using System;
using System.IO;
using System.Drawing;
using System.Reflection;
using System.Collections;
using System.Drawing.Text;
using System.Windows.Forms;
using System.ComponentModel;
using System.Drawing.Imaging;
using UtilityLibrary.Win32;
using UtilityLibrary.Menus;
using UtilityLibrary.General;
using UtilityLibrary.Collections;


namespace UtilityLibrary.Menus
{
	[ToolboxBitmap(typeof(MenuControl))]
	[DefaultProperty("MenuCommands")]
	[DefaultEvent("PopupStart")]
	[Designer(typeof(UtilityLibrary.Menus.MenuControlDesigner))]
	public class MenuControl : ContainerControl, IMessageFilter
	{
		// Class constants
		protected const int _breadthGap = 5;
		protected const int _lengthGap = 3;
		protected const int _boxExpandUpper = 1;
		protected const int _boxExpandSides = 2;
		protected const int _shadowGap = 3;
		protected const int _shadowYOffset = 3;
		protected const int _separatorWidth = 15;
		protected const int _subMenuBorderAdjust = 2;
		protected const int _chevronIndex = 0;
		protected const int _chevronLength = 10;
		protected const int _chevronBreadth = 10;

		// Class constant is marked as 'readonly' to allow non constant initialization
		protected readonly int WM_OPERATEMENU = (int)Win32.Msg.WM_USER + 1;

		// Class fields
		protected static ImageList _menuImages = null;
		protected static bool _supportsLayered = false;

		// Declare the popup change event signature
		public delegate void PopupHandler(MenuCommand item);

		// Instance fields
		protected int _rowWidth;
		protected int _rowHeight;
		protected bool _selected;
		protected int _trackItem;
		protected bool _multiLine;
		protected bool _mouseOver;
		protected IntPtr _oldFocus;
		protected bool _manualFocus;
		protected bool _drawUpwards;
		protected VisualStyle _style;
		protected bool _plainAsBlock;
		protected Direction _direction;
		protected bool _ignoreEscapeUp;
		protected PopupMenu _popupMenu;
		protected bool _dismissTransfer;
		protected bool _ignoreMouseMove;
		protected ArrayList _drawCommands;
		protected MenuCommand _chevronStartCommand;
		protected MenuCommandCollection _menuCommands;

		// Instance fields - events
		public event PopupHandler PopupStart;
		public event PopupHandler PopupEnd;

		static MenuControl()
		{
			// Create a strip of images by loading an embedded bitmap resource
			_menuImages = ResourceUtil.LoadImageListResource(Type.GetType("UtilityLibrary.Menus.MenuControl"),
														 "Resources.ImagesMenu",
														 "MenuControlImages",
														 new Size(_chevronLength, _chevronBreadth),
				                                         true,
														 new Point(0,0));

			// We need to know if the OS supports layered windows
			_supportsLayered = (OSFeature.Feature.GetVersionPresent(OSFeature.LayeredWindows) != null);
		}

		public MenuControl()
		{
			// Set default values
			this.Dock = DockStyle.Top;
			_trackItem = -1;
			_selected = false;
			_multiLine = false;
			_popupMenu = null;
			_mouseOver = false;
			_manualFocus = false;
			_drawUpwards = false;
			_plainAsBlock = false;
			_oldFocus = IntPtr.Zero;
			_ignoreEscapeUp = false;
			_ignoreMouseMove = false;
			_dismissTransfer = false;
			_style = VisualStyle.IDE;
			_chevronStartCommand = null;
			_direction = Direction.Horizontal;
			_menuCommands = new MenuCommandCollection();
			
			// Prevent flicker with double buffering and all painting inside WM_PAINT
			SetStyle(ControlStyles.DoubleBuffer, true);
			SetStyle(ControlStyles.AllPaintingInWmPaint, true);

			// Should not be allowed to select this control
			SetStyle(ControlStyles.Selectable, false);

			// Hookup to collection events
			_menuCommands.Cleared += new CollectionWithEvents.CollectionClear(OnCollectionCleared);
			_menuCommands.Inserted += new CollectionWithEvents.CollectionChange(OnCollectionInserted);
			_menuCommands.Removed += new CollectionWithEvents.CollectionChange(OnCollectionRemoved);

			// Set the default menu color as background
			this.BackColor = SystemColors.Control;

			// Do not allow tab key to select this control
			this.TabStop = false;

			// Default the Font we use
			this.Font = SystemInformation.MenuFont;

			// Calculate the initial height/width of the control
			_rowWidth = _rowHeight = this.Font.Height + _breadthGap * 2 + 1;

