using System;
using System.IO;

namespace MoonWorks.Video
{
	public unsafe class VideoAV1 : IDisposable
	{
		public IntPtr Handle => handle;
		IntPtr handle;

		public int Width => width;
		public int Height => height;
		public double FramesPerSecond => 28.97;
		public Dav1dfile.PixelLayout PixelLayout => pixelLayout;
		public int UVWidth { get; }
		public int UVHeight { get; }

		private int width;
		private int height;
		private double fps;
		private Dav1dfile.PixelLayout pixelLayout;

		bool IsDisposed;

		public VideoAV1(string filename)
		{
			if (!File.Exists(filename))
			{
				throw new ArgumentException("Video file not found!");
			}

			if (Dav1dfile.df_fopen(filename, out handle) == 0)
			{
				throw new Exception("Failed to open video file!");
			}

			Dav1dfile.df_videoinfo(Handle, out width, out height, out pixelLayout);

			if (pixelLayout == Dav1dfile.PixelLayout.I420)
			{
				UVWidth = Width / 2;
				UVHeight = Height / 2;
			}
			else if (pixelLayout == Dav1dfile.PixelLayout.I422)
			{
				UVWidth = Width / 2;
				UVHeight = Height;
			}
			else if (pixelLayout == Dav1dfile.PixelLayout.I444)
			{
				UVWidth = width;
				UVHeight = height;
			}
			else
			{
				throw new NotSupportedException("Unrecognized YUV format!");
			}
		}

		protected virtual void Dispose(bool disposing)
		{
			if (!IsDisposed)
			{
				if (disposing)
				{
					// dispose managed state (managed objects)
				}

				// free unmanaged resources (unmanaged objects)
				Dav1dfile.df_close(Handle);

				IsDisposed = true;
			}
		}

		~VideoAV1()
		{
			Dispose(disposing: false);
		}

		public void Dispose()
		{
			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
			Dispose(disposing: true);
			GC.SuppressFinalize(this);
		}
	}
}