/*
 * 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;
using System.Xml;
using System.IO;
using System.Collections.Generic;
using System.Collections;
using System.Reflection;
using System.Threading;
using OpenMetaverse;
using log4net;
using OpenSim.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes.Scripting;
using OpenSim.Region.Framework.Scenes.Serialization;

namespace OpenSim.Region.Framework.Scenes
{
    public class SceneObjectPartInventory : IEntityInventory
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private string m_inventoryFileName = String.Empty;
        private byte[] m_inventoryFileData = new byte[0];
        private uint m_inventoryFileNameSerial = 0;
        
        /// <value>
        /// The part to which the inventory belongs.
        /// </value>
        private SceneObjectPart m_part;

        /// <summary>
        /// Serial count for inventory file , used to tell if inventory has changed
        /// no need for this to be part of Database backup
        /// </summary>
        protected uint m_inventorySerial = 0;

        /// <summary>
        /// Holds in memory prim inventory
        /// </summary>
        protected TaskInventoryDictionary m_items = new TaskInventoryDictionary();

        /// <summary>
        /// Tracks whether inventory has changed since the last persistent backup
        /// </summary>
        internal bool HasInventoryChanged;
        
        /// <value>
        /// Inventory serial number
        /// </value>
        protected internal uint Serial
        {
            get { return m_inventorySerial; }
            set { m_inventorySerial = value; }
        }

        /// <value>
        /// Raw inventory data
        /// </value>
        protected internal TaskInventoryDictionary Items
        {
            get { return m_items; }
            set
            {
                m_items = value;
                m_inventorySerial++;
            }
        }
        
        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="part">
        /// A <see cref="SceneObjectPart"/>
        /// </param>
        public SceneObjectPartInventory(SceneObjectPart part)
        {
            m_part = part;
        }

        /// <summary>
        /// Force the task inventory of this prim to persist at the next update sweep
        /// </summary>
        public void ForceInventoryPersistence()
        {
            HasInventoryChanged = true;
        }

        /// <summary>
        /// Reset UUIDs for all the items in the prim's inventory.
        /// </summary>
        /// <remarks>
        /// This involves either generating
        /// new ones or setting existing UUIDs to the correct parent UUIDs.
        ///
        /// If this method is called and there are inventory items, then we regard the inventory as having changed.
        /// </remarks>
        public void ResetInventoryIDs()
        {
            if (null == m_part)
                return;
            
            lock (m_items)
            {
                if (0 == m_items.Count)
                    return;

                IList<TaskInventoryItem> items = GetInventoryItems();
                m_items.Clear();

                foreach (TaskInventoryItem item in items)
                {
                    item.ResetIDs(m_part.UUID);
                    m_items.Add(item.ItemID, item);
                }
            }
        }

        public void ResetObjectID()
        {
            lock (Items)
            {
                IList<TaskInventoryItem> items = new List<TaskInventoryItem>(Items.Values);
                Items.Clear();
    
                foreach (TaskInventoryItem item in items)
                {
                    item.ParentPartID = m_part.UUID;
                    item.ParentID = m_part.UUID;
                    Items.Add(item.ItemID, item);
                }
            }
        }

        /// <summary>
        /// Change every item in this inventory to a new owner.
        /// </summary>
        /// <param name="ownerId"></param>
        public void ChangeInventoryOwner(UUID ownerId)
        {
            lock (Items)
            {
                if (0 == Items.Count)
                {
                    return;
                }
            }

            HasInventoryChanged = true;
            m_part.ParentGroup.HasGroupChanged = true;
            List<TaskInventoryItem> items = GetInventoryItems();
            foreach (TaskInventoryItem item in items)
            {
                if (ownerId != item.OwnerID)
                    item.LastOwnerID = item.OwnerID;

                item.OwnerID = ownerId;
                item.PermsMask = 0;
                item.PermsGranter = UUID.Zero;
                item.OwnerChanged = true;
            }
        }

        /// <summary>
        /// Change every item in this inventory to a new group.
        /// </summary>
        /// <param name="groupID"></param>
        public void ChangeInventoryGroup(UUID groupID)
        {
            lock (Items)
            {
                if (0 == Items.Count)
                {
                    return;
                }
            }

            // Don't let this set the HasGroupChanged flag for attachments
            // as this happens during rez and we don't want a new asset
            // for each attachment each time
            if (!m_part.ParentGroup.IsAttachment)
            {
                HasInventoryChanged = true;
                m_part.ParentGroup.HasGroupChanged = true;
            }

            List<TaskInventoryItem> items = GetInventoryItems();
            foreach (TaskInventoryItem item in items)
            {
                if (groupID != item.GroupID)
                    item.GroupID = groupID;
            }
        }

