package com.lij.himeeter.common.filter;

import com.lij.himeeter.common.utils.StringUtils;
import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.http.HttpMethod;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * <pre>
 *
 * 文件名 :  XssFilter
 * 创建时间 : 2024年12月30日 19:04
 *
 * 文件描述 : 防止XSS攻击的过滤器
 *
 * </pre>
 *
 * @author Nobita
 * @version 1.0.0
 */

public class XssFilter implements Filter {

    /**
     * 排除链接
     */
    public List<String> excludes = new ArrayList<>();

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        String tempExcludes = filterConfig.getInitParameter("excludes");
        if (StringUtils.isNotEmpty(tempExcludes)) {
            String[] urls = tempExcludes.split(",");
            for (String url : urls) {
                excludes.add(url);
            }
        }
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;
        if (handleExcludeURL(req, resp)) {
            chain.doFilter(request, response);
            return;
        }
        XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);
        chain.doFilter(xssRequest, response);
    }

    private boolean handleExcludeURL(HttpServletRequest request, HttpServletResponse response) {
        String url = request.getServletPath();
        String method = request.getMethod();
        // GET DELETE 不过滤
        if (method == null || HttpMethod.GET.matches(method) || HttpMethod.DELETE.matches(method)) {
            return true;
        }
        return StringUtils.matches(url, excludes);
    }

    @Override
    public void destroy() {

    }
}
