/*
 * Copyright 1999-2011 Alibaba Group Holding Ltd.
 *
 * 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 com.alibaba.druid.util;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

public class DruidWebUtils {

    public static String getRemoteAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        return ip;
    }
    
    private static String getContextPath_2_5(ServletContext context) {
        String contextPath = context.getContextPath();

        if (contextPath == null || contextPath.length() == 0) {
            contextPath = "/";
        }

        return contextPath;
    }

    public static String getContextPath(ServletContext context) {
        if (context.getMajorVersion() == 2 && context.getMinorVersion() < 5) {
            return null;
        }

        try {
            return getContextPath_2_5(context);
        } catch (NoSuchMethodError error) {
            return null;
        }
    }
}
