/*
 * Equality.cs - Equality operators.
 *
 * Copyright (C) 2003 Southern Storm Software, Pty Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 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
 */
 
namespace Microsoft.JScript
{

using System;
using System.Reflection;

// Dummy class for backwards-compatibility.

public sealed class Equality : BinaryOp
{
	// Constructor.
	public Equality(int operatorTok)
			: base(operatorTok)
			{
				// Nothing to do here.
			}

	// Evaluate an equality operator on two values.
	public bool EvaluateEquality(Object v1, Object v2)
			{
				return JScriptEquals(v1, v2);
			}

	// Determine if two JScript objects are equal.
	public static bool JScriptEquals(Object v1, Object v2)
			{
				// Handle the simple cases first.
				if(v1 is String && v2 is String)
				{
					return ((String)v1) == ((String)v2);
				}
				else if(v1 is double && v2 is double)
				{
					return ((double)v1) == ((double)v2);
				}
				else if(v1 is int && v2 is int)
				{
					return ((int)v1) == ((int)v2);
				}
				else if(v1 is bool && v2 is bool)
				{
					return ((bool)v1) == ((bool)v2);
				}
				else if(v1 == v2)
				{
					return true;
				}

				// Is one of the values null?
				if(v1 == null || DBNull.IsDBNull(v1) || v1 is Missing
			#if ECMA_COMPAT
				  )
			#else
				   || v1 is System.Reflection.Missing)
			#endif
				{
					return (v2 == null || DBNull.IsDBNull(v2) ||
							v2 is Missing
				#if ECMA_COMPAT
						   );
				#else
							|| v2 is System.Reflection.Missing);
				#endif
				}
				else if(v2 == null || DBNull.IsDBNull(v2) || v2 is Missing
			#if ECMA_COMPAT
					   )
			#else
						|| v2 is System.Reflection.Missing)
			#endif
				{
					return false;
				}

				// Convert into primitive values and compare.
				v1 = Convert.ToPrimitive(v1, DefaultValueHint.None);
				if(v1 is bool)
				{
					v1 = Convert.ToNumber(v1);
				}
				v2 = Convert.ToPrimitive(v2, DefaultValueHint.None);
				if(v2 is bool)
				{
					v2 = Convert.ToNumber(v2);
				}
				if(v1 is String)
				{
					if(v2 is String)
					{
						return ((String)v1) == ((String)v2);
					}
					else
					{
						return Convert.ToNumber(v1) == Convert.ToNumber(v2);
					}
				}
				else if(v1 is double)
				{
					return ((double)v1) == Convert.ToNumber(v2);
				}

				// Don't know how to compare the objects.
				return false;
			}

}; // class Equality

}; // namespace Microsoft.JScript
