package crypto

import (
	"crypto/sha512"
	"encoding/hex"
	"io"
	"mime/multipart"
)

func CalculateHashFromRequest(fileHeader *multipart.FileHeader) (string, error) {
	src, err := fileHeader.Open()
	if err != nil {
		return "", err
	}
	defer src.Close()

	h := sha512.New()
	if _, err := io.Copy(h, src); err != nil {
		return "", err
	}

	// return the sha checksum in hex
	return hex.EncodeToString(h.Sum(nil)), nil
	// alternatively return in base64
	//return base64.StdEncoding.EncodeToString(h.Sum(nil)), nil
}