using System.ComponentModel;
using Android.Content;
using Android.Graphics;
using Android.Views;
using Gallery.Droid.Renderers;
using Gallery.UI;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(CardView), typeof(CardViewRenderer))]
namespace Gallery.Droid.Renderers
{
    public class CardViewRenderer : VisualElementRenderer<CardView>
    {
        public CardViewRenderer(Context context) : base(context)
        {
        }

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

            var element = e.NewElement;
            if (element != null)
            {
                var radius = element.CornerRadius;
                if (radius > 0)
                {
                    var density = Resources.DisplayMetrics.Density;

                    OutlineProvider = new CornerRadiusOutlineProvider(element, radius, density);
                    ClipToOutline = true;

                    //var drawable = new RoundCornerDrawable(radius * density);
                    //drawable.SetColorFilter(element.BackgroundColor.ToAndroid(), PorterDuff.Mode.Src);
                    //((Android.Views.View)this).SetBackground(drawable);

                    Elevation = (float)(element.ShadowOffset.Height + 2) * density;
                }
            }
        }

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

            var element = Element;
            if (element == null)
            {
                return;
            }
            switch (e.PropertyName)
            {
                case nameof(CardView.ShadowOffset):
                    var density = Resources.DisplayMetrics.Density;
                    Elevation = (float)(element.ShadowOffset.Height + 2) * density;
                    break;
            }
        }

        class CornerRadiusOutlineProvider : ViewOutlineProvider
        {
            readonly Element element;
            readonly float radius;
            readonly float density;

            public CornerRadiusOutlineProvider(Element formsElement, float radius, float density)
            {
                element = formsElement;
                this.radius = radius * density;
                this.density = density;
            }

            public override void GetOutline(Android.Views.View view, Outline outline)
            {
                float scale = density;
                double width = (double)element.GetValue(VisualElement.WidthProperty) * scale;
                double height = (double)element.GetValue(VisualElement.HeightProperty) * scale;
                var rect = new Android.Graphics.Rect(0, 0, (int)width, (int)height);
                outline.SetRoundRect(rect, radius);
            }
        }
    }
}