        /// <summary>
        /// Start all the scripts contained in this prim's inventory
        /// </summary>
        public void CreateScriptInstances(int startParam, bool postOnRez, string engine, int stateSource)
        {
            List<TaskInventoryItem> scripts = GetInventoryScripts();
            foreach (TaskInventoryItem item in scripts)
                CreateScriptInstance(item, startParam, postOnRez, engine, stateSource);
        }

        public ArrayList GetScriptErrors(UUID itemID)
        {
            ArrayList ret = new ArrayList();

            IScriptModule[] engines = m_part.ParentGroup.Scene.RequestModuleInterfaces<IScriptModule>();

            foreach (IScriptModule e in engines)
            {
                if (e != null)
                {
                    ArrayList errors = e.GetScriptErrors(itemID);
                    foreach (Object line in errors)
                        ret.Add(line);
                }
            }

            return ret;
        }

        /// <summary>
        /// Stop all the scripts in this prim.
        /// </summary>
        /// <param name="sceneObjectBeingDeleted">
        /// Should be true if these scripts are being removed because the scene
        /// object is being deleted.  This will prevent spurious updates to the client.
        /// </param>
        public void RemoveScriptInstances(bool sceneObjectBeingDeleted)
        {
            List<TaskInventoryItem> scripts = GetInventoryScripts();
            foreach (TaskInventoryItem item in scripts)
                RemoveScriptInstance(item.ItemID, sceneObjectBeingDeleted);
        }

        /// <summary>
        /// Start a script which is in this prim's inventory.
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        public void CreateScriptInstance(TaskInventoryItem item, int startParam, bool postOnRez, string engine, int stateSource)
        {
//             m_log.DebugFormat("[PRIM INVENTORY]: Starting script {0} {1} in prim {2} {3} in {4}",
//                 item.Name, item.ItemID, m_part.Name, m_part.UUID, m_part.ParentGroup.Scene.RegionInfo.RegionName);

            if (!m_part.ParentGroup.Scene.Permissions.CanRunScript(item.ItemID, m_part.UUID, item.OwnerID))
                return;

            m_part.AddFlag(PrimFlags.Scripted);

            if (!m_part.ParentGroup.Scene.RegionInfo.RegionSettings.DisableScripts)
            {
                if (stateSource == 2 && // Prim crossing
                        m_part.ParentGroup.Scene.m_trustBinaries)
                {
                    lock (m_items)
                    {
                        m_items[item.ItemID].PermsMask = 0;
                        m_items[item.ItemID].PermsGranter = UUID.Zero;
                    }
                    
                    m_part.ParentGroup.Scene.EventManager.TriggerRezScript(
                        m_part.LocalId, item.ItemID, String.Empty, startParam, postOnRez, engine, stateSource);
                    m_part.ParentGroup.AddActiveScriptCount(1);
                    m_part.ScheduleFullUpdate();
                    return;
                }

                AssetBase asset = m_part.ParentGroup.Scene.AssetService.Get(item.AssetID.ToString());
                if (null == asset)
                {
                    m_log.ErrorFormat(
                        "[PRIM INVENTORY]: Couldn't start script {0}, {1} at {2} in {3} since asset ID {4} could not be found",
                        item.Name, item.ItemID, m_part.AbsolutePosition, 
                        m_part.ParentGroup.Scene.RegionInfo.RegionName, item.AssetID);
                }
                else
                {
                    if (m_part.ParentGroup.m_savedScriptState != null)
                        item.OldItemID = RestoreSavedScriptState(item.LoadedItemID, item.OldItemID, item.ItemID);

                    lock (m_items)
                    {
                        m_items[item.ItemID].OldItemID = item.OldItemID;
                        m_items[item.ItemID].PermsMask = 0;
                        m_items[item.ItemID].PermsGranter = UUID.Zero;
                    }

                    string script = Utils.BytesToString(asset.Data);
                    m_part.ParentGroup.Scene.EventManager.TriggerRezScript(
                        m_part.LocalId, item.ItemID, script, startParam, postOnRez, engine, stateSource);
                    m_part.ParentGroup.AddActiveScriptCount(1);
                    m_part.ScheduleFullUpdate();
                }
            }
        }

        private UUID RestoreSavedScriptState(UUID loadedID, UUID oldID, UUID newID)
        {
            IScriptModule[] engines = m_part.ParentGroup.Scene.RequestModuleInterfaces<IScriptModule>();
            if (engines.Length == 0) // No engine at all
                return oldID;

            UUID stateID = oldID;
            if (!m_part.ParentGroup.m_savedScriptState.ContainsKey(oldID))
                stateID = loadedID;
            if (m_part.ParentGroup.m_savedScriptState.ContainsKey(stateID))
            {
                XmlDocument doc = new XmlDocument();

                doc.LoadXml(m_part.ParentGroup.m_savedScriptState[stateID]);
                
