using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;

using BizHawk.Client.EmuHawk.CustomControls;
using System.Collections;

namespace BizHawk.Client.EmuHawk
{
	public class InputRoll : Control
	{
		private readonly GDIRenderer Gdi;
		private readonly RollColumns _columns = new RollColumns();
		private readonly List<Cell> SelectedItems = new List<Cell>();

		private readonly VScrollBar VBar;

		private readonly HScrollBar HBar;

		private int _horizontalOrientedColumnWidth = 0;
		private int _itemCount = 0;
		private Size _charSize;

		public InputRoll()
		{
			VBar = new VScrollBar
			{
				Location = new Point(Width - 16, 0),
				Visible = false,
				Anchor = AnchorStyles.Top | AnchorStyles.Right | AnchorStyles.Bottom,
				SmallChange = 1,
				LargeChange = 5
			};

			HBar = new HScrollBar
			{
				Location = new Point(0, Height - 16),
				Visible = false,
				Anchor = AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right,
				SmallChange = 1,
				LargeChange = 5
			};

			GridLines = true;
			CellPadding = 3;
			CurrentCell = null;
			Font = new Font("Courier New", 8);  // Only support fixed width

			SetStyle(ControlStyles.AllPaintingInWmPaint, true);
			SetStyle(ControlStyles.UserPaint, true);
			SetStyle(ControlStyles.SupportsTransparentBackColor, true);
			SetStyle(ControlStyles.Opaque, true);

			Gdi = new GDIRenderer();

			using (var g = CreateGraphics())
			using (var LCK = Gdi.LockGraphics(g))
			{
				_charSize = Gdi.MeasureString("A", this.Font);
			}

			this.Controls.Add(VBar);
			this.Controls.Add(HBar);

			VBar.ValueChanged += VerticalBar_ValueChanged;
			HBar.ValueChanged += HorizontalBar_ValueChanged;

			RecalculateScrollBars();
			_columns.ChangedCallback = ColumnChangedCallback;
		}

		protected override void Dispose(bool disposing)
		{
			Gdi.Dispose();
			base.Dispose(disposing);
		}

		#region Properties

		/// <summary>
		/// Gets or sets the amount of padding on the text inside a cell
		/// </summary>
		[DefaultValue(3)]
		[Category("Behavior")]
		public int CellPadding { get; set; }

		// TODO: remove these, it is put here for more convenient replacing of a virtuallistview in tools and minimize the amount of code to refactor, but these properties are useless
		public bool VirtualMode { get; set; }
		public bool BlazingFast { get; set; }
		public bool SelectAllInProgress { get; set; }
		public System.Windows.Forms.View View { get; set; }
		public int selectedItem { get; set; }

		public void ensureVisible(int val)
		{
			LastVisibleIndex = val;
		}

		// ********************************************************

		// TODO: implement this
		/// <summary>
		/// Displays grid lines around cells
		/// </summary>
		[Category("Appearance")]
		[DefaultValue(true)]
		public bool GridLines { get; set; }

		/// <summary>
		/// Gets or sets whether the control is horizontal or vertical
		/// </summary>
		[Category("Behavior")]
		public bool HorizontalOrientation { get; set; }

		/// <summary>
		/// Gets or sets the sets the virtual number of items to be displayed.
		/// </summary>
		[Category("Behavior")]
		public int ItemCount
		{
			get
			{
				return _itemCount;
			}

			set
			{
				_itemCount = value;
				RecalculateScrollBars();
			}
		}

		/// <summary>
		/// Gets or sets the sets the columns can be resized
		/// </summary>
		[Category("Behavior")]
		public bool AllowColumnResize { get; set; }

		/// <summary>
		/// Gets or sets the sets the columns can be reordered
		/// </summary>
		[Category("Behavior")]
		public bool AllowColumnReorder { get; set; }

		/// <summary>
		/// Indicates whether the entire row will always be selected 
		/// </summary>
		[Category("Appearance")]
		[DefaultValue(false)]
		public bool FullRowSelect { get; set; }

