/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.wicket.protocol.http.servlet;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletRequestWrapper;

/**
 * See <a href="http://code.google.com/p/xebia-france/wiki/XForwardedFilter">XForwardedFilter</a>
 * 
 * @author Juergen Donnerstag
 */
public class XForwardedRequestWrapper extends HttpServletRequestWrapper
{
        private SimpleDateFormat[] dateFormats = new SimpleDateFormat[] {
                        new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US),
                        new SimpleDateFormat("EEEEEE, dd-MMM-yy HH:mm:ss zzz", Locale.US),
                        new SimpleDateFormat("EEE MMMM d HH:mm:ss yyyy", Locale.US) };

        private Map<String, List<String>> headers;

        private String remoteAddr;

        private String remoteHost;

        private String scheme;

        private boolean secure;

        private int serverPort;

        /**
         * Construct.
         * 
         * @param request
         */
        @SuppressWarnings("unchecked")
        public XForwardedRequestWrapper(final HttpServletRequest request)
        {
                super(request);

                remoteAddr = request.getRemoteAddr();
                remoteHost = request.getRemoteHost();
                scheme = request.getScheme();
                secure = request.isSecure();
                serverPort = request.getServerPort();

                headers = new HashMap<String, List<String>>();
                Enumeration<?> headerNames = request.getHeaderNames();
                while (headerNames.hasMoreElements())
                {
                        String header = (String)headerNames.nextElement();
                        headers.put(header, Collections.list(request.getHeaders(header)));
                }
        }

        /**
         * @see jakarta.servlet.http.HttpServletRequestWrapper#getDateHeader(java.lang.String)
         */
        @Override
        public long getDateHeader(final String name)
        {
                String value = getHeader(name);
                if (value == null)
                {
                        return -1;
                }

                Date date = null;
                for (int i = 0; ((i < dateFormats.length) && (date == null)); i++)
                {
                        DateFormat dateFormat = dateFormats[i];
                        try
                        {
                                date = dateFormat.parse(value);
                        }
                        catch (Exception ignored)
                        {
                                ; // noop
                        }
                }

                if (date == null)
                {
                        throw new IllegalArgumentException(value);
                }
                else
                {
                        return date.getTime();
                }
        }

        /**
         * @see jakarta.servlet.http.HttpServletRequestWrapper#getHeader(java.lang.String)
         */
        @Override
        public String getHeader(final String name)
        {
                Map.Entry<String, List<String>> header = getHeaderEntry(name);
                if (header == null || header.getValue() == null || header.getValue().isEmpty())
                {
                        return null;
                }
                else
                {
                        return header.getValue().get(0);
                }
        }

        /**
         * 
         * @param name
         * @return The map entry for 'name'
         */
        private Map.Entry<String, List<String>> getHeaderEntry(final String name)
        {
                for (Map.Entry<String, List<String>> entry : headers.entrySet())
                {
                        if (entry.getKey().equalsIgnoreCase(name))
                        {
                                return entry;
                        }
                }
                return null;
        }

        /**
         * @see jakarta.servlet.http.HttpServletRequestWrapper#getHeaderNames()
         */
        @Override
        public Enumeration<String> getHeaderNames()
        {
                return Collections.enumeration(headers.keySet());
        }

        /**
         * @see jakarta.servlet.http.HttpServletRequestWrapper#getHeaders(java.lang.String)
         */
        @Override
        public Enumeration<String> getHeaders(final String name)
        {
                Map.Entry<String, List<String>> header = getHeaderEntry(name);
                if (header == null || header.getValue() == null)
                {
                        return Collections.enumeration(Collections.<String>emptyList());
                }
                else
                {
                        return Collections.enumeration(header.getValue());
                }
        }

        /**
         * @see jakarta.servlet.http.HttpServletRequestWrapper#getIntHeader(java.lang.String)
         */
        @Override
        public int getIntHeader(final String name)
        {
                String value = getHeader(name);
                if (value == null)
                {
                        return -1;
                }
                else
                {
                        return Integer.parseInt(value);
                }
        }

        /**
         * @see jakarta.servlet.ServletRequestWrapper#getRemoteAddr()
         */
        @Override
        public String getRemoteAddr()
        {
                return remoteAddr;
        }

        /**
         * @see jakarta.servlet.ServletRequestWrapper#getRemoteHost()
         */
        @Override
        public String getRemoteHost()
        {
                return remoteHost;
        }

        /**
         * @see jakarta.servlet.ServletRequestWrapper#getScheme()
         */
        @Override
        public String getScheme()
        {
                return scheme;
        }

        /**
         * @see jakarta.servlet.ServletRequestWrapper#getServerPort()
         */
        @Override
        public int getServerPort()
        {
                return serverPort;
        }

        /**
         * @see jakarta.servlet.ServletRequestWrapper#isSecure()
         */
        @Override
        public boolean isSecure()
        {
                return secure;
        }

        /**
         * @param name
         */
        public void removeHeader(final String name)
        {
                Map.Entry<String, List<String>> header = getHeaderEntry(name);
                if (header != null)
                {
                        headers.remove(header.getKey());
                }
        }

        /**
         * 
         * @param name
         * @param value
         */
        public void setHeader(final String name, final String value)
        {
                List<String> values = Arrays.asList(value);
                Map.Entry<String, List<String>> header = getHeaderEntry(name);
                if (header == null)
                {
                        headers.put(name, values);
                }
                else
                {
                        header.setValue(values);
                }
        }

        /**
         * 
         * @param remoteAddr
         */
        public void setRemoteAddr(final String remoteAddr)
        {
                this.remoteAddr = remoteAddr;
        }

        /**
         * 
         * @param remoteHost
         */
        public void setRemoteHost(final String remoteHost)
        {
                this.remoteHost = remoteHost;
        }

        /**
         * 
         * @param scheme
         */
        public void setScheme(final String scheme)
        {
                this.scheme = scheme;
        }

        /**
         * 
         * @param secure
         */
        public void setSecure(final boolean secure)
        {
                this.secure = secure;
        }

        /**
         * 
         * @param serverPort
         */
        public void setServerPort(final int serverPort)
        {
                this.serverPort = serverPort;
        }
}