                ////////// CRUFT WARNING ///////////////////////////////////
                //
                // Old objects will have <ScriptState><State> ...
                // This format is XEngine ONLY
                //
                // New objects have <State Engine="...." ...><ScriptState>...
                // This can be passed to any engine
                //
                XmlNode n = doc.SelectSingleNode("ScriptState");
                if (n != null) // Old format data
                {
                    XmlDocument newDoc = new XmlDocument();

                    XmlElement rootN = newDoc.CreateElement("", "State", "");
                    XmlAttribute uuidA = newDoc.CreateAttribute("", "UUID", "");
                    uuidA.Value = stateID.ToString();
                    rootN.Attributes.Append(uuidA);
                    XmlAttribute engineA = newDoc.CreateAttribute("", "Engine", "");
                    engineA.Value = "XEngine";
                    rootN.Attributes.Append(engineA);

                    newDoc.AppendChild(rootN);

                    XmlNode stateN = newDoc.ImportNode(n, true);
                    rootN.AppendChild(stateN);

                    // This created document has only the minimun data
                    // necessary for XEngine to parse it successfully

                    m_part.ParentGroup.m_savedScriptState[stateID] = newDoc.OuterXml;
                }
                
                foreach (IScriptModule e in engines)
                {
                    if (e != null)
                    {
                        if (e.SetXMLState(newID, m_part.ParentGroup.m_savedScriptState[stateID]))
                            break;
                    }
                }

                m_part.ParentGroup.m_savedScriptState.Remove(stateID);
            }

            return stateID;
        }

        /// <summary>
        /// Start a script which is in this prim's inventory.
        /// </summary>
        /// <param name="itemId">
        /// A <see cref="UUID"/>
        /// </param>
        public void CreateScriptInstance(UUID itemId, int startParam, bool postOnRez, string engine, int stateSource)
        {
            TaskInventoryItem item = GetInventoryItem(itemId);
            if (item != null)
                CreateScriptInstance(item, startParam, postOnRez, engine, stateSource);
            else
                m_log.ErrorFormat(
                    "[PRIM INVENTORY]: Couldn't start script with ID {0} since it couldn't be found for prim {1}, {2} at {3} in {4}",
                    itemId, m_part.Name, m_part.UUID, 
                    m_part.AbsolutePosition, m_part.ParentGroup.Scene.RegionInfo.RegionName);
        }

        /// <summary>
        /// Stop a script which is in this prim's inventory.
        /// </summary>
        /// <param name="itemId"></param>
        /// <param name="sceneObjectBeingDeleted">
        /// Should be true if this script is being removed because the scene
        /// object is being deleted.  This will prevent spurious updates to the client.
        /// </param>
        public void RemoveScriptInstance(UUID itemId, bool sceneObjectBeingDeleted)
        {
            bool scriptPresent = false;

            lock (m_items)
            {
                if (m_items.ContainsKey(itemId))
                    scriptPresent = true;
            }
            
            if (scriptPresent)
            {
                if (!sceneObjectBeingDeleted)
                    m_part.RemoveScriptEvents(itemId);
                
                m_part.ParentGroup.Scene.EventManager.TriggerRemoveScript(m_part.LocalId, itemId);
                m_part.ParentGroup.AddActiveScriptCount(-1);
            }
            else
            {
                m_log.ErrorFormat(
                    "[PRIM INVENTORY]: " +
                    "Couldn't stop script with ID {0} since it couldn't be found for prim {1}, {2} at {3} in {4}",
                    itemId, m_part.Name, m_part.UUID, 
                    m_part.AbsolutePosition, m_part.ParentGroup.Scene.RegionInfo.RegionName);
            }
        }

        /// <summary>
        /// Check if the inventory holds an item with a given name.
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        private bool InventoryContainsName(string name)
        {
            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if (item.Name == name)
                        return true;
                }
            }
            return false;
        }

        /// <summary>
        /// For a given item name, return that name if it is available.  Otherwise, return the next available
        /// similar name (which is currently the original name with the next available numeric suffix).
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        private string FindAvailableInventoryName(string name)
        {
            if (!InventoryContainsName(name))
                return name;

            int suffix=1;
            while (suffix < 256)
            {
                string tryName=String.Format("{0} {1}", name, suffix);
                if (!InventoryContainsName(tryName))
                    return tryName;
                suffix++;
            }
            return String.Empty;
        }

        /// <summary>
        /// Add an item to this prim's inventory.  If an item with the same name already exists, then an alternative
        /// name is chosen.
        /// </summary>
        /// <param name="item"></param>
        public void AddInventoryItem(TaskInventoryItem item, bool allowedDrop)
        {
            AddInventoryItem(item.Name, item, allowedDrop);
        }

