package com.gkhy.assess.common.utils;

import cn.hutool.core.date.DateUtil;
import cn.hutool.crypto.digest.DigestUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.gkhy.assess.common.api.CommonResult;
import com.gkhy.assess.common.exception.ApiException;
import io.swagger.models.auth.In;
import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.crypto.hash.Md5Hash;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * JwtToken生成的工具类
 * JWT token的格式：header.payload.signature
 * header的格式（算法、token的类型）：
 * {"alg": "HS512","typ": "JWT"}
 * payload的格式（用户名、创建时间、生成时间）：
 * {"sub":"wang","created":1489079981393,"exp":1489684781}
 * signature的生成算法：
 * HMACSHA512(base64UrlEncode(header) + "." +base64UrlEncode(payload),secret)
 */
public class JwtTokenUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(JwtTokenUtil.class);

    public static final String USER_LOGIN_TOKEN="Authorization";

    public static final String CLAIM_KEY_USERNAME = "sub";
    public static final String CLAIM_KEY_CREATED = "created";

    public static String SECRET="nms-secret";

    public static String tokenHead="";

    /**Token有效期为1天（Token在reids中缓存时间为两倍）  单位ms*/
    public static final long EXPIRATION=(1 *12) * 60 * 60 * 1000;  //JWT的超期限时间(60*60*24*1)

    /**
     * token有效期还有30分钟，刷新token  单位ms
     */
    public static final long NEED_UPDATE_TIME= 30 * 60 * 1000;

    /**
     * 校验token是否正确
     * @param token
     * @param username
     * @param secret  用户密码
     * @return
     */
    public static boolean verify(String token,String username,String secret,Integer identity){
        try {
            Algorithm algorithm = Algorithm.HMAC256(secret);
            JWTVerifier verifier = JWT.require(algorithm).withClaim("username", username)
                    .withClaim("identity",identity).build();
            DecodedJWT jwt = verifier.verify(token);
            return true;
        }catch (Exception e){
            return false;
        }
    }


    public static boolean isNeedUpdate(String token, String username, String secret,Integer identity){
        Date expertsAt =null;
        try {
            Algorithm algorithm = Algorithm.HMAC256(secret);
            JWTVerifier verifier = JWT.require(algorithm).withClaim("username", username)
                    .withClaim("identity",identity).build();
            expertsAt = verifier.verify(token).getExpiresAt();
        }catch (Exception e){
            throw new ApiException("token非法无效");
        }
        //如果剩余过期时间少于过期时常的一半时 需要更新
        return (expertsAt.getTime()-System.currentTimeMillis()) < NEED_UPDATE_TIME;
    }

    /**
     * 获取token中的信息  无需secret解密也能获得
     * @param token
     * @return
     */
    public static String getUsername(String token){
        try {
            DecodedJWT jwt = JWT.decode(token);
            return jwt.getClaim("username").asString();
        }catch (JWTDecodeException e){
            return null;
        }
    }

    /**
     * 获取token中的信息  无需secret解密也能获得
     * @param token
     * @return
     */
    public static Integer getIdentity(String token){
        try {
            DecodedJWT jwt = JWT.decode(token);
            return jwt.getClaim("identity").asInt();
        }catch (JWTDecodeException e){
            return null;
        }
    }



    /**
     * 生成签名
     * @param username
     * @param secret
     * @return
     */
    public static String sign(String username,String secret,Integer identity){
        Date date=new Date(System.currentTimeMillis()+EXPIRATION);
        Algorithm algorithm=Algorithm.HMAC256(secret);
        return JWT.create().withClaim("username",username)
                .withClaim("identity",identity).withExpiresAt(date).sign(algorithm);
    }

    /**
     * 根据request中的token获取用户账号
     *
     * @param request
     * @return
     * @throws ApiException
     */
    public static String getUserNameByToken(HttpServletRequest request) throws ApiException {
        String accessToken = request.getHeader(USER_LOGIN_TOKEN);
        String username = getUsername(accessToken);
        if (StringUtils.isEmpty(username)) {
            throw new ApiException("未获取到用户");
        }
        return username;
    }


    /**
     * md5加密
     * @param token
     * @return
     */
    public static String md5Encode(String token){

        return DigestUtil.md5Hex(token);
    }


    /**
     * 密码加密
     * @param username
     * @param password
     * @param salt
     * @return
     */
    public static String encryptPassword(String username,String password,String salt){
        if(salt==null){
            salt="";
        }
        return new Md5Hash(username+password+salt).toHex();
    }


    /**
     *
     * @param response
     * @param code
     * @param errorMsg
     */
    public static void responseError(ServletResponse response, String errorMsg) {
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        // issues/I4YH95浏览器显示乱码问题
        httpServletResponse.setHeader("Content-type", "text/html;charset=UTF-8");
        CommonResult jsonResult = CommonResult.failed(errorMsg);
        OutputStream os = null;
        try {
            os = httpServletResponse.getOutputStream();
            httpServletResponse.setCharacterEncoding("UTF-8");
         //   httpServletResponse.setStatus(code);
            os.write(new ObjectMapper().writeValueAsString(jsonResult).getBytes("UTF-8"));
            os.flush();
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }



}