package com.free.utils;

import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.free.config.CustomizationException;
import com.free.config.ExceptionEnum;
import com.free.entity.system.LoginRecord;
import com.free.service.system.LoginRecordService;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTCreator;

import java.time.LocalDateTime;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

@Component
public class JwtUtil {
  public static final String TOKEN_HEADER = "Authorization";
  public static final String TOKEN_PREFIX = "Free ";
  // 过期时间, 半个小时
  private static final long EXPIRE_MIN = 30;
  private static final long EXPIRE_TIME = EXPIRE_MIN * 60 * 1000;
  // 密钥
  private static final String SECRET = "Ziyouyanfa!@#";

  @Autowired
  private LoginRecordService lrs;

  private static JwtUtil jwtUtil = new JwtUtil();

  @PostConstruct
  public void init() {
    jwtUtil = this;
    jwtUtil.lrs = this.lrs;
  }

  /**
   * 生成签名
   *
   * @param map    数据
   * @param secret 密码
   * @return 加密后的token
   */
  public static String sign(Map<String, Object> map) {
    Date date = new Date(System.currentTimeMillis() + EXPIRE_TIME);
    Algorithm algorithm = Algorithm.HMAC256(SECRET); // 使用HS256算法
    JWTCreator.Builder builder = JWT.create();

    for (Map.Entry<String, Object> entry : map.entrySet()) {
      String k = entry.getKey();
      String v = (String) entry.getValue();
      builder.withClaim(k, v);
    }
    String token = builder.withExpiresAt(date)
        .sign(algorithm);
    StringBuilder sb = new StringBuilder();
    sb.append(TOKEN_PREFIX);
    sb.append(token);
    String returnToken = sb.toString();
    // 创建登录数据
    createLoginRecord(token);
    return returnToken;
  }

  /**
   * 注销用户,退出登录
   * 将token置空,在校验的时候会处理没有token的情况
   * 
   * @param token
   */
  public static void logOff(String token) {
    Map<String, Object> map = getDetails(token);
    String user_id = (String) map.get("id");
    String type = (String) map.get("type");
    QueryWrapper<LoginRecord> qw = new QueryWrapper<>();
    qw.eq("user_id", user_id);
    qw.eq("type", type);
    LoginRecord record = jwtUtil.lrs.getOne(qw);
    // 没找到数据不需要处理
    if (null == record) {
      return;
    }
    // token不一致,不需要处理
    String dbToken = record.getToken();
    if (null == dbToken || !dbToken.equals(token)) {
      return;
    }
    // token置空
    LoginRecord lr = new LoginRecord();
    lr.setToken(null);
    lr.setId(record.getId());
    jwtUtil.lrs.updateById(lr);
  }

  /**
   * 创建登录数据
   * 
   * @param token jwt
   */
  public static void createLoginRecord(String token) {
    Map<String, Object> map = getDetails(token);
    String user_id = (String) map.get("id");
    String type = (String) map.get("type");
    // 第一次登录是创建,以后都是更新, 每个用户都有1个登录数据,但是能否使用要看过期时间
    QueryWrapper<LoginRecord> qw = new QueryWrapper<>();
    qw.eq("user_id", user_id);
    qw.eq("type", type);
    LoginRecord histroy = jwtUtil.lrs.getOne(qw);
    // 准备数据
    LocalDateTime last_time = LocalDateTime.now();
    LocalDateTime expire_time = LocalDateTime.now().plusMinutes(EXPIRE_MIN);
    HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
    String ip = request.getRemoteAddr();
    if (null == histroy) {
      // 创建数据
      LoginRecord lr = new LoginRecord();
      lr.setExpire_time(expire_time);
      lr.setLast_time(last_time);
      lr.setToken(token);
      lr.setType(type);
      lr.setUser_id(user_id);
      lr.setLast_ip(ip);
      jwtUtil.lrs.save(lr);
    } else {
      // 修改数据
      LoginRecord lr = new LoginRecord();
      lr.setExpire_time(expire_time);
      lr.setLast_time(last_time);
      lr.setToken(token);
      lr.setLast_ip(ip);
      lr.setId(histroy.getId());
      jwtUtil.lrs.updateById(lr);
    }
  }