        /// <summary>
        /// Add an item to this prim's inventory.  If an item with the same name already exists, it is replaced.
        /// </summary>
        /// <param name="item"></param>
        public void AddInventoryItemExclusive(TaskInventoryItem item, bool allowedDrop)
        {
            List<TaskInventoryItem> il = GetInventoryItems();
            
            foreach (TaskInventoryItem i in il)
            {
                if (i.Name == item.Name)
                {
                    if (i.InvType == (int)InventoryType.LSL)
                        RemoveScriptInstance(i.ItemID, false);

                    RemoveInventoryItem(i.ItemID);
                    break;
                }
            }

            AddInventoryItem(item.Name, item, allowedDrop);
        }

        /// <summary>
        /// Add an item to this prim's inventory.
        /// </summary>
        /// <param name="name">The name that the new item should have.</param>
        /// <param name="item">
        /// The item itself.  The name within this structure is ignored in favour of the name
        /// given in this method's arguments
        /// </param>
        /// <param name="allowedDrop">
        /// Item was only added to inventory because AllowedDrop is set
        /// </param>
        protected void AddInventoryItem(string name, TaskInventoryItem item, bool allowedDrop)
        {
            name = FindAvailableInventoryName(name);
            if (name == String.Empty)
                return;

            item.ParentID = m_part.UUID;
            item.ParentPartID = m_part.UUID;
            item.Name = name;
            item.GroupID = m_part.GroupID;

            lock (m_items)
                m_items.Add(item.ItemID, item);

            if (allowedDrop) 
                m_part.TriggerScriptChangedEvent(Changed.ALLOWED_DROP);
            else
                m_part.TriggerScriptChangedEvent(Changed.INVENTORY);

            m_inventorySerial++;
            //m_inventorySerial += 2;
            HasInventoryChanged = true;
            m_part.ParentGroup.HasGroupChanged = true;
        }

        /// <summary>
        /// Restore a whole collection of items to the prim's inventory at once.
        /// We assume that the items already have all their fields correctly filled out.
        /// The items are not flagged for persistence to the database, since they are being restored
        /// from persistence rather than being newly added.
        /// </summary>
        /// <param name="items"></param>
        public void RestoreInventoryItems(ICollection<TaskInventoryItem> items)
        {
            lock (m_items)
            {
                foreach (TaskInventoryItem item in items)
                {
                    m_items.Add(item.ItemID, item);
//                    m_part.TriggerScriptChangedEvent(Changed.INVENTORY);
                }
                m_inventorySerial++;
            }
        }

        /// <summary>
        /// Returns an existing inventory item.  Returns the original, so any changes will be live.
        /// </summary>
        /// <param name="itemID"></param>
        /// <returns>null if the item does not exist</returns>
        public TaskInventoryItem GetInventoryItem(UUID itemId)
        {
            TaskInventoryItem item;

            lock (m_items)
                m_items.TryGetValue(itemId, out item);

            return item;
        }

        /// <summary>
        /// Get inventory items by name.
        /// </summary>
        /// <param name="name"></param>
        /// <returns>
        /// A list of inventory items with that name.
        /// If no inventory item has that name then an empty list is returned.
        /// </returns>
        public List<TaskInventoryItem> GetInventoryItems(string name)
        {
            List<TaskInventoryItem> items = new List<TaskInventoryItem>();

            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if (item.Name == name)
                        items.Add(item);
                }
            }

            return items;
        }
        
        public SceneObjectGroup GetRezReadySceneObject(TaskInventoryItem item)
        {
            AssetBase rezAsset = m_part.ParentGroup.Scene.AssetService.Get(item.AssetID.ToString());

            if (null == rezAsset)
            {
                m_log.WarnFormat(
                    "[PRIM INVENTORY]: Could not find asset {0} for inventory item {1} in {2}", 
                    item.AssetID, item.Name, m_part.Name);
                return null;
            }

            string xmlData = Utils.BytesToString(rezAsset.Data);
            SceneObjectGroup group = SceneObjectSerializer.FromOriginalXmlFormat(xmlData);

            group.ResetIDs();

            SceneObjectPart rootPart = group.GetPart(group.UUID);

            // Since renaming the item in the inventory does not affect the name stored
            // in the serialization, transfer the correct name from the inventory to the
            // object itself before we rez.
            rootPart.Name = item.Name;
            rootPart.Description = item.Description;

            SceneObjectPart[] partList = group.Parts;

            group.SetGroup(m_part.GroupID, null);

