// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright (C) 1993-1996 by id Software, Inc.
// Copyright (C) 1998-2000 by DooM Legacy Team.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//-----------------------------------------------------------------------------
/// \file
/// \brief Main program, simply calls D_SRB2Main and D_SRB2Loop, the high level loop.

#include "../doomdef.h"
#include "../m_argv.h"
#include "../d_main.h"
#include "../m_misc.h"/* path shit */
#include "../i_system.h"

#if defined (__GNUC__) || defined (__unix__)
#include <unistd.h>
#endif

#if defined (__unix__) || defined(__APPLE__) || defined (UNIXCOMMON)
#include <errno.h>
#endif

#include "time.h" // For log timestamps

#ifdef HAVE_SDL

#ifdef HAVE_TTF
#include "SDL.h"
#include "i_ttf.h"
#endif

#if defined (_WIN32) && !defined (main)
//#define SDLMAIN
#endif

#ifdef SDLMAIN
#include "SDL_main.h"
#elif defined(FORCESDLMAIN)
extern int SDL_main(int argc, char *argv[]);
#endif

#ifdef LOGMESSAGES
FILE *logstream = NULL;
char logfilename[1024];
#endif

#ifndef DOXYGEN
#ifndef O_TEXT
#define O_TEXT 0
#endif

#ifndef O_SEQUENTIAL
#define O_SEQUENTIAL 0
#endif
#endif

#if defined (_WIN32)
#include "../win32/win_dbg.h"
typedef BOOL (WINAPI *p_IsDebuggerPresent)(VOID);
#endif

#if defined (_WIN32)
static inline VOID MakeCodeWritable(VOID)
{
#ifdef USEASM // Disable write-protection of code segment
	DWORD OldRights;
	const DWORD NewRights = PAGE_EXECUTE_READWRITE;
	PBYTE pBaseOfImage = (PBYTE)GetModuleHandle(NULL);
	PIMAGE_DOS_HEADER dosH =(PIMAGE_DOS_HEADER)pBaseOfImage;
	PIMAGE_NT_HEADERS ntH = (PIMAGE_NT_HEADERS)(pBaseOfImage + dosH->e_lfanew);
	PIMAGE_OPTIONAL_HEADER oH = (PIMAGE_OPTIONAL_HEADER)
		((PBYTE)ntH + sizeof (IMAGE_NT_SIGNATURE) + sizeof (IMAGE_FILE_HEADER));
	LPVOID pA = pBaseOfImage+oH->BaseOfCode;
	SIZE_T pS = oH->SizeOfCode;
#if 1 // try to find the text section
	PIMAGE_SECTION_HEADER ntS = IMAGE_FIRST_SECTION (ntH);
	WORD s;
	for (s = 0; s < ntH->FileHeader.NumberOfSections; s++)
	{
		if (memcmp (ntS[s].Name, ".text\0\0", 8) == 0)
		{
			pA = pBaseOfImage+ntS[s].VirtualAddress;
			pS = ntS[s].Misc.VirtualSize;
			break;
		}
	}
#endif

	if (!VirtualProtect(pA,pS,NewRights,&OldRights))
		I_Error("Could not make code writable\n");
#endif
}
#endif

#ifdef LOGMESSAGES
static void InitLogging(void)
{
	const char *logdir = NULL;
	time_t my_time;
	struct tm * timeinfo;
	const char *format;
	const char *reldir;
	int left;
	boolean fileabs;
#if defined (__unix__) || defined(__APPLE__) || defined (UNIXCOMMON)
	const char *link;
#endif

	logdir = D_Home();

	my_time = time(NULL);
	timeinfo = localtime(&my_time);

	if (M_CheckParm("-logfile") && M_IsNextParm())
	{
		format = M_GetNextParm();
		fileabs = M_IsPathAbsolute(format);
	}
	else
	{
		format = "log-%Y-%m-%d_%H-%M-%S.txt";
		fileabs = false;
	}

	if (fileabs)
	{
		strftime(logfilename, sizeof logfilename, format, timeinfo);
	}
	else
	{
		if (M_CheckParm("-logdir") && M_IsNextParm())
			reldir = M_GetNextParm();
		else
			reldir = "logs";

