/*
 * 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;
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 * 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.
 */

#region Header

// FileSystemDatabase.cs
// User: bongiojp

#endregion Header

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using Slash = System.IO.Path;
using System.Reflection;
using System.Xml;

using OpenMetaverse;

using Nini.Config;

using OpenSim.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Region.CoreModules.World.Serialiser;
using OpenSim.Region.CoreModules.World.Terrain;
using OpenSim.Region.Physics.Manager;

using log4net;

namespace OpenSim.Region.OptionalModules.ContentManagement
{
    public class FileSystemDatabase : IContentDatabase
    {
        #region Static Fields

        public static float TimeToDownload = 0;
        public static float TimeToSave = 0;
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        #endregion Static Fields

        #region Fields

        private string m_repodir = null;
        private Dictionary<UUID, Scene> m_scenes = new Dictionary<UUID, Scene>();
        private Dictionary<UUID, IRegionSerialiserModule> m_serialiser = new Dictionary<UUID, IRegionSerialiserModule>();

        #endregion Fields

        #region Constructors

        public FileSystemDatabase()
        {
        }

        #endregion Constructors

        #region Private Methods

        // called by postinitialise
        private void CreateDirectory()
        {
            string scenedir;
            if (!Directory.Exists(m_repodir))
                Directory.CreateDirectory(m_repodir);

            foreach (UUID region in m_scenes.Keys)
            {
                scenedir = m_repodir + Slash.DirectorySeparatorChar + region + Slash.DirectorySeparatorChar;
                if (!Directory.Exists(scenedir))
                    Directory.CreateDirectory(scenedir);
            }
        }

        // called by postinitialise
        private void SetupSerialiser()
        {
            if (m_serialiser.Count == 0)
            {
                foreach (UUID region in m_scenes.Keys)
                {
                    m_serialiser.Add(region, m_scenes[region].RequestModuleInterface<IRegionSerialiserModule>());
                }
            }
        }

        #endregion Private Methods

        #region Public Methods

        public int GetMostRecentRevision(UUID regionid)
        {
            return NumOfRegionRev(regionid);
        }

        public string GetRegionObjectHeightMap(UUID regionid)
        {
            String filename = m_repodir + Slash.DirectorySeparatorChar + regionid +
                Slash.DirectorySeparatorChar + "heightmap.r32";
            FileStream fs = new FileStream( filename, FileMode.Open);
            StreamReader sr = new StreamReader(fs);
            String result = sr.ReadToEnd();
            sr.Close();
            fs.Close();
            return result;
        }

        public string GetRegionObjectHeightMap(UUID regionid, int revision)
        {
            String filename = m_repodir + Slash.DirectorySeparatorChar + regionid +
                Slash.DirectorySeparatorChar + "heightmap.r32";
            FileStream fs = new FileStream( filename, FileMode.Open);
            StreamReader sr = new StreamReader(fs);
            String result = sr.ReadToEnd();
            sr.Close();
            fs.Close();
            return result;
        }

        public System.Collections.ArrayList GetRegionObjectXMLList(UUID regionid, int revision)
        {
            System.Collections.ArrayList objectList = new System.Collections.ArrayList();
            string filename = m_repodir + Slash.DirectorySeparatorChar + regionid + Slash.DirectorySeparatorChar +
                + revision + Slash.DirectorySeparatorChar + "objects.xml";
            XmlDocument doc = new XmlDocument();
            XmlNode rootNode;
            //int primCount = 0;
            //SceneObjectGroup obj = null;

            if (File.Exists(filename))
            {
                XmlTextReader reader = new XmlTextReader(filename);
                reader.WhitespaceHandling = WhitespaceHandling.None;
                doc.Load(reader);
                reader.Close();
                rootNode = doc.FirstChild;
                foreach (XmlNode aPrimNode in rootNode.ChildNodes)
                {
                    objectList.Add(aPrimNode.OuterXml);
                }
                return objectList;
            }
            return null;
        }

        public System.Collections.ArrayList GetRegionObjectXMLList(UUID regionid)
        {
            int revision = NumOfRegionRev(regionid);
            m_log.Info("[FSDB]: found revisions:" + revision);
            System.Collections.ArrayList xmlList = new System.Collections.ArrayList();
            string filename = m_repodir + Slash.DirectorySeparatorChar + regionid + Slash.DirectorySeparatorChar +
                + revision + Slash.DirectorySeparatorChar + "objects.xml";
            XmlDocument doc = new XmlDocument();
            XmlNode rootNode;

            m_log.Info("[FSDB]: Checking if " + filename + " exists.");
            if (File.Exists(filename))
            {
                Stopwatch x = new Stopwatch();
                x.Start();

