/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code 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.

Quake III Arena source code 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.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <pwd.h>

#include "../qcommon/q_shared.h"
#include "../qcommon/qcommon.h"

//=============================================================================

// Used to determine where to store user-specific files
static char homePath[MAX_OSPATH];

/*
================
Sys_Milliseconds
================
*/
/* base time in seconds, that's our origin
   timeval:tv_sec is an int: 
   assuming this wraps every 0x7fffffff - ~68 years since the Epoch (1970) - we're safe till 2038
   using unsigned long data type to work right with Sys_XTimeToSysTime */
unsigned long sys_timeBase = 0;
/* current time in ms, using sys_timeBase as origin
   NOTE: sys_timeBase*1000 + curtime -> ms since the Epoch
     0x7fffffff ms - ~24 days
   although timeval:tv_usec is an int, I'm not sure wether it is actually used as an unsigned int
     (which would affect the wrap period)
*/
int Sys_Milliseconds()
{
	static int curtime;

	struct timeval tp;
	gettimeofday(&tp, NULL);

	if (!sys_timeBase)
	{
		sys_timeBase = tp.tv_sec;
		return tp.tv_usec/1000;
	}

	curtime = (tp.tv_sec - sys_timeBase)*1000 + tp.tv_usec/1000;

	return curtime;
}

#if (defined(__linux__) || defined(__FreeBSD__) || defined(__sun)) && !defined(DEDICATED)
/*
================
Sys_XTimeToSysTime
sub-frame timing of events returned by X
X uses the Time typedef - unsigned long
disable with in_subframe 0

 sys_timeBase*1000 is the number of ms since the Epoch of our origin
 xtime is in ms and uses the Epoch as origin
   Time data type is an unsigned long: 0xffffffff ms - ~49 days period
 I didn't find much info in the XWindow documentation about the wrapping
   we clamp sys_timeBase*1000 to unsigned long, that gives us the current origin for xtime
   the computation will still work if xtime wraps (at ~49 days period since the Epoch) after we set sys_timeBase

================
*/
extern cvar_t *in_subframe;
int Sys_XTimeToSysTime (unsigned long xtime)
{
	int ret, time, test;
	
	if (!in_subframe->value)
	{
		// if you don't want to do any event times corrections
		return Sys_Milliseconds();
	}

	// test the wrap issue
#if 0	
	// reference values for test: sys_timeBase 0x3dc7b5e9 xtime 0x541ea451 (read these from a test run)
	// xtime will wrap in 0xabe15bae ms >~ 0x2c0056 s (33 days from Nov 5 2002 -> 8 Dec)
	//   NOTE: date -d '1970-01-01 UTC 1039384002 seconds' +%c
	// use sys_timeBase 0x3dc7b5e9+0x2c0056 = 0x3df3b63f
	// after around 5s, xtime would have wrapped around
	// we get 7132, the formula handles the wrap safely
	unsigned long xtime_aux,base_aux;
	int test;
//	Com_Printf("sys_timeBase: %p\n", sys_timeBase);
//	Com_Printf("xtime: %p\n", xtime);
	xtime_aux = 500; // 500 ms after wrap
	base_aux = 0x3df3b63f; // the base a few seconds before wrap
	test = xtime_aux - (unsigned long)(base_aux*1000);
	Com_Printf("xtime wrap test: %d\n", test);
#endif

  // some X servers (like suse 8.1's) report weird event times
  // if the game is loading, resolving DNS, etc. we are also getting old events
  // so we only deal with subframe corrections that look 'normal'
  ret = xtime - (unsigned long)(sys_timeBase*1000);
  time = Sys_Milliseconds();
  test = time - ret;
  //printf("delta: %d\n", test);
  if (test < 0 || test > 30) // in normal conditions I've never seen this go above
  {
    return time;
  }

	return ret;
}
#endif


void	Sys_Mkdir( const char *path )
{
    mkdir (path, 0777);
}


//============================================

#define	MAX_FOUND_FILES	0x1000

// bk001129 - new in 1.26
static void Sys_ListFilteredFiles( const char *basedir, const char *subdirs, const char *filter, char **list, int *numfiles ) {
	char		search[MAX_OSPATH], newsubdirs[MAX_OSPATH];
	char		filename[MAX_OSPATH];
	DIR			*fdir;
	struct dirent *d;
	struct stat st;

	if ( *numfiles >= MAX_FOUND_FILES - 1 ) {
		return;
	}

	if (strlen(subdirs)) {
		Com_sprintf( search, sizeof(search), "%s/%s", basedir, subdirs );
	}
	else {
		Com_sprintf( search, sizeof(search), "%s", basedir );
	}

	if ((fdir = opendir(search)) == NULL) {
		return;
	}

	while ((d = readdir(fdir)) != NULL) {
		Com_sprintf(filename, sizeof(filename), "%s/%s", search, d->d_name);
		if (stat(filename, &st) == -1)
			continue;

