/*
 * 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 OpenSim 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;
using System.Collections;
using System.Collections.Generic;
using System.Net;
using System.Reflection;
using System.Threading;
using libsecondlife;
using log4net;
using Nwc.XmlRpc;
using OpenSim.Data;
using OpenSim.Framework;

//using System.Xml;

namespace OpenSim.Grid.MessagingServer
{
    public class MessageService
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private MessageServerConfig m_cfg;
        private UserManager m_userManager;

        //A hashtable of all current presences this server knows about
        private Hashtable m_presences = new Hashtable();

        //a hashtable of all current regions this server knows about
        private Hashtable m_regionInfoCache = new Hashtable();

        //A hashtable containing lists of UUIDs keyed by UUID for fast backreferencing
        private Hashtable m_presence_BackReferences = new Hashtable();

        // Hashtable containing work units that need to be processed
        // private Hashtable m_unProcessedWorkUnits = new Hashtable();

        public MessageService(MessageServerConfig cfg)
        {
            m_cfg = cfg;
            m_userManager = new UserManager();
            UserConfig uc = new UserConfig();
            uc.DatabaseConnect = cfg.DatabaseConnect;
            uc.DatabaseProvider = cfg.DatabaseProvider;

            m_userManager._config = uc;
            m_userManager.AddPlugin(cfg.DatabaseProvider, cfg.DatabaseConnect);
        }



        #region FriendList Methods

        /// <summary>
        /// Process Friendlist subscriptions for a user
        /// The login method calls this for a User
        /// </summary>
        /// <param name="userpresence">The Agent we're processing the friendlist subscriptions</param>
        public void ProcessFriendListSubscriptions(UserPresenceData userpresence)
        {
            lock (m_presences)
            {
                if (!m_presences.Contains(userpresence.agentData.AgentID))
                    m_presences.Add(userpresence.agentData.AgentID, userpresence);
                else
                    m_presences[userpresence.agentData.AgentID] = userpresence;
            }

            List<FriendListItem> uFriendList = userpresence.friendData;
            for (int i = 0; i < uFriendList.Count; i++)
            {
                //m_presence_BackReferences.Add(userpresence.agentData.AgentID, uFriendList[i].Friend);
               // m_presence_BackReferences.Add(uFriendList[i].Friend, userpresence.agentData.AgentID);

                if (m_presences.Contains(uFriendList[i].Friend))
                {
                    UserPresenceData friendup = (UserPresenceData)m_presences[uFriendList[i].Friend];
                    // Add backreference

                    SubscribeToPresenceUpdates(userpresence, friendup, uFriendList[i],i);
                }
            }
        }

        /// <summary>
        /// Does the necessary work to subscribe one agent to another's presence notifications
        /// Gets called by ProcessFriendListSubscriptions.  You shouldn't call this directly
        /// unless you know what you're doing
        /// </summary>
        /// <param name="userpresence">P1</param>
        /// <param name="friendpresence">P2</param>
        /// <param name="uFriendListItem"></param>
        /// <param name="uFriendListIndex"></param>
        public void SubscribeToPresenceUpdates(UserPresenceData userpresence, UserPresenceData friendpresence,
                                                FriendListItem uFriendListItem, int uFriendListIndex)
        {
            if ((uFriendListItem.FriendListOwnerPerms & (uint)FriendRights.CanSeeOnline) != 0)
            {
                // Subscribe and Send Out updates
                if (!friendpresence.subscriptionData.Contains(friendpresence.agentData.AgentID))
                {
                    userpresence.subscriptionData.Add(friendpresence.agentData.AgentID);
                    //Send Region Notice....
                }
                else
                {
                    // we need to send out online status update, but the user is already subscribed
                }
                UserAgentData p2Handle = m_userManager.GetUserAgentData(userpresence.agentData.AgentID);
                if (p2Handle != null)
                {
                    if (userpresence.lookupUserRegionYN)
                    {
                        userpresence.regionData.regionHandle = p2Handle.Handle;
                    }
                    else
                    {
                        userpresence.lookupUserRegionYN = true;
                    }
                    PresenceInformer friendlistupdater = new PresenceInformer();
                    friendlistupdater.presence1 = friendpresence;
                    //friendlistupdater.gridserverurl = m_cfg.GridServerURL;
                    //friendlistupdater.gridserversendkey = m_cfg.GridSendKey;
                    //friendlistupdater.gridserverrecvkey = m_cfg.GridRecvKey;
                    friendlistupdater.presence2 = userpresence;
                    friendlistupdater.OnGetRegionData += GetRegionInfo;
                    friendlistupdater.OnDone += PresenceUpdateDone;
                    WaitCallback cb = new WaitCallback(friendlistupdater.go);
                    ThreadPool.QueueUserWorkItem(cb);