		/// <summary>
		/// Allows multiple items to be selected
		/// </summary>
		[Category("Behavior")]
		[DefaultValue(true)]
		public bool MultiSelect { get; set; }

		/// <summary>
		/// Gets or sets whether or not the control is in input painting mode
		/// </summary>
		[Category("Behavior")]
		[DefaultValue(false)]
		public bool InputPaintingMode { get; set; }

		/// <summary>
		/// The columns shown
		/// </summary>
		[Category("Behavior")]
		public RollColumns Columns { get { return _columns; } }

		public void SelectAll()
		{
			var oldFullRowVal = FullRowSelect;
			FullRowSelect = true;
			for (int i = 0; i < ItemCount; i++)
			{
				SelectItem(i, true);
			}

			FullRowSelect = oldFullRowVal;
		}

		public void DeselectAll()
		{
			SelectedItems.Clear();
		}

		#endregion

		#region Event Handlers

		/// <summary>
		/// Fire the QueryItemText event which requests the text for the passed Listview cell.
		/// </summary>
		[Category("Virtual")]
		public event QueryItemTextHandler QueryItemText;

		/// <summary>
		/// Fire the QueryItemBkColor event which requests the background color for the passed Listview cell
		/// </summary>
		[Category("Virtual")]
		public event QueryItemBkColorHandler QueryItemBkColor;

		/// <summary>
		/// Fires when the mouse moves from one cell to another (including column header cells)
		/// </summary>
		[Category("Mouse")]
		public event CellChangeEventHandler PointedCellChanged;

		/// <summary>
		/// Occurs when a column header is clicked
		/// </summary>
		[Category("Action")]
		public event System.Windows.Forms.ColumnClickEventHandler ColumnClick;

		/// <summary>
		/// Occurs whenever the 'SelectedItems' property for this control changes
		/// </summary>
		[Category("Behavior")]
		public event System.EventHandler SelectedIndexChanged;

		/// <summary>
		/// Occurs whenever the mouse wheel is scrolled while the right mouse button is held
		/// </summary>
		[Category("Behavior")]
		public event RightMouseScrollEventHandler RightMouseScrolled;

		/// <summary>
		/// Retrieve the text for a cell
		/// </summary>
		public delegate void QueryItemTextHandler(int index, int column, out string text);

		/// <summary>
		/// Retrieve the background color for a cell
		/// </summary>
		public delegate void QueryItemBkColorHandler(int index, int column, ref Color color);

		public delegate void CellChangeEventHandler(object sender, CellEventArgs e);

		public delegate void RightMouseScrollEventHandler(object sender, MouseEventArgs e);

		public class CellEventArgs
		{
			public CellEventArgs(Cell oldCell, Cell newCell)
			{
				OldCell = oldCell;
				NewCell = newCell;
			}

			public Cell OldCell { get; private set; }
			public Cell NewCell { get; private set; }
		}

		#endregion

		#region Api

		// TODO: rename this, it is named this for legacy support from VirtualListVIew
		public void SelectItem(int index, bool val)
		{
			if (_columns.Any())
			{
				if (val)
				{
					SelectCell(new Cell
					{
						RowIndex = index,
						Column = _columns[0]
					});
				}
				else
				{
					var items = SelectedItems.Where(i => i.RowIndex == index);
					SelectedItems.RemoveAll(x => items.Contains(x));
				}
			}
		}

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public int? LastSelectedIndex
		{
			get
			{
				if (SelectedIndices.Any())
				{
					return SelectedIndices
						.OrderBy(x => x)
						.Last();
				}

				return null;
			}
		}

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public Cell CurrentCell { get; set; }

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public Cell LastCell { get; set; }

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public bool IsPaintDown { get; set; }

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public bool UseCustomBackground { get; set; }

		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public bool RightButtonHeld { get; set; }

		public string UserSettingsSerialized()
		{
			return string.Empty; // TODO
		}

		// TODO: remove
		public void AddColumns(IEnumerable<RollColumn> columns)
		{
			_columns.AddRange(columns);
			ColumnChanged();
		}

		// TODO: remove
		public void AddColumn(RollColumn column)
		{
			_columns.Add(column);
			ColumnChanged();
		}

