/*
Copyright (C) 1996-1997 Id Software, Inc.

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.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// common.c -- misc functions used in client and server

#include "quakedef.h"

#define NUM_SAFE_ARGVS  7

static const char     *largv[MAX_NUM_ARGVS + NUM_SAFE_ARGVS + 1];
static const char     *argvdummy = " ";

static const char     *safeargvs[NUM_SAFE_ARGVS] =
	{"-stdvid", "-nolan", "-nosound", "-nocdaudio", "-nojoy", "-nomouse", "-dibonly"};

cvar_t	registered = CVAR2("registered","0");
cvar_t  cmdline = CVAR4("cmdline","0", false, true);

qboolean        com_modified;   // set true if using non-id files

qboolean		proghack;

int             static_registered = 1;  // only for startup check, then set

qboolean		msg_suppress_1 = 0;

void COM_InitFilesystem (void);

// if a packfile directory differs from this, it is assumed to be hacked
#define PAK0_COUNT              339
#define PAK0_CRC                32981

char	com_token[1024];
int		com_argc;
const char	**com_argv;

#define CMDLINE_LENGTH	256
char	com_cmdline[CMDLINE_LENGTH];

qboolean		standard_quake = true, rogue, hipnotic;

// this graphic needs to be in the pak file to use registered features
unsigned short pop[] =
{
 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
,0x0000,0x0000,0x6600,0x0000,0x0000,0x0000,0x6600,0x0000
,0x0000,0x0066,0x0000,0x0000,0x0000,0x0000,0x0067,0x0000
,0x0000,0x6665,0x0000,0x0000,0x0000,0x0000,0x0065,0x6600
,0x0063,0x6561,0x0000,0x0000,0x0000,0x0000,0x0061,0x6563
,0x0064,0x6561,0x0000,0x0000,0x0000,0x0000,0x0061,0x6564
,0x0064,0x6564,0x0000,0x6469,0x6969,0x6400,0x0064,0x6564
,0x0063,0x6568,0x6200,0x0064,0x6864,0x0000,0x6268,0x6563
,0x0000,0x6567,0x6963,0x0064,0x6764,0x0063,0x6967,0x6500
,0x0000,0x6266,0x6769,0x6a68,0x6768,0x6a69,0x6766,0x6200
,0x0000,0x0062,0x6566,0x6666,0x6666,0x6666,0x6562,0x0000
,0x0000,0x0000,0x0062,0x6364,0x6664,0x6362,0x0000,0x0000
,0x0000,0x0000,0x0000,0x0062,0x6662,0x0000,0x0000,0x0000
,0x0000,0x0000,0x0000,0x0061,0x6661,0x0000,0x0000,0x0000
,0x0000,0x0000,0x0000,0x0000,0x6500,0x0000,0x0000,0x0000
,0x0000,0x0000,0x0000,0x0000,0x6400,0x0000,0x0000,0x0000
};

/*


All of Quake's data access is through a hierchal file system, but the contents of the file system can be transparently merged from several sources.

The "base directory" is the path to the directory holding the quake.exe and all game directories.  The sys_* files pass this to host_init in quakeparms_t->basedir.  This can be overridden with the "-basedir" command line parm to allow code debugging in a different directory.  The base directory is
only used during filesystem initialization.

The "game directory" is the first tree on the search path and directory that all generated files (savegames, screenshots, demos, config files) will be saved to.  This can be overridden with the "-game" command line parameter.  The game directory can never be changed while quake is executing.  This is a precacution against having a malicious server instruct clients to write files over areas they shouldn't.

The "cache directory" is only used during development to save network bandwidth, especially over ISDN / T1 lines.  If there is a cache directory
specified, when a file is found by the normal search path, it will be mirrored
into the cache directory, then opened there.



FIXME:
The file "parms.txt" will be read out of the game directory and appended to the current command line arguments to allow different games to initialize startup parms differently.  This could be used to add a "-sspeed 22050" for the high quality sound edition.  Because they are added at the end, they will not override an explicit setting on the original command line.

*/

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


// ClearLink is used for new headnodes
void ClearLink (link_t *l)
{
	l->prev = l->next = l;
}

void RemoveLink (link_t *l)
{
	l->next->prev = l->prev;
	l->prev->next = l->next;
}

void InsertLinkBefore (link_t *l, link_t *before)
{
	l->next = before;
	l->prev = before->prev;
	l->prev->next = l;
	l->next->prev = l;
}
void InsertLinkAfter (link_t *l, link_t *after)
{
	l->next = after->next;
	l->prev = after;
	l->prev->next = l;
	l->next->prev = l;
}