                }
                else
                {
                    // Skip because we can't find any data on the user
                }

                //SendRegionPresenceUpdate(friendpresence, userpresence);
            }

            if ((uFriendListItem.FriendPerms & (uint)FriendRights.CanSeeOnline) != 0)
            {
                if (!friendpresence.subscriptionData.Contains(userpresence.agentData.AgentID))
                {
                    friendpresence.subscriptionData.Add(userpresence.agentData.AgentID);
                    //Send Region Notice....
                }
                else
                {
                    // we need to send out online status update, but the user is already subscribed
                }

                UserAgentData p2Handle = m_userManager.GetUserAgentData(friendpresence.agentData.AgentID);

                if (p2Handle != null)
                {

                    friendpresence.regionData.regionHandle = p2Handle.Handle;
                    PresenceInformer friendlistupdater = new PresenceInformer();
                    friendlistupdater.presence1 = userpresence;
                    friendlistupdater.presence2 = friendpresence;
                    //friendlistupdater.gridserverurl = m_cfg.GridServerURL;
                    //friendlistupdater.gridserversendkey = m_cfg.GridSendKey;
                    //friendlistupdater.gridserverrecvkey = m_cfg.GridRecvKey;
                    friendlistupdater.OnGetRegionData += GetRegionInfo;
                    friendlistupdater.OnDone += PresenceUpdateDone;
                    WaitCallback cb2 = new WaitCallback(friendlistupdater.go);
                    ThreadPool.QueueUserWorkItem(cb2);
                }
                else
                {
                    // skip, agent doesn't appear to exist anymore
                }



                //SendRegionPresenceUpdate(userpresence, friendpresence);
            }
        }

        /// <summary>
        /// Adds a backreference so presence specific data doesn't have to be
        /// enumerated for each logged in user every time someone logs on or off.
        /// </summary>
        /// <param name="agentID"></param>
        /// <param name="friendID"></param>
        public void addBackReference(LLUUID agentID, LLUUID friendID)
        {
            if (m_presence_BackReferences.Contains(friendID))
            {
                List<LLUUID> presenseBackReferences = (List<LLUUID>)m_presence_BackReferences[friendID];
                if (!presenseBackReferences.Contains(agentID))
                {
                    presenseBackReferences.Add(agentID);
                }
                m_presence_BackReferences[friendID] = presenseBackReferences;
            }
            else
            {
                List<LLUUID> presenceBackReferences = new List<LLUUID>();
                presenceBackReferences.Add(agentID);
                m_presence_BackReferences[friendID] = presenceBackReferences;
            }
        }

        /// <summary>
        /// Removes a backreference to free up some memory
        /// </summary>
        /// <param name="agentID"></param>
        /// <param name="friendID"></param>
        public void removeBackReference(LLUUID agentID, LLUUID friendID)
        {
            if (m_presence_BackReferences.Contains(friendID))
            {
                List<LLUUID> presenseBackReferences = (List<LLUUID>)m_presence_BackReferences[friendID];
                if (presenseBackReferences.Contains(agentID))
                {
                    presenseBackReferences.Remove(agentID);
                }

