using System;
using System.Globalization;

namespace TBF.Tools
{
	public class ByteFormatter : IFormatProvider, ICustomFormatter
	{
		public ByteFormatter()
		{
		}

		public object GetFormat(Type formatType)
		{
			if (formatType == typeof(ICustomFormatter))
				return this;
			else
				return null;
		}

		public string Format(string fmt, object arg, IFormatProvider formatProvider)
		{
			if (arg.GetType() != typeof(byte))
			{
				try
				{
					return HandleOtherFormats(fmt, arg);
				}
				catch (FormatException e)
				{
					throw new FormatException(String.Format("The format of '{0}' is invalid.", fmt), e);
				}
			}

			///
			/// Convert one byte to string
			///
			byte b = (byte)arg;
			if ((32 <= b) && (b <= 127)) return "'" + ((char)b).ToString() + "'";
			if ((char)b == '\r') return "'\\r'";
			if ((char)b == '\n') return "'\\n'";
			if ((char)b == '\t') return "'\\t'";
			if (b == 17) return "XON";
			if (b == 19) return "XOFF";
			if (b == 26) return "Ctrl-Z";
			return b.ToString();
		}


		private string HandleOtherFormats(string format, object arg)
		{
			if (arg is IFormattable)
				return ((IFormattable)arg).ToString(format, CultureInfo.CurrentCulture);
			else if (arg != null)
				return arg.ToString();
			else
				return String.Empty;
		}
	}
}