		// TODO: remove
		public RollColumn GetColumn(int index)
		{
			return _columns[index];
		}

		/// <summary>
		/// Gets or sets the first visiable row index, if scrolling is needed
		/// </summary>
		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public int ScrollPosition
		{
			get
			{
				if (HorizontalOrientation)
				{
					if (NeedsHScrollbar)
					{
						return HBar.Value;
					}
				}

				if (NeedsVScrollbar)
				{
					return VBar.Value;
				}

				return 0;
			}

			set
			{
				if (HorizontalOrientation)
				{
					if (NeedsHScrollbar)
					{
						HBar.Value = value;
					}
				}

				if (NeedsVScrollbar)
				{
					VBar.Value = value;
				}
			}
		}

		public int LastVisibleIndex
		{
			get
			{
				return ScrollPosition + VisibleRows;
			}

			set
			{
				int i = value - VisibleRows;
				if (i < 0)
				{
					i = 0;
				}

				ScrollPosition = 0;
			}
		}

		/// <summary>
		/// Returns the number of rows currently visible
		/// </summary>
		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public int VisibleRows
		{
			get
			{
				if (HorizontalOrientation)
				{
					return (Width - _horizontalOrientedColumnWidth) / CellWidth;
				}

				return (Height / CellHeight) - 1;
			}
		}

		// TODO: make IEnumerable, IList is for legacy support
		[Browsable(false)]
		[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Hidden)]
		public IList<int> SelectedIndices
		{
			get
			{
				return SelectedItems
					.Where(cell => cell.RowIndex.HasValue)
					.Select(cell => cell.RowIndex.Value)
					.Distinct()
					.ToList();
			}
		}

		#endregion

		#region Paint

		protected override void OnPaint(PaintEventArgs e)
		{
			VBar.Location = new Point(Width - 16, 0);
			using (var LCK = Gdi.LockGraphics(e.Graphics))
			{
				Gdi.StartOffScreenBitmap(Width, Height);

				// Header
				if (_columns.Any())
				{
					DrawColumnBg(e);
					DrawColumnText(e);
				}

				// Background
				DrawBg(e);

				// ForeGround
				DrawData(e);

				Gdi.CopyToScreen();
				Gdi.EndOffScreenBitmap();
			}
		}

		protected override void OnPaintBackground(PaintEventArgs pevent)
		{
			// Do nothing, and this should never be called
		}

		private void DrawColumnText(PaintEventArgs e)
		{
			if (HorizontalOrientation)
			{
				int start = 0;
				Gdi.PrepDrawString(this.Font, this.ForeColor);
				foreach (var column in _columns)
				{
					var point = new Point(CellPadding, start + CellPadding);

					if (IsHoveringOnColumnCell && column == CurrentCell.Column)
					{
						Gdi.PrepDrawString(this.Font, SystemColors.HighlightText);
						Gdi.DrawString(column.Text, point);
						Gdi.PrepDrawString(this.Font, this.ForeColor);
					}
					else
					{
						Gdi.DrawString(column.Text, point);
					}

					start += CellHeight;
				}
			}
			else
			{
				int start = CellPadding;
				Gdi.PrepDrawString(this.Font, this.ForeColor);
				foreach (var column in _columns)
				{
					var point = new Point(start + CellPadding, CellPadding);

					if (IsHoveringOnColumnCell && column == CurrentCell.Column)
					{
						Gdi.PrepDrawString(this.Font, SystemColors.HighlightText);
						Gdi.DrawString(column.Text, point);
						Gdi.PrepDrawString(this.Font, this.ForeColor);
					}
					else
					{
						Gdi.DrawString(column.Text, point);
					}

					start += CalcWidth(column);
				}
			}
		}

		private void DrawData(PaintEventArgs e)
		{
			if (QueryItemText != null)
			{
				if (HorizontalOrientation)
				{
					int startIndex = NeedsHScrollbar ? HBar.Value : 0;
					int endIndex = startIndex + (Width / CellWidth);
					if (endIndex >= ItemCount)
					{
						endIndex = ItemCount;
					}

					int range = endIndex - startIndex;

