// <file>
//     <copyright see="prj:///doc/copyright.txt"/>
//     <license see="prj:///doc/license.txt"/>
//     <owner name="Mike Krüger" email="mike@icsharpcode.net"/>
//     <version>$Revision$</version>
// </file>

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

using ICSharpCode.TextEditor.Document;

namespace ICSharpCode.TextEditor
{
	/// <summary>
	/// This class views the line numbers and folding markers.
	/// </summary>
	public class IconBarMargin : AbstractMargin
	{
		const int iconBarWidth = 18;
		
		static readonly Size iconBarSize = new Size(iconBarWidth, -1);
		
		public override Size Size {
			get {
				return iconBarSize;
			}
		}
		
		public override bool IsVisible {
			get {
				return textArea.TextEditorProperties.IsIconBarVisible;
			}
		}
		
		
		public IconBarMargin(TextArea textArea) : base(textArea)
		{
		}
		
		public override void Paint(Graphics g, Rectangle rect)
		{
			if (rect.Width <= 0 || rect.Height <= 0) {
				return;
			}
			// paint background
			g.FillRectangle(SystemBrushes.Control, new Rectangle(drawingPosition.X, rect.Top, drawingPosition.Width - 1, rect.Height));
			g.DrawLine(SystemPens.ControlDark, base.drawingPosition.Right - 1, rect.Top, base.drawingPosition.Right - 1, rect.Bottom);
			
			// paint icons
			foreach (Bookmark mark in textArea.Document.BookmarkManager.Marks) {
				int lineNumber = textArea.Document.GetVisibleLine(mark.LineNumber);
				int lineHeight = textArea.TextView.FontHeight;
				int yPos = (int)(lineNumber * lineHeight) - textArea.VirtualTop.Y;
				if (IsLineInsideRegion(yPos, yPos + lineHeight, rect.Y, rect.Bottom)) {
					if (lineNumber == textArea.Document.GetVisibleLine(mark.LineNumber - 1)) {
						// marker is inside folded region, do not draw it
						continue;
					}
					mark.Draw(this, g, new Point(0, yPos));
				}
			}
			base.Paint(g, rect);
		}
		
		public override void HandleMouseDown(Point mousePos, MouseButtons mouseButtons)
		{
			int clickedVisibleLine = (mousePos.Y + textArea.VirtualTop.Y) / textArea.TextView.FontHeight;
			int lineNumber = textArea.Document.GetFirstLogicalLine(clickedVisibleLine);
			
			if ((mouseButtons & MouseButtons.Right) == MouseButtons.Right) {
				if (textArea.Caret.Line != lineNumber) {
					textArea.Caret.Line = lineNumber;
				}
			}
			
			IList<Bookmark> marks = textArea.Document.BookmarkManager.Marks;
			List<Bookmark> marksInLine = new List<Bookmark>();
			int oldCount = marks.Count;
			foreach (Bookmark mark in marks) {
				if (mark.LineNumber == lineNumber) {
					marksInLine.Add(mark);
				}
			}
			for (int i = marksInLine.Count - 1; i >= 0; i--) {
				Bookmark mark = marksInLine[i];
				if (mark.Click(textArea, new MouseEventArgs(mouseButtons, 1, mousePos.X, mousePos.Y, 0))) {
					if (oldCount != marks.Count) {
						textArea.UpdateLine(lineNumber);
					}
					return;
				}
			}
			base.HandleMouseDown(mousePos, mouseButtons);
		}
		
		#region Drawing functions
		public void DrawBreakpoint(Graphics g, int y, bool isEnabled, bool isHealthy)
		{
			int diameter = Math.Min(iconBarWidth - 2, textArea.TextView.FontHeight);
			Rectangle rect = new Rectangle(1,
			                               y + (textArea.TextView.FontHeight - diameter) / 2,
			                               diameter,
			                               diameter);
			
			
			using (GraphicsPath path = new GraphicsPath()) {
				path.AddEllipse(rect);
				using (PathGradientBrush pthGrBrush = new PathGradientBrush(path)) {
					pthGrBrush.CenterPoint = new PointF(rect.Left + rect.Width / 3 , rect.Top + rect.Height / 3);
					pthGrBrush.CenterColor = Color.MistyRose;
					Color[] colors = {isHealthy ? Color.Firebrick : Color.Olive};
					pthGrBrush.SurroundColors = colors;
					
					if (isEnabled) {
						g.FillEllipse(pthGrBrush, rect);
					} else {
						g.FillEllipse(SystemBrushes.Control, rect);
						using (Pen pen = new Pen(pthGrBrush)) {
							g.DrawEllipse(pen, new Rectangle(rect.X + 1, rect.Y + 1, rect.Width - 2, rect.Height - 2));
						}
					}
				}
			}
		}
		
		public void DrawBookmark(Graphics g, int y, bool isEnabled)
		{
			int delta = textArea.TextView.FontHeight / 8;
			Rectangle rect = new Rectangle(1, y + delta, base.drawingPosition.Width - 4, textArea.TextView.FontHeight - delta * 2);
			
