get ex. output: 0000XSNJG0MQJHBF4QX1EFD6Y3
func Get() string {
   return generateUlid().String()
}

//Validation ulid string check size
func Validation(id string) error {
   if len(id) != ulid.EncodedSize {
       return errors.New("Unique ID generator validation error: length is not match")
   }
   return nil
}