					Gdi.PrepDrawString(this.Font, this.ForeColor);
					for (int i = 0; i < range; i++)
					{
						for (int j = 0; j < _columns.Count; j++)
						{
							string text;
							int x = _horizontalOrientedColumnWidth + CellPadding + (CellWidth * i);
							int y = j * CellHeight;
							var point = new Point(x, y);
							QueryItemText(i + startIndex, j, out text);
							Gdi.DrawString(text, point);
						}
					}
				}
				else
				{
					int startIndex = NeedsVScrollbar ? VBar.Value : 0;
					int endIndex = startIndex + (Height / CellHeight);
					
					if (endIndex >= ItemCount)
					{
						endIndex = ItemCount;
					}

					int range = endIndex - startIndex;

					Gdi.PrepDrawString(this.Font, this.ForeColor);
					for (int i = 0; i < range; i++)
					{
						int x = 1;
						for (int j = 0; j < _columns.Count; j++)
						{
							string text;
							var point = new Point(x + CellPadding, (i + 1) * CellHeight); // +1 accounts for the column header
							QueryItemText(i + startIndex, j, out text);
							Gdi.DrawString(text, point);
							x += CalcWidth(_columns[j]);
						}
					}
				}
			}
		}

		private void DrawColumnBg(PaintEventArgs e)
		{
			Gdi.SetBrush(SystemColors.ControlLight);
			Gdi.SetSolidPen(Color.Black);

			if (HorizontalOrientation)
			{
				Gdi.DrawRectangle(0, 0, _horizontalOrientedColumnWidth + 1, Height);
				Gdi.FillRectangle(1, 1, _horizontalOrientedColumnWidth, Height - 3);

				int start = 0;
				foreach (var column in _columns)
				{
					start += CellHeight;
					Gdi.Line(1, start, _horizontalOrientedColumnWidth, start);
				}
			}
			else
			{
				Gdi.DrawRectangle(0, 0, Width, CellHeight);
				Gdi.FillRectangle(1, 1, Width - 2, CellHeight);

				int start = 0;
				foreach (var column in _columns)
				{
					start += CalcWidth(column);
					Gdi.Line(start, 0, start, CellHeight);
				}
			}

			// If the user is hovering over a column
			if (IsHoveringOnColumnCell)
			{
				if (HorizontalOrientation)
				{
					for (int i = 0; i < _columns.Count; i++)
					{
						if (_columns[i] == CurrentCell.Column)
						{
							Gdi.SetBrush(SystemColors.Highlight);
							Gdi.FillRectangle(
								1,
								(i * CellHeight) + 1,
								_horizontalOrientedColumnWidth - 1,
								CellHeight - 1);
						}
					}
				}
				else
				{
					int start = 0;
					for (int i = 0; i < _columns.Count; i++)
					{
						var width = CalcWidth(_columns[i]);
						if (_columns[i] == CurrentCell.Column)
						{
							Gdi.SetBrush(SystemColors.Highlight);
							Gdi.FillRectangle(start + 1, 1, width - 1, CellHeight - 1);
						}

						start += width;
					}
				}
			}
		}

		private void DrawBg(PaintEventArgs e)
		{
			var startPoint = StartBg();

			Gdi.SetBrush(Color.White);
			Gdi.SetSolidPen(Color.Black);
			Gdi.DrawRectangle(startPoint.X, startPoint.Y, Width, Height);

			Gdi.SetSolidPen(SystemColors.ControlLight);
			if (HorizontalOrientation)
			{
				// Columns
				for (int i = 1; i < Width / CellWidth; i++)
				{
					var x = _horizontalOrientedColumnWidth + 1 + (i * CellWidth);
					var y2 = (_columns.Count * CellHeight) - 1;
					if (y2 > Height)
					{
						y2 = Height - 2;
					}

