package cn.home1.oss.lib.common.crypto;
   
   import io.jsonwebtoken.Claims;
   import io.jsonwebtoken.Clock;
   import io.jsonwebtoken.Jws;
   import io.jsonwebtoken.Jwts;
   import io.jsonwebtoken.impl.FixedClock;
   
   import lombok.Getter;
  
  import org.joda.time.DateTime;
  
  import cn.home1.oss.lib.common.Defaults;
  
  /**
   * Created by zhanghaolun on 16/11/17.
   */
  public class JwtDecryptor implements EncodeDecryptor {
  
    @Getter
    private final JwtKey key;
  
    public JwtDecryptor(final KeyExpression keyExpression) {
      this.key = new JwtKey(keyExpression);
    }
  
    /**
     * decrypt.
     *
     * @param encryptedAndEncoded compactJws
     */
    @Override
    public String decrypt(final String encryptedAndEncoded) {
      final Jws<Claims> jws = encryptedAndEncoded != null ? //
        this.parseCompactJws(encryptedAndEncoded, Defaults.now()) : null;
      return jws != null ? jws.getBody().getSubject() : null;
    }
  
    public Jws<Claims> parseCompactJws(final String compactJws, final DateTime dateTime) {
      final Clock clock = new FixedClock(dateTime.toDate());
      return compactJws != null ? //
        Jwts.parser().setClock(clock).setSigningKey(this.key.getSignatureKey()).parseClaimsJws(compactJws) : null;
    }
  }