                // If there are no more backreferences for this agent,
                // remove it to free up memory.
                if (presenseBackReferences.Count == 0)
                {
                    m_presence_BackReferences.Remove(agentID);
                }
            }
        }

        /// <summary>
        /// Logoff Processor.  Call this to clean up agent presence data and send logoff presence notifications
        /// </summary>
        /// <param name="AgentID"></param>
        private void ProcessLogOff(LLUUID AgentID)
        {
            m_log.Info("[LOGOFF]: Processing Logoff");
            UserPresenceData AgentData = null;
            List<LLUUID> AgentsNeedingNotification = new List<LLUUID>();
            UserPresenceData friendd = null;
            lock (m_presences)
            {
                if (m_presences.Contains(AgentID))
                {
                    AgentData = (UserPresenceData)m_presences[AgentID];
                }
            }

            if (AgentData != null)
            {
                 AgentsNeedingNotification = AgentData.subscriptionData;
                 AgentData.OnlineYN = false;
                //lock (m_presence_BackReferences)
                //{
                    //if (m_presence_BackReferences.Contains(AgentID))
                    //{
                        //AgentsNeedingNotification = (List<LLUUID>)m_presence_BackReferences[AgentID];
                    //}
                //}

                for (int i = 0; i < AgentsNeedingNotification.Count; i++)
                {
                    // TODO: Do Region Notifications
                    lock (m_presences)
                    {
                        if (m_presences.Contains(AgentsNeedingNotification[i]))
                        {
                            friendd = (UserPresenceData)m_presences[AgentsNeedingNotification[i]];
                        }
                    }

                    // This might need to be enumerated and checked before we try to remove it.
                    if (friendd != null)
                    {
                        lock (friendd)
                        {
                            friendd.subscriptionData.Remove(AgentID);

                            List<FriendListItem> fl = friendd.friendData;
                            for (int j = 0; j < fl.Count; j++)
                            {
                                if (fl[j].Friend == AgentID)
                                {
                                    fl[j].onlinestatus = false;
                                }
                            }

                            friendd.friendData = fl;
                            m_presences[AgentsNeedingNotification[i]] = friendd;
                        }

                        UserAgentData p2Handle = m_userManager.GetUserAgentData(friendd.agentData.AgentID);
                        if (p2Handle != null)
                        {


                                friendd.regionData.regionHandle = p2Handle.Handle;
                                PresenceInformer friendlistupdater = new PresenceInformer();
                                friendlistupdater.presence1 = AgentData;
                                friendlistupdater.presence2 = friendd;

                                //friendlistupdater.gridserverurl = m_cfg.GridServerURL;
                                //friendlistupdater.gridserversendkey = m_cfg.GridSendKey;
                                //friendlistupdater.gridserverrecvkey = m_cfg.GridRecvKey;

                                friendlistupdater.OnGetRegionData += GetRegionInfo;
                                friendlistupdater.OnDone += PresenceUpdateDone;

                                WaitCallback cb3 = new WaitCallback(friendlistupdater.go);
                                ThreadPool.QueueUserWorkItem(cb3);



                        }
                        else
                        {
                            // skip, agent can't be found
                        }
                        //SendRegionPresenceUpdate(AgentData, friendd);

                        //removeBackReference(AgentID, AgentsNeedingNotification[i]);
                    }
                }
            }
        }

        #endregion

        public void PresenceUpdateDone(PresenceInformer obj)
        {
            obj.OnGetRegionData -= GetRegionInfo;
            obj.OnDone -= PresenceUpdateDone;
        }

        #region UserServer Comms

        /// <summary>
        /// Returns a list of FriendsListItems that describe the friends and permissions in the friend relationship for LLUUID friendslistowner
        /// </summary>
        /// <param name="friendlistowner">The agent that we're retreiving the friends Data.</param>
        public List<FriendListItem> GetUserFriendList(LLUUID friendlistowner)
        {
            List<FriendListItem> buddylist = new List<FriendListItem>();

            try
            {
                Hashtable param = new Hashtable();
                param["ownerID"] = friendlistowner.UUID.ToString();