            // TODO: Remove magic number badness
            if ((rootPart.OwnerID != item.OwnerID) || (item.CurrentPermissions & 16) != 0 || (item.Flags & (uint)InventoryItemFlags.ObjectSlamPerm) != 0) // Magic number
            {
                if (m_part.ParentGroup.Scene.Permissions.PropagatePermissions())
                {
                    foreach (SceneObjectPart part in partList)
                    {
                        if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteEveryone) != 0)
                            part.EveryoneMask = item.EveryonePermissions;
                        if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteNextOwner) != 0)
                            part.NextOwnerMask = item.NextPermissions;
                        if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteGroup) != 0)
                            part.GroupMask = item.GroupPermissions;
                    }
                    
                    group.ApplyNextOwnerPermissions();
                }
            }

            foreach (SceneObjectPart part in partList)
            {
                // TODO: Remove magic number badness
                if ((part.OwnerID != item.OwnerID) || (item.CurrentPermissions & 16) != 0 || (item.Flags & (uint)InventoryItemFlags.ObjectSlamPerm) != 0) // Magic number
                {
                    part.LastOwnerID = part.OwnerID;
                    part.OwnerID = item.OwnerID;
                    part.Inventory.ChangeInventoryOwner(item.OwnerID);
                }
                
                if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteEveryone) != 0)
                    part.EveryoneMask = item.EveryonePermissions;
                if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteNextOwner) != 0)
                    part.NextOwnerMask = item.NextPermissions;
                if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteGroup) != 0)
                    part.GroupMask = item.GroupPermissions;
            }
            
            rootPart.TrimPermissions(); 
            
            return group;
        }
        
        /// <summary>
        /// Update an existing inventory item.
        /// </summary>
        /// <param name="item">The updated item.  An item with the same id must already exist
        /// in this prim's inventory.</param>
        /// <returns>false if the item did not exist, true if the update occurred successfully</returns>
        public bool UpdateInventoryItem(TaskInventoryItem item)
        {
            return UpdateInventoryItem(item, true, true);
        }

        public bool UpdateInventoryItem(TaskInventoryItem item, bool fireScriptEvents)
        {
            return UpdateInventoryItem(item, fireScriptEvents, true);
        }

        public bool UpdateInventoryItem(TaskInventoryItem item, bool fireScriptEvents, bool considerChanged)
        {
            TaskInventoryItem it = GetInventoryItem(item.ItemID);
            if (it != null)
            {
//                m_log.DebugFormat("[PRIM INVENTORY]: Updating item {0} in {1}", item.Name, m_part.Name);
                
                item.ParentID = m_part.UUID;
                item.ParentPartID = m_part.UUID;

                // If group permissions have been set on, check that the groupID is up to date in case it has
                // changed since permissions were last set.
                if (item.GroupPermissions != (uint)PermissionMask.None)
                    item.GroupID = m_part.GroupID;

                if (item.AssetID == UUID.Zero)
                    item.AssetID = it.AssetID;

                lock (m_items)
                {
                    m_items[item.ItemID] = item;
                    m_inventorySerial++;
                }
                
                if (fireScriptEvents)
                    m_part.TriggerScriptChangedEvent(Changed.INVENTORY);
                
                if (considerChanged)
                {
                    HasInventoryChanged = true;
                    m_part.ParentGroup.HasGroupChanged = true;
                }
                
                return true;
            }
            else
            {
                m_log.ErrorFormat(
                    "[PRIM INVENTORY]: " +
                    "Tried to retrieve item ID {0} from prim {1}, {2} at {3} in {4} but the item does not exist in this inventory",
                    item.ItemID, m_part.Name, m_part.UUID, 
                    m_part.AbsolutePosition, m_part.ParentGroup.Scene.RegionInfo.RegionName);
            }
            return false;

        }

        /// <summary>
        /// Remove an item from this prim's inventory
        /// </summary>
        /// <param name="itemID"></param>
        /// <returns>Numeric asset type of the item removed.  Returns -1 if the item did not exist
        /// in this prim's inventory.</returns>
        public int RemoveInventoryItem(UUID itemID)
        {
            TaskInventoryItem item = GetInventoryItem(itemID);
            if (item != null)
            {
                int type = m_items[itemID].InvType;
                if (type == 10) // Script
                {
                    m_part.RemoveScriptEvents(itemID);
                    m_part.ParentGroup.Scene.EventManager.TriggerRemoveScript(m_part.LocalId, itemID);
                }
                m_items.Remove(itemID);
                m_inventorySerial++;
                m_part.TriggerScriptChangedEvent(Changed.INVENTORY);

                HasInventoryChanged = true;
                m_part.ParentGroup.HasGroupChanged = true;

                if (!ContainsScripts())
                    m_part.RemFlag(PrimFlags.Scripted);

                m_part.ScheduleFullUpdate();

                return type;
                
