using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using UnityEngine;

namespace Photon.Bolt
{
	public static class ConsoleWriter
	{
#if UNITY_STANDALONE_WIN
		static class PInvoke
		{
			public const int STD_OUTPUT_HANDLE = -11;

			[DllImport("kernel32.dll", SetLastError = true)]
			public static extern bool AttachConsole(uint dwProcessId);

			[DllImport("kernel32.dll", SetLastError = true)]
			public static extern bool AllocConsole();

			[DllImport("kernel32.dll", SetLastError = true)]
			public static extern bool FreeConsole();

			[DllImport("kernel32.dll", EntryPoint = "GetStdHandle", SetLastError = true, CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
			public static extern IntPtr GetStdHandle(int nStdHandle);

			[DllImport("kernel32.dll")]
			public static extern bool SetConsoleTitle(string lpConsoleTitle);
		}

		static TextWriter realOut;
#endif

		public static void Open()
		{
#if UNITY_STANDALONE_WIN
			if (realOut == null)
			{
				realOut = Console.Out;
			}

			var hasConsole = PInvoke.AttachConsole(0x0ffffffff);
			if (hasConsole == false)
			{
				PInvoke.AllocConsole();
			}

			try
			{
				// grab handle ptr
				var outHandlePtr = PInvoke.GetStdHandle(PInvoke.STD_OUTPUT_HANDLE);

				// we can then create a filestream from this handle
#pragma warning disable 0618
				var fileStream = new FileStream(outHandlePtr, FileAccess.Write);
#pragma warning restore 0618

				// and then create a new stream writer (using ASCII) 
				var stdOut = new StreamWriter(fileStream, Encoding.ASCII)
				{
					AutoFlush = true
				};

				// and force unity to use this
				Console.SetOut(stdOut);
			}
			catch (Exception e)
			{
				Debug.Log(e);
			}
#endif
		}

		public static void Close()
		{
#if UNITY_STANDALONE_WIN
			PInvoke.FreeConsole();

			Console.SetOut(realOut);
			realOut = null;
#endif
		}
	}
}