/**
 * Copyright (c) 2008, Contributors. All rights reserved.
 * 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 Organizations nor the names of Individual
 *       Contributors may be used to endorse or promote products derived from 
 *       this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR 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 
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 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using log4net;
using Nini.Config;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Framework.Communications;
using OpenSim.Framework.Servers;
using OpenSim.Framework.Servers.Interfaces;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Region.CoreModules.Communications.REST;

using OpenMetaverse.StructuredData;

namespace OpenSim.Region.CoreModules.Hypergrid
{
    public class HGStandaloneInventoryService : IRegionModule
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
        private static bool initialized = false;
        private static bool enabled = false;
        
        Scene m_scene;
        //InventoryService m_inventoryService;
        
        #region IRegionModule interface

        public void Initialise(Scene scene, IConfigSource config)
        {
            if (!initialized)
            {
                initialized = true;
                m_scene = scene;

                // This module is only on for standalones
                enabled = !config.Configs["Startup"].GetBoolean("gridmode", true) && config.Configs["Startup"].GetBoolean("hypergrid", false);
            }
        }

        public void PostInitialise()
        {
            if (enabled)
            {
                m_log.Info("[HGStandaloneInvService]: Starting...");
                //m_inventoryService = new InventoryService(m_scene);
                new InventoryService(m_scene);
            }
        }

        public void Close()
        {
        }

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

        public bool IsSharedModule
        {
            get { return true; }
        }

        #endregion
    }

    public class InventoryService 
    {
        private static readonly ILog m_log
            = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
        
        private InventoryServiceBase m_inventoryService;
        private UserManagerBase m_userService;
        private Scene m_scene;
        private bool m_doLookup = false;
        private string m_thisInventoryUrl = "http://localhost:9000";

        public bool DoLookup
        {
            get { return m_doLookup; }
            set { m_doLookup = value; }
        }

        public InventoryService(Scene _m_scene)
        {
            m_scene = _m_scene;
            m_inventoryService = (InventoryServiceBase)m_scene.CommsManager.SecureInventoryService;
            m_userService = (UserManagerBase)m_scene.CommsManager.UserService;
            m_thisInventoryUrl = m_scene.CommsManager.NetworkServersInfo.InventoryURL;
            if (!m_thisInventoryUrl.EndsWith("/"))
                m_thisInventoryUrl += "/";

            AddHttpHandlers();
        }

        protected void AddHttpHandlers()
        {
            IHttpServer httpServer = m_scene.CommsManager.HttpServer;

            httpServer.AddHTTPHandler("/InvCap/", CapHandler);

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<Guid, InventoryCollection>(
                    "POST", "/GetInventory/", GetUserInventory, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                    "POST", "/NewFolder/", m_inventoryService.AddFolder, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                    "POST", "/UpdateFolder/", m_inventoryService.UpdateFolder, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                    "POST", "/MoveFolder/", m_inventoryService.MoveFolder, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                    "POST", "/PurgeFolder/", m_inventoryService.PurgeFolder, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryItemBase, bool>(
                    "POST", "/NewItem/", m_inventoryService.AddItem, CheckAuthSession));

            httpServer.AddStreamHandler(
                new RestDeserialiseSecureHandler<InventoryItemBase, bool>(
                    "POST", "/DeleteItem/", m_inventoryService.DeleteItem, CheckAuthSession));

            //// WARNING: Root folders no longer just delivers the root and immediate child folders (e.g
            //// system folders such as Objects, Textures), but it now returns the entire inventory skeleton.
            //// It would have been better to rename this request, but complexities in the BaseHttpServer
            //// (e.g. any http request not found is automatically treated as an xmlrpc request) make it easier
            //// to do this for now.
            //m_scene.AddStreamHandler(
            //    new RestDeserialiseTrustedHandler<Guid, List<InventoryFolderBase>>
            //        ("POST", "/RootFolders/", GetInventorySkeleton, CheckTrustSource));

            //// for persistent active gestures
            //m_scene.AddStreamHandler(
            //    new RestDeserialiseTrustedHandler<Guid, List<InventoryItemBase>>
            //        ("POST", "/ActiveGestures/", GetActiveGestures, CheckTrustSource));
        }


