using System;

namespace ScreenConnect;

public class NativeBitmap : RootBitmap
{
	public IntPtr DibBits { get; }

	public IntPtr BitmapHandle { get; }

	public IntPtr OldBitmapHandle { get; }

	public IntPtr DeviceContextHandle { get; }

	public NativeBitmap(PixelModel pixelModel, int width, int height, int stride, IntPtr scan0, IntPtr dibBits, IntPtr bitmapHandle, IntPtr oldBitmapHandle, IntPtr deviceContextHandle)
		: base(pixelModel, width, height, stride, scan0)
	{
		DibBits = dibBits;
		BitmapHandle = bitmapHandle;
		OldBitmapHandle = oldBitmapHandle;
		DeviceContextHandle = deviceContextHandle;
	}

	protected override void Dispose(bool disposing)
	{
		NativeCleanup(DeviceContextHandle, BitmapHandle, OldBitmapHandle);
	}

	private static void NativeCleanup(IntPtr deviceContextHandle, IntPtr dibHandle, IntPtr oldDibHandle)
	{
		if (oldDibHandle != (IntPtr)0)
		{
			WindowsNative.SelectObject(deviceContextHandle, oldDibHandle);
		}
		if (dibHandle != (IntPtr)0)
		{
			WindowsNative.DeleteObject(dibHandle);
		}
		if (deviceContextHandle != (IntPtr)0)
		{
			WindowsNative.DeleteDC(deviceContextHandle);
		}
	}

	public static WindowsNative.BITMAPINFO GetBitmapInfo(int width, int height, int bitsPerPixel = 32, bool topDownOrBottomUp = true)
	{
		WindowsNative.BITMAPINFO result = new WindowsNative.BITMAPINFO
		{
			bmiHeader = 
			{
				biSize = WindowsNative.BitmapInfoHeaderStructureSize,
				biWidth = width,
				biHeight = height,
				biPlanes = 1,
				biBitCount = (short)bitsPerPixel
			}
		};
		if (topDownOrBottomUp)
		{
			result.bmiHeader.biHeight *= -1;
		}
		return result;
	}

	public static NativeBitmap CreateBitmap(int width, int height, int bitsPerPixel = 32, bool topDownOrBottomUp = true)
	{
		return CreateBitmap(GetBitmapInfo(width, height, bitsPerPixel, topDownOrBottomUp));
	}

	public static NativeBitmap CreateBitmap(WindowsNative.BITMAPINFO bitmapInfo)
	{
		PixelModel pixelModel = null;
		if (bitmapInfo.bmiHeader.biBitCount == 32)
		{
			pixelModel = new BgrPixelModel24(32);
		}
		else
		{
			if (bitmapInfo.bmiHeader.biBitCount != 24)
			{
				throw new InvalidOperationException("Bit depth not supported: " + bitmapInfo.bmiHeader.biBitCount);
			}
			pixelModel = new BgrPixelModel24(24);
		}
		IntPtr intPtr = default(IntPtr);
		IntPtr intPtr2 = default(IntPtr);
		IntPtr intPtr3 = default(IntPtr);
		IntPtr ppvBits = default(IntPtr);
		WindowsNative.BITMAP lpObject = default(WindowsNative.BITMAP);
		try
		{
			if ((intPtr = WindowsNative.CreateCompatibleDC((IntPtr)0)) == (IntPtr)0)
			{
				WindowsExtensions.ThrowLastError();
			}
			if ((intPtr2 = WindowsNative.CreateDIBSection(intPtr, ref bitmapInfo, 0u, out ppvBits, IntPtr.Zero, 0u)) == (IntPtr)0)
			{
				WindowsExtensions.ThrowLastError();
			}
			intPtr3 = WindowsNative.SelectObject(intPtr, intPtr2);
			if (WindowsNative.GetObjectBitmap(intPtr2, WindowsNative.BitmapStructureSize, ref lpObject) == 0)
			{
				WindowsExtensions.ThrowLastError();
			}
			return new NativeBitmap(pixelModel, bitmapInfo.bmiHeader.biWidth, Math.Abs(bitmapInfo.bmiHeader.biHeight), lpObject.bmWidthBytes * ((bitmapInfo.bmiHeader.biHeight < 0) ? 1 : (-1)), new IntPtr(ppvBits.ToInt64() + ((bitmapInfo.bmiHeader.biHeight >= 0) ? (lpObject.bmWidthBytes * (bitmapInfo.bmiHeader.biHeight - 1)) : 0)), ppvBits, intPtr2, intPtr3, intPtr);
		}
		catch
		{
			NativeCleanup(intPtr, intPtr2, intPtr3);
			throw;
		}
	}
}