            }
            else
            {
                m_log.ErrorFormat(
                    "[PRIM INVENTORY]: " +
                    "Tried to remove item ID {0} from prim {1}, {2} at {3} in {4} but the item does not exist in this inventory",
                    itemID, m_part.Name, m_part.UUID,
                    m_part.AbsolutePosition, m_part.ParentGroup.Scene.RegionInfo.RegionName);
            }

            return -1;
        }

        private bool CreateInventoryFile()
        {
//            m_log.DebugFormat(
//                "[PRIM INVENTORY]: Creating inventory file for {0} {1} {2}, serial {3}",
//                m_part.Name, m_part.UUID, m_part.LocalId, m_inventorySerial);

            if (m_inventoryFileName == String.Empty ||
                m_inventoryFileNameSerial < m_inventorySerial)
            {
                // Something changed, we need to create a new file
                m_inventoryFileName = "inventory_" + UUID.Random().ToString() + ".tmp";
                m_inventoryFileNameSerial = m_inventorySerial;

                InventoryStringBuilder invString = new InventoryStringBuilder(m_part.UUID, UUID.Zero);

                lock (m_items)
                {
                    foreach (TaskInventoryItem item in m_items.Values)
                    {
//                        m_log.DebugFormat(
//                            "[PRIM INVENTORY]: Adding item {0} {1} for serial {2} on prim {3} {4} {5}",
//                            item.Name, item.ItemID, m_inventorySerial, m_part.Name, m_part.UUID, m_part.LocalId);

                        UUID ownerID = item.OwnerID;
                        uint everyoneMask = 0;
                        uint baseMask = item.BasePermissions;
                        uint ownerMask = item.CurrentPermissions;
                        uint groupMask = item.GroupPermissions;

                        invString.AddItemStart();
                        invString.AddNameValueLine("item_id", item.ItemID.ToString());
                        invString.AddNameValueLine("parent_id", m_part.UUID.ToString());

                        invString.AddPermissionsStart();

                        invString.AddNameValueLine("base_mask", Utils.UIntToHexString(baseMask));
                        invString.AddNameValueLine("owner_mask", Utils.UIntToHexString(ownerMask));
                        invString.AddNameValueLine("group_mask", Utils.UIntToHexString(groupMask));
                        invString.AddNameValueLine("everyone_mask", Utils.UIntToHexString(everyoneMask));
                        invString.AddNameValueLine("next_owner_mask", Utils.UIntToHexString(item.NextPermissions));

                        invString.AddNameValueLine("creator_id", item.CreatorID.ToString());
                        invString.AddNameValueLine("owner_id", ownerID.ToString());

                        invString.AddNameValueLine("last_owner_id", item.LastOwnerID.ToString());

                        invString.AddNameValueLine("group_id", item.GroupID.ToString());
                        invString.AddSectionEnd();

                        invString.AddNameValueLine("asset_id", item.AssetID.ToString());
                        invString.AddNameValueLine("type", Utils.AssetTypeToString((AssetType)item.Type));
                        invString.AddNameValueLine("inv_type", Utils.InventoryTypeToString((InventoryType)item.InvType));
                        invString.AddNameValueLine("flags", Utils.UIntToHexString(item.Flags));

                        invString.AddSaleStart();
                        invString.AddNameValueLine("sale_type", "not");
                        invString.AddNameValueLine("sale_price", "0");
                        invString.AddSectionEnd();

                        invString.AddNameValueLine("name", item.Name + "|");
                        invString.AddNameValueLine("desc", item.Description + "|");

                        invString.AddNameValueLine("creation_date", item.CreationDate.ToString());
                        invString.AddSectionEnd();
                    }
                }

                m_inventoryFileData = Utils.StringToBytes(invString.BuildString);

                return true;
            }

            // No need to recreate, the existing file is fine
            return false;
        }

        /// <summary>
        /// Serialize all the metadata for the items in this prim's inventory ready for sending to the client
        /// </summary>
        /// <param name="xferManager"></param>
        public void RequestInventoryFile(IClientAPI client, IXfer xferManager)
        {
            lock (m_items)
            {
                // Don't send a inventory xfer name if there are no items.  Doing so causes viewer 3 to crash when rezzing
                // a new script if any previous deletion has left the prim inventory empty.
                if (m_items.Count == 0) // No inventory
                {
//                    m_log.DebugFormat(
//                        "[PRIM INVENTORY]: Not sending inventory data for part {0} {1} {2} for {3} since no items",
//                        m_part.Name, m_part.LocalId, m_part.UUID, client.Name);

                    client.SendTaskInventory(m_part.UUID, 0, new byte[0]);
                    return;
                }

                CreateInventoryFile();
    