                IList parameters = new ArrayList();
                parameters.Add(param);
                XmlRpcRequest req = new XmlRpcRequest("get_user_friend_list", parameters);
                XmlRpcResponse resp = req.Send(m_cfg.UserServerURL, 3000);
                Hashtable respData = (Hashtable)resp.Value;

                if (respData.Contains("avcount"))
                {
                    buddylist = ConvertXMLRPCDataToFriendListItemList(respData);
                }

            }
            catch (WebException e)
            {
                m_log.Warn("Error when trying to fetch Avatar's friends list: " +
                                      e.Message);
                // Return Empty list (no friends)
            }
            return buddylist;
        }

        /// <summary>
        /// Converts XMLRPC Friend List to FriendListItem Object
        /// </summary>
        /// <param name="data">XMLRPC response data Hashtable</param>
        /// <returns></returns>
        public List<FriendListItem> ConvertXMLRPCDataToFriendListItemList(Hashtable data)
        {
            List<FriendListItem> buddylist = new List<FriendListItem>();
            int buddycount = Convert.ToInt32((string)data["avcount"]);

            for (int i = 0; i < buddycount; i++)
            {
                FriendListItem buddylistitem = new FriendListItem();

                buddylistitem.FriendListOwner = new LLUUID((string)data["ownerID" + i.ToString()]);
                buddylistitem.Friend = new LLUUID((string)data["friendID" + i.ToString()]);
                buddylistitem.FriendListOwnerPerms = (uint)Convert.ToInt32((string)data["ownerPerms" + i.ToString()]);
                buddylistitem.FriendPerms = (uint)Convert.ToInt32((string)data["friendPerms" + i.ToString()]);

                buddylist.Add(buddylistitem);
            }

            return buddylist;
        }

        /// <summary>
        /// UserServer sends an expect_user method
        /// this handles the method and provisions the
        /// necessary info for presence to work
        /// </summary>
        /// <param name="request">UserServer Data</param>
        /// <returns></returns>
        public XmlRpcResponse UserLoggedOn(XmlRpcRequest request)
        {
            m_log.Info("[LOGON]: User logged on, building indexes for user");
            Hashtable requestData = (Hashtable)request.Params[0];

            //requestData["sendkey"] = serv.sendkey;
            //requestData["agentid"] = agentID.ToString();
            //requestData["sessionid"] = sessionID.ToString();
            //requestData["regionid"] = RegionID.ToString();
            //requestData["regionhandle"] = regionhandle.ToString();
            //requestData["positionx"] = positionX.ToString();
            //requestData["positiony"] = positionY.ToString();
            //requestData["positionz"] = positionZ.ToString();
            //requestData["firstname"] = firstname;
            //requestData["lastname"] = lastname;

            AgentCircuitData agentData = new AgentCircuitData();
            agentData.SessionID = new LLUUID((string)requestData["sessionid"]);
            agentData.SecureSessionID = new LLUUID((string)requestData["secure_session_id"]);
            agentData.firstname = (string)requestData["firstname"];
            agentData.lastname = (string)requestData["lastname"];
            agentData.AgentID = new LLUUID((string)requestData["agentid"]);
            agentData.circuitcode = Convert.ToUInt32(requestData["circuit_code"]);
            agentData.CapsPath = (string)requestData["caps_path"];

            if (requestData.ContainsKey("child_agent") && requestData["child_agent"].Equals("1"))
            {
                agentData.child = true;
            }
            else
            {
                agentData.startpos =
                     new LLVector3(Convert.ToUInt32(requestData["positionx"]),
                                  Convert.ToUInt32(requestData["positiony"]),
                                  Convert.ToUInt32(requestData["positionz"]));
                agentData.child = false;
            }

            ulong regionHandle = Convert.ToUInt64((string)requestData["regionhandle"]);

