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using System;
using System.Net;
using System.Collections.Generic;
using Nini.Config;
using OpenMetaverse;
using OpenSim.Data.Null;
using OpenSim.Framework;
using OpenSim.Framework.Communications;
using OpenSim.Framework.Console;
using OpenSim.Framework.Servers;
using OpenSim.Framework.Servers.HttpServer;
using OpenSim.Region.Physics.Manager;
using OpenSim.Region.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Region.CoreModules.Avatar.Gods;
using OpenSim.Region.CoreModules.Asset;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.Asset;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.Authentication;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.Inventory;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.Grid;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.UserAccounts;
using OpenSim.Region.CoreModules.ServiceConnectorsOut.Presence;
using OpenSim.Services.Interfaces;
using OpenSim.Tests.Common.Mock;
using GridRegion = OpenSim.Services.Interfaces.GridRegion;

namespace OpenSim.Tests.Common
{
    /// <summary>
    /// Helpers for setting up scenes.
    /// </summary>
    public class SceneHelpers
    {
        /// <summary>
        /// We need a scene manager so that test clients can retrieve a scene when performing teleport tests.
        /// </summary>
        public SceneManager SceneManager { get; private set; }

        public ISimulationDataService SimDataService { get; private set; }

        private AgentCircuitManager m_acm = new AgentCircuitManager();
        private IEstateDataService m_estateDataService = null;

        private LocalAssetServicesConnector m_assetService;
        private LocalAuthenticationServicesConnector m_authenticationService;
        private LocalInventoryServicesConnector m_inventoryService;
        private LocalGridServicesConnector m_gridService;
        private LocalUserAccountServicesConnector m_userAccountService;
        private LocalPresenceServicesConnector m_presenceService;

        private CoreAssetCache m_cache;

        public SceneHelpers() : this(null) {}

        public SceneHelpers(CoreAssetCache cache)
        {
            SceneManager = new SceneManager();

            m_assetService          = StartAssetService(cache);
            m_authenticationService = StartAuthenticationService();
            m_inventoryService      = StartInventoryService();
            m_gridService           = StartGridService();
            m_userAccountService    = StartUserAccountService();
            m_presenceService       = StartPresenceService();

            m_inventoryService.PostInitialise();
            m_assetService.PostInitialise();
            m_userAccountService.PostInitialise();
            m_presenceService.PostInitialise();

            m_cache = cache;

            SimDataService 
                = OpenSim.Server.Base.ServerUtils.LoadPlugin<ISimulationDataService>("OpenSim.Tests.Common.dll", null);
        }

        /// <summary>
        /// Set up a test scene
        /// </summary>
        /// <remarks>
        /// Automatically starts services, as would the normal runtime.
        /// </remarks>
        /// <returns></returns>
        public TestScene SetupScene()
        {
            return SetupScene("Unit test region", UUID.Random(), 1000, 1000);
        }

        public TestScene SetupScene(string name, UUID id, uint x, uint y)
        {
            return SetupScene(name, id, x, y, new IniConfigSource());
        }

        public TestScene SetupScene(string name, UUID id, uint x, uint y, IConfigSource configSource)
        {
            return SetupScene(name, id, x, y, Constants.RegionSize, Constants.RegionSize, configSource);
        }

        /// <summary>
        /// Set up a scene.
        /// </summary>
        /// <param name="name">Name of the region</param>
        /// <param name="id">ID of the region</param>
        /// <param name="x">X co-ordinate of the region</param>
        /// <param name="y">Y co-ordinate of the region</param>
        /// <param name="sizeX">X size of scene</param>
        /// <param name="sizeY">Y size of scene</param>
        /// <param name="configSource"></param>
        /// <returns></returns>
        public TestScene SetupScene(
            string name, UUID id, uint x, uint y, uint sizeX, uint sizeY, IConfigSource configSource)
        {
            Console.WriteLine("Setting up test scene {0}", name);

            // We must set up a console otherwise setup of some modules may fail
            MainConsole.Instance = new MockConsole();
            
            RegionInfo regInfo = new RegionInfo(x, y, new IPEndPoint(IPAddress.Loopback, 9000), "127.0.0.1");
            regInfo.RegionName = name;
            regInfo.RegionID = id;
            regInfo.RegionSizeX = sizeX;
            regInfo.RegionSizeY = sizeY;

