package update

import (
	"bytes"
	"crypto/ed25519"
	_ "embed"
	"encoding/base64"
	"errors"
	"strings"
)

//go:embed release.pub
var embeddedPublicKey string

var (
	ErrPublicKeyFormat      = errors.New("the public key is not a base64 encoded 32 byte ed25519 key")
	ErrPlaceholderPublicKey = errors.New("the placeholder public key has not been replaced: run task release:keygen and commit the real key as internal/infrastructure/update/release.pub")
)

func EmbeddedPublicKey() (ed25519.PublicKey, error) {
	return ParsePublicKey(embeddedPublicKey)
}

func ParsePublicKey(text string) (ed25519.PublicKey, error) {
	decoded, err := base64.StdEncoding.DecodeString(strings.TrimSpace(text))
	if err != nil || len(decoded) != ed25519.PublicKeySize {
		return nil, ErrPublicKeyFormat
	}
	return ed25519.PublicKey(decoded), nil
}

func IsPlaceholderPublicKey(key ed25519.PublicKey) bool {
	return bytes.Equal(key, make([]byte, ed25519.PublicKeySize))
}

func EncodePublicKey(key ed25519.PublicKey) string {
	return base64.StdEncoding.EncodeToString(key)
}