		if (M_IsPathAbsolute(reldir))
		{
			left = snprintf(logfilename, sizeof logfilename,
					"%s"PATHSEP, reldir);
		}
		else
#ifdef DEFAULTDIR
		if (logdir)
		{
			left = snprintf(logfilename, sizeof logfilename,
					"%s"PATHSEP DEFAULTDIR PATHSEP"%s"PATHSEP, logdir, reldir);
		}
		else
#endif/*DEFAULTDIR*/
		{
			left = snprintf(logfilename, sizeof logfilename,
					"."PATHSEP"%s"PATHSEP, reldir);
		}

		strftime(&logfilename[left], sizeof logfilename - left,
				format, timeinfo);
	}

	M_MkdirEachUntil(logfilename,
			M_PathParts(logdir) - 1,
			M_PathParts(logfilename) - 1, 0755);

#if defined (__unix__) || defined(__APPLE__) || defined (UNIXCOMMON)
	logstream = fopen(logfilename, "w");
#ifdef DEFAULTDIR
	if (logdir)
		link = va("%s/"DEFAULTDIR"/latest-log.txt", logdir);
	else
#endif/*DEFAULTDIR*/
		link = "latest-log.txt";
	unlink(link);
	if (symlink(logfilename, link) == -1)
	{
		I_OutputMsg("Error symlinking latest-log.txt: %s\n", strerror(errno));
	}
#else/*defined (__unix__) || defined(__APPLE__) || defined (UNIXCOMMON)*/
	logstream = fopen("latest-log.txt", "wt+");
#endif/*defined (__unix__) || defined(__APPLE__) || defined (UNIXCOMMON)*/
}
#endif


/**	\brief	The main function

	\param	argc	number of arg
	\param	*argv	string table

	\return	int
*/
#if defined (__GNUC__) && (__GNUC__ >= 4)
#pragma GCC diagnostic ignored "-Wmissing-noreturn"
#endif

#ifdef FORCESDLMAIN
int SDL_main(int argc, char **argv)
#else
int main(int argc, char **argv)
#endif
{
	myargc = argc;
	myargv = argv; /// \todo pull out path to exe from this string

#ifdef HAVE_TTF
#ifdef _WIN32
	I_StartupTTF(FONTPOINTSIZE, SDL_INIT_VIDEO|SDL_INIT_AUDIO, SDL_SWSURFACE);
#else
	I_StartupTTF(FONTPOINTSIZE, SDL_INIT_VIDEO, SDL_SWSURFACE);
#endif
#endif

#ifdef LOGMESSAGES
	if (!M_CheckParm("-nolog"))
		InitLogging();
#endif/*LOGMESSAGES*/

	//I_OutputMsg("I_StartupSystem() ...\n");
	I_StartupSystem();
#if defined (_WIN32)
	{
#if 0 // just load the DLL
		p_IsDebuggerPresent pfnIsDebuggerPresent = (p_IsDebuggerPresent)GetProcAddress(GetModuleHandleA("kernel32.dll"), "IsDebuggerPresent");
		if ((!pfnIsDebuggerPresent || !pfnIsDebuggerPresent())
#ifdef BUGTRAP
			&& !InitBugTrap()
#endif
			)
#endif
		{
			LoadLibraryA("exchndl.dll");
		}
	}
#ifndef __MINGW32__
	prevExceptionFilter = SetUnhandledExceptionFilter(RecordExceptionInfo);
#endif
	MakeCodeWritable();
#endif

	// startup SRB2
	CONS_Printf("Setting up SRB2...\n");
	D_SRB2Main();
#ifdef LOGMESSAGES
	if (!M_CheckParm("-nolog"))
		CONS_Printf("Logfile: %s\n", logfilename);
#endif
	CONS_Printf("Entering main game loop...\n");
	// never return
	D_SRB2Loop();

#ifdef BUGTRAP
	// This is safe even if BT didn't start.
	ShutdownBugTrap();
#endif

	// return to OS
	return 0;
}
#endif