@Component
public class JWTUtil implements Serializable {

	private static final long serialVersionUID = 1L;

	@Value("${springbootwebfluxjjwt.jjwt.secret}")
	private String secret;

	@Value("${springbootwebfluxjjwt.jjwt.expiration}")
	private String expirationTime;

	public Claims getAllClaimsFromToken(String token) {
		return Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
	}

	public String getUsernameFromToken(String token) {
		return getAllClaimsFromToken(token).getSubject();
	}

	public Date getExpirationDateFromToken(String token) {
		return getAllClaimsFromToken(token).getExpiration();
	}

	private Boolean isTokenExpired(String token) {
		final Date expiration = getExpirationDateFromToken(token);
		return expiration.before(new Date());
	}

	public String generateToken(User user) {
		Map<String, Object> claims = new HashMap<>();
		claims.put("role", user.getRoles());
		claims.put("enable", user.getEnabled());
		return doGenerateToken(claims, user.getUsername());
	}

	private String doGenerateToken(Map<String, Object> claims, String username) {
		Long expirationTimeLong = Long.parseLong(expirationTime); //in second

		final Date createdDate = new Date();
		final Date expirationDate = new Date(createdDate.getTime() + expirationTimeLong * 1000);
		return Jwts.builder()
				.setClaims(claims)
				.setSubject(username)
				.setIssuedAt(createdDate)
				.setExpiration(expirationDate)
				.signWith(SignatureAlgorithm.HS512, secret)
				.compact();
	}

	public Boolean validateToken(String token) {
		return !isTokenExpired(token);
	}

}