package com.macro.mall.component;

import com.macro.mall.util.JwtTokenUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

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

/**
 * JWT登录授权过滤器
 */
public class JwtAuthenticationTokenFilter extends OncePerRequestFilter {
    private static final Logger LOGGER = LoggerFactory.getLogger(JwtAuthenticationTokenFilter.class);
   /*声明Log4jUtils类，处理Logger的操作*/
    @Autowired
    private UserDetailsService userDetailsService;//用户详细信息服务
    @Autowired
    private JwtTokenUtil jwtTokenUtil;//jwt登录授权
    @Value("${jwt.tokenHeader}")
    private String tokenHeader;//登录表头
    @Value("${jwt.tokenHead}")
    private String tokenHead;

    @Override
    protected void doFilterInternal(HttpServletRequest request,
                                    HttpServletResponse response,
                                    FilterChain chain) throws ServletException, IOException {
    	 /*Filter方法，实现过滤功能*/
        String authHeader = request.getHeader(this.tokenHeader);
        if (authHeader != null && authHeader.startsWith(this.tokenHead)) {
            String authToken = authHeader.substring(this.tokenHead.length());// The part after "Bearer "
            String username = jwtTokenUtil.getUserNameFromToken(authToken);
            LOGGER.info("checking username:{}", username);
            if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {
                UserDetails userDetails = this.userDetailsService.loadUserByUsername(username);
                if (jwtTokenUtil.validateToken(authToken, userDetails)) {
                	/*将验证信息放入SecurityContextHolder中，UsernamePasswordAuthenticationToken是Security验证账号密码的工具类*/
                    UsernamePasswordAuthenticationToken authentication = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                    authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                    LOGGER.info("authenticated user:{}", username);
                    SecurityContextHolder.getContext().setAuthentication(authentication);
                }
            }
        }
        chain.doFilter(request, response);//将请求转发给过滤器链上下一个对象
    }
}