package org.codiki.core.security;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.security.web.csrf.CsrfToken;
import org.springframework.web.filter.OncePerRequestFilter;
import org.springframework.web.util.WebUtils;

public class XSRFTokenFilter extends OncePerRequestFilter {
	private static final String XSRF_TOKEN_PATH = "/";
	private static final String XSRF_TOKEN = "XSRF-TOKEN";

	@Override
	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
			throws ServletException, IOException {
		CsrfToken csrf = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
		if(csrf != null) {
			Cookie cookie = WebUtils.getCookie(request, XSRF_TOKEN);
			String token = csrf.getToken();
			if(cookie == null || token != null && !token.equals(cookie.getValue())) {
				cookie = new Cookie(XSRF_TOKEN, token);
				cookie.setPath(XSRF_TOKEN_PATH);
				response.addCookie(cookie);
			}
		}
		filterChain.doFilter(request, response);
	}
}
