#nullable enable
using System;
using System.Threading;
 
#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
{
	internal class ImageSourceServiceResultManager
	{
		CancellationTokenSource? _sourceCancellation;
		IDisposable? _sourceResult;
 
		public CancellationToken Token =>
			_sourceCancellation?.Token ?? default;
 
		public bool IsResolutionDependent { get; private set; }
 
		public float CurrentResolution { get; private set; } = 1.0f;
 
		public CancellationToken BeginLoad()
		{
			_sourceResult?.Dispose();
 
			_sourceCancellation?.Cancel();
			_sourceCancellation = new CancellationTokenSource();
 
			return Token;
		}
 
		public void CompleteLoad<T>(IImageSourceServiceResult<T>? result, PlatformView uiContext)
		{
			CompleteLoad((IDisposable?)result);
 
			IsResolutionDependent = result?.IsResolutionDependent ?? false;
 
#if IOS || MACCATALYST || WINDOWS
			CurrentResolution = uiContext.GetDisplayDensity();
#endif
		}
 
		public bool RequiresReload(PlatformView uiContext)
		{
			if (!IsResolutionDependent)
				return false;
 
#if IOS || MACCATALYST || WINDOWS
			if (uiContext is not null)
			{
				var newResolution = uiContext.GetDisplayDensity();
				return CurrentResolution != newResolution;
			}
#endif
 
			return false;
		}
 
		public void CompleteLoad(IDisposable? result)
		{
			_sourceResult = result;
			_sourceCancellation?.Dispose();
			_sourceCancellation = null;
 
			IsResolutionDependent = false;
			CurrentResolution = 1.0f;
		}
 
		public void Reset()
		{
			BeginLoad();
			CompleteLoad(null);
		}
	}
}