            SceneCommunicationService scs = new SceneCommunicationService();

            TestScene testScene = new TestScene(
                regInfo, m_acm, scs, SimDataService, m_estateDataService, configSource, null);

            INonSharedRegionModule godsModule = new GodsModule();
            godsModule.Initialise(new IniConfigSource());
            godsModule.AddRegion(testScene);

            // Add scene to services
            m_assetService.AddRegion(testScene);

            if (m_cache != null)
            {
                m_cache.AddRegion(testScene);
                m_cache.RegionLoaded(testScene);
                testScene.AddRegionModule(m_cache.Name, m_cache);
            }

            m_assetService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_assetService.Name, m_assetService);

            m_authenticationService.AddRegion(testScene);
            m_authenticationService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_authenticationService.Name, m_authenticationService);

            m_inventoryService.AddRegion(testScene);
            m_inventoryService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_inventoryService.Name, m_inventoryService);

            m_gridService.AddRegion(testScene);
            m_gridService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_gridService.Name, m_gridService);

            m_userAccountService.AddRegion(testScene);
            m_userAccountService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_userAccountService.Name, m_userAccountService);

            m_presenceService.AddRegion(testScene);
            m_presenceService.RegionLoaded(testScene);
            testScene.AddRegionModule(m_presenceService.Name, m_presenceService);
            
            testScene.RegionInfo.EstateSettings.EstateOwner = UUID.Random();
            testScene.SetModuleInterfaces();

            testScene.LandChannel = new TestLandChannel(testScene);
            testScene.LoadWorldMap();

            PhysicsPluginManager physicsPluginManager = new PhysicsPluginManager();
            physicsPluginManager.LoadPluginsFromAssembly("Physics/OpenSim.Region.Physics.BasicPhysicsPlugin.dll");
            Vector3 regionExtent = new Vector3( regInfo.RegionSizeX, regInfo.RegionSizeY, regInfo.RegionSizeZ);
            testScene.PhysicsScene
                = physicsPluginManager.GetPhysicsScene("basicphysics", "ZeroMesher", new IniConfigSource(), "test", regionExtent);

            testScene.RegionInfo.EstateSettings = new EstateSettings();
            testScene.LoginsEnabled = true;
            testScene.RegisterRegionWithGrid();

            SceneManager.Add(testScene);

            return testScene;
        }

        private static LocalAssetServicesConnector StartAssetService(CoreAssetCache cache)
        {
            IConfigSource config = new IniConfigSource();
            config.AddConfig("Modules");            
            config.Configs["Modules"].Set("AssetServices", "LocalAssetServicesConnector");            
            config.AddConfig("AssetService");
            config.Configs["AssetService"].Set("LocalServiceModule", "OpenSim.Services.AssetService.dll:AssetService");            
            config.Configs["AssetService"].Set("StorageProvider", "OpenSim.Tests.Common.dll");

            LocalAssetServicesConnector assetService = new LocalAssetServicesConnector();
            assetService.Initialise(config);

            if (cache != null)
            {
                IConfigSource cacheConfig = new IniConfigSource();
                cacheConfig.AddConfig("Modules");
                cacheConfig.Configs["Modules"].Set("AssetCaching", "CoreAssetCache");
                cacheConfig.AddConfig("AssetCache");

                cache.Initialise(cacheConfig);
            }
            
            return assetService;
        }

        private static LocalAuthenticationServicesConnector StartAuthenticationService()
        {
            IConfigSource config = new IniConfigSource();
            config.AddConfig("Modules");
            config.AddConfig("AuthenticationService");
            config.Configs["Modules"].Set("AuthenticationServices", "LocalAuthenticationServicesConnector");
            config.Configs["AuthenticationService"].Set(
                "LocalServiceModule", "OpenSim.Services.AuthenticationService.dll:PasswordAuthenticationService");
            config.Configs["AuthenticationService"].Set("StorageProvider", "OpenSim.Data.Null.dll");

            LocalAuthenticationServicesConnector service = new LocalAuthenticationServicesConnector();
            service.Initialise(config);

            return service;
        }

        private static LocalInventoryServicesConnector StartInventoryService()
        {
            IConfigSource config = new IniConfigSource();            
            config.AddConfig("Modules");
            config.AddConfig("InventoryService");
            config.Configs["Modules"].Set("InventoryServices", "LocalInventoryServicesConnector");
            config.Configs["InventoryService"].Set("LocalServiceModule", "OpenSim.Services.InventoryService.dll:XInventoryService");
            config.Configs["InventoryService"].Set("StorageProvider", "OpenSim.Tests.Common.dll");

