/*
 *  Copyright (c) 2026 Kaiy Ragur
 *
 *  This Source Code Form is subject to the terms of the Mozilla Public
 *  License, v. 2.0. If a copy of the MPL was not distributed with this
 *  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
package utils

import (
	"crypto/ed25519"
	"crypto/sha512"

	"filippo.io/edwards25519"
)

func PubEd25519ToX25519(pub ed25519.PublicKey) ([]byte, error) {
	point, err := edwards25519.NewIdentityPoint().SetBytes(pub)
	if err != nil {
		return nil, err
	}
	x25519Pub := point.BytesMontgomery()

	return x25519Pub, nil
}

func PrivEd25519ToX25519(priv ed25519.PrivateKey) ([]byte, error) {
	seed := priv.Seed()
	h := sha512.Sum512(seed)
	x25519Priv := h[:32]
	return x25519Priv, nil
}