                XmlTextReader reader = new XmlTextReader(filename);
                reader.WhitespaceHandling = WhitespaceHandling.None;
                doc.Load(reader);
                reader.Close();
                rootNode = doc.FirstChild;

                foreach (XmlNode aPrimNode in rootNode.ChildNodes)
                {
                    xmlList.Add(aPrimNode.OuterXml);
                }

                x.Stop();
                TimeToDownload += x.ElapsedMilliseconds;
                m_log.Info("[FileSystemDatabase] Time spent retrieving xml files so far: " + TimeToDownload);

                return xmlList;
            }
            return null;
        }

        public void Initialise(Scene scene, string dir)
        {
            lock (this)
            {
                if (m_repodir == null)
                    m_repodir = dir;
            }
            lock (m_scenes)
                m_scenes.Add(scene.RegionInfo.RegionID, scene);
        }

        public System.Collections.Generic.SortedDictionary<string, string> ListOfRegionRevisions(UUID regionid)
        {
            SortedDictionary<string, string> revisionDict = new SortedDictionary<string,string>();

            string scenedir = m_repodir + Slash.DirectorySeparatorChar + regionid + Slash.DirectorySeparatorChar;
            string[] directories = Directory.GetDirectories(scenedir);

            FileStream fs = null;
            StreamReader sr = null;
            String logMessage = "";
            String logLocation = "";
            foreach (string revisionDir in directories)
            {
                try
                {
                    logLocation = revisionDir + Slash.DirectorySeparatorChar + "log";
                    fs = new FileStream( logLocation, FileMode.Open);
                    sr = new StreamReader(fs);
                    logMessage = sr.ReadToEnd();
                    sr.Close();
                    fs.Close();
                    revisionDict.Add(revisionDir, logMessage);
                }
                catch (Exception)
                {
                }
            }

            return revisionDict;
        }

        public int NumOfRegionRev(UUID regionid)
        {
            string scenedir = m_repodir + Slash.DirectorySeparatorChar + regionid + Slash.DirectorySeparatorChar;
            m_log.Info("[FSDB]: Reading scene dir: " + scenedir);
            string[] directories = Directory.GetDirectories(scenedir);
            return directories.Length;
        }

        // Run once and only once.
        public void PostInitialise()
        {
            SetupSerialiser();

            m_log.Info("[FSDB]: Creating repository in " + m_repodir + ".");
            CreateDirectory();
        }

        public void SaveRegion(UUID regionid, string regionName, string logMessage)
        {
            m_log.Info("[FSDB]: ...............................");
            string scenedir = m_repodir + Slash.DirectorySeparatorChar + regionid + Slash.DirectorySeparatorChar;

            m_log.Info("[FSDB]: checking if scene directory exists: " + scenedir);
            if (!Directory.Exists(scenedir))
                Directory.CreateDirectory(scenedir);

            int newRevisionNum = GetMostRecentRevision(regionid)+1;
            string revisiondir = scenedir + newRevisionNum + Slash.DirectorySeparatorChar;

            m_log.Info("[FSDB]: checking if revision directory exists: " + revisiondir);
            if (!Directory.Exists(revisiondir))
                Directory.CreateDirectory(revisiondir);

            try {
                Stopwatch x = new Stopwatch();
                x.Start();
                if (m_scenes.ContainsKey(regionid))
                {
                    m_serialiser[regionid].SerialiseRegion(m_scenes[regionid], revisiondir);
                }
                x.Stop();
                TimeToSave += x.ElapsedMilliseconds;
                m_log.Info("[FileSystemDatabase] Time spent serialising regions to files on disk for " + regionName + ": " + x.ElapsedMilliseconds);
                m_log.Info("[FileSystemDatabase] Time spent serialising regions to files on disk so far: " + TimeToSave);
            }
            catch (Exception e)
            {
                m_log.ErrorFormat("[FSDB]: Serialisation of region failed: " + e);
                return;
            }

            try {
                // Finish by writing log message.
                FileStream file = new FileStream(revisiondir + "log", FileMode.Create, FileAccess.ReadWrite);
                StreamWriter sw = new StreamWriter(file);
                sw.Write(logMessage);
                sw.Close();
            }
            catch (Exception e)
            {
                m_log.ErrorFormat("[FSDB]: Failed trying to save log file " + e);
                return;
            }
        }

        #endregion Public Methods
    }
}