/*
============================================================================

					LIBRARY REPLACEMENT FUNCTIONS

============================================================================
*/

void Q_memset (void *dest, int fill, int count)
{
	int             i;

	if ( (((long)dest | count) & 3) == 0)
	{
		count >>= 2;
		fill = fill | (fill<<8) | (fill<<16) | (fill<<24);
		for (i=0 ; i<count ; i++)
			((int *)dest)[i] = fill;
	}
	else
		for (i=0 ; i<count ; i++)
			((byte *)dest)[i] = fill;
}

void Q_memcpy (void *dest, const void *src, int count)
{
	int             i;

	if (( ( (long)dest | (long)src | count) & 3) == 0 )
	{
		count>>=2;
		for (i=0 ; i<count ; i++)
			((int *)dest)[i] = ((int *)src)[i];
	}
	else
		for (i=0 ; i<count ; i++)
			((byte *)dest)[i] = ((byte *)src)[i];
}

int Q_memcmp (const void *m1, const void *m2, int count)
{
	while(count)
	{
		count--;
		if (((byte *)m1)[count] != ((byte *)m2)[count])
			return -1;
	}
	return 0;
}

void Q_strcpy (char *dest, const char *src)
{
	while (*src)
	{
		*dest++ = *src++;
	}
	*dest++ = 0;
}

void Q_strncpy (char *dest, const char *src, int count)
{
	while (*src && count--)
	{
		*dest++ = *src++;
	}
	if (count)
		*dest++ = 0;
}

int Q_strlen (const char *str)
{
	int             count;

	count = 0;
	while (str[count])
		count++;

	return count;
}

char *Q_strrchr(const char *s, char c)
{
    int len = Q_strlen(s);
    s += len;
    while (len--)
	if (*--s == c) return (char*)  s;
    return 0;
}

void Q_strcat (char *dest, const char *src)
{
	dest += Q_strlen(dest);
	Q_strcpy (dest, src);
}

int Q_strcmp (const char *s1, const char *s2)
{
	while (1)
	{
		if (*s1 != *s2)
			return -1;              // strings not equal
		if (!*s1)
			return 0;               // strings are equal
		s1++;
		s2++;
	}

	return -1;
}

int Q_strncmp (const char *s1, const char *s2, int count)
{
	while (1)
	{
		if (!count--)
			return 0;
		if (*s1 != *s2)
			return -1;              // strings not equal
		if (!*s1)
			return 0;               // strings are equal
		s1++;
		s2++;
	}

	return -1;
}

int Q_strncasecmp (const char *s1, const char *s2, int n)
{
	int             c1, c2;

	while (1)
	{
		c1 = *s1++;
		c2 = *s2++;

		if (!n--)
			return 0;               // strings are equal until end point

		if (c1 != c2)
		{
			if (c1 >= 'a' && c1 <= 'z')
				c1 -= ('a' - 'A');
			if (c2 >= 'a' && c2 <= 'z')
				c2 -= ('a' - 'A');
			if (c1 != c2)
				return -1;              // strings not equal
		}
		if (!c1)
			return 0;               // strings are equal
//              s1++;
//              s2++;
	}

	return -1;
}

int Q_strcasecmp (const char *s1, const char *s2)
{
	return Q_strncasecmp (s1, s2, 99999);
}

int Q_atoi (const char *str)
{
	int             val;
	int             sign;
	int             c;

	if (*str == '-')
	{
		sign = -1;
		str++;
	}
	else
		sign = 1;

	val = 0;

//
// check for hex
//
	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X') )
	{
		str += 2;
		while (1)
		{
			c = *str++;
			if (c >= '0' && c <= '9')
				val = (val<<4) + c - '0';
			else if (c >= 'a' && c <= 'f')
				val = (val<<4) + c - 'a' + 10;
			else if (c >= 'A' && c <= 'F')
				val = (val<<4) + c - 'A' + 10;
			else
				return val*sign;
		}
	}

//
// check for character
//
	if (str[0] == '\'')
	{
		return sign * str[1];
	}

//
// assume decimal
//
	while (1)
	{
		c = *str++;
		if (c <'0' || c > '9')
			return val*sign;
		val = val*10 + c - '0';
	}

	return 0;
}


float Q_atof (const char *str)
{
	double			val;
	int             sign;
	int             c;
	int             decimal, total;

	if (*str == '-')
	{
		sign = -1;
		str++;
	}
	else
		sign = 1;

	val = 0;

//
// check for hex
//
	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X') )
	{
		str += 2;
		while (1)
		{
			c = *str++;
			if (c >= '0' && c <= '9')
				val = (val*16) + c - '0';
			else if (c >= 'a' && c <= 'f')
				val = (val*16) + c - 'a' + 10;
			else if (c >= 'A' && c <= 'F')
				val = (val*16) + c - 'A' + 10;
			else
				return val*sign;
		}
	}