            UserPresenceData up = new UserPresenceData();
            up.agentData = agentData;
            List<FriendListItem> flData = GetUserFriendList(agentData.AgentID);
            up.friendData = flData;
            RegionProfileData riData = GetRegionInfo(regionHandle);
            up.regionData = riData;
            up.OnlineYN = true;
            up.lookupUserRegionYN = false;
            ProcessFriendListSubscriptions(up);

            return new XmlRpcResponse();
        }

        /// <summary>
        /// The UserServer got a Logoff message
        /// Cleanup time for that user.  Send out presence notifications
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        public XmlRpcResponse UserLoggedOff(XmlRpcRequest request)
        {
            m_log.Info("[USERLOGOFF]: User logged off called");
            Hashtable requestData = (Hashtable)request.Params[0];

            LLUUID AgentID = new LLUUID((string)requestData["agentid"]);

            ProcessLogOff(AgentID);

            return new XmlRpcResponse();
        }

        #endregion

        #region regioninfo gathering

        /// <summary>
        /// Gets and caches a RegionInfo object from the gridserver based on regionhandle
        /// if the regionhandle is already cached, use the cached values
        /// Gets called by lots of threads!!!!!
        /// </summary>
        /// <param name="regionhandle">handle to the XY of the region we're looking for</param>
        /// <returns>A RegionInfo object to stick in the presence info</returns>
        public RegionProfileData GetRegionInfo(ulong regionhandle)
        {
            RegionProfileData regionInfo = null;
            bool lookup = false;

            lock (m_regionInfoCache)
            {
                if (m_regionInfoCache.Contains(regionhandle))
                {
                    regionInfo = (RegionProfileData)m_regionInfoCache[regionhandle];
                }
                else
                {
                    // Don't lock the cache while we're looking up the region!
                    lookup = true;
                }
            }

            if (lookup)
            {
                regionInfo = RequestRegionInfo(regionhandle);

                if (regionInfo != null)
                {
                    lock (m_regionInfoCache)
                    {
                        if (m_regionInfoCache.Contains(regionhandle))
                        {
                            m_regionInfoCache[regionhandle] = regionInfo;
                        }
                        else
                        {
                            m_regionInfoCache.Add(regionhandle, regionInfo);
                        }
                    }
                }
            }

            return regionInfo;
        }

        public int ClearRegionCache()
        {
            int cachecount = 0;

            lock (m_regionInfoCache)
            {
                cachecount = m_regionInfoCache.Count;
                m_regionInfoCache.Clear();
            }

            return cachecount;
        }

        /// <summary>
        /// Get RegionProfileData from the GridServer
        /// We'll Cache this information and use it for presence updates
        /// </summary>
        /// <param name="regionHandle"></param>
        /// <returns></returns>
        public RegionProfileData RequestRegionInfo(ulong regionHandle)
        {   RegionProfileData regionProfile = null;
            try
            {
                Hashtable requestData = new Hashtable();
                requestData["region_handle"] = regionHandle.ToString();
                requestData["authkey"] = m_cfg.GridSendKey;
                ArrayList SendParams = new ArrayList();
                SendParams.Add(requestData);
                XmlRpcRequest GridReq = new XmlRpcRequest("simulator_data_request", SendParams);
                XmlRpcResponse GridResp = GridReq.Send(m_cfg.GridServerURL, 3000);

