// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
//
// Author:
//	Jordi Mas i Hernandez <jordi@ximian.com>
//
// Datagrid drawing logic
//

// NOT COMPLETE

using System.Drawing;
using System.Drawing.Drawing2D;

namespace System.Windows.Forms
{
	internal class DataGridDrawing
	{
		#region	Local Variables

		private DataGrid grid;

		// Areas
		internal Rectangle caption_area;
		internal Rectangle parent_rows;
		internal Rectangle columnshdrs_area;	// Used columns header area
		internal int columnshdrs_maxwidth; 	// Total width (max width) for columns headrs
		internal Rectangle rowshdrs_area;	// Used Headers rows area
		internal int rowshdrs_maxheight; 	// Total height for rows (max height)
		internal Rectangle cells_area;
		internal Font font_newrow = new Font (FontFamily.GenericSansSerif, 16);
		#endregion // Local Variables


		public DataGridDrawing (DataGrid datagrid)
		{
			 grid = datagrid;			 
		}

		#region Public Instance Methods

		// Calc the max with of all columns
		internal int CalcAllColumnsWidth ()
		{
			int width = 0;
			int cnt = grid.CurrentTableStyle.GridColumnStyles.Count;

			for (int col = 0; col < cnt; col++) {
				width += grid.CurrentTableStyle.GridColumnStyles[col].Width;
			}

			return width;
		}

		// Gets a column from a pixel
		public int FromPixelToColumn (int pixel)
		{
			int width = 0;
			int cnt = grid.CurrentTableStyle.GridColumnStyles.Count;

			if (cnt == 0)
				return 0;
				
			if (grid.CurrentTableStyle.CurrentRowHeadersVisible)
				width += rowshdrs_area.X + rowshdrs_area.Width;

			for (int col = 0; col < cnt; col++) {
				width += grid.CurrentTableStyle.GridColumnStyles[col].Width;

				if (pixel < width)
					return col;
			}

			return cnt - 1;
		}

		//
		public int GetColumnStartingPixel (int my_col)
		{
			int width = 0;
			int cnt = grid.CurrentTableStyle.GridColumnStyles.Count;

			for (int col = 0; col < cnt; col++) {

				if (my_col == col)
					return width;

				width += grid.CurrentTableStyle.GridColumnStyles[col].Width;
			}

			return 0;
		}
		
		// Which column has to be the first visible column to ensure a column visibility
		public int GetFirstColumnForColumnVisilibility (int current_first_visiblecolumn, int column)
		{
			int new_col = column;
			int width = 0;
			
			if (column > current_first_visiblecolumn) { // Going forward								
				for (new_col = column; new_col >= 0; new_col--){
					width += grid.CurrentTableStyle.GridColumnStyles[new_col].Width;
					
					if (width >= cells_area.Width)
						return new_col + 1;
						//return new_col < grid.CurrentTableStyle.GridColumnStyles.Count ? new_col + 1 : grid.CurrentTableStyle.GridColumnStyles.Count;
				}
				return 0;
			} else {				
				return  column;
			}			
		}

		public void CalcGridAreas ()
		{
			if (grid.IsHandleCreated == false) // Delay calculations until the handle is created
				return;

			/* Order is important. E.g. row headers max. height depends on caption */
			grid.horz_pixeloffset = 0;			
			CalcCaption ();
			CalcParentRows ();
			CalcRowsHeaders ();
			CalcColumnsHeader ();
			CalcCellsArea ();

			UpdateVisibleRowCount (); // need it to be able to calcultate the need of horz scrollbar
			if (SetUpVerticalScrollBar ()) { // We need a Vertical ScrollBar
				
				if (grid.ShowParentRowsVisible) {
					parent_rows.Width -= grid.vert_scrollbar.Width;
				}

				if (grid.columnheaders_visible == false || grid.CurrentTableStyle.GridColumnStyles.Count == 0) {
					if (columnshdrs_area.X + columnshdrs_area.Width > grid.vert_scrollbar.Location.X) {
						columnshdrs_area.Width -= grid.vert_scrollbar.Width;
					}
				}