//
// check for character
//
	if (str[0] == '\'')
	{
		return sign * str[1];
	}

//
// assume decimal
//
	decimal = -1;
	total = 0;
	while (1)
	{
		c = *str++;
		if (c == '.')
		{
			decimal = total;
			continue;
		}
		if (c <'0' || c > '9')
			break;
		val = val*10 + c - '0';
		total++;
	}

	if (decimal == -1)
		return val*sign;
	while (total > decimal)
	{
		val /= 10;
		total--;
	}

	return val*sign;
}

/*
============================================================================

					BYTE ORDER FUNCTIONS

============================================================================
*/

qboolean        bigendien;

short   (*BigShort) (short l);
short   (*LittleShort) (short l);
int     (*BigLong) (int l);
int     (*LittleLong) (int l);
float   (*BigFloat) (float l);
float   (*LittleFloat) (float l);

short   ShortSwap (short l)
{
	byte    b1,b2;

	b1 = l&255;
	b2 = (l>>8)&255;

	return (b1<<8) + b2;
}

short   ShortNoSwap (short l)
{
	return l;
}

int    LongSwap (int l)
{
	byte    b1,b2,b3,b4;

	b1 = l&255;
	b2 = (l>>8)&255;
	b3 = (l>>16)&255;
	b4 = (l>>24)&255;

	return ((int)b1<<24) + ((int)b2<<16) + ((int)b3<<8) + b4;
}

int     LongNoSwap (int l)
{
	return l;
}

float FloatSwap (float f)
{
	union
	{
		float   f;
		byte    b[4];
	} dat1, dat2;


	dat1.f = f;
	dat2.b[0] = dat1.b[3];
	dat2.b[1] = dat1.b[2];
	dat2.b[2] = dat1.b[1];
	dat2.b[3] = dat1.b[0];
	return dat2.f;
}

float FloatNoSwap (float f)
{
	return f;
}

/*
==============================================================================

			MESSAGE IO FUNCTIONS

Handles byte ordering and avoids alignment errors
==============================================================================
*/

//
// writing functions
//

void MSG_WriteChar (sizebuf_t *sb, int c)
{
	byte    *buf;

#ifdef PARANOID
	if (c < -128 || c > 127)
		Sys_Error ("MSG_WriteChar: range error");
#endif

	buf = (byte*) SZ_GetSpace (sb, 1);
	buf[0] = c;
}

void MSG_WriteByte (sizebuf_t *sb, int c)
{
	byte    *buf;

#ifdef PARANOID
	if (c < 0 || c > 255)
		Sys_Error ("MSG_WriteByte: range error");
#endif

	buf = (byte*) SZ_GetSpace (sb, 1);
	buf[0] = c;
}

void MSG_WriteShort (sizebuf_t *sb, int c)
{
	byte    *buf;

#ifdef PARANOID
	if (c < ((short)0x8000) || c > (short)0x7fff)
		Sys_Error ("MSG_WriteShort: range error");
#endif

	buf = (byte*) SZ_GetSpace (sb, 2);
	buf[0] = c&0xff;
	buf[1] = c>>8;
}

void MSG_WriteLong (sizebuf_t *sb, int c)
{
	byte    *buf;

	buf = (byte*) SZ_GetSpace (sb, 4);
	buf[0] = c&0xff;
	buf[1] = (c>>8)&0xff;
	buf[2] = (c>>16)&0xff;
	buf[3] = c>>24;
}

void MSG_WriteFloat (sizebuf_t *sb, float f)
{
	union
	{
		float   f;
		int     l;
	} dat;


	dat.f = f;
	dat.l = LittleLong (dat.l);

	SZ_Write (sb, &dat.l, 4);
}

void MSG_WriteString (sizebuf_t *sb, const char *s)
{
	if (!s)
		SZ_Write (sb, "", 1);
	else
		SZ_Write (sb, s, Q_strlen(s)+1);
}

void MSG_WriteCoord (sizebuf_t *sb, float f)
{
	MSG_WriteShort (sb, (int)(f*8));
}

void MSG_WriteAngle (sizebuf_t *sb, float f)
{
	MSG_WriteByte (sb, ((int)f*256/360) & 255);
}

//
// reading functions
//
int                     msg_readcount;
qboolean        msg_badread;

void MSG_BeginReading (void)
{
	msg_readcount = 0;
	msg_badread = false;
}

// returns -1 and sets msg_badread if no more characters are available
int MSG_ReadChar (void)
{
	int     c;

	if (msg_readcount+1 > net_message.cursize)
	{
		msg_badread = true;
		return -1;
	}

	c = (signed char)net_message.data[msg_readcount];
	msg_readcount++;

	return c;
}

int MSG_ReadByte (void)
{
	int     c;

	if (msg_readcount+1 > net_message.cursize)
	{
		msg_badread = true;
		return -1;
	}

	c = (unsigned char)net_message.data[msg_readcount];
	msg_readcount++;

	return c;
}

int MSG_ReadShort (void)
{
	int     c;

	if (msg_readcount+2 > net_message.cursize)
	{
		msg_badread = true;
		return -1;
	}

	c = (short)(net_message.data[msg_readcount]
	+ (net_message.data[msg_readcount+1]<<8));

	msg_readcount += 2;

	return c;
}

int MSG_ReadLong (void)
{
	int     c;

	if (msg_readcount+4 > net_message.cursize)
	{
		msg_badread = true;
		return -1;
	}

	c = net_message.data[msg_readcount]
	+ (net_message.data[msg_readcount+1]<<8)
	+ (net_message.data[msg_readcount+2]<<16)
	+ (net_message.data[msg_readcount+3]<<24);

	msg_readcount += 4;

