package be.mentoringsystems.merke.security;

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.DecodedJWT;
import java.nio.charset.StandardCharsets;
import javax.servlet.http.HttpServletRequest;

/**
 *
 * @author anthonyarents
 */
public final class JWSHelper {

    private static final String SECRET = "F6deJ;xShXD+juV,%dtt}3/z:pZ6-H";
    public static final String TOKEN_PREFIX = "Bearer ";
    public static final String HEADER_NAME = "Authorization";

    private JWSHelper() {
        //
    }

    public static String getJwsSubject(final HttpServletRequest hsr) {
        String subject = null;
        String authorization = hsr.getHeader(HEADER_NAME);
        if (authorization == null) {
            authorization = hsr.getParameter(HEADER_NAME);
        }
        if (authorization != null && authorization.startsWith(TOKEN_PREFIX)) {
            DecodedJWT decoded = JWT.require(Algorithm.HMAC512(SECRET.getBytes(StandardCharsets.UTF_8))).build().verify(authorization.replace(TOKEN_PREFIX, ""));
            subject = decoded.getSubject();
        }
        return subject;
    }

    public static String generateJwsWithSubject(final String subject) {
        return JWT.create().withSubject(subject).sign(Algorithm.HMAC512(SECRET.getBytes(StandardCharsets.UTF_8)));
    }
}