/*
 * 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
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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Reflection;
using System.Xml;
using log4net;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Framework.Serialization;
using OpenSim.Framework.Serialization.External;
using OpenSim.Framework.Communications;
using OpenSim.Framework.Communications.Cache;
using OpenSim.Framework.Communications.Osp;
using OpenSim.Region.CoreModules.World.Archiver;
using OpenSim.Region.Framework.Scenes;

namespace OpenSim.Region.CoreModules.Avatar.Inventory.Archiver
{
    public class InventoryArchiveWriteRequest
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <value>
        /// Used to select all inventory nodes in a folder but not the folder itself
        /// </value>
        private const string STAR_WILDCARD = "*";

        private InventoryArchiverModule m_module;
        private CachedUserInfo m_userInfo;
        private string m_invPath;        
        protected TarArchiveWriter m_archiveWriter;
        protected UuidGatherer m_assetGatherer;

        /// <value>
        /// Used to collect the uuids of the assets that we need to save into the archive
        /// </value>
        protected Dictionary<UUID, int> m_assetUuids = new Dictionary<UUID, int>();

        /// <value>
        /// Used to collect the uuids of the users that we need to save into the archive
        /// </value>
        protected Dictionary<UUID, int> m_userUuids = new Dictionary<UUID, int>();

        /// <value>
        /// The stream to which the inventory archive will be saved.
        /// </value>
        private Stream m_saveStream;

        /// <summary>
        /// Constructor
        /// </summary>
        public InventoryArchiveWriteRequest(
            InventoryArchiverModule module, CachedUserInfo userInfo, string invPath, string savePath)
            : this(
                module,
                userInfo,
                invPath,
                new GZipStream(new FileStream(savePath, FileMode.Create), CompressionMode.Compress))
        {
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public InventoryArchiveWriteRequest(
            InventoryArchiverModule module, CachedUserInfo userInfo, string invPath, Stream saveStream)
        {
            m_module = module;
            m_userInfo = userInfo;
            m_invPath = invPath;
            m_saveStream = saveStream;
            m_assetGatherer = new UuidGatherer(m_module.AssetService);
        }

        protected void ReceivedAllAssets(ICollection<UUID> assetsFoundUuids, ICollection<UUID> assetsNotFoundUuids)
        {
            Exception reportedException = null;
            bool succeeded = true;

            try
            {
                m_archiveWriter.Close();
            }
            catch (IOException e)
            {
                m_saveStream.Close();
                reportedException = e;
                succeeded = false;
            }

            m_module.TriggerInventoryArchiveSaved(succeeded, m_userInfo, m_invPath, m_saveStream, reportedException);
        }

        protected void SaveInvItem(InventoryItemBase inventoryItem, string path)
        {
            string filename = string.Format("{0}{1}_{2}.xml", path, inventoryItem.Name, inventoryItem.ID);            

            // Record the creator of this item for user record purposes (which might go away soon)
            m_userUuids[inventoryItem.CreatorIdAsUuid] = 1;

            InventoryItemBase saveItem = (InventoryItemBase)inventoryItem.Clone();
            saveItem.CreatorId = OspResolver.MakeOspa(saveItem.CreatorIdAsUuid, m_module.CommsManager);

            string serialization = UserInventoryItemSerializer.Serialize(saveItem);
            m_archiveWriter.WriteFile(filename, serialization);

            m_assetGatherer.GatherAssetUuids(saveItem.AssetID, (AssetType)saveItem.AssetType, m_assetUuids);
        }

        /// <summary>
        /// Save an inventory folder
        /// </summary>
        /// <param name="inventoryFolder">The inventory folder to save</param>
        /// <param name="path">The path to which the folder should be saved</param>
        /// <param name="saveThisFolderItself">If true, save this folder itself.  If false, only saves contents</param>
        protected void SaveInvFolder(InventoryFolderImpl inventoryFolder, string path, bool saveThisFolderItself)
        {
            if (saveThisFolderItself)
            {
                path +=
                    string.Format(
                        "{0}{1}{2}/",
                        inventoryFolder.Name,
                        ArchiveConstants.INVENTORY_NODE_NAME_COMPONENT_SEPARATOR,
                        inventoryFolder.ID);

                // We need to make sure that we record empty folders            
                m_archiveWriter.WriteDir(path);
            }

            List<InventoryFolderImpl> childFolders = inventoryFolder.RequestListOfFolderImpls();
            List<InventoryItemBase> items = inventoryFolder.RequestListOfItems();

            /*
            Dictionary identicalFolderNames = new Dictionary<string, int>();

            foreach (InventoryFolderImpl folder in inventories)
            {

                if (!identicalFolderNames.ContainsKey(folder.Name))
                    identicalFolderNames[folder.Name] = 0;
                else
                    identicalFolderNames[folder.Name] = identicalFolderNames[folder.Name]++;

                int folderNameNumber = identicalFolderName[folder.Name];