                // In principle, we should only do the rest if the inventory changed;
                // by sending m_inventorySerial to the client, it ought to know
                // that nothing changed and that it doesn't need to request the file. 
                // Unfortunately, it doesn't look like the client optimizes this; 
                // the client seems to always come back and request the Xfer, 
                // no matter what value m_inventorySerial has.
                // FIXME: Could probably be > 0 here rather than > 2
                if (m_inventoryFileData.Length > 2)
                {
                    // Add the file for Xfer
    //                m_log.DebugFormat(
    //                    "[PRIM INVENTORY]: Adding inventory file {0} (length {1}) for transfer on {2} {3} {4}",
    //                    m_inventoryFileName, m_inventoryFileData.Length, m_part.Name, m_part.UUID, m_part.LocalId);
                    
                    xferManager.AddNewFile(m_inventoryFileName, m_inventoryFileData);
                }
    
                // Tell the client we're ready to Xfer the file
                client.SendTaskInventory(m_part.UUID, (short)m_inventorySerial,
                        Util.StringToBytes256(m_inventoryFileName));
            }
        }

        /// <summary>
        /// Process inventory backup
        /// </summary>
        /// <param name="datastore"></param>
        public void ProcessInventoryBackup(ISimulationDataService datastore)
        {
            if (HasInventoryChanged)
            {
                HasInventoryChanged = false;
                List<TaskInventoryItem> items = GetInventoryItems();
                datastore.StorePrimInventory(m_part.UUID, items);

            }
        }

        public class InventoryStringBuilder
        {
            public string BuildString = String.Empty;

            public InventoryStringBuilder(UUID folderID, UUID parentID)
            {
                BuildString += "\tinv_object\t0\n\t{\n";
                AddNameValueLine("obj_id", folderID.ToString());
                AddNameValueLine("parent_id", parentID.ToString());
                AddNameValueLine("type", "category");
                AddNameValueLine("name", "Contents|");
                AddSectionEnd();
            }

            public void AddItemStart()
            {
                BuildString += "\tinv_item\t0\n";
                AddSectionStart();
            }

            public void AddPermissionsStart()
            {
                BuildString += "\tpermissions 0\n";
                AddSectionStart();
            }

            public void AddSaleStart()
            {
                BuildString += "\tsale_info\t0\n";
                AddSectionStart();
            }

            protected void AddSectionStart()
            {
                BuildString += "\t{\n";
            }

            public void AddSectionEnd()
            {
                BuildString += "\t}\n";
            }

            public void AddLine(string addLine)
            {
                BuildString += addLine;
            }

            public void AddNameValueLine(string name, string value)
            {
                BuildString += "\t\t";
                BuildString += name + "\t";
                BuildString += value + "\n";
            }

            public void Close()
            {
            }
        }

        public uint MaskEffectivePermissions()
        {
            uint mask=0x7fffffff;

            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Copy) == 0)
                        mask &= ~((uint)PermissionMask.Copy >> 13);
                    if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Transfer) == 0)
                        mask &= ~((uint)PermissionMask.Transfer >> 13);
                    if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Modify) == 0)
                        mask &= ~((uint)PermissionMask.Modify >> 13);

                    if (item.InvType != (int)InventoryType.Object)
                    {
                        if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Copy) == 0)
                            mask &= ~((uint)PermissionMask.Copy >> 13);
                        if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Transfer) == 0)
                            mask &= ~((uint)PermissionMask.Transfer >> 13);
                        if ((item.CurrentPermissions & item.NextPermissions & (uint)PermissionMask.Modify) == 0)
                            mask &= ~((uint)PermissionMask.Modify >> 13);
                    }
                    else
                    {
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Copy >> 13)) == 0)
                            mask &= ~((uint)PermissionMask.Copy >> 13);
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Transfer >> 13)) == 0)
                            mask &= ~((uint)PermissionMask.Transfer >> 13);
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Modify >> 13)) == 0)
                            mask &= ~((uint)PermissionMask.Modify >> 13);
                    }
    
                    if ((item.CurrentPermissions & (uint)PermissionMask.Copy) == 0)
                        mask &= ~(uint)PermissionMask.Copy;
                    if ((item.CurrentPermissions & (uint)PermissionMask.Transfer) == 0)
                        mask &= ~(uint)PermissionMask.Transfer;
                    if ((item.CurrentPermissions & (uint)PermissionMask.Modify) == 0)
                        mask &= ~(uint)PermissionMask.Modify;
                }
            }
                