	return c;
}

float MSG_ReadFloat (void)
{
	union
	{
		byte    b[4];
		float   f;
		int     l;
	} dat;

	dat.b[0] =      net_message.data[msg_readcount];
	dat.b[1] =      net_message.data[msg_readcount+1];
	dat.b[2] =      net_message.data[msg_readcount+2];
	dat.b[3] =      net_message.data[msg_readcount+3];
	msg_readcount += 4;

	dat.l = LittleLong (dat.l);

	return dat.f;
}

char *MSG_ReadString (void)
{
	static char     string[2048];
	int             l,c;

	l = 0;
	do
	{
		c = MSG_ReadChar ();
		if (c == -1 || c == 0)
			break;
		string[l] = c;
		l++;
	} while (l < (int) (sizeof(string)-1));

	string[l] = 0;

	return string;
}

float MSG_ReadCoord (void)
{
	return MSG_ReadShort() * (1.0/8);
}

float MSG_ReadAngle (void)
{
	return MSG_ReadChar() * (360.0/256);
}



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

void SZ_Alloc (sizebuf_t *buf, int startsize)
{
	if (startsize < 256)
		startsize = 256;
	buf->data = (byte*) Hunk_AllocName (startsize, "sizebuf");
	buf->maxsize = startsize;
	buf->cursize = 0;
}


void SZ_Free (sizebuf_t *buf)
{
//      Z_Free (buf->data);
//      buf->data = NULL;
//      buf->maxsize = 0;
	buf->cursize = 0;
}

void SZ_Clear (sizebuf_t *buf)
{
	buf->cursize = 0;
}

void *SZ_GetSpace (sizebuf_t *buf, int length)
{
	void    *data;

	if (buf->cursize + length > buf->maxsize)
	{
		if (!buf->allowoverflow)
			Sys_Error ("SZ_GetSpace: overflow without allowoverflow set");

		if (length > buf->maxsize)
			Sys_Error ("SZ_GetSpace: %i is > full buffer size", length);

		buf->overflowed = true;
		Con_Printf ("SZ_GetSpace: overflow");
		SZ_Clear (buf);
	}

	data = buf->data + buf->cursize;
	buf->cursize += length;

	return data;
}

void SZ_Write (sizebuf_t *buf, const void *data, int length)
{
	Q_memcpy (SZ_GetSpace(buf,length),data,length);
}

void SZ_Print (sizebuf_t *buf, const char *data)
{
	int             len;

	len = Q_strlen(data)+1;

// byte * cast to keep VC++ happy
	if (buf->data[buf->cursize-1])
		Q_memcpy ((byte *)SZ_GetSpace(buf, len),data,len); // no trailing 0
	else
		Q_memcpy ((byte *)SZ_GetSpace(buf, len-1)-1,data,len); // write over trailing 0
}


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


/*
============
COM_SkipPath
============
*/
const char *COM_SkipPath (const char *pathname)
{
	const char    *last;

	last = pathname;
	while (*pathname)
	{
		if (*pathname=='/')
			last = pathname+1;
		pathname++;
	}
	return last;
}

/*
============
COM_StripExtension
============
*/
void COM_StripExtension (const char *in, char *out)
{
	while (*in && *in != '.')
		*out++ = *in++;
	*out = 0;
}

/*
============
COM_FileExtension
============
*/
const char *COM_FileExtension (const char *in)
{
	static char exten[8];
	int             i;

	while (*in && *in != '.')
		in++;
	if (!*in)
		return "";
	in++;
	for (i=0 ; i<7 && *in ; i++,in++)
		exten[i] = *in;
	exten[i] = 0;
	return exten;
}

/*
============
COM_FileBase
============
*/
void COM_FileBase (const char *in, char *out, size_t outSize)
{
	// Get the "base" part of a path, make sure we don't exceed outSize bytes

	const char* start;
	const char* end;
	size_t len;

	if(!outSize)
		return;

	start = strrchr(in, '/');
	if(start)
	{
		start++;
	}
	else
	{
		start = in;
	}

	// Start now points to the beginning of the filename part of the file.

	end = strrchr(start, '.');

	if(!end)
	{
		end = start + strlen(start);
	}

	// end now points one character beyond the end of the base part of the file.

	len = end - start;
	if(len > outSize - 1)
		len = outSize - 1;

	memcpy(out, start, len);
	out[len] = 0;
}


/*
==================
COM_DefaultExtension
==================
*/
void COM_DefaultExtension (char *path, const char *extension)
{
	char    *src;
//
// if path doesn't have a .EXT, append extension
// (extension should include the .)
//
	src = path + strlen(path) - 1;

	while (*src != '/' && src != path)
	{
		if (*src == '.')
			return;                 // it has an extension
		src--;
	}

	strcat (path, extension);
}


/*
==============
COM_Parse

Parse a token out of a string
==============
*/
char *COM_Parse (char *data)
{
	int             c;
	int             len;

	len = 0;
	com_token[0] = 0;

	if (!data)
		return NULL;

