using System;
using System.Threading;
using System.Collections.Generic;
using System.Text;
using libsecondlife;
using libsecondlife.Packets;

namespace OpenSim.world
{
    public class World
    {
        public Dictionary<libsecondlife.LLUUID, Entity> Entities;
        public float[] LandMap;
        public ScriptEngine Scripts;
        public uint _localNumber = 0;
        public PhysicsEngine physics;

        private libsecondlife.TerrainManager TerrainManager;
        private Random Rand = new Random();

        public World()
        {
            OpenSim_Main.localcons.WriteLine("World.cs - creating new entitities instance");
            Entities = new Dictionary<libsecondlife.LLUUID, Entity>();

            OpenSim_Main.localcons.WriteLine("World.cs - creating LandMap");
            TerrainManager = new TerrainManager(new SecondLife());
        }

        public void InitLoop()
        {
            OpenSim_Main.localcons.WriteLine("World.cs:StartLoop() - Initialising physics");
            this.physics = new PhysicsEngine();
            physics.Startup();
        }

        public void DoStuff()
        {
            lock (this)
            {
                physics.DoStuff(this);
                this.Update();
            }
        }

        public void Update()
        {
            foreach (libsecondlife.LLUUID UUID in Entities.Keys)
            {
                if (Entities[UUID].needupdate)
                {
                    Entities[UUID].update();

                    if (Entities[UUID] is Avatar)
                    {
                        Avatar avatar = (Avatar)Entities[UUID];
                        if ((avatar.oldpos != avatar.position) || (avatar.oldvel != avatar.velocity) || avatar.walking)
                        {
                            ImprovedTerseObjectUpdatePacket.ObjectDataBlock terseBlock = Entities[UUID].CreateTerseBlock();
                            foreach (OpenSimClient client in OpenSim_Main.sim.ClientThreads.Values)
                            {
                                ImprovedTerseObjectUpdatePacket terse = new ImprovedTerseObjectUpdatePacket();
                                terse.RegionData.RegionHandle = OpenSim_Main.cfg.RegionHandle; // FIXME
                                terse.RegionData.TimeDilation = 0;
                                terse.ObjectData = new ImprovedTerseObjectUpdatePacket.ObjectDataBlock[1];
                                terse.ObjectData[0] = terseBlock;
                                client.OutPacket(terse);
                            }
                        }
                    }
                }
            }
        }

        public void SendLayerData(OpenSimClient RemoteClient)
        {
            int[] patches = new int[4];

            for (int y = 0; y < 16; y++)
            {
                for (int x = 0; x < 16; x = x + 4)
                {
                    patches[0] = x + 0 + y * 16;
                    patches[1] = x + 1 + y * 16;
                    patches[2] = x + 2 + y * 16;
                    patches[3] = x + 3 + y * 16;

                    Packet layerpack = TerrainManager.CreateLandPacket(LandMap, patches);
                    RemoteClient.OutPacket(layerpack);
                }
            }
        }

        public void AddViewerAgent(OpenSimClient AgentClient)
        {
            OpenSim_Main.localcons.WriteLine("World.cs:AddViewerAgent() - Creating new avatar for remote viewer agent");
            Avatar NewAvatar = new Avatar(AgentClient);
            OpenSim_Main.localcons.WriteLine("World.cs:AddViewerAgent() - Adding new avatar to world");
            this.Entities.Add(AgentClient.AgentID, NewAvatar);
            OpenSim_Main.localcons.WriteLine("World.cs:AddViewerAgent() - Starting RegionHandshake ");
            NewAvatar.SendRegionHandshake(this);
            this.Update();		// will work for now, but needs to be optimised so we don't update everything in the sim for each new user
        }

        public bool Backup()
        {
            /* TODO: Save the current world entities state. */

            return false;
        }
    }
}