/*
* 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.IO;
using System.Text;
using OpenSim.Region.Environment.Interfaces;

namespace OpenSim.Region.Environment.Modules.Terrain.FileLoaders
{
    /// <summary>
    /// Terragen File Format Loader
    /// Built from specification at
    /// http://www.planetside.co.uk/terragen/dev/tgterrain.html
    /// </summary>
    class Terragen : ITerrainLoader
    {
        private static readonly log4net.ILog m_log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        #region ITerrainLoader Members

        public ITerrainChannel LoadFile(string filename)
        {
            TerrainChannel retval = new TerrainChannel();

            FileInfo file = new FileInfo(filename);
            FileStream s = file.Open(FileMode.Open, FileAccess.Read);
            BinaryReader bs = new BinaryReader(s);

            bool eof = false;

            if (ASCIIEncoding.ASCII.GetString(bs.ReadBytes(16)) == "TERRAGENTERRAIN")
            {
                // Terragen file
                while (eof == false)
                {
                    int w = 256;
                    int h = 256;
                    string tmp = ASCIIEncoding.ASCII.GetString(bs.ReadBytes(4));
                    switch (tmp)
                    {
                        case "SIZE":
                            int sztmp = bs.ReadInt16() + 1;
                            w = sztmp;
                            h = sztmp;
                            bs.ReadInt16();
                            break;
                        case "XPTS":
                            w = bs.ReadInt16();
                            bs.ReadInt16();
                            break;
                        case "YPTS":
                            h = bs.ReadInt16();
                            bs.ReadInt16();
                            break;
                        case "ALTW":
                            eof = true;
                            Int16 heightScale = bs.ReadInt16();
                            Int16 baseHeight = bs.ReadInt16();
                            retval = new TerrainChannel(w, h);
                            int x, y;
                            for (x = 0; x < w; x++)
                            {
                                for (y = 0; y < h; y++)
                                {
                                    retval[x, y] = (double)baseHeight + (double)bs.ReadInt16() * (double)heightScale / 65536.0;
                                }
                            }
                            break;
                        default:
                            bs.ReadInt32();
                            break;
                    }
                }
            }

            bs.Close();
            s.Close();

            return retval;
        }

        public void SaveFile(string filename, ITerrainChannel map)
        {
            char[] header = "TERRAGENTERRAIN".ToCharArray();
            throw new NotImplementedException();
        }

        #endregion
    }
}