using System;

namespace MoonWorks.Video
{
	internal class VideoAV1Stream
	{
		public IntPtr Handle => handle;
		IntPtr handle;

		public bool Ended => Dav1dfile.df_eos(Handle) == 1;

		public IntPtr yDataHandle;
		public IntPtr uDataHandle;
		public IntPtr vDataHandle;
		public uint yDataLength;
		public uint uvDataLength;
		public uint yStride;
		public uint uvStride;

		public bool FrameDataUpdated { get; private set; }

		bool IsDisposed;

		public VideoAV1Stream(VideoAV1 video)
		{
			if (Dav1dfile.df_fopen(video.Filename, out handle) == 0)
			{
				throw new Exception("Failed to open video file!");
			}

			Reset();
		}

		public void Reset()
		{
			lock (this)
			{
				Dav1dfile.df_reset(Handle);
				ReadNextFrame();
			}
		}

		public void ReadNextFrame()
		{
			lock (this)
			{
				if (Dav1dfile.df_readvideo(
					Handle,
					1,
					out yDataHandle,
					out uDataHandle,
					out vDataHandle,
					out yDataLength,
					out uvDataLength,
					out yStride,
					out uvStride) == 1
				) {
					FrameDataUpdated = true;
				}
			}
		}

		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;
			}
		}

		~VideoAV1Stream()
		{
			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);
		}
	}
}