					Gdi.Line(x, 1, x, y2);
				}

				// Rows
				for (int i = 1; i < _columns.Count + 1; i++)
				{
					Gdi.Line(_horizontalOrientedColumnWidth + 1, i * CellHeight, Width - 2, i * CellHeight);
				}
			}
			else
			{
				// Columns
				int x = 0;
				int y = CellHeight + 1;
				foreach (var column in _columns)
				{
					x += CalcWidth(column);
					Gdi.Line(x, y, x, Height - 1);
				}

				// Rows
				for (int i = 2; i < (Height / CellHeight) + 1; i++)
				{
					Gdi.Line(1, (i * CellHeight) + 1, Width - 2, (i * CellHeight) + 1);
				}
			}

			if (QueryItemBkColor != null && UseCustomBackground)
			{
				DoBackGroundCallback(e);
			}

			if (SelectedItems.Any())
			{
				DoSelectionBG(e);
			}
		}

		private void DoSelectionBG(PaintEventArgs e)
		{
			foreach(var cell in SelectedItems)
			{
				DrawCellBG(SystemColors.Highlight, cell);
			}
		}

		private void DrawCellBG(Color color, Cell cell)
		{
			int x = 0,
				y = 0,
				w = 0,
				h = 0;

			if (HorizontalOrientation)
			{
				x = (cell.RowIndex.Value * CellWidth) + 2 + _horizontalOrientedColumnWidth;
				w = CellWidth - 1;
				y = (CellHeight * _columns.IndexOf(cell.Column)) + 1; // We can't draw without row and column, so assume they exist and fail catastrophically if they don't
				h = CellHeight - 1;
			}
			else
			{
				foreach (var column in _columns)
				{
					if (cell.Column == column)
					{
						w = CalcWidth(column) - 1;
						break;
					}
					else
					{
						x += CalcWidth(column);
					}
				}

				x += 1;
				y = (CellHeight * (cell.RowIndex.Value + 1)) + 2; // We can't draw without row and column, so assume they exist and fail catastrophically if they don't
				h = CellHeight - 1;
			}

			Gdi.SetBrush(color);
			Gdi.FillRectangle(x, y, w, h);
		}

		private void DoBackGroundCallback(PaintEventArgs e)
		{
			if (HorizontalOrientation)
			{
				for (int i = 0; i < VisibleRows; i++)
				{
					for (int j = 0; j < _columns.Count; j++)
					{
						Color color = Color.White;
						QueryItemBkColor(i, j, ref color);

						// TODO: refactor to use DrawCellBG
						if (color != Color.White) // An easy optimization, don't draw unless the user specified something other than the default
						{
							Gdi.SetBrush(color);
							Gdi.FillRectangle(
								_horizontalOrientedColumnWidth + (i * CellWidth) + 2,
								(j * CellHeight) + 1,
								CellWidth - 1,
								CellHeight - 1);
						}
					}
				}
			}
			else
			{
				for (int i = 1; i < VisibleRows; i++)
				{
					int x = 1;
					for (int j = 0; j < _columns.Count; j++)
					{
						Color color = Color.White;
						QueryItemBkColor(i, j, ref color);

						var width = CalcWidth(_columns[j]);
						if (color != Color.White) // An easy optimization, don't draw unless the user specified something other than the default
						{
							Gdi.SetBrush(color);
							Gdi.FillRectangle(x, (i * CellHeight) + 2, width - 1, CellHeight - 1);
						}

						x += width;
					}
				}
			}
		}

		#endregion

		#region Mouse and Key Events

		protected override void OnKeyDown(KeyEventArgs e)
		{
			if (e.Control && !e.Alt && !e.Shift && e.KeyCode == Keys.R) // Ctrl + R
			{
				HorizontalOrientation ^= true;
				Refresh();
			}

			base.OnKeyDown(e);
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			CalculatePointedCell(e.X, e.Y);
			base.OnMouseMove(e);
		}

		protected override void OnMouseEnter(EventArgs e)
		{
			CurrentCell = new Cell
			{
				Column = null,
				RowIndex = null
			};

			base.OnMouseEnter(e);
		}

		protected override void OnMouseLeave(EventArgs e)
		{
			CurrentCell = null;
			IsPaintDown = false;
			Refresh();
			base.OnMouseLeave(e);
		}

