package com.diagbot.config.security;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;
import org.springframework.stereotype.Service;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;

/**
 * @Description: 自定义权限拦截
 * @author: gaodm
 * @time: 2018/8/23 13:47
 */
@Service
public class UrlFilterSecurityInterceptor extends AbstractSecurityInterceptor implements Filter {


    @Autowired
    private FilterInvocationSecurityMetadataSource securityMetadataSource;

    @Autowired
    public void setUrlAccessDecisionManager(UrlAccessDecisionManager urlAccessDecisionManager) {
        super.setAccessDecisionManager(urlAccessDecisionManager);
    }


    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

        FilterInvocation fi = new FilterInvocation(request, response, chain);
        invoke(fi);
    }


    public void invoke(FilterInvocation fi) throws IOException, ServletException {
        //fi里面有一个被拦截的url
        //里面调用UrlMetadataSource的getAttributes(Object object)这个方法获取fi对应的所有权限
        //再调用UrlAccessDecisionManager的decide方法来校验用户的权限是否足够
        InterceptorStatusToken token = super.beforeInvocation(fi);
        try {
            //执行下一个拦截器
            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
        } finally {
            super.afterInvocation(token, null);
        }
    }


    @Override
    public void destroy() {

    }

    @Override
    public Class<?> getSecureObjectClass() {
        return FilterInvocation.class;

    }

    @Override
    public SecurityMetadataSource obtainSecurityMetadataSource() {
        return this.securityMetadataSource;
    }
}
