// 
// HeaderBox.cs
//  
// Author:
//       Lluis Sanchez Gual <lluis@novell.com>
// 
// Copyright (c) 2011 Novell, Inc (http://www.novell.com)
// 
// 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.
using System;
using Gtk;
using Mono.TextEditor;

namespace MonoDevelop.Components
{
	public class HeaderBox: Bin
	{
		Gtk.Widget child;
		int topMargin;
		int bottomMargin;
		int leftMargin;
		int rightMargin;
		
		int topPadding;
		int bottomPadding;
		int leftPadding;
		int rightPadding;
		Gdk.Color? backgroundColor;
		bool showTopShadow;
		bool useChildBackgroundColor;
		int shadowSize = 3;
		double shadowStrengh = 0.1;

		public HeaderBox ()
		{
		}
		
		public HeaderBox (int topMargin, int bottomMargin, int leftMargin, int rightMargin)
		{
			SetMargins (topMargin, bottomMargin, leftMargin, rightMargin);
		}
		
		public void SetMargins (int topMargin, int bottomMargin, int leftMargin, int rightMargin)
		{
			this.topMargin = topMargin;
			this.bottomMargin = bottomMargin;
			this.leftMargin = leftMargin;
			this.rightMargin = rightMargin;
		}
		
		public void SetPadding (int topPadding, int bottomPadding, int leftPadding, int rightPadding)
		{
			this.topPadding = topPadding;
			this.bottomPadding = bottomPadding;
			this.leftPadding = leftPadding;
			this.rightPadding = rightPadding;
		}

		public bool ShowTopShadow {
			get { return showTopShadow; }
			set {
				showTopShadow = value;
				QueueDraw ();
			}
		}

		public int ShadowSize {
			get {
				return shadowSize;
			}
			set {
				shadowSize = value;
				QueueDraw ();
			}
		}

		public double ShadowStrengh {
			get {
				return shadowStrengh;
			}
			set {
				shadowStrengh = value;
				QueueDraw ();
			}
		}
		
		public bool GradientBackround { get; set; }

		public Gdk.Color? BorderColor { get; set; }

		public Gdk.Color? BackgroundColor {
			get { return backgroundColor; }
			set {
				backgroundColor = value;
				QueueDraw ();
			}
		}

		public bool UseChildBackgroundColor {
			get {
				return useChildBackgroundColor;
			}
			set {
				useChildBackgroundColor = value;
				QueueDraw ();
			}
		}

		protected override void OnAdded (Widget widget)
		{
			base.OnAdded (widget);
			child = widget;
		}

		protected override void OnSizeRequested (ref Requisition requisition)
		{
			if (child != null) {
				requisition = child.SizeRequest ();
				requisition.Width += leftMargin + rightMargin + leftPadding + rightPadding;
				requisition.Height += topMargin + bottomMargin + topPadding + bottomPadding;
			} else {
				requisition.Width = 0;
				requisition.Height = 0;
			}
		}

		protected override void OnSizeAllocated (Gdk.Rectangle allocation)
		{
			base.OnSizeAllocated (allocation);
			if (allocation.Width > leftMargin + rightMargin + leftPadding + rightPadding) {
				allocation.X += leftMargin + leftPadding;
				allocation.Width -= leftMargin + rightMargin + leftPadding + rightPadding;
			}
			if (allocation.Height > topMargin + bottomMargin + topPadding + bottomPadding) {
				allocation.Y += topMargin + topPadding;
				allocation.Height -= topMargin + bottomMargin + topPadding + bottomPadding;
			}
			if (child != null)
				child.SizeAllocate (allocation);
		}

		protected override bool OnExposeEvent (Gdk.EventExpose evnt)
		{
			Gdk.Rectangle rect;
			
			if (GradientBackround) {
				rect = new Gdk.Rectangle (Allocation.X, Allocation.Y, Allocation.Width, Allocation.Height);
				var gcol = Style.Background (Gtk.StateType.Normal).ToXwtColor ();
				
				using (Cairo.Context cr = Gdk.CairoHelper.Create (GdkWindow)) {
					cr.NewPath ();
					cr.MoveTo (rect.X, rect.Y);
					cr.RelLineTo (rect.Width, 0);
					cr.RelLineTo (0, rect.Height);
					cr.RelLineTo (-rect.Width, 0);
					cr.RelLineTo (0, -rect.Height);
					cr.ClosePath ();
					using (Cairo.Gradient pat = new Cairo.LinearGradient (rect.X, rect.Y, rect.X, rect.Bottom)) {
						pat.AddColorStop (0, gcol.ToCairoColor ());
						gcol.Light -= 0.1;
						if (gcol.Light < 0)
							gcol.Light = 0;
						pat.AddColorStop (1, gcol.ToCairoColor ());
						cr.SetSource (pat);
						cr.FillPreserve ();
					}
				}
			} else if (BackgroundColor != null) {
				using (Cairo.Context cr = Gdk.CairoHelper.Create (GdkWindow)) {
					cr.Rectangle (Allocation.X, Allocation.Y, Allocation.Width, Allocation.Height);
					cr.SetSourceColor (BackgroundColor.Value.ToCairoColor ());
					cr.Fill ();
				}
			} else if (useChildBackgroundColor && Child != null) {
				using (Cairo.Context cr = Gdk.CairoHelper.Create (GdkWindow)) {
					cr.Rectangle (Allocation.X, Allocation.Y, Allocation.Width, Allocation.Height);
					cr.SetSourceColor (Child.Style.Base (StateType.Normal).ToCairoColor ());
					cr.Fill ();
				}
			}
			
			bool res = base.OnExposeEvent (evnt);
			
			var borderColor = new Gdk.GC (GdkWindow);
			borderColor.RgbFgColor = BorderColor != null ? BorderColor.Value : Style.Dark (Gtk.StateType.Normal);

			rect = Allocation;
			for (int n=0; n<topMargin; n++)
				GdkWindow.DrawLine (borderColor, rect.X, rect.Y + n, rect.Right - 1, rect.Y + n);
			
			for (int n=0; n<bottomMargin; n++)
				GdkWindow.DrawLine (borderColor, rect.X, rect.Bottom - n, rect.Right, rect.Bottom - n);
			
			for (int n=0; n<leftMargin; n++)
				GdkWindow.DrawLine (borderColor, rect.X + n, rect.Y, rect.X + n, rect.Bottom);
			
			for (int n=0; n<rightMargin; n++)
				GdkWindow.DrawLine (borderColor, rect.Right - n, rect.Y, rect.Right - n, rect.Bottom);

			if (showTopShadow) {
				using (Cairo.Context cr = Gdk.CairoHelper.Create (GdkWindow)) {
					cr.Rectangle (Allocation.X, Allocation.Y, Allocation.Width, shadowSize);
					using (Cairo.Gradient pat = new Cairo.LinearGradient (rect.X, rect.Y, rect.X, rect.Y + shadowSize)) {
						pat.AddColorStop (0, new Cairo.Color (0, 0, 0, shadowStrengh));
						pat.AddColorStop (1, new Cairo.Color (0, 0, 0, 0));
						cr.SetSource (pat);
						cr.Fill ();
					}
				}
			}

			borderColor.Dispose ();
			return res;
		}
	}
}