				if (cells_area.X + cells_area.Width >= grid.vert_scrollbar.Location.X) {
					cells_area.Width -= grid.vert_scrollbar.Width;
				}
			}

			if (SetUpHorizontalScrollBar ()) { // We need a Horizontal ScrollBar
				cells_area.Height -= grid.horiz_scrollbar.Height;

				if (rowshdrs_area.Y + rowshdrs_area.Height > grid.ClientRectangle.Y + grid.ClientRectangle.Height) {
					rowshdrs_area.Height -= grid.horiz_scrollbar.Height;
					rowshdrs_maxheight -= grid.horiz_scrollbar.Height;
				}
			}

			// Reajust scrollbars to avoid overlapping at the corners
			if (grid.vert_scrollbar.Visible && grid.horiz_scrollbar.Visible) {
				grid.horiz_scrollbar.Width -= grid.vert_scrollbar.Width;
				grid.vert_scrollbar.Height -= grid.horiz_scrollbar.Height;
			}

			UpdateVisibleColumn ();
			UpdateVisibleRowCount ();

			//Console.WriteLine ("DataGridDrawing.CalcGridAreas caption_area:{0}", caption_area);
			//Console.WriteLine ("DataGridDrawing.CalcGridAreas parent_rows:{0}", parent_rows);
			//Console.WriteLine ("DataGridDrawing.CalcGridAreas rowshdrs_area:{0}", rowshdrs_area);
			//Console.WriteLine ("DataGridDrawing.CalcGridAreas columnshdrs_area:{0}", columnshdrs_area);
			//Console.WriteLine ("DataGridDrawing.CalcGridAreas cells:{0}", cells_area);
		}

		public void CalcCaption ()
		{
			if (grid.caption_visible == false) {
				caption_area = Rectangle.Empty;
				return;
			}

			caption_area.X = grid.ClientRectangle.X;
			caption_area.Y = grid.ClientRectangle.Y;
			caption_area.Width = grid.ClientRectangle.Width;
			caption_area.Height = grid.CaptionFont.Height + 6;

			//Console.WriteLine ("DataGridDrawing.CalcCaption {0}", caption_area);
		}

		public void CalcCellsArea ()
		{
			if (grid.caption_visible) {
				cells_area.Y = caption_area.Y + caption_area.Height;
			} else {
				cells_area.Y = grid.ClientRectangle.Y;
			}

			if (grid.ShowParentRowsVisible) {
				cells_area.Y += parent_rows.Height;
			}

			if (!(grid.columnheaders_visible == false || grid.CurrentTableStyle.GridColumnStyles.Count == 0)) {
				cells_area.Y += columnshdrs_area.Height;
			}

			cells_area.X = grid.ClientRectangle.X + rowshdrs_area.Width;
			cells_area.Width = grid.ClientRectangle.X + grid.ClientRectangle.Width - cells_area.X;
			cells_area.Height = grid.ClientRectangle.Y + grid.ClientRectangle.Height - cells_area.Y;

			//Console.WriteLine ("DataGridDrawing.CalcCellsArea {0}", cells_area);
		}

		public void CalcColumnsHeader ()
		{
			int width_all_cols, max_width_cols;
			
			if (grid.columnheaders_visible == false || grid.CurrentTableStyle.GridColumnStyles.Count == 0) {
				columnshdrs_area = Rectangle.Empty;				
				return;
			}

			if (grid.caption_visible) {
				columnshdrs_area.Y = caption_area.Y + caption_area.Height;
			} else {
				columnshdrs_area.Y = grid.ClientRectangle.Y;
			}

			if (grid.ShowParentRowsVisible) {
				columnshdrs_area.Y += parent_rows.Height;
			}

			columnshdrs_area.X = grid.ClientRectangle.X;
			columnshdrs_area.Height = ColumnsHeaderHeight;
			width_all_cols = CalcAllColumnsWidth ();