		protected override void OnMouseClick(MouseEventArgs e)
		{
			if (IsHoveringOnColumnCell)
			{
				ColumnClickEvent(ColumnAtX(e.X));
			}
			else if (IsHoveringOnDataCell)
			{
				if (ModifierKeys == Keys.Alt)
				{
					MessageBox.Show("Alt click logic is not yet implemented");
				}
				else if (ModifierKeys == Keys.Shift)
				{
					if (SelectedItems.Any())
					{
						MessageBox.Show("Shift click logic is not yet implemented");
					}
					else
					{
						SelectCell(CurrentCell);
					}
				}
				else if (ModifierKeys == Keys.Control)
				{
					SelectCell(CurrentCell);
				}
				else
				{
					SelectedItems.Clear();
					SelectCell(CurrentCell);
				}

				Refresh();
			}

			base.OnMouseClick(e);
		}

		protected override void OnMouseDown(MouseEventArgs e)
		{
			if (e.Button == MouseButtons.Left && InputPaintingMode)
			{
				IsPaintDown = true;
			}

			if (e.Button == MouseButtons.Right)
			{
				RightButtonHeld = true;
			}

			base.OnMouseDown(e);
		}

		protected override void OnMouseUp(MouseEventArgs e)
		{
			IsPaintDown = false;
			RightButtonHeld = false;

			base.OnMouseUp(e);
		}

		protected override void OnMouseWheel(MouseEventArgs e)
		{
			if (RightButtonHeld)
			{
				DoRightMouseScroll(this, e);
			}
			else
			{
				base.OnMouseWheel(e);
			}
		}

		#endregion

		#region Change Events

		protected override void OnResize(EventArgs e)
		{
			RecalculateScrollBars();
			base.OnResize(e);
			Refresh();
		}

		#endregion

		#region Helpers

		private void DoRightMouseScroll(object sender, MouseEventArgs e)
		{
			if (RightMouseScrolled != null)
			{
				RightMouseScrolled(sender, e);
			}
		}

		private void VerticalBar_ValueChanged(object sender, EventArgs e)
		{
			Refresh();
		}

		private void HorizontalBar_ValueChanged(object sender, EventArgs e)
		{
			Refresh();
		}

		private void ColumnChangedCallback()
		{
			RecalculateScrollBars();
		}

		private void RecalculateScrollBars()
		{
			if (NeedsVScrollbar)
			{
				
				int max;

				if (HorizontalOrientation)
				{
					max = (((_columns.Count * CellHeight) - Height) / CellHeight) + 1;
				}
				else
				{
					max = (((ItemCount * CellHeight) - Height) / CellHeight) + 1;
				}

				if (VBar.Value > max)
				{
					VBar.Value = max;
				}

				VBar.Maximum = max + VBar.LargeChange; // TODO: why can't it be 1?
				VBar.Size = new Size(VBar.Width, Height);
				VBar.Visible = true;
			}
			else
			{
				VBar.Visible = false;
			}

			if (NeedsHScrollbar)
			{
				HBar.Visible = true;
				if (HorizontalOrientation)
				{
					HBar.Maximum = (_columns.Sum(c => CalcWidth(c)) - Width) / CellWidth;
				}
				else
				{
					HBar.Maximum = ((ItemCount * CellWidth) - Width) / CellWidth;
				}
			}
			else
			{
				HBar.Visible = false;
			}
		}

		private void SelectCell(Cell cell)
		{
			if (!MultiSelect)
			{
				SelectedItems.Clear();
			}

			if (FullRowSelect)
			{
				foreach (var column in _columns)
				{
					SelectedItems.Add(new Cell
					{
						RowIndex = cell.RowIndex,
						Column = column
					});
				}
			}
			else
			{
				SelectedItems.Add(CurrentCell);
			}