// skip whitespace
skipwhite:
	while ( (c = *data) <= ' ')
	{
		if (c == 0)
			return NULL;                    // end of file;
		data++;
	}

// skip // comments
	if (c=='/' && data[1] == '/')
	{
		while (*data && *data != '\n')
			data++;
		goto skipwhite;
	}


// handle quoted strings specially
	if (c == '\"')
	{
		data++;
		while (1)
		{
			c = *data++;
			if (c=='\"' || !c)
			{
				com_token[len] = 0;
				return data;
			}
			com_token[len] = c;
			len++;
		}
	}

// parse single characters
	if (c=='{' || c=='}'|| c==')'|| c=='(' || c=='\'' || c==':')
	{
		com_token[len] = c;
		len++;
		com_token[len] = 0;
		return data+1;
	}

// parse a regular word
	do
	{
		com_token[len] = c;
		data++;
		len++;
		c = *data;
	if (c=='{' || c=='}'|| c==')'|| c=='(' || c=='\'' || c==':')
			break;
	} while (c>32);

	com_token[len] = 0;
	return data;
}


/*
================
COM_CheckParm

Returns the position (1 to argc-1) in the program's argument list
where the given parameter apears, or 0 if not present
================
*/
int COM_CheckParm (const char *parm)
{
	int             i;

	for (i=1 ; i<com_argc ; i++)
	{
		if (!com_argv[i])
			continue;               // NEXTSTEP sometimes clears appkit vars.
		if (!Q_strcmp (parm,com_argv[i]))
			return i;
	}

	return 0;
}

/*
================
COM_CheckRegistered

Looks for the pop.txt file and verifies it.
Sets the "registered" cvar.
Immediately exits out if an alternate game was attempted to be started without
being registered.
================
*/
void COM_CheckRegistered (void)
{
	int             h;
	unsigned short  check[128];
	int                     i;

	COM_OpenFile("gfx/pop.lmp", &h);
	static_registered = 0;

	if (h == -1)
	{
#if WINDED
	Sys_Error ("This dedicated server requires a full registered copy of Quake");
#endif
		Con_Printf ("Playing shareware version.\n");
		if (com_modified)
			Sys_Error ("You must have the registered version to use modified games");

#ifdef USE_OPENGLES
		// For development purposes pretend we're registered. This allows glquake
		// file caching to work:

		static_registered = 1;
#endif // USE_OPENGLES
		return;
	}

	Sys_FileRead (h, check, sizeof(check));
	COM_CloseFile (h);

	for (i=0 ; i<128 ; i++)
		if (pop[i] != (unsigned short)BigShort (check[i]))
			Sys_Error ("Corrupted data file.");

	Cvar_Set ("cmdline", com_cmdline);
	Cvar_Set ("registered", "1");
	static_registered = 1;
	Con_Printf ("Playing registered version.\n");
}


void COM_Path_f (void);


/*
================
COM_InitArgv
================
*/
void COM_InitArgv (int argc, const char **argv)
{
	qboolean        safe;
	int             i, j, n;

// reconstitute the command line for the cmdline externally visible cvar
	n = 0;

	for (j=0 ; (j<MAX_NUM_ARGVS) && (j< argc) ; j++)
	{
		i = 0;

		while ((n < (CMDLINE_LENGTH - 1)) && argv[j][i])
		{
			com_cmdline[n++] = argv[j][i++];
		}

		if (n < (CMDLINE_LENGTH - 1))
			com_cmdline[n++] = ' ';
		else
			break;
	}

	com_cmdline[n] = 0;

	safe = false;

	for (com_argc=0 ; (com_argc<MAX_NUM_ARGVS) && (com_argc < argc) ;
		 com_argc++)
	{
		largv[com_argc] = argv[com_argc];
		if (!Q_strcmp ("-safe", argv[com_argc]))
			safe = true;
	}

	if (safe)
	{
	// force all the safe-mode switches. Note that we reserved extra space in
	// case we need to add these, so we don't need an overflow check
		for (i=0 ; i<NUM_SAFE_ARGVS ; i++)
		{
			largv[com_argc] = safeargvs[i];
			com_argc++;
		}
	}

	largv[com_argc] = argvdummy;
	com_argv = largv;

	if (COM_CheckParm ("-rogue"))
	{
		rogue = true;
		standard_quake = false;
	}

	if (COM_CheckParm ("-hipnotic"))
	{
		hipnotic = true;
		standard_quake = false;
	}
}


/*
================
COM_Init
================
*/

typedef union swapTest_ {
    byte b[2];
    short s;
} swapTest;

void COM_Init (const char *basedir)
{
	swapTest swaptest;
	swaptest.b[0] = 1;
	swaptest.b[1] = 0;

// set the byte swapping variables in a portable manner
	if ( swaptest.s == 1)
	{
		bigendien = false;
		BigShort = ShortSwap;
		LittleShort = ShortNoSwap;
		BigLong = LongSwap;
		LittleLong = LongNoSwap;
		BigFloat = FloatSwap;
		LittleFloat = FloatNoSwap;
	}
	else
	{
		bigendien = true;
		BigShort = ShortNoSwap;
		LittleShort = ShortSwap;
		BigLong = LongNoSwap;
		LittleLong = LongSwap;
		BigFloat = FloatNoSwap;
		LittleFloat = FloatSwap;
	}