			// TODO: take into account Scrollbars
			columnshdrs_maxwidth = grid.ClientRectangle.X + grid.ClientRectangle.Width - columnshdrs_area.X;
			max_width_cols = columnshdrs_maxwidth;

			if (grid.CurrentTableStyle.CurrentRowHeadersVisible) {
				max_width_cols -= grid.RowHeaderWidth;
			}

			if (width_all_cols > max_width_cols) {
				columnshdrs_area.Width = columnshdrs_maxwidth;
			} else {
				columnshdrs_area.Width = width_all_cols;

				if (grid.CurrentTableStyle.CurrentRowHeadersVisible) {
					columnshdrs_area.Width += grid.RowHeaderWidth;
				}
			}

			//Console.WriteLine ("DataGridDrawing.CalcColumnsHeader {0}", columnshdrs_area);
		}

		public void CalcParentRows ()
		{
			if (grid.ShowParentRowsVisible == false) {
				parent_rows = Rectangle.Empty;
				return;
			}

			if (grid.caption_visible) {
				parent_rows.Y = caption_area.Y + caption_area.Height;

			} else {
				parent_rows.Y = grid.ClientRectangle.Y;
			}

			parent_rows.X = grid.ClientRectangle.X;
			parent_rows.Width = grid.ClientRectangle.Width;
			parent_rows.Height = grid.CaptionFont.Height + 3;

			//Console.WriteLine ("DataGridDrawing.CalcParentRows {0}", parent_rows);
		}

		public void CalcRowsHeaders ()
		{
			if (grid.CurrentTableStyle.CurrentRowHeadersVisible == false) {
				rowshdrs_area = Rectangle.Empty;
				return;
			}

			if (grid.caption_visible) {
				rowshdrs_area.Y = caption_area.Y + caption_area.Height;
			} else {
				rowshdrs_area.Y = grid.ClientRectangle.Y;
			}

			if (grid.ShowParentRowsVisible) {
				rowshdrs_area.Y += parent_rows.Height;
			}

			if (!(grid.columnheaders_visible == false || grid.CurrentTableStyle.GridColumnStyles.Count == 0)) { // first block is painted by ColumnHeader
				rowshdrs_area.Y += ColumnsHeaderHeight;
			}

			rowshdrs_area.X = grid.ClientRectangle.X;
			rowshdrs_area.Width = grid.RowHeaderWidth;
			rowshdrs_area.Height = grid.visiblerow_count * grid.RowHeight;
			rowshdrs_maxheight = grid.ClientRectangle.Height + grid.ClientRectangle.Y - rowshdrs_area.Y;

			//Console.WriteLine ("DataGridDrawing.CalcRowsHeaders {0} {1}", rowshdrs_area,
			//	rowshdrs_maxheight);
		}

		public void UpdateVisibleColumn ()
		{
			if (grid.CurrentTableStyle.GridColumnStyles.Count == 0) {
				grid.visiblecolumn_count = 0;
				return;	
			}
			
			int col;
			int max_pixel = grid.horz_pixeloffset + cells_area.Width;
			grid.first_visiblecolumn = FromPixelToColumn (grid.horz_pixeloffset);

			col = FromPixelToColumn (max_pixel);
			
			grid.visiblecolumn_count = 1 + col - grid.first_visiblecolumn;
			
			if (grid.first_visiblecolumn + grid.visiblecolumn_count + 1 < grid.CurrentTableStyle.GridColumnStyles.Count) { 
				grid.visiblecolumn_count++; // Partially visible column
			}
		}

		public void UpdateVisibleRowCount ()
		{
			int max_height = cells_area.Height;
			int total_rows = grid.RowsCount;
			
			if (grid.ShowEditRow && grid.RowsCount > 0) {
				total_rows++;
			}

			int rows_height = (total_rows - grid.first_visiblerow) * grid.RowHeight;
			int max_rows = max_height / grid.RowHeight;
						
			if (max_rows > total_rows) {
				max_rows = total_rows;
			}

			if (rows_height > cells_area.Height) {
				grid.visiblerow_count = max_rows;
			} else {
				grid.visiblerow_count = total_rows;
			}	

