using System;
using System.Drawing;
using System.Windows.Forms;

namespace ScreenConnect;

public class VfwEncoder : CriticalFinalizerDisposableObject, IVideoFileEncoder, IBlittable, IDisposable
{
	private IntPtr pfile;

	private IntPtr pstream;

	private IntPtr pcompstream;

	private ICursor cursor;

	private CorePoint cursorPosition;

	private NativeBitmap screenBitmap;

	private NativeBitmap cursorBackBuffer;

	public string ContentType => "video/avi";

	public string FileExtension => ".avi";

	public int FramesPerSecond => 4;

	public void StartEncoding(string filePath, int width, int height)
	{
		if (screenBitmap != null)
		{
			throw new InvalidOperationException("Already started");
		}
		WindowsNative.AVISTREAMINFO ptr_streaminfo = new WindowsNative.AVISTREAMINFO
		{
			fccType = (uint)WindowsNative.mmioStringToFOURCC("vids", 0),
			dwScale = 1u,
			dwRate = (uint)FramesPerSecond,
			rcFrame = 
			{
				bottom = height,
				right = width
			},
			szName = new ushort[64]
		};
		WindowsNative.AVICOMPRESSOPTIONS lpOptions = new WindowsNative.AVICOMPRESSOPTIONS
		{
			fccType = (uint)WindowsNative.mmioStringToFOURCC("vids", 0),
			fccHandler = (uint)WindowsNative.mmioStringToFOURCC("msvc", 0),
			dwFlags = 12u,
			dwKeyFrameEvery = (uint)(FramesPerSecond * 10),
			dwQuality = 8000u
		};
		WindowsNative.BITMAPINFO lpFormat = NativeBitmap.GetBitmapInfo(width, height, 32, topDownOrBottomUp: false);
		try
		{
			WindowsNative.AVIFileInit();
			screenBitmap = NativeBitmap.CreateBitmap(lpFormat);
			WindowsNative.AVIFileOpen(out pfile, filePath, 4097u, 0).AssertWin32ResultZero();
			WindowsNative.AVIFileCreateStream(pfile, out pstream, ref ptr_streaminfo).AssertWin32ResultZero();
			WindowsNative.AVIMakeCompressedStream(out pcompstream, pstream, ref lpOptions, IntPtr.Zero).AssertWin32ResultZero();
			WindowsNative.AVIStreamSetFormat(pcompstream, 0, ref lpFormat, lpFormat.bmiHeader.biSize).AssertWin32ResultZero();
		}
		catch
		{
			Dispose();
			throw;
		}
	}

	public void StopEncoding()
	{
		Dispose();
	}

	public void WriteFrame(int frameIndex)
	{
		if (screenBitmap == null)
		{
			throw new InvalidOperationException("Cannot write frame until recording started.");
		}
		if (cursor != null)
		{
			Rectangle rectangle = new Rectangle(cursorPosition.X - cursor.HotSpot.X, cursorPosition.Y - cursor.HotSpot.Y, cursor.Size.Width, cursor.Size.Height);
			if (cursorBackBuffer == null || cursorBackBuffer.Width < cursor.Size.Width || cursorBackBuffer.Height < cursor.Size.Height)
			{
				cursorBackBuffer.DisposeQuietly();
				cursorBackBuffer = NativeBitmap.CreateBitmap(cursor.Size.Width, cursor.Size.Height, 32, topDownOrBottomUp: false);
			}
			WindowsNative.BitBlt(cursorBackBuffer.DeviceContextHandle, 0, 0, cursor.Size.Width, cursor.Size.Height, screenBitmap.DeviceContextHandle, rectangle.X, rectangle.Y, WindowsNative.TernaryRasterOperations.SRCCOPY);
			Graphics val = Graphics.FromHdc(screenBitmap.DeviceContextHandle);
			try
			{
				cursor.RawObject.To<Cursor>().Draw(val, rectangle);
			}
			finally
			{
				((IDisposable)val)?.Dispose();
			}
		}
		WindowsNative.AVIStreamWrite(pcompstream, frameIndex, 1, screenBitmap.DibBits, Math.Abs(screenBitmap.Stride) * screenBitmap.Height, 0, (IntPtr)0, (IntPtr)0).AssertWin32ResultZero();
		if (cursor != null)
		{
			Rectangle rectangle2 = new Rectangle(cursorPosition.X - cursor.HotSpot.X, cursorPosition.Y - cursor.HotSpot.Y, cursor.Size.Width, cursor.Size.Height);
			WindowsNative.BitBlt(screenBitmap.DeviceContextHandle, rectangle2.X, rectangle2.Y, cursor.Size.Width, cursor.Size.Height, cursorBackBuffer.DeviceContextHandle, 0, 0, WindowsNative.TernaryRasterOperations.SRCCOPY);
		}
	}

	protected override void Dispose(bool disposing)
	{
		Extensions.ReleaseIntPtrIfNotNull(ref pcompstream, WindowsNative.AVIStreamRelease);
		Extensions.ReleaseIntPtrIfNotNull(ref pstream, WindowsNative.AVIStreamRelease);
		Extensions.ReleaseIntPtrIfNotNull(ref pfile, WindowsNative.AVIFileRelease);
		if (screenBitmap != null)
		{
			Extensions.DisposeQuietly(ref screenBitmap);
			WindowsNative.AVIFileExit();
		}
	}

	public void SetCursor(ICursor cursor, CorePoint position)
	{
		this.cursor = cursor;
		cursorPosition = position;
	}

	public IBitmapData AcquireBits(CoreRect bounds)
	{
		return screenBitmap.AssertNonNull().AcquireBits(bounds);
	}

	public void ReleaseBits(IBitmapData bitmapData)
	{
		screenBitmap.AssertNonNull().ReleaseBits(bitmapData);
	}
}