		if (st.st_mode & S_IFDIR) {
			if (Q_stricmp(d->d_name, ".") && Q_stricmp(d->d_name, "..")) {
				if (strlen(subdirs)) {
					Com_sprintf( newsubdirs, sizeof(newsubdirs), "%s/%s", subdirs, d->d_name);
				}
				else {
					Com_sprintf( newsubdirs, sizeof(newsubdirs), "%s", d->d_name);
				}
				Sys_ListFilteredFiles( basedir, newsubdirs, filter, list, numfiles );
			}
		}
		if ( *numfiles >= MAX_FOUND_FILES - 1 ) {
			break;
		}
		Com_sprintf( filename, sizeof(filename), "%s/%s", subdirs, d->d_name );
		if (!Com_FilterPath( filter, filename ))
			continue;
		list[ *numfiles ] = CopyString( filename );
		(*numfiles)++;
	}

	closedir(fdir);
}

char **Sys_ListFiles( const char *directory, const char *extension, const char *filter, int *numfiles, qboolean wantsubs )
{
	struct dirent *d;
	DIR		*fdir;
	qboolean dironly = wantsubs;
	char		search[MAX_OSPATH];
	int			nfiles;
	char		**listCopy;
	char		*list[MAX_FOUND_FILES];
	int			i;
	struct stat st;

	int			extLen;

	if (filter) {

		nfiles = 0;
		Sys_ListFilteredFiles( directory, "", filter, list, &nfiles );

		list[ nfiles ] = NULL;
		*numfiles = nfiles;

		if (!nfiles)
			return NULL;

		listCopy = (char**)Z_Malloc( ( nfiles + 1 ) * sizeof( *listCopy ) );
		for ( i = 0 ; i < nfiles ; i++ ) {
			listCopy[i] = list[i];
		}
		listCopy[i] = NULL;

		return listCopy;
	}

	if ( !extension)
		extension = "";

	if ( extension[0] == '/' && extension[1] == 0 ) {
		extension = "";
		dironly = qtrue;
	}

	extLen = strlen( extension );
	
	// search
	nfiles = 0;

	if ((fdir = opendir(directory)) == NULL) {
		*numfiles = 0;
		return NULL;
	}

	while ((d = readdir(fdir)) != NULL) {
		Com_sprintf(search, sizeof(search), "%s/%s", directory, d->d_name);
		if (stat(search, &st) == -1)
			continue;
		if ((dironly && !(st.st_mode & S_IFDIR)) ||
			(!dironly && (st.st_mode & S_IFDIR)))
			continue;

		if (*extension) {
			if ( strlen( d->d_name ) < strlen( extension ) ||
				Q_stricmp( 
					d->d_name + strlen( d->d_name ) - strlen( extension ),
					extension ) ) {
				continue; // didn't match
			}
		}

		if ( nfiles == MAX_FOUND_FILES - 1 )
			break;
		list[ nfiles ] = CopyString( d->d_name );
		nfiles++;
	}

	list[ nfiles ] = NULL;

	closedir(fdir);

	// return a copy of the list
	*numfiles = nfiles;

	if ( !nfiles ) {
		return NULL;
	}

	listCopy = (char**)Z_Malloc( ( nfiles + 1 ) * sizeof( *listCopy ) );
	for ( i = 0 ; i < nfiles ; i++ ) {
		listCopy[i] = list[i];
	}
	listCopy[i] = NULL;

	return listCopy;
}

void	Sys_FreeFileList( char **list ) {
	int		i;

	if ( !list ) {
		return;
	}

	for ( i = 0 ; list[i] ; i++ ) {
		Z_Free( list[i] );
	}

	Z_Free( list );
}

const char* Sys_Cwd()
{
	static char cwd[MAX_OSPATH];

	getcwd( cwd, sizeof( cwd ) - 1 );
	cwd[MAX_OSPATH-1] = 0;

	return cwd;
}

void Sys_SetDefaultHomePath(const char *path)
{
	Q_strncpyz(homePath, path, sizeof(homePath));
}

const char* Sys_DefaultHomePath()
{
	if (*homePath)
		return homePath;

	const char* p;
	if (p = getenv("HOME")) {
		Q_strncpyz(homePath, p, sizeof(homePath));
#ifdef MACOS_X
		Q_strcat(homePath, sizeof(homePath), "/Library/Application Support/Quake3");
#else
		Q_strcat(homePath, sizeof(homePath), "/.q3a");
#endif
		if (mkdir(homePath, 0777)) {
			if (errno != EEXIST) 
				Sys_Error("Unable to create directory \"%s\", error is %s(%d)\n", homePath, strerror(errno), errno);
		}
		return homePath;
	}

	return ""; // assume current dir
}

//============================================

void Sys_ShowConsole( int visLevel, qboolean quitOnClose )
{
}

const char* Sys_GetCurrentUser()
{
	const struct passwd* p;

	if (!(p = getpwuid(getuid())))
		return "player";

	return p->pw_name;
}