            LocalInventoryServicesConnector inventoryService = new LocalInventoryServicesConnector();
            inventoryService.Initialise(config);
            
            return inventoryService;           
        }

        private static LocalGridServicesConnector StartGridService()
        {
            IConfigSource config = new IniConfigSource();
            config.AddConfig("Modules");
            config.AddConfig("GridService");
            config.Configs["Modules"].Set("GridServices", "LocalGridServicesConnector");
            config.Configs["GridService"].Set("StorageProvider", "OpenSim.Data.Null.dll:NullRegionData");
            config.Configs["GridService"].Set("LocalServiceModule", "OpenSim.Services.GridService.dll:GridService");
            config.Configs["GridService"].Set("ConnectionString", "!static");

            LocalGridServicesConnector gridService = new LocalGridServicesConnector();
            gridService.Initialise(config);
            
            return gridService;
        }

        /// <summary>
        /// Start a user account service
        /// </summary>
        /// <param name="testScene"></param>
        /// <returns></returns>
        private static LocalUserAccountServicesConnector StartUserAccountService()
        {
            IConfigSource config = new IniConfigSource();
            config.AddConfig("Modules");
            config.AddConfig("UserAccountService");
            config.Configs["Modules"].Set("UserAccountServices", "LocalUserAccountServicesConnector");
            config.Configs["UserAccountService"].Set("StorageProvider", "OpenSim.Data.Null.dll");
            config.Configs["UserAccountService"].Set(
                "LocalServiceModule", "OpenSim.Services.UserAccountService.dll:UserAccountService");

            LocalUserAccountServicesConnector userAccountService = new LocalUserAccountServicesConnector();
            userAccountService.Initialise(config);
            
            return userAccountService;
        }

        /// <summary>
        /// Start a presence service
        /// </summary>
        /// <param name="testScene"></param>
        private static LocalPresenceServicesConnector StartPresenceService()
        {
            // Unfortunately, some services share data via statics, so we need to null every time to stop interference
            // between tests.
            // This is a massive non-obvious pita.
            NullPresenceData.Instance = null;

            IConfigSource config = new IniConfigSource();
            config.AddConfig("Modules");
            config.AddConfig("PresenceService");
            config.Configs["Modules"].Set("PresenceServices", "LocalPresenceServicesConnector");
            config.Configs["PresenceService"].Set("StorageProvider", "OpenSim.Data.Null.dll");
            config.Configs["PresenceService"].Set(
                "LocalServiceModule", "OpenSim.Services.PresenceService.dll:PresenceService");

            LocalPresenceServicesConnector presenceService = new LocalPresenceServicesConnector();
            presenceService.Initialise(config);
            
            return presenceService;
        }

        /// <summary>
        /// Setup modules for a scene using their default settings.
        /// </summary>
        /// <param name="scene"></param>
        /// <param name="modules"></param>
        public static void SetupSceneModules(Scene scene, params object[] modules)
        {
            SetupSceneModules(scene, new IniConfigSource(), modules);
        }

        /// <summary>
        /// Setup modules for a scene.
        /// </summary>
        /// <remarks>
        /// If called directly, then all the modules must be shared modules.
        /// </remarks>
        /// <param name="scenes"></param>
        /// <param name="config"></param>
        /// <param name="modules"></param>
        public static void SetupSceneModules(Scene scene, IConfigSource config, params object[] modules)
        {
            SetupSceneModules(new Scene[] { scene }, config, modules);
        }

        /// <summary>
        /// Setup modules for a scene using their default settings.
        /// </summary>
        /// <param name="scenes"></param>
        /// <param name="modules"></param>
        public static void SetupSceneModules(Scene[] scenes, params object[] modules)
        {
            SetupSceneModules(scenes, new IniConfigSource(), modules);
        }

