using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace System.Linq.jvm
{
	internal class Conversion
	{
		internal static object ConvertPrimitiveUnChecked (Type from, Type to, object value) 
		{
			unchecked {
				switch (Type.GetTypeCode (from)) {
				case TypeCode.Byte:
					return ConvertByte ((byte) value, to);
				case TypeCode.Char:
					return ConvertChar ((char) value, to);
				case TypeCode.Decimal:
					return ConvertDecimal ((decimal) value, to);
				case TypeCode.Double:
					return ConvertDouble ((double) value, to);
				case TypeCode.Int16:
					return ConvertShort ((short) value, to);
				case TypeCode.Int32:
					return ConvertInt ((int) value, to);
				case TypeCode.Int64:
					return ConvertLong ((long) value, to);
				case TypeCode.SByte:
					return ConvertSByte ((sbyte) value, to);
				case TypeCode.Single:
					return ConvertFloat ((float) value, to);
				case TypeCode.UInt16:
					return ConvertUShort ((ushort) value, to);
				case TypeCode.UInt32:
					return ConvertUInt ((uint) value, to);
				case TypeCode.UInt64:
					return ConvertULong ((ulong) value, to);
				default:
					throw new NotImplementedException ();
				}
			}	
		}

		static object ConvertByte (byte b, Type to) 
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertChar (char b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertDecimal (decimal b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertDouble (double b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertShort (short b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertInt (int b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertLong (long b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertSByte (sbyte b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertFloat (float b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertUShort (ushort b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertUInt (uint b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}

		static object ConvertULong (ulong b, Type to)
		{
			unchecked {
				switch (Type.GetTypeCode (to)) {
				case TypeCode.Byte:
					return (byte) b;
				case TypeCode.Char:
					return (char) b;
				case TypeCode.Decimal:
					return (decimal) b;
				case TypeCode.Double:
					return (double) b;
				case TypeCode.Int16:
					return (short) b;
				case TypeCode.Int32:
					return (int) b;
				case TypeCode.Int64:
					return (long) b;
				case TypeCode.SByte:
					return (sbyte) b;
				case TypeCode.Single:
					return (float) b;
				case TypeCode.UInt16:
					return (ushort) b;
				case TypeCode.UInt32:
					return (uint) b;
				case TypeCode.UInt64:
					return (ulong) b;
				}
				return null;
			}
		}
	}
}