			if (isEnabled) {
				using (Brush brush = new LinearGradientBrush(new Point(rect.Left, rect.Top),
				                                             new Point(rect.Right, rect.Bottom),
				                                             Color.SkyBlue,
				                                             Color.White)) {
					FillRoundRect(g, brush, rect);
				}
			} else {
				FillRoundRect(g, Brushes.White, rect);
			}
			using (Brush brush = new LinearGradientBrush(new Point(rect.Left, rect.Top),
			                                             new Point(rect.Right, rect.Bottom),
			                                             Color.SkyBlue,
			                                             Color.Blue)) {
				using (Pen pen = new Pen(brush)) {
					DrawRoundRect(g, pen, rect);
				}
			}
		}

		public void DrawArrow(Graphics g, int y)
		{
			int delta = textArea.TextView.FontHeight / 8;
			Rectangle rect = new Rectangle(1, y + delta, base.drawingPosition.Width - 4, textArea.TextView.FontHeight - delta * 2);
			using (Brush brush = new LinearGradientBrush(new Point(rect.Left, rect.Top),
			                                             new Point(rect.Right, rect.Bottom),
			                                             Color.LightYellow,
			                                             Color.Yellow)) {
				FillArrow(g, brush, rect);
			}
			
			using (Brush brush = new LinearGradientBrush(new Point(rect.Left, rect.Top),
			                                             new Point(rect.Right, rect.Bottom),
			                                             Color.Yellow,
			                                             Color.Brown)) {
				using (Pen pen = new Pen(brush)) {
					DrawArrow(g, pen, rect);
				}
			}
		}
		
		GraphicsPath CreateArrowGraphicsPath(Rectangle r)
		{
			GraphicsPath gp = new GraphicsPath();
			int halfX = r.Width / 2;
			int halfY = r.Height/ 2;
			gp.AddLine(r.X, r.Y + halfY/2, r.X + halfX, r.Y + halfY/2);
			gp.AddLine(r.X + halfX, r.Y + halfY/2, r.X + halfX, r.Y);
			gp.AddLine(r.X + halfX, r.Y, r.Right, r.Y + halfY);
			gp.AddLine(r.Right, r.Y + halfY, r.X + halfX, r.Bottom);
			gp.AddLine(r.X + halfX, r.Bottom, r.X + halfX, r.Bottom - halfY/2);
			gp.AddLine(r.X + halfX, r.Bottom - halfY/2, r.X, r.Bottom - halfY/2);
			gp.AddLine(r.X, r.Bottom - halfY/2, r.X, r.Y + halfY/2);
			gp.CloseFigure();
			return gp;
		}
		
		GraphicsPath CreateRoundRectGraphicsPath(Rectangle r)
		{
			GraphicsPath gp = new GraphicsPath();
			int radius = r.Width / 2;
			gp.AddLine(r.X + radius, r.Y, r.Right - radius, r.Y);
			gp.AddArc(r.Right - radius, r.Y, radius, radius, 270, 90);
			
			gp.AddLine(r.Right, r.Y + radius, r.Right, r.Bottom - radius);
			gp.AddArc(r.Right - radius, r.Bottom - radius, radius, radius, 0, 90);
			
			gp.AddLine(r.Right - radius, r.Bottom, r.X + radius, r.Bottom);
			gp.AddArc(r.X, r.Bottom - radius, radius, radius, 90, 90);
			
			gp.AddLine(r.X, r.Bottom - radius, r.X, r.Y + radius);
			gp.AddArc(r.X, r.Y, radius, radius, 180, 90);
			
			gp.CloseFigure();
			return gp;
		}
		
		void DrawRoundRect(Graphics g, Pen p , Rectangle r)
		{
			using (GraphicsPath gp = CreateRoundRectGraphicsPath(r)) {
				g.DrawPath(p, gp);
			}
		}
		
		void FillRoundRect(Graphics g, Brush b , Rectangle r)
		{
			using (GraphicsPath gp = CreateRoundRectGraphicsPath(r)) {
				g.FillPath(b, gp);
			}
		}

		void DrawArrow(Graphics g, Pen p , Rectangle r)
		{
			using (GraphicsPath gp = CreateArrowGraphicsPath(r)) {
				g.DrawPath(p, gp);
			}
		}
		
		void FillArrow(Graphics g, Brush b , Rectangle r)
		{
			using (GraphicsPath gp = CreateArrowGraphicsPath(r)) {
				g.FillPath(b, gp);
			}
		}

		#endregion
		
		static bool IsLineInsideRegion(int top, int bottom, int regionTop, int regionBottom)
		{
			if (top >= regionTop && top <= regionBottom) {
				// Region overlaps the line's top edge.
				return true;
			} else if(regionTop > top && regionTop < bottom) {
				// Region's top edge inside line.
				return true;
			}
			return false;
		}
	}
}