			// Default to one line of items
			this.Height = _rowHeight;

			// Add ourself to the application filtering list
			Application.AddMessageFilter(this);
		}

		[Category("Behaviour")]
		[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
		public MenuCommandCollection MenuCommands
		{
			get { return _menuCommands; }

			set
			{
				_menuCommands.Clear();
				_menuCommands = value;

				Recalculate();
				Invalidate();
			}
		} 

		[Category("Appearance")]
		public VisualStyle Style
		{
			get { return _style; }
			
			set
			{
				if (_style != value)
				{
					_style = value;

					Recalculate();
					Invalidate();
				}
			}
		}

		[Category("Appearance")]
		public override Font Font
		{
			get { return base.Font; }
			
			set
			{
				base.Font = value;

				// Resize to take into accout the new height
				_rowHeight = this.Font.Height + _lengthGap * 2;

				Recalculate();
				Invalidate();
			}
		}

		[Category("Appearance")]
		[DefaultValue(false)]
		public bool PlainAsBlock
		{
			get { return _plainAsBlock; }

			set
			{
				if (_plainAsBlock != value)
				{
					_plainAsBlock = value;

					Recalculate();
					Invalidate();
				}
			}
		}

		[Category("Appearance")]
		[DefaultValue(false)]
		public bool MultiLine
		{
			get { return _multiLine; }

			set
			{
				if (_multiLine != value)
				{
					_multiLine = value;

					Recalculate();
					Invalidate();
				}
			}
		}

		[Category("Appearance")]
		public Direction Direction
		{
			get { return _direction; }

			set
			{
				if (_direction != value)
				{
					_direction = value;

					Recalculate();
					Invalidate();
				}
			}
		}

		public override DockStyle Dock
		{
			get { return base.Dock; }

			set
			{
				base.Dock = value;

				switch(value)
				{
				case DockStyle.None:
					_direction = Direction.Horizontal;
					break;
				case DockStyle.Top:
				case DockStyle.Bottom:
					this.Height = 0;
					_direction = Direction.Horizontal;
					break;
				case DockStyle.Left:
				case DockStyle.Right:
					this.Width = 0;
					_direction = Direction.Vertical;
					break;
				}

				Recalculate();
				Invalidate();
			}
		}

		protected void OnPopupStart(MenuCommand mc)
		{
			if (PopupStart != null)
				PopupStart(mc);
		}
		
		protected void OnPopupEnd(MenuCommand mc)
		{
			if (PopupEnd != null)
				PopupEnd(mc);
		}

		protected void OnCollectionCleared()
		{
			// Reset state ready for a recalculation
			_selected = false;
			_trackItem = -1;

			Recalculate();
			Invalidate();
		}

		protected void OnCollectionInserted(int index, object value)
		{
			MenuCommand mc = value as MenuCommand;

			// We need notification whenever the properties of this command change
			mc.PropertyChanged += new MenuCommand.PropChangeHandler(OnCommandChanged);
				
			// Reset state ready for a recalculation
			_selected = false;
			_trackItem = -1;

			Recalculate();
			Invalidate();
		}

		protected void OnCollectionRemoved(int index, object value)
		{
			// Reset state ready for a recalculation
			_selected = false;
			_trackItem = -1;

			Recalculate();
			Invalidate();
		}

		protected void OnCommandChanged(MenuCommand item, MenuCommand.Property prop)
		{
			Recalculate();
			Invalidate();
		}

		protected override void OnMouseDown(MouseEventArgs e)
		{
			Point pos = new Point(e.X, e.Y);

			for(int i=0; i<_drawCommands.Count; i++)
			{
				DrawCommand dc = _drawCommands[i] as DrawCommand;

				// Find the DrawCommand this is over
				if (dc.DrawRect.Contains(pos))
				{
					// Is an item already selected?
					if (_selected)
					{
						// Is it this item that is already selected?
						if (_trackItem == i)
						{
							// Is a popupMenu showing
							if (_popupMenu != null)
							{
								// Dismiss the submenu
								_popupMenu.Dismiss();

								// No reference needed
								_popupMenu = null;
							}
						}
					}
					else
					{
						// Select the tracked item
						_selected = true;
						_drawUpwards = false;
								
						GrabTheFocus();
				
						// Is there a change in tracking?
						if (_trackItem != i)
						{
							// Modify the display of the two items 
							_trackItem = SwitchTrackingItem(_trackItem, i);
						}
						else
						{
							// Update display to show as selected
							DrawCommand(_trackItem, true);
						}