			CalcRowsHeaders (); // Height depends on num of visible rows		
			
			if (grid.visiblerow_count + grid.first_visiblerow > total_rows)
				grid.visiblerow_count = total_rows - grid.first_visiblerow;

			if (grid.visiblerow_count < max_rows) {
				grid.visiblerow_count = max_rows;
				grid.first_visiblerow = total_rows - max_rows;
				grid.Invalidate ();
			}
			
		}

		// From Point to Cell
		public DataGrid.HitTestInfo HitTest (int x, int y)
		{
			DataGrid.HitTestInfo hit = new DataGrid.HitTestInfo ();

			// TODO: Add missing ColumnResize and RowResize checks
			if (columnshdrs_area.Contains (x, y)) {
				hit.type = DataGrid.HitTestType.ColumnHeader;
				hit.column = FromPixelToColumn (x + grid.horz_pixeloffset);
				return hit;
			}

			if (rowshdrs_area.Contains (x, y)) {
				hit.type = DataGrid.HitTestType.RowHeader;
				int posy;
				int rcnt = grid.FirstVisibleRow + grid.VisibleRowCount;
				for (int r = grid.FirstVisibleRow; r < rcnt; r++) {
					posy = cells_area.Y + ((r - grid.FirstVisibleRow) * grid.RowHeight);
					if (y <= posy + grid.RowHeight) { // Found row
						hit.row = r;
						break;
					}
				}
				return hit;
			}

			if (caption_area.Contains (x, y)) {
				hit.type = DataGrid.HitTestType.Caption;
				return hit;
			}

			if (parent_rows.Contains (x, y)) {
				hit.type = DataGrid.HitTestType.ParentRows;
				return hit;
			}

			int pos_y, pos_x, width;
			int rowcnt = grid.FirstVisibleRow + grid.VisibleRowCount;
			for (int row = grid.FirstVisibleRow; row < rowcnt; row++) {
				pos_y = cells_area.Y + ((row - grid.FirstVisibleRow) * grid.RowHeight);

				if (y <= pos_y + grid.RowHeight) { // Found row
					hit.row = row;
					hit.type = DataGrid.HitTestType.Cell;					
					int col_pixel;
					int column_cnt = grid.first_visiblecolumn + grid.visiblecolumn_count;
					for (int column = grid.first_visiblecolumn; column < column_cnt; column++) {

						col_pixel = GetColumnStartingPixel (column);
						pos_x = cells_area.X + col_pixel - grid.horz_pixeloffset;
						width = grid.CurrentTableStyle.GridColumnStyles[column].Width;

						if (x <= pos_x + width) { // Column found
							hit.column = column;
							break;
						}
					}

					break;
				}
			}

			return hit;
		}

		public Rectangle GetCellBounds (int row, int col)
		{
			Rectangle bounds = new Rectangle ();
			int col_pixel;

			bounds.Width = grid.CurrentTableStyle.GridColumnStyles[col].Width;
			bounds.Height = grid.RowHeight;
			bounds.Y = cells_area.Y + ((row - grid.FirstVisibleRow) * grid.RowHeight);
			col_pixel = GetColumnStartingPixel (col);
			bounds.X = cells_area.X + col_pixel - grid.horz_pixeloffset;
			return bounds;
		}

		public void InvalidateCaption ()
		{
			if (caption_area.IsEmpty)
				return;

			grid.Invalidate (caption_area);
		}
		
		
		public void InvalidateRow (int row)
		{
			if (row < grid.FirstVisibleRow || row > grid.FirstVisibleRow + grid.VisibleRowCount) {
				return;
			}

			Rectangle rect_row = new Rectangle ();

			rect_row.X = cells_area.X;
			rect_row.Width = cells_area.Width;
			rect_row.Height = grid.RowHeight;
			rect_row.Y = cells_area.Y + ((row - grid.FirstVisibleRow) * grid.RowHeight);
			grid.Invalidate (rect_row);
		}

		public void InvalidateRowHeader (int row)
		{
			Rectangle rect_rowhdr = new Rectangle ();
			rect_rowhdr.X = rowshdrs_area.X;
			rect_rowhdr.Width = rowshdrs_area.Width;
			rect_rowhdr.Height = grid.RowHeight;
			rect_rowhdr.Y = rowshdrs_area.Y + ((row - grid.FirstVisibleRow) * grid.RowHeight);
			grid.Invalidate (rect_rowhdr);
		}	

