/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
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* modification, are permitted provided that the following conditions are met:
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*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
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*/

using Nini.Config;
using System;
using System.Collections;
using System.Collections.Generic;
using OpenSim.Framework;
using OpenSim.Framework.Console;
using OpenSim.Region.Environment.Modules;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;
using libsecondlife;

namespace OpenSim.Region.Environment.Modules.Terrain
{
    public interface ITerrainPaintableEffect
    {
        void PaintEffect(ITerrainChannel map, double x, double y, double strength);
    }

    public interface ITerrainFloodEffect
    {
        void FloodEffect(ITerrainChannel map, Boolean[,] fillArea, double strength);
    }

    public interface ITerrainEffect
    {
        void RunEffect(ITerrainChannel map, double strength);
    }

    public interface ITerrainLoader 
    {
        ITerrainChannel LoadFile(string filename);
        void SaveFile(string filename);
    }

    /// <summary>
    /// A new version of the old Channel class, simplified
    /// </summary>
    public class TerrainChannel : ITerrainChannel
    {
        private double[,] map;

        public int Width
        {
            get { return map.GetLength(0); }
        }

        public int Height
        {
            get { return map.GetLength(1); }
        }

        public TerrainChannel Copy()
        {
            TerrainChannel copy = new TerrainChannel(false);
            copy.map = (double[,])this.map.Clone();

            return copy;
        }

        public double this[int x, int y]
        {
            get
            {
                return map[x, y];
            }
            set
            {
                map[x, y] = value;
            }
        }

        public TerrainChannel()
        {
            map = new double[Constants.RegionSize, Constants.RegionSize];
        }

        public TerrainChannel(bool createMap)
        {
            if (createMap)
                map = new double[Constants.RegionSize, Constants.RegionSize];
        }

        public TerrainChannel(int w, int h)
        {
            map = new double[w, h];
        }
    }

    public enum StandardTerrainEffects : byte
    {
        Flatten = 0,
        Raise = 1,
        Lower = 2,
        Smooth = 3,
        Noise = 4,
        Revert = 5
    }

    public class TerrainModule : IRegionModule
    {
        private static readonly log4net.ILog m_log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        private Dictionary<StandardTerrainEffects, ITerrainPaintableEffect> m_painteffects =
            new Dictionary<StandardTerrainEffects, ITerrainPaintableEffect>();
        private Dictionary<StandardTerrainEffects, ITerrainFloodEffect> m_floodeffects =
            new Dictionary<StandardTerrainEffects, ITerrainFloodEffect>();
        private Dictionary<string, ITerrainLoader> m_loaders = new Dictionary<string, ITerrainLoader>();
        Scene m_scene;
        ITerrainChannel m_channel;
        private IConfigSource m_gConfig;

        private void InstallDefaultEffects()
        {
            m_painteffects[StandardTerrainEffects.Raise] = new PaintBrushes.RaiseSphere();
            m_floodeffects[StandardTerrainEffects.Raise] = new FloodBrushes.RaiseArea();

            // Float[256,256] array format (RAW32)
            m_loaders[".r32"] = new FileLoaders.RAW32();
            m_loaders[".f32"] = m_loaders[".r32"];
            m_loaders[".ter"] = new FileLoaders.Terragen();
        }

        public void LoadFromFile(string filename)
        {
            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
            {
                if (filename.EndsWith(loader.Key))
                {
                    loader.Value.LoadFile(filename);
                    return;
                }
            }
        }

        public void SaveToFile(string filename)
        {
            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
            {
                if (filename.EndsWith(loader.Key))
                {
                    loader.Value.SaveFile(filename);
                    return;
                }
            }
        }

        public void Initialise(Scene scene, IConfigSource config)
        {
            m_scene = scene;
            m_gConfig = config;

            m_channel = new TerrainChannel();
            m_scene.EventManager.OnNewClient += EventManager_OnNewClient;
        }

        void EventManager_OnNewClient(IClientAPI client)
        {
            client.OnModifyTerrain += client_OnModifyTerrain;
        }

        void client_OnModifyTerrain(float height, float seconds, byte size, byte action, float north, float west, float south, float east, IClientAPI remoteClient)
        {
            // Not a good permissions check, if in area mode, need to check the entire area.
            if (m_scene.PermissionsMngr.CanTerraform(remoteClient.AgentId, new LLVector3(north, west, 0)))
            {

                if (north == south && east == west)
                {
                    if (m_painteffects.ContainsKey((StandardTerrainEffects)action))
                    {
                        m_painteffects[(StandardTerrainEffects)action].PaintEffect(
                            m_channel, west, south, Math.Pow(size, 2.0));
                    }
                    else
                    {
                        m_log.Debug("Unknown terrain brush type " + action.ToString());
                    }
                }
                else
                {
                    if (m_floodeffects.ContainsKey((StandardTerrainEffects)action))
                    {
                        bool[,] fillArea = new bool[m_channel.Width, m_channel.Height];

                        fillArea.Initialize();

                        int x, y;
                        for (x = 0; x < m_channel.Width; x++)
                        {
                            for (y = 0; y < m_channel.Height; y++)
                            {
                                fillArea[x, y] = true;
                            }
                        }

                        m_floodeffects[(StandardTerrainEffects)action].FloodEffect(
                            m_channel, fillArea, Math.Pow(size, 2.0));
                    }
                    else
                    {
                        m_log.Debug("Unknown terrain flood type " + action.ToString());
                    }
                }
            }
        }

        public void PostInitialise()
        {
            InstallDefaultEffects();
        }

        public void Close()
        {
        }

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

        public bool IsSharedModule
        {
            get { return false; }
        }
    }
}