			SelectedIndexChanged(this, new EventArgs());
		}

		private bool IsHoveringOnColumnCell
		{
			get
			{
				return CurrentCell != null &&
					CurrentCell.Column != null &&
					!CurrentCell.RowIndex.HasValue;
			}
		}

		private bool IsHoveringOnDataCell
		{
			get
			{
				return CurrentCell != null &&
					CurrentCell.Column != null &&
					CurrentCell.RowIndex.HasValue;
			}
		}

		private void CalculatePointedCell(int x, int y)
		{
			bool wasHoveringColumnCell = IsHoveringOnColumnCell;
			var newCell = new Cell();

			// If pointing to a column header
			if (_columns.Any())
			{
				if (HorizontalOrientation)
				{
					if (x < _horizontalOrientedColumnWidth)
					{
						newCell.RowIndex = null;
					}
					else
					{
						newCell.RowIndex = (x - _horizontalOrientedColumnWidth) / CellWidth;
					}

					int colIndex = (y / CellHeight);
					if (colIndex >= 0 && colIndex < _columns.Count)
					{
						newCell.Column = _columns[colIndex];
					}
				}
				else
				{
					if (y < CellHeight)
					{
						newCell.RowIndex = null;
					}
					else
					{
						newCell.RowIndex = (y / CellHeight) - 1;
					}

					int start = 0;
					//for (int i = 0; i < Columns.Count; i++)
					foreach (var column in _columns)
					{
						if (x > start)
						{
							start += CalcWidth(column);
							if (x <= start)
							{
								newCell.Column = column;
								break;
							}
						}
					}
				}
			}

			if (!newCell.Equals(CurrentCell))
			{
				CellChanged(CurrentCell, newCell);
				LastCell = CurrentCell;
				CurrentCell = newCell;

				if (IsHoveringOnColumnCell ||
					(wasHoveringColumnCell && !IsHoveringOnColumnCell))
				{
					Refresh();
				}
			}
		}

		private void CellChanged(Cell oldCell, Cell newCell)
		{
			if (PointedCellChanged != null)
			{
				PointedCellChanged(this, new CellEventArgs(oldCell, newCell));
			}
		}

		private void ColumnClickEvent(RollColumn column)
		{
			if (ColumnClick != null)
			{
				ColumnClick(this, new ColumnClickEventArgs(_columns.IndexOf(column)));
			}
		}

		private bool NeedToUpdateScrollbar()
		{
			return true;
		}

		// TODO: Calculate this on Orientation change instead of call it every time
		private Point StartBg()
		{
			if (_columns.Any())
			{
				if (HorizontalOrientation)
				{
					var x = _horizontalOrientedColumnWidth;
					var y = 0;
					return new Point(x, y);
				}
				else
				{
					var y = CellHeight;
					return new Point(0, y);
				}
			}

			return new Point(0, 0);
		}

		// TODO: calculate this on Cell Padding change instead of calculate it every time
		private int CellHeight
		{
			get
			{
				return _charSize.Height + (CellPadding * 2);
			}
		}

		// TODO: calculate this on Cell Padding change instead of calculate it every time
		private int CellWidth
		{
			get
			{
				return _charSize.Width + (CellPadding * 4); // Double the padding for horizontal because it looks better
			}
		}

		private bool NeedsVScrollbar
		{
			get
			{
				if (HorizontalOrientation)
				{
					return _columns.Count > Height / CellHeight;
				}

				return ItemCount > Height / CellHeight;
			}
		}

		private bool NeedsHScrollbar
		{
			get
			{
				if (HorizontalOrientation)
				{
					return ItemCount > (Width - _horizontalOrientedColumnWidth) / CellWidth;
				}

				return _columns.Sum(column => CalcWidth(column)) > Width;
			}
		}

		private void ColumnChanged()
		{
			var text = _columns.Max(c => c.Text.Length);
			_horizontalOrientedColumnWidth = (text * _charSize.Width) + (CellPadding * 2);
		}

