using System;
using PlatformView = UIKit.UIView;
 
namespace Microsoft.Maui.Handlers
{
	public partial class ContentViewHandler : ViewHandler<IContentView, ContentView>
	{
		protected override ContentView CreatePlatformView()
		{
			_ = VirtualView ?? throw new InvalidOperationException($"{nameof(VirtualView)} must be set to create a {nameof(ContentView)}");
			_ = MauiContext ?? throw new InvalidOperationException($"{nameof(MauiContext)} cannot be null");
 
			return new ContentView
			{
				CrossPlatformLayout = VirtualView
			};
		}
 
		public override void SetVirtualView(IView view)
		{
			base.SetVirtualView(view);
			_ = PlatformView ?? throw new InvalidOperationException($"{nameof(PlatformView)} should have been set by base class.");
			_ = VirtualView ?? throw new InvalidOperationException($"{nameof(VirtualView)} should have been set by base class.");
 
			PlatformView.View = view;
			PlatformView.CrossPlatformLayout = VirtualView;
		}
 
		static void UpdateContent(IContentViewHandler handler)
		{
			_ = handler.PlatformView ?? throw new InvalidOperationException($"{nameof(PlatformView)} should have been set by base class.");
			_ = handler.VirtualView ?? throw new InvalidOperationException($"{nameof(VirtualView)} should have been set by base class.");
			_ = handler.MauiContext ?? throw new InvalidOperationException($"{nameof(MauiContext)} should have been set by base class.");
 
			// Cleanup the old view when reused
			handler.PlatformView.ClearSubviews();
 
			if (handler.VirtualView.PresentedContent is IView view)
			{
				var platformView = view.ToPlatform(handler.MauiContext);
				handler.PlatformView.AddSubview(platformView);
 
				if (view.FlowDirection == FlowDirection.MatchParent)
				{
					platformView.UpdateFlowDirection(view);
				}
			}
		}
 
		public static partial void MapContent(IContentViewHandler handler, IContentView page)
		{
			UpdateContent(handler);
		}
 
		protected override void DisconnectHandler(ContentView platformView)
		{
			platformView.CrossPlatformLayout = null;
			platformView.RemoveFromSuperview();
			base.DisconnectHandler(platformView);
		}
	}
}