#region "  © Copyright 2005-07 to Marcos Meli - http://www.marcosmeli.com.ar" 

// Errors, suggestions, contributions, send a mail to: marcos@filehelpers.com.

#endregion

using System.IO;
using System.Text;

namespace FileHelpers
{

#if NET_1_1 || MINI

	internal sealed class StreamHelper
	{
		private StreamHelper()
		{
		}

#else
	internal static class StreamHelper
	{
#endif
		internal static TextWriter CreateFileAppender(string fileName, Encoding encode, bool correctEnd)
		{
			return CreateFileAppender(fileName, encode, correctEnd, true);
		}

		internal static TextWriter CreateFileAppender(string fileName, Encoding encode, bool correctEnd, bool disposeStream)
		{
			TextWriter res;

			if (correctEnd)
			{
				FileStream fs = null;

				try
				{
					fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);

					if (fs.Length >= 2)
					{
						fs.Seek(-2, SeekOrigin.End);

						if (fs.ReadByte() == 13)
						{
							if (fs.ReadByte() == 10)
							{
								int nowRead;
								do
								{
									fs.Seek(-2, SeekOrigin.Current);
									nowRead = fs.ReadByte();
								} while (nowRead == 13 || nowRead == 10);
							}
						}
						else
							fs.ReadByte();

						fs.WriteByte(13);
						fs.WriteByte(10);

					}

					res = new StreamWriter(fs, encode);

				}
				finally
				{
					if (disposeStream && fs != null)
						fs.Close();
				}
			}
			else
			{
				res = new StreamWriter(fileName, true, encode);
			}

			return res;
		}

	}
}