                Hashtable responseData = (Hashtable)GridResp.Value;

                if (responseData.ContainsKey("error"))
                {
                    m_log.Error("[GRID]: error received from grid server" + responseData["error"]);
                    return null;
                }

                uint regX = Convert.ToUInt32((string)responseData["region_locx"]);
                uint regY = Convert.ToUInt32((string)responseData["region_locy"]);
                string internalIpStr = (string)responseData["sim_ip"];
                // uint port = Convert.ToUInt32(responseData["sim_port"]);
                // string externalUri = (string)responseData["sim_uri"];
                // string neighbourExternalUri = externalUri;

                regionProfile = new RegionProfileData();
                regionProfile.httpPort = (uint)Convert.ToInt32((string)responseData["http_port"]);
                regionProfile.httpServerURI = "http://" + internalIpStr + ":" + regionProfile.httpPort + "/";
                regionProfile.regionHandle = Helpers.UIntsToLong((regX * Constants.RegionSize), (regY * Constants.RegionSize));
                regionProfile.regionLocX = regX;
                regionProfile.regionLocY = regY;

                regionProfile.remotingPort = Convert.ToUInt32((string)responseData["remoting_port"]);
                regionProfile.UUID = new LLUUID((string)responseData["region_UUID"]);
                regionProfile.regionName = (string)responseData["region_name"];
                lock (m_regionInfoCache)
                {
                    if (!m_regionInfoCache.Contains(regionHandle))
                    {
                        m_regionInfoCache.Add(regionHandle, regionProfile);
                    }
                }
            }
            catch (WebException)
            {
                m_log.Error("[GRID]: " +
                            "Region lookup failed for: " + regionHandle.ToString() +
                            " - Is the GridServer down?");
                return null;
            }

            return regionProfile;
        }

        public bool registerWithUserServer ()
        {
            Hashtable UserParams = new Hashtable();
            // Login / Authentication

            if (m_cfg.HttpSSL)
            {
                UserParams["uri"] = "https://" + m_cfg.MessageServerIP + ":" + m_cfg.HttpPort;
            }
            else
            {
                UserParams["uri"] = "http://" + m_cfg.MessageServerIP + ":" + m_cfg.HttpPort;
            }

            UserParams["recvkey"] = m_cfg.UserRecvKey;
            UserParams["sendkey"] = m_cfg.UserRecvKey;

            // Package into an XMLRPC Request
            ArrayList SendParams = new ArrayList();
            SendParams.Add(UserParams);

            // Send Request
            XmlRpcRequest UserReq;
            XmlRpcResponse UserResp;
            try
            {
                UserReq = new XmlRpcRequest("register_messageserver", SendParams);
                UserResp = UserReq.Send(m_cfg.UserServerURL, 16000);
            } catch (Exception ex)
            {
                m_log.Error("Unable to connect to grid. Grid server not running?");
                throw(ex);
            }
            Hashtable GridRespData = (Hashtable)UserResp.Value;
            // Hashtable griddatahash = GridRespData;

            // Process Response
            if (GridRespData.ContainsKey("responsestring"))
            {

                return true;
            }
            else
            {
                return false;
            }
        }

        public bool deregisterWithUserServer()
        {
            Hashtable UserParams = new Hashtable();
            // Login / Authentication

            if (m_cfg.HttpSSL)
            {
                UserParams["uri"] = "https://" + m_cfg.MessageServerIP + ":" + m_cfg.HttpPort;
            }
            else
            {
                UserParams["uri"] = "http://" + m_cfg.MessageServerIP + ":" + m_cfg.HttpPort;
            }

            UserParams["recvkey"] = m_cfg.UserRecvKey;
            UserParams["sendkey"] = m_cfg.UserRecvKey;

            // Package into an XMLRPC Request
            ArrayList SendParams = new ArrayList();
            SendParams.Add(UserParams);

            // Send Request
            XmlRpcRequest UserReq;
            XmlRpcResponse UserResp;
            try
            {
                UserReq = new XmlRpcRequest("deregister_messageserver", SendParams);
                UserResp = UserReq.Send(m_cfg.UserServerURL, 16000);
            }
            catch (Exception ex)
            {
                m_log.Error("Unable to connect to grid. Grid server not running?");
                throw (ex);
            }
            Hashtable UserRespData = (Hashtable)UserResp.Value;
            // Hashtable userdatahash = UserRespData;

            // Process Response
            if (UserRespData.ContainsKey("responsestring"))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        #endregion
    }
}