using System;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.Experimental.Rendering;

public static class ClipboardImage
{
	[DllImport("UnityClipboard")] private static extern bool Open();
	[DllImport("UnityClipboard")] private static extern int Width();
	[DllImport("UnityClipboard")] private static extern int Height();
	[DllImport("UnityClipboard")] private static extern int BitsPerPixel();
	[DllImport("UnityClipboard")] private static extern IntPtr Read();

	public static Texture2D Copy()
	{
		try
		{
			// no image in clipboard
			if (Open() == false)
				return null;
			
			var width  = Width();
			var height = Height();
			var step   = BitsPerPixel() / 8;
			var ptr	= Read();
			
			var tex = new Texture2D(width, height, GraphicsFormat.R8G8B8A8_SRGB, 0, TextureCreationFlags.None);
			
			var bytes = new byte[width * height * step];
			Marshal.Copy(ptr, bytes, 0, width * height * step);
			
			for (var y = 0; y < height; y++)
			for (var x = 0; x < width; x++)
			{
				var pos = (y * width + x) * 4;
				
				// read in bgra format
				var b = bytes[pos];
				var g = bytes[pos + 1];
				var r = bytes[pos + 2];
				var a = bytes[pos + 3];
				
				tex.SetPixel(x, height - y, new Color32(r, g, b, a));
			}

			tex.Apply();
			return tex;
		}
		catch (Exception e)
		{
			Debug.LogError($"Can't past image from clipboard {e}");
		}
		
		return null;
	}
}