	Cvar_RegisterVariable (&registered);
	Cvar_RegisterVariable (&cmdline);
	Cmd_AddCommand ("path", COM_Path_f);

	COM_InitFilesystem ();
	COM_CheckRegistered ();
}


/*
============
va

does a varargs printf into a temp buffer, so I don't need to have
varargs versions of all text functions.
FIXME: make this buffer size safe someday
============
*/
char    *va(const char *format, ...)
{
	va_list         argptr;
	static char             string[1024];

	va_start (argptr, format);
	vsprintf (string, format,argptr);
	va_end (argptr);

	return string;
}


/// just for debugging
int     memsearch (const byte *start, int count, int search)
{
	int             i;

	for (i=0 ; i<count ; i++)
		if (start[i] == search)
			return i;
	return -1;
}

/*
=============================================================================

QUAKE FILESYSTEM

=============================================================================
*/

int     com_filesize;


//
// in memory
//

typedef struct
{
	char    name[MAX_QPATH];
	int             filepos, filelen;
} packfile_t;

typedef struct pack_s
{
	char    filename[MAX_OSPATH];
	int             handle;
	int             numfiles;
	packfile_t      *files;
} pack_t;

//
// on disk
//
typedef struct
{
	char    name[56];
	int             filepos, filelen;
} dpackfile_t;

typedef struct
{
	char    id[4];
	int             dirofs;
	int             dirlen;
} dpackheader_t;

#define MAX_FILES_IN_PACK       2048

char    com_cachedir[MAX_OSPATH];
char    com_gamedir[MAX_OSPATH];

typedef struct searchpath_s
{
	char    filename[MAX_OSPATH];
	pack_t  *pack;          // only one of filename / pack will be used
	struct searchpath_s *next;
} searchpath_t;

searchpath_t    *com_searchpaths;//store all pack_t sturck file . every pak 

/*
============
COM_Path_f

============
*/
void COM_Path_f (void)
{
	searchpath_t    *s;

	Con_Printf ("Current search path:\n");
	for (s=com_searchpaths ; s ; s=s->next)
	{
		if (s->pack)
		{
			Con_Printf ("%s (%i files)\n", s->pack->filename, s->pack->numfiles);
		}
		else
			Con_Printf ("%s\n", s->filename);
	}
}

/*
============
COM_WriteFile

The filename will be prefixed by the current game directory
============
*/
void COM_WriteFile (const char *filename, void *data, int len)
{
	int             handle;
	char    name[MAX_OSPATH];

	sprintf (name, "%s/%s", com_gamedir, filename);

	handle = Sys_FileOpenWrite (name);
	if (handle == -1)
	{
		Sys_Printf ("COM_WriteFile: failed on %s\n", name);
		return;
	}

	Sys_Printf ("COM_WriteFile: %s\n", name);
	Sys_FileWrite (handle, data, len);
	Sys_FileClose (handle);
}


/*
============
COM_CreatePath

Only used for CopyFile
============
*/
void    COM_CreatePath (const char *path)
{
    char    *ofs;

	for (ofs = (char*) path+1 ; *ofs ; ofs++)
	{
		if (*ofs == '/')
		{       // create the directory
			*ofs = 0;
			Sys_mkdir (path);
			*ofs = '/';
		}
	}
}


/*
===========
COM_CopyFile

Copies a file over from the net to the local cache, creating any directories
needed.  This is for the convenience of developers using ISDN from home.
===========
*/
void COM_CopyFile (const char *netpath, const char *cachepath)
{
	int             in, out;
	int             remaining, count;
	char    buf[4096];

	remaining = Sys_FileOpenRead (netpath, &in);
	COM_CreatePath (cachepath);     // create directories up to the cache file
	out = Sys_FileOpenWrite (cachepath);

	while (remaining)
	{
		if (remaining < (int) sizeof(buf))
			count = remaining;
		else
			count = sizeof(buf);
		Sys_FileRead (in, buf, count);
		Sys_FileWrite (out, buf, count);
		remaining -= count;
	}

	Sys_FileClose (in);
	Sys_FileClose (out);
}

/*
===========
COM_FindFile

Finds the file in the search path.
Sets com_filesize and one of handle or file
===========
if handle is not null , fill it
if handle is null, fill file parameter
*/
int COM_FindFile (const char *filename, int *handle, FILE **file)
{
	searchpath_t    *search;
	char            netpath[MAX_OSPATH];
	char            cachepath[MAX_OSPATH];
	pack_t          *pak;
	int                     i;
	int                     findtime, cachetime;

	if (file && handle)
		Sys_Error ("COM_FindFile: both handle and file set");
	if (!file && !handle)
		Sys_Error ("COM_FindFile: neither handle or file set");

