package state

import (
	"crypto/md5"
	"fmt"
)

func KeyOfStrings(parts ...any) StringsKey {
	nonEmpty := make([]string, 0, len(parts))
	for i := range parts {
		if parts[i] == nil {
			continue
		}

		switch s := parts[i].(type) {
		case string:
			if s != "" {
				nonEmpty = append(nonEmpty, s)
			}
		case fmt.Stringer:
			if out := s.String(); out != "" {
				nonEmpty = append(nonEmpty, out)
			}
		}
	}

	return nonEmpty
}

type StringsKey []string

func (k StringsKey) Bytes() []byte {
	if len(k) == 0 {
		return nil
	}

	h := md5.New()
	for i := range k {
		_, _ = h.Write([]byte(k[i]))
	}

	return h.Sum(nil)
}

type PlainKey []byte

func (k PlainKey) Bytes() []byte {
	return k
}