using System;
using System.ComponentModel;
using System.Threading.Tasks;
using Microsoft.Maui.Handlers;
 
#if IOS || MACCATALYST
using PlatformImage = UIKit.UIImage;
using PlatformView = UIKit.UIView;
#elif ANDROID
using PlatformImage = Android.Graphics.Drawables.Drawable;
using PlatformView = Android.Views.View;
#elif WINDOWS
using PlatformImage = Microsoft.UI.Xaml.Media.ImageSource;
using PlatformView = Microsoft.UI.Xaml.FrameworkElement;
#elif TIZEN
using PlatformImage = Microsoft.Maui.Platform.MauiImageSource;
using PlatformView = Tizen.NUI.BaseComponents.View;
#elif (NETSTANDARD || !PLATFORM) || (NET6_0_OR_GREATER && !IOS && !ANDROID && !TIZEN)
using PlatformImage = System.Object;
using PlatformView = System.Object;
#endif
 
namespace Microsoft.Maui.Platform
{
	public partial class ImageSourcePartLoader
	{
#if IOS || ANDROID || WINDOWS || TIZEN
		IImageSourceServiceProvider? _imageSourceServiceProvider;
#endif
 
#if ANDROID
		// This is a temporary workaround for Android so that images don't just keep vanishing
		// We will have a better fix in the next release that's better integrated with Glide
		internal bool CheckForImageLoadedOnAttached { get; set; }
#endif
 
		readonly IImageSourcePartSetter _setter;
 
		internal ImageSourceServiceResultManager SourceManager { get; } = new ImageSourceServiceResultManager();
 
		[EditorBrowsable(EditorBrowsableState.Never)]
		[Obsolete("Use ImageSourcePartLoader(IImageSourcePartSetter setter) instead.", true)]
		public ImageSourcePartLoader(IElementHandler handler, Func<IImageSourcePart?> imageSourcePart, Action<PlatformImage?> setImage)
			: this((IImageSourcePartSetter)handler)
		{
		}
 
		public ImageSourcePartLoader(IImageSourcePartSetter setter) =>
			_setter = setter;
 
		internal IImageSourcePartSetter Setter => _setter;
 
		public void Reset()
		{
			SourceManager.Reset();
		}
 
		public async Task UpdateImageSourceAsync()
		{
			if (Setter.Handler is not IElementHandler handler || handler.PlatformView is not PlatformView platformView)
			{
				return;
			}
 
			var token = SourceManager.BeginLoad();
			var imageSource = Setter.ImageSourcePart;
 
			if (imageSource?.Source is not null)
			{
#if IOS || ANDROID || WINDOWS || TIZEN
				_imageSourceServiceProvider ??= handler.GetRequiredService<IImageSourceServiceProvider>();
#endif
 
#if IOS || WINDOWS
				var scale = handler.MauiContext?.GetOptionalPlatformWindow()?.GetDisplayDensity() ?? 1.0f;
				var result = await imageSource.UpdateSourceAsync(platformView, _imageSourceServiceProvider, Setter.SetImageSource, scale, token)
					.ConfigureAwait(false);
 
				SourceManager.CompleteLoad(result);
#elif ANDROID || TIZEN
				var result = await imageSource.UpdateSourceAsync(platformView, _imageSourceServiceProvider, Setter.SetImageSource, token)
					.ConfigureAwait(false);
#else
				await Task.CompletedTask;
#endif
 
#if ANDROID
				CheckForImageLoadedOnAttached = true;
#endif
			}
			else
			{
				Setter.SetImageSource(null);
#if ANDROID
				CheckForImageLoadedOnAttached = false;
#endif
			}
		}
	}
}