        ///// <summary>
        ///// Check that the source of an inventory request is one that we trust.
        ///// </summary>
        ///// <param name="peer"></param>
        ///// <returns></returns>
        //public bool CheckTrustSource(IPEndPoint peer)
        //{
        //    if (m_doLookup)
        //    {
        //        m_log.InfoFormat("[GRID AGENT INVENTORY]: Checking trusted source {0}", peer);
        //        UriBuilder ub = new UriBuilder(m_userserver_url);
        //        IPAddress[] uaddrs = Dns.GetHostAddresses(ub.Host);
        //        foreach (IPAddress uaddr in uaddrs)
        //        {
        //            if (uaddr.Equals(peer.Address))
        //            {
        //                return true;
        //            }
        //        }

        //        m_log.WarnFormat(
        //            "[GRID AGENT INVENTORY]: Rejecting request since source {0} was not in the list of trusted sources",
        //            peer);

        //        return false;
        //    }
        //    else
        //    {
        //        return true;
        //    }
        //}

        /// <summary>
        /// Check that the source of an inventory request for a particular agent is a current session belonging to
        /// that agent.
        /// </summary>
        /// <param name="session_id"></param>
        /// <param name="avatar_id"></param>
        /// <returns></returns>
        public bool CheckAuthSession(string session_id, string avatar_id)
        {
            if (m_doLookup)
            {
                m_log.InfoFormat("[HGStandaloneInvService]: checking authed session {0} {1}", session_id, avatar_id);
                UUID userID = UUID.Zero;
                UUID sessionID = UUID.Zero;
                UUID.TryParse(avatar_id, out userID);
                UUID.TryParse(session_id, out sessionID);
                if (userID.Equals(UUID.Zero) || sessionID.Equals(UUID.Zero))
                {
                    m_log.Info("[HGStandaloneInvService]: Invalid user or session id " + avatar_id + "; " + session_id);
                    return false;
                }
                UserProfileData userProfile = m_userService.GetUserProfile(userID);
                if (userProfile != null && userProfile.CurrentAgent != null &&
                    userProfile.CurrentAgent.SessionID == sessionID)
                {
                    m_log.Info("[HGStandaloneInvService]: user is logged in and session is valid. Authorizing access.");
                    return true;
                }

                m_log.Warn("[HGStandaloneInvService]: unknown user or session_id, request rejected");
                return false;
            }
            else
            {
                return true;
            }
        }

        // In truth, this is not called from the outside, for standalones. I'm just making it
        // a handler already so that this can be reused for the InventoryServer.
        public string CreateCapUrl(Guid _userid)
        {
            UUID userID = new UUID(_userid);
            UUID random = UUID.Random();
            string url = m_thisInventoryUrl + random.ToString() + "/";
            m_log.InfoFormat("[HGStandaloneInvService] Creating Cap URL {0} for user {1}", url, userID.ToString());
            return url;
        }


        /// <summary>
        /// Return a user's entire inventory
        /// </summary>
        /// <param name="rawUserID"></param>
        /// <returns>The user's inventory.  If an inventory cannot be found then an empty collection is returned.</returns>
        public InventoryCollection GetUserInventory(Guid rawUserID)
        {
            UUID userID = new UUID(rawUserID);

            m_log.Info("[HGStandaloneInvService]: Processing request for inventory of " + userID);

            // Uncomment me to simulate a slow responding inventory server
            //Thread.Sleep(16000);

            InventoryCollection invCollection = new InventoryCollection();

            List<InventoryFolderBase> allFolders = ((InventoryServiceBase)m_inventoryService).GetInventorySkeleton(userID);

            if (null == allFolders)
            {
                m_log.WarnFormat("[HGStandaloneInvService]: No inventory found for user {0}", rawUserID);

                return invCollection;
            }

            List<InventoryItemBase> allItems = new List<InventoryItemBase>();

            foreach (InventoryFolderBase folder in allFolders)
            {
                List<InventoryItemBase> items = ((InventoryServiceBase)m_inventoryService).RequestFolderItems(folder.ID);

                if (items != null)
                {
                    allItems.InsertRange(0, items);
                }
            }

            invCollection.UserID = userID;
            invCollection.Folders = allFolders;
            invCollection.Items = allItems;

            //            foreach (InventoryFolderBase folder in invCollection.Folders)
            //            {
            //                m_log.DebugFormat("[GRID AGENT INVENTORY]: Sending back folder {0} {1}", folder.Name, folder.ID);
            //            }
            //
            //            foreach (InventoryItemBase item in invCollection.Items)
            //            {
            //                m_log.DebugFormat("[GRID AGENT INVENTORY]: Sending back item {0} {1}, folder {2}", item.Name, item.ID, item.Folder);
            //            }

            m_log.InfoFormat(
                "[HGStandaloneInvService]: Sending back inventory response to user {0} containing {1} folders and {2} items",
                invCollection.UserID, invCollection.Folders.Count, invCollection.Items.Count);

            return invCollection;
        }

        public InventoryCollection FetchDescendants(InventoryFolderBase fb)
        {
            m_log.Info("[HGStandaloneInvService]: Processing request for folder " + fb.ID);

