/*
 * 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.Reflection;
using OpenMetaverse;
using log4net;
using Nini.Config;
using OpenSim.Framework;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;
using OpenSim.Framework.Communications.Cache;

namespace OpenSim.Region.Environment.Modules.Avatar.Inventory.Transfer
{
    public class InventoryTransferModule : IInventoryTransferModule, IRegionModule
    {
        private static readonly ILog m_log
            = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        private List<Scene> m_Scenelist = new List<Scene>();
        private Dictionary<UUID, Scene> m_AgentRegions =
                new Dictionary<UUID, Scene>();

        #region IRegionModule Members

        public void Initialise(Scene scene, IConfigSource config)
        {
            if (config.Configs["Messaging"] != null)
            {
                // Allow disabling this module in config
                //
                if (config.Configs["Messaging"].GetString(
                        "InventoryTransferModule", "InventoryTransferModule") !=
                        "InventoryTransferModule")
                    return;
            }

            if (!m_Scenelist.Contains(scene))
            {
                m_Scenelist.Add(scene);

                scene.RegisterModuleInterface<IInventoryTransferModule>(this);

                scene.EventManager.OnNewClient += OnNewClient;
                scene.EventManager.OnClientClosed += ClientLoggedOut;
            }
        }

        public void PostInitialise()
        {
        }

        public void Close()
        {
        }

        public string Name
        {
            get { return "InventoryModule"; }
        }

        public bool IsSharedModule
        {
            get { return true; }
        }

        #endregion

        private void OnNewClient(IClientAPI client)
        {
            // Inventory giving is conducted via instant message
            client.OnInstantMessage += OnInstantMessage;
        }

        private Scene FindClientScene(UUID agentId)
        {
            lock (m_Scenelist)
            {
                foreach (Scene scene in m_Scenelist)
                {
                    ScenePresence presence = scene.GetScenePresence(agentId);
                    if (presence != null)
                    {
                        if (!presence.IsChildAgent)
                            return scene;
                    }
                }
            }
            return null;
        }

        private void OnInstantMessage(IClientAPI client, GridInstantMessage im)
        {
            Scene scene = FindClientScene(client.AgentId);

            if (scene == null) // Something seriously wrong here.
                return;

            if (im.dialog == (byte) InstantMessageDialog.InventoryOffered)
            {
                ScenePresence user =
                        scene.GetScenePresence(new UUID(im.toAgentID));

                // First byte of the array is probably the item type
                // Next 16 bytes are the UUID

                UUID itemID = new UUID(im.binaryBucket, 1);

                m_log.DebugFormat("[AGENT INVENTORY]: Inserting item {0} "+
                        "into agent {1}'s inventory",
                        itemID, new UUID(im.toAgentID));

                InventoryItemBase itemCopy = scene.GiveInventoryItem(
                        new UUID(im.toAgentID),
                        client.AgentId, itemID);

                byte[] itemCopyID = itemCopy.ID.GetBytes();

                Array.Copy(itemCopyID, 0, im.binaryBucket, 1, 16);

                // Send the IM to the recipient. The item is already
                // in their inventory, so it will not be lost if
                // they are offline.
                //
                if (user != null && !user.IsChildAgent)
                {
                    // User is online. So, let's make the item visible
                    //
                    user.ControllingClient.SendBulkUpdateInventory(itemCopy);

                    // And notify. Transaction ID is the item ID. We get that
                    // same ID back on the reply so we know what to act on
                    //
                    user.ControllingClient.SendInstantMessage(
                            new UUID(im.fromAgentID), im.message,
                            new UUID(im.toAgentID),
                            im.fromAgentName, im.dialog, im.timestamp,
                            itemCopy.ID, false, im.binaryBucket);

                    return;
                }
                else
                {
                    // Send via grid services
                    //
                    // TODO: Implement grid sending
                }
            }
            else if (im.dialog == (byte) InstantMessageDialog.InventoryAccepted)
            {
                ScenePresence user = scene.GetScenePresence(new UUID(im.toAgentID));

                if (user != null) // Local
                {
                    user.ControllingClient.SendInstantMessage(
                            new UUID(im.fromAgentID), im.message,
                            new UUID(im.toAgentID),
                            im.fromAgentName, im.dialog, im.timestamp,
                            UUID.Zero, false, im.binaryBucket);
                }
                else
                {
                    // Send via grid
                    //
                    // TODO: Implement sending via grid
                }
            }
            else if (im.dialog == (byte) InstantMessageDialog.InventoryDeclined)
            {
                UUID itemID = new UUID(im.imSessionID); // The item, back from it's trip

                // Here, the recipient is local and we can assume that the
                // inventory is loaded. Courtesy of the above bulk update,
                // It will have been pushed to the client, too
                //
                
                CachedUserInfo userInfo =
                        scene.CommsManager.UserProfileCacheService.
                        GetUserDetails(client.AgentId);

                if (userInfo != null)
                {
                    InventoryFolderImpl trashFolder =
                        userInfo.FindFolderForType((int)AssetType.TrashFolder);

                    InventoryItemBase item =
                            userInfo.RootFolder.FindItem(itemID);

                    if (trashFolder != null && item != null)
                    {
                        item.Folder = trashFolder.ID;

                        userInfo.DeleteItem(itemID);

                        scene.AddInventoryItem(client, item);
                    }
                    else
                    {
                        string reason = "";
                        if (trashFolder == null)
                            reason += " Trash folder not found.";
                        if (item == null)
                            reason += " Item not found.";
                        client.SendAgentAlertMessage("Unable to delete "+
                                "received item"+reason, false);
                    }
                }

                ScenePresence user = scene.GetScenePresence(new UUID(im.toAgentID));

                if (user != null) // Local
                {
                    user.ControllingClient.SendInstantMessage(
                            new UUID(im.fromAgentID), im.message,
                            new UUID(im.toAgentID),
                            im.fromAgentName, im.dialog, im.timestamp,
                            UUID.Zero, false, im.binaryBucket);
                }
                else
                {
                    // Send via grid
                    //
                    // TODO: Implement sending via grid
                }
            }
        }

        public void SetRootAgentScene(UUID agentID, Scene scene)
        {
            m_AgentRegions[agentID] = scene;
        }

        public bool NeedSceneCacheClear(UUID agentID, Scene scene)
        {
            if (!m_AgentRegions.ContainsKey(agentID))
            {
                // Since we can get here two ways, we need to scan
                // the scenes here. This is somewhat more expensive
                // but helps avoid a nasty bug
                //

                foreach (Scene s in m_Scenelist)
                {
                    ScenePresence presence;

                    if (s.TryGetAvatar(agentID, out presence))
                    {
                        // If the agent is in this scene, then we
                        // are being called twice in a single
                        // teleport. This is wasteful of cycles
                        // but harmless due to this 2nd level check
                        //
                        // If the agent is found in another scene
                        // then the list wasn't current
                        //
                        // If the agent is totally unknown, then what
                        // are we even doing here??
                        //
                        if (s == scene)
                            return true;
                        else
                            return false;
                    }
                }
                return true;
            }

            // The agent is left in current Scene, so we must be
            // going to another instance
            //
            if (m_AgentRegions[agentID] == scene)
            {
                m_AgentRegions.Remove(agentID);
                return true;
            }

            // Another region has claimed the agent
            //
            return false;
        }

        public void ClientLoggedOut(UUID agentID)
        {
            if (m_AgentRegions.ContainsKey(agentID))
                m_AgentRegions.Remove(agentID);
        }
    }
}