//
// search through the path, one element at a time
//
	search = com_searchpaths;
	if (proghack)
	{	// gross hack to use quake 1 progs with quake 2 maps
		if (!strcmp(filename, "progs.dat"))
			search = search->next;
	}

	for ( ; search ; search = search->next)
	{
	// is the element a pak file?
		if (search->pack)
		{
		// look through all the pak file elements
			pak = search->pack;
			for (i=0 ; i<pak->numfiles ; i++)
				if (!strcmp (pak->files[i].name, filename))
				{       // found it!
					// Sys_Printf ("PackFile: %s : %s\n",pak->filename, filename);
					if (handle)
					{
						*handle = pak->handle;
						Sys_FileSeek (pak->handle, pak->files[i].filepos);
					}
					else
					{       // open a new file on the pakfile
						*file = fopen (pak->filename, "rb");
						if (*file)
							fseek (*file, pak->files[i].filepos, SEEK_SET);
					}
					com_filesize = pak->files[i].filelen;
					return com_filesize;
				}
		}
		else
		{
	// check a file in the directory tree
			if (!static_registered)
			{       // if not a registered version, don't ever go beyond base
				if ( strchr (filename, '/') || strchr (filename,'\\'))
					continue;
			}

			sprintf (netpath, "%s/%s",search->filename, filename);

			findtime = Sys_FileTime (netpath);
			if (findtime == -1)
				continue;

		// see if the file needs to be updated in the cache
			if (!com_cachedir[0])
				strcpy (cachepath, netpath);
			else
			{
#if defined(_WIN32)
				if ((strlen(netpath) < 2) || (netpath[1] != ':'))
					sprintf (cachepath,"%s%s", com_cachedir, netpath);
				else
					sprintf (cachepath,"%s%s", com_cachedir, netpath+2);
#else
				sprintf (cachepath,"%s%s", com_cachedir, netpath);
#endif

				cachetime = Sys_FileTime (cachepath);

				if (cachetime < findtime)
					COM_CopyFile (netpath, cachepath);
				strcpy (netpath, cachepath);
			}

			// Sys_Printf ("FindFile: %s\n",netpath);
			com_filesize = Sys_FileOpenRead (netpath, &i);
			if (handle)
				*handle = i;
			else
			{
				Sys_FileClose (i);
				*file = fopen (netpath, "rb");
			}
			return com_filesize;
		}

	}

	Sys_Printf ("FindFile: can't find %s\n", filename);

	if (handle)
		*handle = -1;
	else
		*file = NULL;
	com_filesize = -1;
	return -1;
}


/*
===========
COM_OpenFile

filename never has a leading slash, but may contain directory walks
returns a handle and a length
it may actually be inside a pak file
===========
*/
int COM_OpenFile (const char *filename, int *handle)
{
	return COM_FindFile (filename, handle, NULL);
}

/*
===========
COM_FOpenFile

If the requested file is inside a packfile, a new FILE * will be opened
into the file.
===========
*/
int COM_FOpenFile (const char *filename, FILE **file)
{
	return COM_FindFile (filename, NULL, file);
}

/*
============
COM_CloseFile

If it is a pak file handle, don't really close it
============
*/
void COM_CloseFile (int h)
{
	searchpath_t    *s;

	for (s = com_searchpaths ; s ; s=s->next)
		if (s->pack && s->pack->handle == h)
			return;

	Sys_FileClose (h);
}


/*
============
COM_LoadFile

Filename are reletive to the quake directory.
Allways appends a 0 byte.
============
*/
cache_user_t *loadcache;
byte    *loadbuf;
int             loadsize;
byte *COM_LoadFile (const char *path, int usehunk)
{
	int             h;
	byte    *buf;
	char    base[32];
	int             len;

	buf = NULL;     // quiet compiler warning

// look for it in the filesystem or pack files
	len = COM_OpenFile (path, &h);
	if (h == -1)
		return NULL;

// extract the filename base name for hunk tag
	COM_FileBase (path, base, sizeof(base));

	if (usehunk == 1)
		buf = (byte*) Hunk_AllocName (len+1, base);
	else if (usehunk == 2)
		buf = (byte*) Hunk_TempAlloc (len+1);
	else if (usehunk == 0)
		buf = (byte*) Z_Malloc (len+1);
	else if (usehunk == 3)
		buf = (byte*) Cache_Alloc (loadcache, len+1, base);
	else if (usehunk == 4)
	{
		if (len+1 > loadsize)
			buf = (byte*) Hunk_TempAlloc (len+1);
		else
			buf = loadbuf;
	}
	else
		Sys_Error ("COM_LoadFile: bad usehunk");

	if (!buf)
		Sys_Error ("COM_LoadFile: not enough space for %s", path);

	((byte *)buf)[len] = 0;

	Draw_BeginDisc ();
	Sys_FileRead (h, buf, len);
	COM_CloseFile (h);
	Draw_EndDisc ();

	return buf;
}

byte *COM_LoadHunkFile (const char *path)
{
	return COM_LoadFile (path, 1);
}

byte *COM_LoadTempFile (const char *path)
{
	return COM_LoadFile (path, 2);
}

void COM_LoadCacheFile (char *path, struct cache_user_s *cu)
{
	loadcache = cu;
	COM_LoadFile (path, 3);
}

// uses temp hunk if larger than bufsize
byte *COM_LoadStackFile (const char *path, void *buffer, int bufsize)
{
	byte    *buf;

	loadbuf = (byte *)buffer;
	loadsize = bufsize;
	buf = COM_LoadFile (path, 4);

	return buf;
}

/*
=================
COM_LoadPackFile

Takes an explicit (not game tree related) path to a pak file.