            return mask;
        }

        public void ApplyNextOwnerPermissions()
        {
            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if (item.InvType == (int)InventoryType.Object && (item.CurrentPermissions & 7) != 0)
                    {
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Copy >> 13)) == 0)
                            item.CurrentPermissions &= ~(uint)PermissionMask.Copy;
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Transfer >> 13)) == 0)
                            item.CurrentPermissions &= ~(uint)PermissionMask.Transfer;
                        if ((item.CurrentPermissions & ((uint)PermissionMask.Modify >> 13)) == 0)
                            item.CurrentPermissions &= ~(uint)PermissionMask.Modify;
                    }
                    item.CurrentPermissions &= item.NextPermissions;
                    item.BasePermissions &= item.NextPermissions;
                    item.EveryonePermissions &= item.NextPermissions;
                    item.OwnerChanged = true;
                    item.PermsMask = 0;
                    item.PermsGranter = UUID.Zero;
                }
            }
        }

        public void ApplyGodPermissions(uint perms)
        {
            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    item.CurrentPermissions = perms;
                    item.BasePermissions = perms;
                }
            }
            
            m_inventorySerial++;
            HasInventoryChanged = true;
        }

        /// <summary>
        /// Returns true if this part inventory contains any scripts.  False otherwise.
        /// </summary>
        /// <returns></returns>
        public bool ContainsScripts()
        {
            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if (item.InvType == (int)InventoryType.LSL)
                    {
                        return true;
                    }
                }
            }

            return false;
        }

        /// <summary>
        /// Returns the count of scripts in this parts inventory.
        /// </summary>
        /// <returns></returns>
        public int ScriptCount()
        {
            int count = 0;
            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                {
                    if (item.InvType == (int)InventoryType.LSL)
                    {
                        count++;
                    }
                }
            }

            return count;
        }
        /// <summary>
        /// Returns the count of running scripts in this parts inventory.
        /// </summary>
        /// <returns></returns>
        public int RunningScriptCount()
        {
            IScriptModule[] engines = m_part.ParentGroup.Scene.RequestModuleInterfaces<IScriptModule>();
            if (engines.Length == 0)
                return 0;

            int count = 0;
            List<TaskInventoryItem> scripts = GetInventoryScripts();

            foreach (TaskInventoryItem item in scripts)
            {
                foreach (IScriptModule engine in engines)
                {
                    if (engine != null)
                    {
                        if (engine.GetScriptState(item.ItemID))
                        {
                            count++;
                        }
                    }
                }
            }
            return count;
        }

        public List<UUID> GetInventoryList()
        {
            List<UUID> ret = new List<UUID>();

            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                    ret.Add(item.ItemID);
            }

            return ret;
        }

        public List<TaskInventoryItem> GetInventoryItems()
        {
            List<TaskInventoryItem> ret = new List<TaskInventoryItem>();

            lock (m_items)
                ret = new List<TaskInventoryItem>(m_items.Values);

            return ret;
        }

        public List<TaskInventoryItem> GetInventoryScripts()
        {
            List<TaskInventoryItem> ret = new List<TaskInventoryItem>();

            lock (m_items)
            {
                foreach (TaskInventoryItem item in m_items.Values)
                    if (item.InvType == (int)InventoryType.LSL)
                        ret.Add(item);
            }

            return ret;
        }
        
        public Dictionary<UUID, string> GetScriptStates()
        {
            Dictionary<UUID, string> ret = new Dictionary<UUID, string>();            
            
            if (m_part.ParentGroup.Scene == null) // Group not in a scene
                return ret;
            
            IScriptModule[] engines = m_part.ParentGroup.Scene.RequestModuleInterfaces<IScriptModule>();
            
            if (engines.Length == 0) // No engine at all
                return ret;

            List<TaskInventoryItem> scripts = GetInventoryScripts();

            foreach (TaskInventoryItem item in scripts)
            {
                foreach (IScriptModule e in engines)
                {
                    if (e != null)
                    {
                        string n = e.GetXMLState(item.ItemID);
                        if (n != String.Empty)
                        {
                            if (!ret.ContainsKey(item.ItemID))
                                ret[item.ItemID] = n;
                            break;
                        }
                    }
                }
            }
            
            return ret;
        }
        
        public void ResumeScripts()
        {
            IScriptModule[] engines = m_part.ParentGroup.Scene.RequestModuleInterfaces<IScriptModule>();
            if (engines.Length == 0)
                return;

            List<TaskInventoryItem> scripts = GetInventoryScripts();

            foreach (TaskInventoryItem item in scripts)
            {
                foreach (IScriptModule engine in engines)
                {
                    if (engine != null)
                    {
                        if (item.OwnerChanged)
                            engine.PostScriptEvent(item.ItemID, "changed", new Object[] { (int)Changed.OWNER });
                        item.OwnerChanged = false;
                        engine.ResumeScript(item.ItemID);
                    }
                }
            }
        }
    }
}