        /// <summary>
        /// Setup modules for scenes.
        /// </summary>
        /// <remarks>
        /// If called directly, then all the modules must be shared modules.
        /// 
        /// We are emulating here the normal calls made to setup region modules 
        /// (Initialise(), PostInitialise(), AddRegion, RegionLoaded()).
        /// TODO: Need to reuse normal runtime module code.
        /// </remarks>
        /// <param name="scenes"></param>
        /// <param name="config"></param>
        /// <param name="modules"></param>
        public static void SetupSceneModules(Scene[] scenes, IConfigSource config, params object[] modules)
        {
            List<IRegionModuleBase> newModules = new List<IRegionModuleBase>();
            foreach (object module in modules)
            {
                IRegionModuleBase m = (IRegionModuleBase)module;
//                Console.WriteLine("MODULE {0}", m.Name);
                m.Initialise(config);
                newModules.Add(m);
            }

            foreach (IRegionModuleBase module in newModules)
            {
                if (module is ISharedRegionModule) ((ISharedRegionModule)module).PostInitialise();
            }

            foreach (IRegionModuleBase module in newModules)
            {
                foreach (Scene scene in scenes)
                {
                    module.AddRegion(scene);
                    scene.AddRegionModule(module.Name, module);
                }
            }

            // RegionLoaded is fired after all modules have been appropriately added to all scenes
            foreach (IRegionModuleBase module in newModules)
                foreach (Scene scene in scenes)
                    module.RegionLoaded(scene);

            foreach (Scene scene in scenes) { scene.SetModuleInterfaces(); }
        }

        /// <summary>
        /// Generate some standard agent connection data.
        /// </summary>
        /// <param name="agentId"></param>
        /// <returns></returns>
        public static AgentCircuitData GenerateAgentData(UUID agentId)
        {
            AgentCircuitData acd = GenerateCommonAgentData();

            acd.AgentID = agentId;
            acd.firstname = "testfirstname";
            acd.lastname = "testlastname";
            acd.ServiceURLs = new Dictionary<string, object>();

            return acd;
        }

        /// <summary>
        /// Generate some standard agent connection data.
        /// </summary>
        /// <param name="agentId"></param>
        /// <returns></returns>
        public static AgentCircuitData GenerateAgentData(UserAccount ua)
        {
            AgentCircuitData acd = GenerateCommonAgentData();

            acd.AgentID = ua.PrincipalID;
            acd.firstname = ua.FirstName;
            acd.lastname = ua.LastName;
            acd.ServiceURLs = ua.ServiceURLs;

            return acd;
        }

        private static AgentCircuitData GenerateCommonAgentData()
        {
            AgentCircuitData acd = new AgentCircuitData();

            // XXX: Sessions must be unique, otherwise one presence can overwrite another in NullPresenceData.
            acd.SessionID = UUID.Random();
            acd.SecureSessionID = UUID.Random();

            acd.circuitcode = 123;
            acd.BaseFolder = UUID.Zero;
            acd.InventoryFolder = UUID.Zero;
            acd.startpos = Vector3.Zero;
            acd.CapsPath = "http://wibble.com";
            acd.Appearance = new AvatarAppearance();

            return acd;
        }

        /// <summary>
        /// Add a root agent where the details of the agent connection (apart from the id) are unimportant for the test
        /// </summary>
        /// <remarks>
        /// XXX: Use the version of this method that takes the UserAccount structure wherever possible - this will
        /// make the agent circuit data (e.g. first, lastname) consistent with the user account data.
        /// </remarks>
        /// <param name="scene"></param>
        /// <param name="agentId"></param>
        /// <returns></returns>
        public static ScenePresence AddScenePresence(Scene scene, UUID agentId)
        {
            return AddScenePresence(scene, GenerateAgentData(agentId));
        }

        /// <summary>
        /// Add a root agent.
        /// </summary>
        /// <param name="scene"></param>
        /// <param name="ua"></param>
        /// <returns></returns>
        public static ScenePresence AddScenePresence(Scene scene, UserAccount ua)
        {
            return AddScenePresence(scene, GenerateAgentData(ua));
        }