		// On Column Change calculate this for every column
		private int CalcWidth(RollColumn col)
		{
			return col.Width ?? ((col.Text.Length * _charSize.Width) + (CellPadding * 4));
		}

		private RollColumn ColumnAtX(int x)
		{
			int start = 0;
			foreach (var column in _columns)
			{
				start += CalcWidth(column);
				if (start > x)
				{
					return column;
				}
			}

			return null;
		}

		#endregion

		#region Classes

		public class RollColumns : List<RollColumn>
		{
			// For legacy support
			public void Add(ColumnHeader column)
			{
				Add(new RollColumn
				{
					Group = "",
					Width = column.Width,
					Name = column.Name,
					Text = column.Text,
					Type = RollColumn.InputType.Text,
				});
			}

			// For legacy support
			public void AddRange(ColumnHeader[] columns)
			{
				foreach (var column in columns)
				{
					Add(column); // TODO: this fires the change event each time, convert to an AddRange Call
				}
			}

			public RollColumn this[string name]
			{
				get
				{
					return this.SingleOrDefault(column => column.Name == name);
				}
			}
			
			public Action ChangedCallback { get; set; }

			private void DoChangeCallback()
			{
				if (ChangedCallback != null)
				{
					ChangedCallback();
				}
			}

			public new void Add(RollColumn column)
			{
				if (this.Any(c => c.Name == column.Name))
				{
					throw new InvalidOperationException("A column with this name already exists.");
				}

				base.Add(column);
				ChangedCallback();
			}

			public new void AddRange(IEnumerable<RollColumn> collection)
			{
				foreach(var column in collection)
				{
					if (this.Any(c => c.Name == column.Name))
					{
						throw new InvalidOperationException("A column with this name already exists.");
					}
				}

				base.AddRange(collection);
				ChangedCallback();
			}

			public new void Insert(int index, RollColumn column)
			{
				if (this.Any(c => c.Name == column.Name))
				{
					throw new InvalidOperationException("A column with this name already exists.");
				}

				base.Insert(index, column);
				ChangedCallback();
			}

			public new void InsertRange(int index, IEnumerable<RollColumn> collection)
			{
				foreach (var column in collection)
				{
					if (this.Any(c => c.Name == column.Name))
					{
						throw new InvalidOperationException("A column with this name already exists.");
					}
				}

				base.InsertRange(index, collection);
				ChangedCallback();
			}

			public new bool Remove(RollColumn column)
			{
				var result = base.Remove(column);
				ChangedCallback();
				return result;
			}

			public new int RemoveAll(Predicate<RollColumn> match)
			{
				var result = base.RemoveAll(match);
				ChangedCallback();
				return result;
			}

			public new void RemoveAt(int index)
			{
				base.RemoveAt(index);
				ChangedCallback();
			}

			public new void RemoveRange(int index, int count)
			{
				base.RemoveRange(index, count);
				ChangedCallback();
			}

			public new void Clear()
			{
				base.Clear();
				ChangedCallback();
			}

			public IEnumerable<string> Groups
			{
				get
				{
					return this
						.Select(x => x.Group)
						.Distinct();
				}
			}
		}

		public class RollColumn
		{
			public enum InputType { Boolean, Float, Text, Image }

			public string Group { get; set; }
			public int? Width { get; set; }
			public string Name { get; set; }
			public string Text { get; set; }
			public InputType Type { get; set; }

			public static bool operator ==(RollColumn column, string name)
			{
				return column.Name == name;
			}

			public static bool operator !=(RollColumn column, string name)
			{
				return column.Name != name;
			}

			public override int GetHashCode()
			{
				return Name.GetHashCode();
			}

			public override bool Equals(object obj)
			{
				if (obj is string)
				{
					return Name == (string)obj;
				}

				return base.Equals(obj);
			}
		}

		public class Cell
		{
			public RollColumn Column { get; set; }
			public int? RowIndex { get; set; }

			public Cell() { }

			public Cell(Cell cell)
			{
				Column = cell.Column;
				RowIndex = cell.RowIndex;
			}

			public override bool Equals(object obj)
			{
				if (obj is Cell)
				{
					var cell = obj as Cell;
					return this.Column == cell.Column && this.RowIndex == cell.RowIndex;
				}

				return base.Equals(obj);
			}

			public override int GetHashCode()
			{
				return Column.GetHashCode() + RowIndex.GetHashCode();
			}
		}

		#endregion
	}
}