//Copyright (C) 2005 Richard J. Northedge
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

//This file is based on the BinaryGISModelWriter.java source file found in the
//original java implementation of MaxEnt.  That source file contains the following header:

// Copyright (C) 2001 Jason Baldridge and Gann Bierner
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

using System;
using System.IO;

namespace BotSharp.MachineLearning.IO
{
	/// <summary>
	/// A writer for GIS models that saves models in the binary format used by the java 
	/// version of MaxEnt.  This binary format stores data using big-endian values, which means
	/// that the C# version must reverse the byte order of each value in turn, making it
	/// less efficient.  Use only for compatibility with the java MaxEnt library.
	/// </summary>
	/// <author> 
	/// Jason Baldridge
	/// </author>
	/// <author>
	/// Richard J. Northedge
	/// </author>
	/// <version>
	/// based on BinaryGISModelWriter.java $Revision: 1.1.1.1 $, $Date: 2001/10/23 14:06:53 $
	/// </version>
	public class JavaBinaryGisModelWriter : GisModelWriter
	{
		private Stream mOutput;
		private byte[] mBuffer = new byte[7];
		private System.Text.Encoding mEncoding = System.Text.Encoding.UTF8;
		
		/// <summary>
		/// Default constructor.
		/// </summary>
		public JavaBinaryGisModelWriter()
		{
		}
			
		/// <summary> Takes a GisModel and a File and
		/// writes the model to that file.
		/// </summary>
		/// <param name="model">The GisModel which is to be persisted.
		/// </param>
		/// <param name="fileName">The name of the file in which the model is to be persisted.
		/// </param>
		public void Persist(GisModel model, string fileName)
		{
			using (mOutput = new FileStream(fileName, FileMode.Create))
			{
				base.Persist(model);
			}
		}

		/// <summary>
		/// Takes a GisModel and a Stream and writes the model to that stream.
		/// </summary>
		/// <param name="model">
		/// The GIS model which is to be persisted.
		/// </param>
		/// <param name="dataOutputStream">
		/// The Stream which will be used to persist the model.
		/// </param>
		public void Persist(GisModel model, Stream dataOutputStream)
		{
			using (mOutput = dataOutputStream)
			{
				base.Persist(model);
			}
		}

		/// <summary>
		/// Writes a UTF-8 encoded string to the model file.
		/// </summary>
		/// /// <param name="data">
		/// The string data to be persisted.
		/// </param>
		protected override void WriteString(string data)
		{
			mOutput.WriteByte((byte)(mEncoding.GetByteCount(data) / 256));
			mOutput.WriteByte((byte)(mEncoding.GetByteCount(data) % 256));
			mOutput.Write(mEncoding.GetBytes(data), 0, mEncoding.GetByteCount(data));
		}
		
		/// <summary>
		/// Writes a 32-bit signed integer to the model file.
		/// </summary>
		/// /// <param name="data">
		/// The integer data to be persisted.
		/// </param>
		protected override void WriteInt32(int data)
		{
			mBuffer = BitConverter.GetBytes(data);
			Array.Reverse(mBuffer);
			mOutput.Write(mBuffer, 0, 4);
		}
		
		/// <summary>
		/// Writes a double-precision floating point number to the model file.
		/// </summary>
		/// /// <param name="data">
		/// The floating point data to be persisted.
		/// </param>
		protected override void WriteDouble(double data)
		{
			mBuffer = BitConverter.GetBytes(data);
			Array.Reverse(mBuffer);
			mOutput.Write(mBuffer, 0, 8);
		}
	}
}