package cc.mrbird.febs.common.interceptor;

import cc.mrbird.febs.common.entity.FebsResponse;
import cc.mrbird.febs.common.utils.AppContants;
import cc.mrbird.febs.common.utils.RedisUtils;
import cc.mrbird.febs.common.utils.SpringContextUtil;
import cc.mrbird.febs.mall.entity.MallMember;
import cn.hutool.core.util.StrUtil;
import cn.hutool.crypto.asymmetric.KeyType;
import cn.hutool.crypto.asymmetric.RSA;
import com.alibaba.fastjson.JSON;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.HttpStatus;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author xxx
 * @date 2020-08-24
 **/
@Slf4j
public class LoginInterceptor implements HandlerInterceptor {

    private final RedisUtils redisUtils = SpringContextUtil.getBean(RedisUtils.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String headerToken = request.getHeader("token");
        if (StringUtils.isBlank(headerToken)) {
            responseUnAuth(response);
            return false;
        }

        String token = resolveToken(headerToken);

        if (token == null || AppContants.TIME_OUT.equals(token)) {
            responseUnAuth(response);
            return false;
        }

        String userJsonStr = redisUtils.getString(token);
        if (StringUtils.isBlank(userJsonStr)) {
            responseUnAuth(response);
            return false;
        }
        MallMember member = JSON.parseObject(userJsonStr, MallMember.class);

        request.getSession().setAttribute("member", member);
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }

    private void responseUnAuth(HttpServletResponse response) throws IOException {
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/json; charset=utf-8");
        response.getWriter().write(new ObjectMapper().writeValueAsString(new FebsResponse().code(HttpStatus.UNAUTHORIZED)));
    }

    private String resolveToken(String token) {
        try {
            RSA rsa = new RSA(AppContants.PRIVATE_KEY, null);
            String[] tokens = StrUtil.split(rsa.decryptStr(token, KeyType.PrivateKey), "_");
            if (verifyTokenExpired(Long.parseLong(tokens[1]))) {
                return tokens[0];
            } else {
                return AppContants.TIME_OUT;
            }
        } catch (Exception e) {
            log.error("#解析token异常#", e);
            return null;
        }
    }

    private Boolean verifyTokenExpired(Long time) {
        boolean isDebug = false;
        if (!isDebug) {
            long currentTime = System.currentTimeMillis();
            return currentTime - time <= 30000;
        }
        return true;
    }
}