                SaveInvDir(
                    folder,
                    string.Format(
                        "{0}{1}{2}/",
                        path, ArchiveConstants.INVENTORY_NODE_NAME_COMPONENT_SEPARATOR, folderNameNumber));
            }
            */

            foreach (InventoryFolderImpl childFolder in childFolders)
            {
                SaveInvFolder(childFolder, path, true);
            }

            foreach (InventoryItemBase item in items)
            {
                SaveInvItem(item, path);
            }
        }

        /// <summary>
        /// Execute the inventory write request
        /// </summary>
        public void Execute()
        {
            InventoryFolderImpl inventoryFolder = null;
            InventoryItemBase inventoryItem = null;

            if (!m_userInfo.HasReceivedInventory)
            {
                // If the region server has access to the user admin service (by which users are created),
                // then we'll assume that it's okay to fiddle with the user's inventory even if they are not on the
                // server.
                //
                // FIXME: FetchInventory should probably be assumed to by async anyway, since even standalones might
                // use a remote inventory service, though this is vanishingly rare at the moment.
                if (null == m_module.CommsManager.UserAdminService)
                {
                    m_log.ErrorFormat(
                        "[INVENTORY ARCHIVER]: Have not yet received inventory info for user {0} {1}",
                        m_userInfo.UserProfile.Name, m_userInfo.UserProfile.ID);

                    return;
                }
                else
                {
                    m_userInfo.FetchInventory();
                }
            }

            bool foundStar = false;

            // Eliminate double slashes and any leading / on the path.  This might be better done within InventoryFolderImpl
            // itself (possibly at a small loss in efficiency).
            string[] components
                = m_invPath.Split(new string[] { InventoryFolderImpl.PATH_DELIMITER }, StringSplitOptions.RemoveEmptyEntries);

            int maxComponentIndex = components.Length - 1;

            // If the path terminates with a STAR then later on we want to archive all nodes in the folder but not the
            // folder itself.  This may get more sophisicated later on
            if (maxComponentIndex >= 0 && components[maxComponentIndex] == STAR_WILDCARD)
            {
                foundStar = true;
                maxComponentIndex--;                
            }

            m_invPath = String.Empty;
            for (int i = 0; i <= maxComponentIndex; i++)
            {
                m_invPath += components[i] + InventoryFolderImpl.PATH_DELIMITER;
            }

            // Annoyingly Split actually returns the original string if the input string consists only of delimiters
            // Therefore if we still start with a / after the split, then we need the root folder
            if (m_invPath.Length == 0)
            {
                inventoryFolder = m_userInfo.RootFolder;
            }
            else
            {
                m_invPath = m_invPath.Remove(m_invPath.LastIndexOf(InventoryFolderImpl.PATH_DELIMITER));
                inventoryFolder = m_userInfo.RootFolder.FindFolderByPath(m_invPath);
            }

            // The path may point to an item instead
            if (inventoryFolder == null)
            {
                inventoryItem = m_userInfo.RootFolder.FindItemByPath(m_invPath);
            }

            m_archiveWriter = new TarArchiveWriter(m_saveStream);

            if (null == inventoryFolder)
            {
                if (null == inventoryItem)
                {
                    // We couldn't find the path indicated 
                    m_saveStream.Close();
                    m_module.TriggerInventoryArchiveSaved(
                        false, m_userInfo, m_invPath, m_saveStream,
                        new Exception(string.Format("Could not find inventory entry at path {0}", m_invPath)));
                    return;
                }
                else
                {
                    m_log.DebugFormat(
                        "[INVENTORY ARCHIVER]: Found item {0} {1} at {2}",
                        inventoryItem.Name, inventoryItem.ID, m_invPath);

                    SaveInvItem(inventoryItem, ArchiveConstants.INVENTORY_PATH);
                }
            }
            else
            {
                m_log.DebugFormat(
                    "[INVENTORY ARCHIVER]: Found folder {0} {1} at {2}",
                    inventoryFolder.Name, inventoryFolder.ID, m_invPath);

                //recurse through all dirs getting dirs and files
                SaveInvFolder(inventoryFolder, ArchiveConstants.INVENTORY_PATH, !foundStar);
            }

            SaveUsers();
            new AssetsRequest(
                new AssetsArchiver(m_archiveWriter), m_assetUuids.Keys, 
                m_module.AssetService, ReceivedAllAssets).Execute();
        }

        /// <summary>
        /// Save information for the users that we've collected.
        /// </summary>
        protected void SaveUsers()
        {
            m_log.InfoFormat("[INVENTORY ARCHIVER]: Saving user information for {0} users", m_userUuids.Count);

            foreach (UUID creatorId in m_userUuids.Keys)
            {
                // Record the creator of this item
                CachedUserInfo creator 
                    = m_module.CommsManager.UserProfileCacheService.GetUserDetails(creatorId);

                if (creator != null)
                {
                    m_archiveWriter.WriteFile(
                        ArchiveConstants.USERS_PATH + creator.UserProfile.Name + ".xml",
                        UserProfileSerializer.Serialize(creator.UserProfile));
                }
                else
                {
                    m_log.WarnFormat("[INVENTORY ARCHIVER]: Failed to get creator profile for {0}", creatorId);
                }
            }
        }
    }
}