package nebula

import (
	"bytes"
	"errors"
	"fmt"

	"github.com/jxskiss/base62"
)

func encodeWithPrefix(prefix []byte, b []byte) []byte {
	res := make([]byte, 0, len(prefix)+len(b)*4)
	res = append(res, prefix...)
	res = base62.EncodeToBuf(res, b)
	return res
}

func decodeWithPrefix(prefix []byte, b []byte) ([]byte, error) {
	if len(b) < len(prefix) {
		return nil, errors.New("input is too short")
	} else if !bytes.HasPrefix(b, prefix) {
		return nil, fmt.Errorf("missing expected prefix %q", prefix)
	}
	return base62.Decode(b[len(prefix):])
}