            // Uncomment me to simulate a slow responding inventory server
            //Thread.Sleep(16000);

            InventoryCollection invCollection = new InventoryCollection();

            List<InventoryItemBase> items = ((InventoryServiceBase)m_inventoryService).RequestFolderItems(fb.ID);
            List<InventoryFolderBase> folders = ((InventoryServiceBase)m_inventoryService).RequestSubFolders(fb.ID);

            invCollection.UserID = fb.Owner;
            invCollection.Folders = folders;
            invCollection.Items = items;

            m_log.DebugFormat("[HGStandaloneInvService]: Found {0} items and {1} folders", items.Count, folders.Count);

            return invCollection;
        }

        public InventoryItemBase GetInventoryItem(InventoryItemBase item)
        {
            m_log.Info("[HGStandaloneInvService]: Processing request for item " + item.ID);

            item = ((InventoryServiceBase)m_inventoryService).GetInventoryItem(item.ID);
            if (item == null)
                m_log.Debug("[HGStandaloneInvService]: null item");
            return item;
        }

        /// <summary>
        /// Guid to UUID wrapper for same name IInventoryServices method
        /// </summary>
        /// <param name="rawUserID"></param>
        /// <returns></returns>
        public List<InventoryFolderBase> GetInventorySkeleton(Guid rawUserID)
        {
            UUID userID = new UUID(rawUserID);
            return ((InventoryServiceBase)m_inventoryService).GetInventorySkeleton(userID);
        }

        public List<InventoryItemBase> GetActiveGestures(Guid rawUserID)
        {
            UUID userID = new UUID(rawUserID);

            m_log.InfoFormat("[HGStandaloneInvService]: fetching active gestures for user {0}", userID);

            return ((InventoryServiceBase)m_inventoryService).GetActiveGestures(userID);
        }


        #region Caps

        Dictionary<UUID, List<string>> invCaps = new Dictionary<UUID, List<string>>();

        public Hashtable CapHandler(Hashtable request)
        {
            m_log.Debug("[CONNECTION DEBUGGING]: InvCapHandler Called");

            m_log.Debug("---------------------------");
            m_log.Debug(" >> uri=" + request["uri"]);
            m_log.Debug(" >> content-type=" + request["content-type"]);
            m_log.Debug(" >> http-method=" + request["http-method"]);
            m_log.Debug("---------------------------\n");

            // these are requests if the type
            // http://inventoryserver/InvCap/uuuuuuuu-uuuu-uuuu-uuuu-uuuuuuuuuuuu/kkkkkkkk-kkkk-kkkk-kkkk-kkkkkkkkkkkk/

            Hashtable responsedata = new Hashtable();
            responsedata["content_type"] = "text/plain";

            UUID userID;
            string authToken = string.Empty;
            string authority = string.Empty;
            if (!GetParams(request, out userID, out authority, out authToken))
            {
                m_log.InfoFormat("[HGStandaloneInvService]: Invalid parameters for InvCap message {0}", request["uri"]);
                responsedata["int_response_code"] = 404;
                responsedata["str_response_string"] = "Not found";

                return responsedata;
            }

            // Next, let's parse the verb
            string method = (string)request["http-method"];
            if (method.Equals("GET"))
            {
                DoInvCapPost(request, responsedata, userID, authToken);
                return responsedata;
            }
            //else if (method.Equals("DELETE"))
            //{
            //    DoAgentDelete(request, responsedata, agentID, action, regionHandle);

            //    return responsedata;
            //}
            else
            {
                m_log.InfoFormat("[HGStandaloneInvService]: method {0} not supported in agent message", method);
                responsedata["int_response_code"] = 405;
                responsedata["str_response_string"] = "Method not allowed";

                return responsedata;
            }

        }

        public virtual void DoInvCapPost(Hashtable request, Hashtable responsedata, UUID userID, string authToken)
        {

