using System;
using System.Threading;
using System.Windows.Forms;
using Diagnostics = System.Diagnostics;

namespace ProcessInfo
{
	public class ProcessListView : ListView
	{
		private ProcessListViewItemComparer comparer;
		private delegate void ListViewItemDelegate( ListViewItem item );

		public ProcessListView()
			: base()
		{
			this.View = View.Details;

			// columns must be added in same order they appear in ProcessField
			this.Columns.Add( "PID", 100, HorizontalAlignment.Right );
			this.Columns.Add( "Image Name", 150, HorizontalAlignment.Left );
			this.Columns.Add( "Working Set", 100, HorizontalAlignment.Right );

			comparer = new ProcessListViewItemComparer();
			this.ListViewItemSorter = comparer;
			this.Sort( ProcessField.Pid, true );
		}

		public void Sort( ProcessField sortField )
		{
			if ( sortField.Equals( comparer.CompareField ) )
			{
				this.Sort( sortField, !comparer.Ascending );
			}
			else
			{
				this.Sort( sortField, true );
			}
		}

		public void Sort( ProcessField sortField, bool ascending )
		{
			comparer.CompareField = sortField;
			comparer.Ascending = ascending;
			this.Sort();
		}

		// thread-safe
		public void RefreshProcesses()
		{
			// must access Control on thread that created it
			this.Invoke( new MethodInvoker( this.Items.Clear ) );

			foreach( Diagnostics.Process process in Diagnostics.Process.GetProcesses() )
			{
				ProcessListViewItem listViewItem = new ProcessListViewItem( new Process( process ) );
				process.Dispose();

				ListViewItemDelegate addItem = new ListViewItemDelegate( AddItem );
				Object[] parameters = new Object[]{ listViewItem };
				
				this.Invoke( addItem, parameters );
			}
		}

		protected override void OnColumnClick( ColumnClickEventArgs e )
		{
			this.Sort( (ProcessField)Enum.ToObject( typeof(ProcessField), e.Column ) );
		}

		// for cross-thread calls
		private void AddItem( ListViewItem item )
		{
			this.Items.Add( item );
		}

	}
}