		public void InvalidateColumn (DataGridColumnStyle column)
		{
			Rectangle rect_col = new Rectangle ();
			int col_pixel;
			int col = -1;

			col = grid.CurrentTableStyle.GridColumnStyles.IndexOf (column);

			if (col == -1) {
				return;
			}

			rect_col.Width = column.Width;
			col_pixel = GetColumnStartingPixel (col);
			rect_col.X = cells_area.X + col_pixel - grid.horz_pixeloffset;
			rect_col.Y = cells_area.Y;
			rect_col.Height = cells_area.Height;
			grid.Invalidate (rect_col);
		}
				
		// Return true if the scrollbar is needed
		public bool SetUpHorizontalScrollBar ()
		{
			int width_all = CalcAllColumnsWidth ();

			if (width_all <= cells_area.Width) {
				grid.horiz_scrollbar.Visible = false;
				grid.Controls.Remove (grid.horiz_scrollbar);
				return false;
			}

			grid.horiz_scrollbar.Location = new Point (grid.ClientRectangle.X, grid.ClientRectangle.Y +
				grid.ClientRectangle.Height - grid.horiz_scrollbar.Height);

			grid.horiz_scrollbar.Size = new Size (grid.ClientRectangle.Width,
				grid.horiz_scrollbar.Height);

			grid.horiz_scrollbar.Maximum = width_all;// - cells_area.Width;
			grid.horiz_scrollbar.LargeChange = cells_area.Width;
			grid.Controls.Add (grid.horiz_scrollbar);
			grid.horiz_scrollbar.Visible = true;
			return true;
		}

		// Return true if the scrollbar is needed
		public bool SetUpVerticalScrollBar ()
		{
			int y, height;
			int allrows = grid.RowsCount;

			if (grid.ShowEditRow && grid.RowsCount > 0) {
				allrows++;
			}
			
			if (grid.visiblerow_count == allrows) {
				grid.vert_scrollbar.Visible = false;
				grid.Controls.Remove (grid.vert_scrollbar);
				return false;
			}
			
			if (grid.caption_visible) {
				y = grid.ClientRectangle.Y + caption_area.Height;
				height = grid.ClientRectangle.Height - caption_area.Height;
			} else {
				y = grid.ClientRectangle.Y;
				height = grid.ClientRectangle.Height;
			}

			grid.vert_scrollbar.Location = new Point (grid.ClientRectangle.X +
				grid.ClientRectangle.Width - grid.vert_scrollbar.Width, y);

			grid.vert_scrollbar.Size = new Size (grid.vert_scrollbar.Width,
				height);

			grid.vert_scrollbar.Maximum = grid.RowsCount;
			
			if (grid.ShowEditRow && grid.RowsCount > 0) {
				grid.vert_scrollbar.Maximum++;	
			}
			
			grid.vert_scrollbar.LargeChange = VLargeChange;

			grid.Controls.Add (grid.vert_scrollbar);
			grid.vert_scrollbar.Visible = true;
			return true;
		}

		#endregion // Public Instance Methods

		#region Instance Properties
		public Rectangle CellsArea {
			get {
				return cells_area;
			}
		}

		// Returns the ColumnsHeader area excluding the rectangle shared with RowsHeader
		public Rectangle ColumnsHeadersArea {
			get {
				Rectangle columns_area = columnshdrs_area;

				if (grid.CurrentTableStyle.CurrentRowHeadersVisible) {
					columns_area.X += grid.RowHeaderWidth;
					columns_area.Width -= grid.RowHeaderWidth;
				}
				return columns_area;
			}
		}

		public int ColumnsHeaderHeight {
			get {
				return grid.CurrentTableStyle.HeaderFont.Height + 6;
			}
		}

		public Rectangle RowsHeadersArea {
			get {
				return rowshdrs_area;
			}
		}

		public int VLargeChange {
			get {
				return cells_area.Height / grid.RowHeight;
			}
		}

		#endregion Instance Properties
	}
}