using System.ComponentModel;
using Android.Graphics.Drawables;
using Android.OS;
using Android.Widget;

namespace Xamarin.Forms.Platform.Android
{
	public class SliderRenderer : ViewRenderer<Slider, SeekBar>, SeekBar.IOnSeekBarChangeListener
	{
		double _max;
		double _min;

		public SliderRenderer()
		{
			AutoPackage = false;
		}

		double Value
		{
			get { return _min + (_max - _min) * (Control.Progress / 1000.0); }
			set { Control.Progress = (int)((value - _min) / (_max - _min) * 1000.0); }
		}

		void SeekBar.IOnSeekBarChangeListener.OnProgressChanged(SeekBar seekBar, int progress, bool fromUser)
		{
			((IElementController)Element).SetValueFromRenderer(Slider.ValueProperty, Value);
		}

		void SeekBar.IOnSeekBarChangeListener.OnStartTrackingTouch(SeekBar seekBar)
		{
		}

		void SeekBar.IOnSeekBarChangeListener.OnStopTrackingTouch(SeekBar seekBar)
		{
		}

		protected override SeekBar CreateNativeControl()
		{
			return new FormsSeekBar(Context);
		}

		protected override void OnElementChanged(ElementChangedEventArgs<Slider> e)
		{
			base.OnElementChanged(e);

			if (e.OldElement == null)
			{
				var seekBar = CreateNativeControl();
				SetNativeControl(seekBar);

				seekBar.Max = 1000;

				seekBar.SetOnSeekBarChangeListener(this);
			}

			Slider slider = e.NewElement;
			_min = slider.Minimum;
			_max = slider.Maximum;
			Value = slider.Value;
		}

		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
		{
			base.OnElementPropertyChanged(sender, e);

			Slider view = Element;
			switch (e.PropertyName)
			{
				case "Maximum":
					_max = view.Maximum;
					break;
				case "Minimum":
					_min = view.Minimum;
					break;
				case "Value":
					if (Value != view.Value)
						Value = view.Value;
					break;
			}
		}

		protected override void OnLayout(bool changed, int l, int t, int r, int b)
		{
			base.OnLayout(changed, l, t, r, b);

			BuildVersionCodes androidVersion = Build.VERSION.SdkInt;
			if (androidVersion >= BuildVersionCodes.JellyBean)
			{
				// Thumb only supported JellyBean and higher

				if (Control == null)
					return;

				SeekBar seekbar = Control;

				Drawable thumb = seekbar.Thumb;
				int thumbTop = seekbar.Height / 2 - thumb.IntrinsicHeight / 2;

				thumb.SetBounds(thumb.Bounds.Left, thumbTop, thumb.Bounds.Left + thumb.IntrinsicWidth, thumbTop + thumb.IntrinsicHeight);
			}
		}
	}
}