						// Is there a submenu to show?
						if (dc.Chevron || (dc.MenuCommand.MenuCommands.Count > 0))
							WindowsAPI.PostMessage(this.Handle, WM_OPERATEMENU, 1, 0);
					}

					break;
				}
			}

			base.OnMouseDown(e);
		}

		protected override void OnMouseUp(MouseEventArgs e)
		{
			// Is an item currently being tracked?
			if (_trackItem != -1)
			{
				// Is it also selected?
				if (_selected == true)
				{
					// Is it also showing a submenu
					if (_popupMenu == null)
					{
						// Deselect the item
						_selected = false;
						_drawUpwards = false;

						DrawCommand(_trackItem, true);

						ReturnTheFocus();
					}
				}
			}

			base.OnMouseUp(e);
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			// Sometimes we need to ignore this message
			if (_ignoreMouseMove)
				_ignoreMouseMove = false;
			else
			{
				// Is the first time we have noticed a mouse movement over our window
				if (!_mouseOver)
				{
					// Crea the structure needed for WindowsAPI call
					Win32.TRACKMOUSEEVENTS tme = new Win32.TRACKMOUSEEVENTS();

					// Fill in the structure
					tme.cbSize = 16;									
					tme.dwFlags = (uint)Win32.TrackerEventFlags.TME_LEAVE;
					tme.hWnd = this.Handle;								
					tme.dwHoverTime = 0;								

					// Request that a message gets sent when mouse leaves this window
					WindowsAPI.TrackMouseEvent(ref tme);

					// Yes, we know the mouse is over window
					_mouseOver = true;
				}

				Form parentForm = this.FindForm();

				// Only hot track if this Form is active
				if ((parentForm != null) && parentForm.ContainsFocus)
				{
					Point pos = new Point(e.X, e.Y);

					int i = 0;

					for(i=0; i<_drawCommands.Count; i++)
					{
						DrawCommand dc = _drawCommands[i] as DrawCommand;

						// Find the DrawCommand this is over
						if (dc.DrawRect.Contains(pos))
						{
							// Is there a change in selected item?
							if (_trackItem != i)
							{
								// We we currently selecting an item
								if (_selected)
								{
									if (_popupMenu != null)
									{
										// Note that we are dismissing the submenu but not removing
										// the selection of items, this flag is tested by the routine
										// that will return because the submenu has been finished
										_dismissTransfer = true;

										// Dismiss the submenu
										_popupMenu.Dismiss();
		
										// Default to downward drawing
										_drawUpwards = false;
									}

									// Modify the display of the two items 
									_trackItem = SwitchTrackingItem(_trackItem, i);

									// Does the newly selected item have a submenu?
									if (dc.Chevron || (dc.MenuCommand.MenuCommands.Count > 0))	
										WindowsAPI.PostMessage(this.Handle, WM_OPERATEMENU, 1, 0);
								}
								else
								{
									// Modify the display of the two items 
									_trackItem = SwitchTrackingItem(_trackItem, i);
								}
							}

							break;
						}
					}

					// If not in selected mode
					if (!_selected)
					{
						// None of the commands match?
						if (i == _drawCommands.Count)
						{
							// Modify the display of the two items 
							_trackItem = SwitchTrackingItem(_trackItem, -1);
						}
					}
				}
			}

			base.OnMouseMove(e);
		}

		protected override void OnMouseLeave(EventArgs e)
		{
			_mouseOver = false;

			// If we manually grabbed focus then do not switch
			// selection when the mouse leaves the control area
			if (!_manualFocus)
			{
				if (_trackItem != -1)
				{
					// If an item is selected then do not change tracking item when the 
					// mouse leaves the control area, as a popup menu might be showing and 
					// so keep the tracking and selection indication visible
					if (_selected == false)
						_trackItem = SwitchTrackingItem(_trackItem, -1);
				}
			}

			base.OnMouseLeave(e);
		}

		protected override void OnResize(EventArgs e)
		{
			Recalculate();

			// Any resize of control should redraw all of it otherwise when you 
			// stretch to the right it will not paint correctly as we have a one
			// pixel gao between text and min button which is not honoured otherwise
			this.Invalidate();

			base.OnResize(e);
		}

		internal void DrawSelectionUpwards()
		{
			// Double check the state is correct for this method to be called
			if ((_trackItem != -1) && (_selected))
			{
				// This flag is tested in the DrawCommand method
				_drawUpwards = true;

				// Force immediate redraw of the item
				DrawCommand(_trackItem, true);
			}
		}

		protected void Recalculate()
		{
			int length;

			if (_direction == Direction.Horizontal)
				length = this.Width;
			else