// Copyright Epic Games, Inc. All Rights Reserved.

#include <zencore/commandline.h>
#include <zencore/string.h>

#if ZEN_PLATFORM_WINDOWS
#	include <zencore/windows.h>
ZEN_THIRD_PARTY_INCLUDES_START
#	include <shellapi.h>  // For command line parsing
ZEN_THIRD_PARTY_INCLUDES_END
#endif

#if ZEN_PLATFORM_MAC
#	include <crt_externs.h>
#endif

#include <functional>

namespace zen {

void
IterateCommandlineArgs(std::function<void(const std::string_view& Arg)>& ProcessArg)
{
#if ZEN_PLATFORM_WINDOWS
	// It might seem odd to do this here in addition to at start of main functions but the InitGMalloc() function is called before main (via
	// static data) so we need to make sure we set the locale before parsing the command line
	setlocale(LC_ALL, "en_us.UTF8");

	int			  ArgC	  = 0;
	const LPWSTR  CmdLine = ::GetCommandLineW();
	const LPWSTR* ArgV	  = ::CommandLineToArgvW(CmdLine, &ArgC);

	if (ArgC > 1)
	{
		for (int i = 1; i < ArgC; ++i)
		{
			StringBuilder<4096> ArgString8;

			WideToUtf8(ArgV[i], ArgString8);

			ProcessArg(ArgString8);
		}
	}

	::LocalFree(HLOCAL(ArgV));
#elif ZEN_PLATFORM_MAC
	int	   ArgC = *_NSGetArgc();
	char** ArgV = *_NSGetArgv();
	if (ArgC > 1)
	{
		for (int i = 1; i < ArgC; ++i)
		{
			ProcessArg(ArgV[i]);
		}
	}
#elif ZEN_PLATFORM_LINUX
	if (FILE* CmdLineFile = fopen("/proc/self/cmdline", "r"))
	{
		const char* ArgV[255] = {};
		int			ArgC	  = 0;

		char*  Arg	= nullptr;
		size_t Size = 0;
		while (getdelim(&Arg, &Size, 0, CmdLineFile) != -1)
		{
			ArgV[ArgC++] = Arg;
			Arg			 = nullptr;	 // getdelim will allocate buffer for next Arg
		}
		if (Arg)
		{
			// getdelim allocated one last arg buffer that we didn't use
			free(Arg);
		}
		fclose(CmdLineFile);

		if (ArgC > 1)
		{
			for (int i = 1; i < ArgC; ++i)
			{
				ProcessArg(ArgV[i]);
			}
		}

		// cleanup after getdelim
		while (ArgC > 0)
		{
			free((void*)ArgV[--ArgC]);
		}
	}
#else
#	error Unknown platform
#endif
}

}  // namespace zen