        /// <summary>
        /// Add a root agent.
        /// </summary>
        /// <remarks>
        /// This function
        ///
        /// 1)  Tells the scene that an agent is coming.  Normally, the login service (local if standalone, from the
        /// userserver if grid) would give initial login data back to the client and separately tell the scene that the
        /// agent was coming.
        ///
        /// 2)  Connects the agent with the scene
        ///
        /// This function performs actions equivalent with notifying the scene that an agent is
        /// coming and then actually connecting the agent to the scene.  The one step missed out is the very first
        /// </remarks>
        /// <param name="scene"></param>
        /// <param name="agentData"></param>
        /// <returns></returns>
        public static ScenePresence AddScenePresence(Scene scene, AgentCircuitData agentData)
        {
            return AddScenePresence(scene, new TestClient(agentData, scene), agentData);
        }

        /// <summary>
        /// Add a root agent.
        /// </summary>
        /// <remarks>
        /// This function
        ///
        /// 1)  Tells the scene that an agent is coming.  Normally, the login service (local if standalone, from the
        /// userserver if grid) would give initial login data back to the client and separately tell the scene that the
        /// agent was coming.
        ///
        /// 2)  Connects the agent with the scene
        ///
        /// This function performs actions equivalent with notifying the scene that an agent is
        /// coming and then actually connecting the agent to the scene.  The one step missed out is the very first
        /// </remarks>
        /// <param name="scene"></param>
        /// <param name="agentData"></param>
        /// <returns></returns>
        public static ScenePresence AddScenePresence(
            Scene scene, IClientAPI client, AgentCircuitData agentData)
        {
            // We emulate the proper login sequence here by doing things in four stages

            // Stage 0: login
            // We need to punch through to the underlying service because scene will not, correctly, let us call it
            // through it's reference to the LPSC
            LocalPresenceServicesConnector lpsc = (LocalPresenceServicesConnector)scene.PresenceService;
            lpsc.m_PresenceService.LoginAgent(agentData.AgentID.ToString(), agentData.SessionID, agentData.SecureSessionID);

            // Stages 1 & 2
            ScenePresence sp = IntroduceClientToScene(scene, client, agentData, TeleportFlags.ViaLogin);

            // Stage 3: Complete the entrance into the region.  This converts the child agent into a root agent.
            sp.CompleteMovement(sp.ControllingClient, true);

            return sp;
        }

        /// <summary>
        /// Introduce an agent into the scene by adding a new client.
        /// </summary>
        /// <returns>The scene presence added</returns>
        /// <param name='scene'></param>
        /// <param name='testClient'></param>
        /// <param name='agentData'></param>
        /// <param name='tf'></param>
        private static ScenePresence IntroduceClientToScene(
            Scene scene, IClientAPI client, AgentCircuitData agentData, TeleportFlags tf)
        {
            string reason;

            // Stage 1: tell the scene to expect a new user connection
            if (!scene.NewUserConnection(agentData, (uint)tf, null, out reason))
                Console.WriteLine("NewUserConnection failed: " + reason);

            // Stage 2: add the new client as a child agent to the scene
            scene.AddNewAgent(client, PresenceType.User);

            return scene.GetScenePresence(client.AgentId);
        }

        public static ScenePresence AddChildScenePresence(Scene scene, UUID agentId)
        {
            AgentCircuitData acd = GenerateAgentData(agentId);
            acd.child = true;

            // XXX: ViaLogin may not be correct for child agents
            TestClient client = new TestClient(acd, scene);
            return IntroduceClientToScene(scene, client, acd, TeleportFlags.ViaLogin);
        }

        /// <summary>
        /// Add a test object
        /// </summary>
        /// <param name="scene"></param>
        /// <returns></returns>
        public static SceneObjectGroup AddSceneObject(Scene scene)
        {
            return AddSceneObject(scene, "Test Object", UUID.Zero);
        }

        /// <summary>
        /// Add a test object
        /// </summary>
        /// <param name="scene"></param>
        /// <param name="name"></param>
        /// <param name="ownerId"></param>
        /// <returns></returns>
        public static SceneObjectGroup AddSceneObject(Scene scene, string name, UUID ownerId)
        {
            SceneObjectGroup so = new SceneObjectGroup(CreateSceneObjectPart(name, UUID.Random(), ownerId));

