package cn.home1.oss.lib.security.crypto;
   
   import static org.apache.commons.lang3.StringUtils.isNotBlank;
   
   import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
   import org.springframework.security.crypto.password.PasswordEncoder;
   
   import java.security.SecureRandom;
   
  /**
   * Created by zhanghaolun on 16/7/8.
   */
  public class ReentrantBCryptPasswordEncoder implements PasswordEncoder {
  
    private static final char FIELD_SEPERATOR = '$';
    private final BCryptPasswordEncoder delegate;
  
    public ReentrantBCryptPasswordEncoder() {
      this(-1);
    }
  
    /**
     * constructor with strength.
     * 
     * @param strength the log rounds to use
     */
    public ReentrantBCryptPasswordEncoder(final int strength) {
      this(strength, null);
    }
  
    /**
     * constructor with strength and random.
     * 
     * @param strength the log rounds to use
     * @param random the secure random instance to use
     */
    public ReentrantBCryptPasswordEncoder(final int strength, final SecureRandom random) {
      this.delegate = new BCryptPasswordEncoder(strength, random);
    }
  
    public static Boolean isBCryptEncoded(final CharSequence encodedPassword) {
      return isNotBlank(encodedPassword) && encodedPassword.length() == 60
          && encodedPassword.charAt(0) == FIELD_SEPERATOR
          && encodedPassword.charAt(3) == FIELD_SEPERATOR
          && encodedPassword.charAt(6) == FIELD_SEPERATOR;
    }
  
    @Override
    public String encode(final CharSequence rawPassword) {
      return this.isEncoded(rawPassword) ? (rawPassword != null ? rawPassword.toString() : null)
          : this.delegate.encode(rawPassword);
    }
  
    @Override
    public boolean matches(final CharSequence rawPassword, final String encodedPassword) {
      return this.delegate.matches(rawPassword, encodedPassword);
    }
  
    public boolean isEncoded(final CharSequence encodedPassword) {
      return isBCryptEncoded(encodedPassword);
    }
  }