            // This is the meaning of POST agent

            // Check Auth Token
            if (!(m_userService is IAuthentication))
            {
                m_log.Debug("[HGStandaloneInvService]: UserService is not IAuthentication. Denying access to inventory.");
                responsedata["int_response_code"] = 501;
                responsedata["str_response_string"] = "Not implemented";
                return;
            }

            bool success = ((IAuthentication)m_userService).VerifyKey(userID, authToken);

            if (success)
            {

                m_log.DebugFormat("[HGStandaloneInvService]: User has been authorized. Creating service handlers.");
                
                // Then establish secret service handlers

                RegisterCaps(userID, authToken);

                responsedata["int_response_code"] = 200;
                responsedata["str_response_string"] = "OK";
            }
            else
            {
                m_log.DebugFormat("[HGStandaloneInvService]: User has is unauthorized. Denying service handlers.");
                responsedata["int_response_code"] = 403;
                responsedata["str_response_string"] = "Forbidden";
            }
        }


        /// <summary>
        /// Extract the params from a request.
        /// </summary>
        public static bool GetParams(Hashtable request, out UUID uuid, out string authority, out string authKey)
        {
            uuid = UUID.Zero;
            authority = string.Empty;
            authKey = string.Empty;

            string uri = (string)request["uri"];
            uri = uri.Trim(new char[] { '/' });
            string[] parts = uri.Split('/');
            if (parts.Length <= 1)
            {
                return false;
            }
            else
            {
                if (!UUID.TryParse(parts[1], out uuid))
                    return false;

                if (parts.Length >= 3)
                {
                    authKey = parts[2];
                    return true;
                }
            }

            Uri authUri;
            Hashtable headers = (Hashtable)request["headers"];

            // Authorization keys look like this:
            // http://orgrid.org:8002/<uuid>
            if (headers.ContainsKey("authorization"))
            {
                if (Uri.TryCreate((string)headers["authorization"], UriKind.Absolute, out authUri))
                {
                    authority = authUri.Authority;
                    authKey = authUri.PathAndQuery.Trim('/');
                    m_log.DebugFormat("[HGStandaloneInvService]: Got authority {0} and key {1}", authority, authKey);
                    return true;
                }
                else
                    m_log.Debug("[HGStandaloneInvService]: Wrong format for Authorization header: " + (string)headers["authorization"]);
            }
            else
                m_log.Debug("[HGStandaloneInvService]: Authorization header not found");

            return false;
        }

        void RegisterCaps(UUID userID, string authToken)
        {
            IHttpServer httpServer = m_scene.CommsManager.HttpServer;

            lock (invCaps)
            {
                if (invCaps.ContainsKey(userID))
                {
                    // Remove the old ones
                    DeregisterCaps(httpServer, invCaps[userID]);
                    invCaps.Remove(userID);
                }
            }

            List<string> caps = new List<string>();

            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<Guid, InventoryCollection>(
                                        "POST", AddAndGetCapUrl(authToken, "/GetInventory/", caps), GetUserInventory, CheckAuthSession));

            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryFolderBase, InventoryCollection>(
                                        "POST", AddAndGetCapUrl(authToken, "/FetchDescendants/", caps), FetchDescendants, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryItemBase, InventoryItemBase>(
                                        "POST", AddAndGetCapUrl(authToken, "/GetItem/", caps), GetInventoryItem, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/NewFolder/", caps), m_inventoryService.AddFolder, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/UpdateFolder/", caps), m_inventoryService.UpdateFolder, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/MoveFolder/", caps), m_inventoryService.MoveFolder, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryFolderBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/PurgeFolder/", caps), m_inventoryService.PurgeFolder, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryItemBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/NewItem/", caps), m_inventoryService.AddItem, CheckAuthSession));
            httpServer.AddStreamHandler(new RestDeserialiseSecureHandler<InventoryItemBase, bool>(
                                        "POST", AddAndGetCapUrl(authToken, "/DeleteItem/", caps), m_inventoryService.DeleteItem, CheckAuthSession));
            
            lock (invCaps)
                invCaps.Add(userID, caps);
        }

        string AddAndGetCapUrl(string authToken, string capType, List<string> caps)
        {
            string capUrl = "/" + authToken + capType;

            m_log.Debug("[HGStandaloneInvService] Adding inventory cap " + capUrl);
            caps.Add(capUrl);
            return capUrl;
        }

        void DeregisterCaps(IHttpServer httpServer, List<string> caps)
        {
            foreach (string capUrl in caps)
            {
                m_log.Debug("[HGStandaloneInvService] Removing inventory cap " + capUrl);
                httpServer.RemoveStreamHandler("POST", capUrl);
            }
        }

        #endregion Caps
    }
}