/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*     * Redistributions of source code must retain the above copyright
*       notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright
*       notice, this list of conditions and the following disclaimer in the
*       documentation and/or other materials provided with the distribution.
*     * Neither the name of the OpenSimulator Project nor the
*       names of its contributors may be used to endorse or promote products
*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/

using System.Collections;
using System.Reflection;
using System.Xml;
using log4net;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Framework.Capabilities;
using OpenSim.Framework.Servers;
using OpenSim.Framework.Servers.HttpServer;
using OpenSim.Region.Framework.Scenes;
using Caps = OpenSim.Framework.Capabilities.Caps;

namespace OpenSim.Region.DataSnapshot
{
    public class DataRequestHandler
    {
//        private Scene m_scene = null;
        private DataSnapshotManager m_externalData = null;
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
        private ExpiringCache<string, int> throotleGen = new ExpiringCache<string, int>();

        public DataRequestHandler(Scene scene, DataSnapshotManager externalData)
        {
//            m_scene = scene;
            m_externalData = externalData;

            //Register HTTP handler
            if (MainServer.UnSecureInstance.AddHTTPHandler("collector", OnGetSnapshot))
            {
                m_log.Info("[DATASNAPSHOT]: Set up snapshot service");
            }
            // Register validation callback handler
            MainServer.UnSecureInstance.AddHTTPHandler("validate", OnValidate);

        }

        private string GetClientString(Hashtable request)
        {
            string clientstring = "";
            if (!request.ContainsKey("headers"))
                return clientstring;

            Hashtable requestinfo = (Hashtable)request["headers"];
            if (requestinfo.ContainsKey("x-forwarded-for"))
            {
                object str = requestinfo["x-forwarded-for"];
                if (str != null)
                {
                    if (!string.IsNullOrEmpty(str.ToString()))
                    {
                        return str.ToString();
                    }
                }
            }
            if (!requestinfo.ContainsKey("remote_addr"))
                return clientstring;

            object remote_addrobj = requestinfo["remote_addr"];
            if (remote_addrobj != null)
            {
                if (!string.IsNullOrEmpty(remote_addrobj.ToString()))
                {
                    clientstring = remote_addrobj.ToString();
                }
            }

            return clientstring;
        }

        public Hashtable OnGetSnapshot(Hashtable keysvals)
        {
            Hashtable reply = new Hashtable();
            string reqtag;
            string snapObj = (string)keysvals["region"];
            if(string.IsNullOrWhiteSpace(snapObj))
                reqtag = GetClientString(keysvals);
            else
                reqtag = snapObj + GetClientString(keysvals);


            if(!string.IsNullOrWhiteSpace(reqtag))
            {
                if(throotleGen.Contains(reqtag))
                {
                    reply["str_response_string"] = "Please try your request again later";
                    reply["int_response_code"] = 503;
                    reply["content_type"] = "text/plain";
                    m_log.Debug("[DATASNAPSHOT] Collection request spam. reply try later");
                    return reply;
                }

                throotleGen.AddOrUpdate(reqtag, 0, 60);
            }

            if(string.IsNullOrWhiteSpace(snapObj))
                m_log.DebugFormat("[DATASNAPSHOT] Received collection request for all");
            else
               m_log.DebugFormat("[DATASNAPSHOT] Received collection request for {0}", snapObj);

            XmlDocument response = m_externalData.GetSnapshot(snapObj);
            if(response == null)
            {
                reply["str_response_string"] = "Please try your request again later";
                reply["int_response_code"] = 503;
                reply["content_type"] = "text/plain";
                m_log.Debug("[DATASNAPSHOT] Collection request spam. reply try later");
                return reply;
            }

            reply["str_response_string"] = response.OuterXml;
            reply["int_response_code"] = 200;
            reply["content_type"] = "text/xml";
            return reply;
        }

        public Hashtable OnValidate(Hashtable keysvals)
        {
            m_log.Debug("[DATASNAPSHOT] Received validation request");
            Hashtable reply = new Hashtable();
            int statuscode = 200;

            string secret = (string)keysvals["secret"];
            if (secret == m_externalData.Secret.ToString())
                statuscode = 403;

            reply["str_response_string"] = string.Empty;
            reply["int_response_code"] = statuscode;
            reply["content_type"] = "text/plain";

            return reply;
        }

    }
}