package com.care.util;

import cn.hutool.json.JSONUtil;
import com.care.common.vo.UserLogindConvertVO;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;
import java.util.Date;

/**
 * Created by y on 2017/11/16.
 * @author y
 */
@Component
@PropertySource(value = "classpath:common.properties", ignoreResourceNotFound = true)
public class JwtUtils {

    private static final Logger logger = LoggerFactory.getLogger(JwtUtils.class);

    @Resource
    private Environment env;

    /**
     * 由字符串生成加密key
     * @return
     */
    public SecretKey generalKey() {
        String stringKey = env.getProperty("auth.jwt.id") + env.getProperty("auth.jwt.secret");
        byte[] encodedKey = Base64.decodeBase64(stringKey);
        SecretKey key = new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");
        return key;
    }

    public String generalToken(UserLogindConvertVO userLogindConvertDTO) {
        String compactJws = null;
        try {
            long nowMillis = System.currentTimeMillis();
            Date now = new Date(nowMillis);
            Key key = generalKey();
            compactJws = Jwts.builder()
                    .setSubject(JSONUtil.toJsonStr(userLogindConvertDTO))
                    .setIssuedAt(now)
                    .signWith(SignatureAlgorithm.HS512, key)
                    .setExpiration(new Date(nowMillis + env.getProperty("auth.jwt.ttl.ms", Long.class)))
                    .compact();
        } catch (Exception e) {
            logger.error("生成TOKEN出现异常.", e);
        }
        return compactJws;
    }

    /**
     * 解密jwt
     * @param jwt
     * @return
     * @throws Exception
     */
    public Claims tokenParse(String jwt) {
        SecretKey key = generalKey();
        Claims claims = null;
        try {
            claims = Jwts.parser()
                    .setSigningKey(key)
                    .parseClaimsJws(jwt).getBody();
        } catch (io.jsonwebtoken.ExpiredJwtException e) {
            System.out.println("当前TOKEN已过期, 请重新登录.");
        } catch (Exception e) {
            System.out.println("校验TOKEN出现异常, 请重新登录.");
        }
        return claims;
    }

}