package com.xcong.excoin.configurations.security;

import cn.hutool.core.util.StrUtil;
import cn.hutool.crypto.asymmetric.KeyType;
import cn.hutool.crypto.asymmetric.RSA;
import com.alibaba.fastjson.JSONObject;
import com.xcong.excoin.common.contants.AppContants;
import com.xcong.excoin.common.system.bean.LoginUserBean;
import com.xcong.excoin.configurations.properties.ApplicationProperties;
import com.xcong.excoin.configurations.properties.SecurityProperties;
import com.xcong.excoin.utils.RedisUtils;
import com.xcong.excoin.utils.SpringContextHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.GenericFilterBean;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.util.ArrayList;

/**
 * @author wzy
 * @date 2020-05-12
 **/
@Slf4j
public class TokenFilter extends GenericFilterBean {

    private final ApplicationProperties applicationProperties = SpringContextHolder.getBean(ApplicationProperties.class);

    private final SecurityProperties securityProperties = SpringContextHolder.getBean(SecurityProperties.class);

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

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String token = resolveToken(request);
        if (StrUtil.isNotBlank(token)) {
            String loginStr = (String) redisUtils.get(AppContants.APP_LOGIN_PREFIX + token);
            if (StrUtil.isNotBlank(loginStr)) {
                LoginUserBean loginUser = JSONObject.parseObject(loginStr, LoginUserBean.class);
                Authentication authentication = new UsernamePasswordAuthenticationToken(loginUser.getMemberEntity(), token, new ArrayList<>());
                SecurityContextHolder.getContext().setAuthentication(authentication);
                redisUtils.expire(AppContants.APP_LOGIN_PREFIX + token, 300000);
            } else {
                SecurityContextHolder.clearContext();
            }
        } else {
            SecurityContextHolder.clearContext();
        }

        filterChain.doFilter(servletRequest, servletResponse);
    }

    /**
     * 解析前端传来的token，先去掉Bearer，在rsa解密得到token_time，返回token，并判断time与当前是否在5s内
     *
     * @param request
     * @return
     */
    private String resolveToken(HttpServletRequest request) {
        try {
            // TODO debug模式下写死用户
            String bearerToken = "";
            if (applicationProperties.isDebug()) {
                bearerToken = "Bearer JSEre1ZUKEu2Ga5ORM+juxXv6yBwmt+FgLhxaeHf1EEJfIb3oRir4pXqe5JDhS6sXfLYOXRIAyBpq+SYBwAtGigxwzGVPn+k4Pt6vNxZ4h8Pk4IeG4+FqbFD0guzvu3WN2eRnnzYqCepl429v9Ju7n4jSG0Hj5ViM3MHQZs3qHo=";
            } else {
                bearerToken = request.getHeader(AppContants.TOKEN_HEADER);
            }
            if (StringUtils.hasText(bearerToken) && bearerToken.startsWith(AppContants.TOKEN_START_WITH)) {
                // 去掉令牌前缀
                String rsaToken = bearerToken.replace(AppContants.TOKEN_START_WITH, "");
                RSA rsa = new RSA(securityProperties.getPrivateKey(), null);
                String[] tokens = StrUtil.split(rsa.decryptStr(rsaToken, KeyType.PrivateKey), "_");
                if (verifyTokenExpired(Long.parseLong(tokens[1]))) {
                    return tokens[0];
                }
                return null;
            }
        } catch (Exception e) {
            log.error("#解析token异常#", e);
            return null;
        }
        return null;
    }

    private Boolean verifyTokenExpired(Long time) {
        boolean isDebug = applicationProperties.isDebug();
        if (!isDebug) {
            long currentTime = System.currentTimeMillis();
            return currentTime - time <= 5000;
        }
        return true;
    }
}