/**
 * Copyright (c) 2018-2028, Chill Zhuang 庄骞 (smallchill@163.com).
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springblade.gateway.utils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import org.springblade.core.launch.constant.TokenConstant;

import java.nio.charset.StandardCharsets;
import java.util.Base64;

/**
 * JwtUtil
 *
 * @author Chill
 */
public class JwtUtil {

	public static String SIGN_KEY = TokenConstant.SIGN_KEY;
	public static String BEARER = TokenConstant.BEARER;
	public static Integer AUTH_LENGTH = 7;

	public static String BASE64_SECURITY = Base64.getEncoder().encodeToString(SIGN_KEY.getBytes(StandardCharsets.UTF_8));

	/**
	 * 获取token串
	 *
	 * @param auth token
	 * @return String
	 */
	public static String getToken(String auth) {
		if ((auth != null) && (auth.length() > AUTH_LENGTH)) {
			String headStr = auth.substring(0, 6).toLowerCase();
			if (headStr.compareTo(BEARER) == 0) {
				auth = auth.substring(7);
			}
			return auth;
		}
		return null;
	}

	/**
	 * 解析jsonWebToken
	 *
	 * @param jsonWebToken token串
	 * @return Claims
	 */
	public static Claims parseJWT(String jsonWebToken) {
		try {
			return Jwts.parserBuilder()
				.setSigningKey(Base64.getDecoder().decode(JwtUtil.BASE64_SECURITY)).build()
				.parseClaimsJws(jsonWebToken).getBody();
		} catch (Exception ex) {
			return null;
		}
	}

}
