/*
 * Copyright (c) 2023 - present Dromara, All rights reserved.
 *
 *   https://visor.dromara.org
 *   https://visor.dromara.org.cn
 *   https://visor.orionsec.cn
 *
 * Members:
 *   Jiahang Li - ljh1553488six@139.com - author
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.dromara.visor.framework.datasource.core.filter;

import com.alibaba.druid.util.Utils;
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;

/**
 * druid 广告过滤器
 *
 * @author Jiahang Li
 * @version 1.0.0
 * @since 2023/6/23 17:23
 */
public class DruidAdRemoveFilter extends OncePerRequestFilter {

    /**
     * common.js 的路径
     */
    private static final String COMMON_JS_ILE_PATH = "support/http/resources/js/common.js";

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {
        chain.doFilter(request, response);
        // 重置缓冲区 响应头不会被重置
        response.resetBuffer();
        // 获取 common.js
        String text = Utils.readFromResource(COMMON_JS_ILE_PATH);
        // 正则替换 banner 除去底部的广告信息
        text = text.replaceAll("<a.*?banner\"></a><br/>", "");
        text = text.replaceAll("powered.*?shrek.wang</a>", "");
        response.getWriter().write(text);
    }

}