  /**
   * token续期
   * 
   * @param token jwt
   */
  public static void renewal(String token) {
    Map<String, Object> map = getDetails(token);
    String user_id = (String) map.get("id");
    String type = (String) map.get("type");
    QueryWrapper<LoginRecord> qw = new QueryWrapper<>();
    qw.eq("user_id", user_id).eq("type", type);
    LoginRecord histroy = jwtUtil.lrs.getOne(qw);
    // 准备数据
    LocalDateTime expire_time = LocalDateTime.now().plusMinutes(EXPIRE_MIN);
    LocalDateTime last_time = LocalDateTime.now();
    HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
    String ip = request.getRemoteAddr();
    if (null == histroy) {
      // 没有数据,转至创建
      createLoginRecord(token);
    } else {
      // 修改过期时间,使用时间,使用ip
      LoginRecord lr = new LoginRecord();
      lr.setExpire_time(expire_time);
      lr.setId(histroy.getId());
      lr.setLast_ip(ip);
      lr.setLast_time(last_time);
      lr.setToken(token);
      jwtUtil.lrs.updateById(lr);
    }
  }

  /**
   * 校验token是否正确
   *
   * @param token 令牌
   * @return 是否正确
   */
  public static void verify(String token) {
    // 解开token,查看数据
    Map<String, Object> map = getDetails(token);
    String user_id = (String) map.get("id");
    String type = (String) map.get("type");
    QueryWrapper<LoginRecord> qw = new QueryWrapper<>();
    qw.eq("user_id", user_id).eq("type", type);
    LoginRecord histroy = jwtUtil.lrs.getOne(qw);
    if (null == histroy) {
      throw new CustomizationException(ExceptionEnum.NO_LOGIN_RECORD);
    }
    // 获取数据库的token
    String dbToken = histroy.getToken();
    if (null == dbToken) {
      throw new CustomizationException(ExceptionEnum.ACCOUNT_IS_LOGOUT);
    }
    // 取出过期时间,和当前时间进行比较
    LocalDateTime nowTime = LocalDateTime.now();
    boolean is_after = histroy.getExpire_time().isAfter(nowTime);
    if (!is_after) {
      throw new CustomizationException(ExceptionEnum.TOKEN_INVALID);
    }
    // token对比,如果时间允许,但是token码不一致,则说明在其他地点登录
    if (!dbToken.equals(token)) {
      throw new CustomizationException(ExceptionEnum.OTHER_PLACE_LOGIN);
    }
    // 如果需要校准 ip,再加上即可
  }

  /**
   * 获得token中的信息
   *
   * @return token中包含的名称
   */
  public static Map<String, Object> getDetails(String token) {
    if (null == token) {
      token = getToken();
    }
    try {
      DecodedJWT jwt = JWT.decode(token);
      Map<String, Claim> map = jwt.getClaims();
      Map<String, Object> returnMap = new HashMap<>();
      for (Map.Entry<String, Claim> entry : map.entrySet()) {
        String k = entry.getKey();
        String v = jwt.getClaim(k).asString();
        returnMap.put(k, v);
      }
      return returnMap;
    } catch (Exception e) {
      return null;
    }
  }

  /**
   * 根据请求头获取token
   * 
   * @return
   */
  public static String getToken() {
    HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
    String tokenHeader = request.getHeader(TOKEN_HEADER);
    if (StringUtils.isBlank(tokenHeader)) {
      throw new CustomizationException(ExceptionEnum.TOKEN_NOT_FOUND);
    }
    String token = tokenHeader.replace(JwtUtil.TOKEN_PREFIX, "");
    if (StringUtils.isBlank(tokenHeader)) {
      throw new CustomizationException(ExceptionEnum.TOKEN_NOT_FOUND);
    }
    return token;
  }
}