using System;
using CoreGraphics;
using Foundation;
using Shared.IO;
using UIKit;


namespace Shared
{
	/// <summary>
	/// 色板
	/// </summary>
	public class ColorPicker :View
	{
		MyUIImageView myUIImageView
		{
			get
			{
				return uiView as MyUIImageView;
			}
			set
			{
				uiView = value;
			}
		}

		/// <summary>
		/// Initializes a new instance of the <see cref="Shared.Button"/> class.
		/// </summary>
		public ColorPicker()
		{
			myUIImageView = new MyUIImageView(this);
		}

		public override void Refresh()
		{
			base.Refresh();
			//Width = (int)myUIImageView.Image.Size.Width;
			//Height = (int)myUIImageView.Image.Size.Height;
		}

		string colorImagePath;
		/// <summary>
		/// 色板图
		/// </summary>
		/// <value>The color image path.</value>
		public string ColorImagePath
		{
			get {
				return colorImagePath;
			}
			set
			{
				colorImagePath = value;

                myUIImageView.Image = UIImage.FromFile(FileUtils.GetImageFilePath(colorImagePath));
			}
		}

		/// <summary>
		/// 颜色变化
		/// </summary>
		public event EventHandler<byte[]> ColorChaged;

		class MyUIImageView : UIImageView
		{
			View _view;
			public MyUIImageView(View view)
			{
				_view = view;
				UserInteractionEnabled = true;
			}



			/// <summary>
			/// 点击开始
			/// </summary>
			/// <param name="touches">Touches.</param>
			/// <param name="evt">Evt.</param>
			public override void TouchesBegan(NSSet touches, UIEvent evt)
			{
				//base.TouchesBegan(touches, evt);
				UITouch touch = touches.AnyObject as UITouch;
				_view.TouchEvent(EventActions.Down, touch.LocationInView(this));
				colorChaged(colorAtPixel(touch.LocationInView(this)));
			}
			/// <summary>
			///  移动
			/// </summary>
			/// <param name="touches">Touches.</param>
			/// <param name="evt">Evt.</param>
			public override void TouchesMoved(NSSet touches, UIEvent evt)
			{
				//base.TouchesMoved(touches, evt);
				UITouch touch = touches.AnyObject as UITouch;
				_view.TouchEvent(EventActions.Move, touch.LocationInView(this));
				colorChaged(colorAtPixel(touch.LocationInView(this)));
			}

			void colorChaged(UIColor uiColor)
			{
				nfloat r, g, b, a;
				uiColor.GetRGBA(out r, out g, out b, out a);
				if (r == 0 && g == 0 && b == 0)
				{
					return;
				}
				if (_view != null && ((ColorPicker)_view).ColorChaged != null)
				{
					(_view as ColorPicker).ColorChaged(_view, new byte[] {(byte)(r * 255),(byte)(g * 255),(byte)(b*255)});
				}
			}
			/// <summary>
			/// 点击弹起
			/// </summary>
			/// <param name="touches">Touches.</param>
			/// <param name="evt">Evt.</param>
			public override void TouchesEnded(NSSet touches, UIEvent evt)
			{
				//base.TouchesEnded(touches, evt);
				UITouch touch = touches.AnyObject as UITouch;
				_view.TouchEvent(EventActions.Up, touch.LocationInView(this));
				colorChaged(colorAtPixel(touch.LocationInView(this)));
			}
			

			UIColor colorAtPixel(CGPoint point)
			{
				var pointX = (int)(point.X *Image.Size.Width/ Frame.Width);
				var pointY = (int)(point.Y * Image.Size.Height / Frame.Height);
				var cgImage = Image.CGImage;
				var colorSpace = CGColorSpace.CreateDeviceRGB();
				int bytesPerPixel = 4;
				int bytesPerRow = bytesPerPixel * 1;
				var bitsPerComponent = 8;
				byte[] pixelData = { 0, 0, 0, 0 };
				var context = new CGBitmapContext(pixelData,
															 1,
															 1,
															 bitsPerComponent,
															 bytesPerRow,
												 colorSpace, CGBitmapFlags.PremultipliedLast | CGBitmapFlags.ByteOrder32Big);

				context.SetBlendMode(CGBlendMode.Copy);

				context.TranslateCTM(-pointX, pointY - Image.Size.Height);
				context.DrawImage(new CGRect(0.0f, 0.0f, Image.Size.Width, Image.Size.Height), cgImage);
				var red = pixelData[0] / 255.0f;
				var green = pixelData[1] / 255.0f;
				var blue = pixelData[2] / 255.0f;
				var alpha = pixelData[3] / 255.0f;
				return UIColor.FromRGBA(red, green, blue, alpha);
			}
		}

	}

}