            //part.UpdatePrimFlags(false, false, true);
            //part.ObjectFlags |= (uint)PrimFlags.Phantom;

            scene.AddNewSceneObject(so, false);

            return so;
        }

        /// <summary>
        /// Add a test object
        /// </summary>
        /// <param name="scene"></param>
        /// <param name="parts">
        /// The number of parts that should be in the scene object
        /// </param>
        /// <param name="ownerId"></param>
        /// <param name="partNamePrefix">
        /// The prefix to be given to part names.  This will be suffixed with "Part<part no>"
        /// (e.g. mynamePart1 for the root part)
        /// </param>
        /// <param name="uuidTail">
        /// The hexadecimal last part of the UUID for parts created.  A UUID of the form "00000000-0000-0000-0000-{0:XD12}"
        /// will be given to the root part, and incremented for each part thereafter.
        /// </param>
        /// <returns></returns>
        public static SceneObjectGroup AddSceneObject(Scene scene, int parts, UUID ownerId, string partNamePrefix, int uuidTail)
        {
            SceneObjectGroup so = CreateSceneObject(parts, ownerId, partNamePrefix, uuidTail);

            scene.AddNewSceneObject(so, false);

            return so;
        }
        
        /// <summary>
        /// Create a scene object part.
        /// </summary>
        /// <param name="name"></param>
        /// <param name="id"></param>
        /// <param name="ownerId"></param>
        /// <returns></returns>
        public static SceneObjectPart CreateSceneObjectPart(string name, UUID id, UUID ownerId)
        {            
            return new SceneObjectPart(
                ownerId, PrimitiveBaseShape.Default, Vector3.Zero, Quaternion.Identity, Vector3.Zero) 
                    { Name = name, UUID = id, Scale = new Vector3(1, 1, 1) };            
        }

        /// <summary>
        /// Create a scene object but do not add it to the scene.
        /// </summary>
        /// <remarks>
        /// UUID always starts at 00000000-0000-0000-0000-000000000001.  For some purposes, (e.g. serializing direct
        /// to another object's inventory) we do not need a scene unique ID.  So it would be better to add the
        /// UUID when we actually add an object to a scene rather than on creation.
        /// </remarks>
        /// <param name="parts">The number of parts that should be in the scene object</param>
        /// <param name="ownerId"></param>
        /// <returns></returns>
        public static SceneObjectGroup CreateSceneObject(int parts, UUID ownerId)
        {            
            return CreateSceneObject(parts, ownerId, 0x1);
        }
        
        /// <summary>
        /// Create a scene object but do not add it to the scene.
        /// </summary>
        /// <param name="parts">The number of parts that should be in the scene object</param>
        /// <param name="ownerId"></param>
        /// <param name="uuidTail">
        /// The hexadecimal last part of the UUID for parts created.  A UUID of the form "00000000-0000-0000-0000-{0:XD12}"
        /// will be given to the root part, and incremented for each part thereafter.
        /// </param>
        /// <returns></returns>
        public static SceneObjectGroup CreateSceneObject(int parts, UUID ownerId, int uuidTail)
        {            
            return CreateSceneObject(parts, ownerId, "", uuidTail);
        }          
        
        /// <summary>
        /// Create a scene object but do not add it to the scene.
        /// </summary>
        /// <param name="parts">
        /// The number of parts that should be in the scene object
        /// </param>
        /// <param name="ownerId"></param>
        /// <param name="partNamePrefix">
        /// The prefix to be given to part names.  This will be suffixed with "Part<part no>"
        /// (e.g. mynamePart1 for the root part)
        /// </param>
        /// <param name="uuidTail">
        /// The hexadecimal last part of the UUID for parts created.  A UUID of the form "00000000-0000-0000-0000-{0:XD12}"
        /// will be given to the root part, and incremented for each part thereafter.
        /// </param>
        /// <returns></returns>
        public static SceneObjectGroup CreateSceneObject(int parts, UUID ownerId, string partNamePrefix, int uuidTail)
        {            
            string rawSogId = string.Format("00000000-0000-0000-0000-{0:X12}", uuidTail);
            
            SceneObjectGroup sog 
                = new SceneObjectGroup(
                    CreateSceneObjectPart(string.Format("{0}Part1", partNamePrefix), new UUID(rawSogId), ownerId));
            
            if (parts > 1)
                for (int i = 2; i <= parts; i++)
                    sog.AddPart(
                        CreateSceneObjectPart(
                            string.Format("{0}Part{1}", partNamePrefix, i), 
                            new UUID(string.Format("00000000-0000-0000-0000-{0:X12}", uuidTail + i - 1)),
                            ownerId));
            
            return sog;
        }        
    }
}