using System;
using System.Collections;

namespace ProcessInfo
{
	public class ProcessComparer : IComparer
	{
		private ProcessField compareField;

		public ProcessComparer( ProcessField compareField )
		{
			this.compareField = compareField;
		}

		public int Compare( Process a, Process b )
		{
			if ( ( a == null ) || ( b == null ) )
			{
				throw new ArgumentNullException();
			}

			switch ( compareField )
			{
				case ProcessField.Pid:
				{
					return a.Pid.CompareTo( b.Pid );
				}
				case ProcessField.Name:
				{
					return a.Name.CompareTo( b.Name );
				}
				case ProcessField.WorkingSet:
				{
					return a.WorkingSet.CompareTo( b.WorkingSet );
				}
				default:
				{
					return a.Pid.CompareTo( b.Pid );
				}
			}
		}

		int IComparer.Compare( Object a, Object b )
		{
			return this.Compare( (Process)a, (Process)b );
		}
	}
}