Loads the header and directory, adding the files at the beginning
of the list so they override previous pack files.
=================
*/
pack_t *COM_LoadPackFile (const char *packfile)
{
	dpackheader_t   header;
	int                             i;
	packfile_t              *newfiles;
	int                             numpackfiles;
	pack_t                  *pack;
	int                             packhandle;
	dpackfile_t             info[MAX_FILES_IN_PACK];
	unsigned short          crc;

	if (Sys_FileOpenRead (packfile, &packhandle) == -1)
	{
//              Con_Printf ("Couldn't open %s\n", packfile);
		return NULL;
	}
	Sys_FileRead (packhandle, (void *)&header, sizeof(header));
	if (header.id[0] != 'P' || header.id[1] != 'A'
	|| header.id[2] != 'C' || header.id[3] != 'K')
		Sys_Error ("%s is not a packfile", packfile);
	header.dirofs = LittleLong (header.dirofs);
	header.dirlen = LittleLong (header.dirlen);

	numpackfiles = header.dirlen / sizeof(dpackfile_t);

	if (numpackfiles > MAX_FILES_IN_PACK)
		Sys_Error ("%s has %i files", packfile, numpackfiles);

	if (numpackfiles != PAK0_COUNT)
		com_modified = true;    // not the original file

	newfiles = (packfile_t*) Hunk_AllocName (numpackfiles * sizeof(packfile_t), "packfile");

	Sys_FileSeek (packhandle, header.dirofs);
	Sys_FileRead (packhandle, (void *)info, header.dirlen);

// crc the directory to check for modifications
	CRC_Init (&crc);
	for (i=0 ; i<header.dirlen ; i++)
		CRC_ProcessByte (&crc, ((byte *)info)[i]);
	if (crc != PAK0_CRC)
		com_modified = true;

// parse the directory
	for (i=0 ; i<numpackfiles ; i++)
	{
		strcpy (newfiles[i].name, info[i].name);
		//Con_Printf("%d name:%s", i, info[i].name);
		newfiles[i].filepos = LittleLong(info[i].filepos);
		newfiles[i].filelen = LittleLong(info[i].filelen);
	}

	pack = (pack_t*) Hunk_Alloc (sizeof (pack_t));
	strcpy (pack->filename, packfile);
	pack->handle = packhandle;
	pack->numfiles = numpackfiles;
	pack->files = newfiles;

	Con_Printf ("Added packfile %s (%i files)\n", packfile, numpackfiles);
	return pack;
}


/*
================
COM_AddGameDirectory

Sets com_gamedir, adds the directory to the head of the path,
then loads and adds pak1.pak pak2.pak ...
================
*/
void COM_AddGameDirectory (char *dir)
{
	int                             i;
	searchpath_t    *search;
	pack_t                  *pak;
	char                    pakfile[MAX_OSPATH];

	strcpy (com_gamedir, dir);

//
// add the directory to the search path
//
	search = (searchpath_t*) Hunk_Alloc (sizeof(searchpath_t));
	strcpy (search->filename, dir);
	search->next = com_searchpaths;
	com_searchpaths = search;

//
// add any pak files in the format pak0.pak pak1.pak, ...
//
	for (i=0 ; ; i++)
	{
		sprintf (pakfile, "%s/pak%i.pak", dir, i);
		pak = COM_LoadPackFile (pakfile);
		if (!pak)
			break;
		search = (searchpath_t*) Hunk_Alloc (sizeof(searchpath_t));
		search->pack = pak;
		search->next = com_searchpaths;
		com_searchpaths = search;
	}

//
// add the contents of the parms.txt file to the end of the command line
//

}

/*
================
COM_InitFilesystem
================
*/
void COM_InitFilesystem (void)
{
	int             i, j;
	char    basedir[MAX_OSPATH];
	searchpath_t    *search;

//
// -basedir <path>
// Overrides the system supplied base directory (under GAMENAME)
//
	i = COM_CheckParm ("-basedir");
	if (i && i < com_argc-1)
		strcpy (basedir, com_argv[i+1]);
	else
		strcpy (basedir, host_parms.basedir);

	j = strlen (basedir);

	if (j > 0)
	{
		if ((basedir[j-1] == '\\') || (basedir[j-1] == '/'))
			basedir[j-1] = 0;
	}

//
// -cachedir <path>
// Overrides the system supplied cache directory (NULL or /qcache)
// -cachedir - will disable caching.
//
	i = COM_CheckParm ("-cachedir");
	if (i && i < com_argc-1)
	{
		if (com_argv[i+1][0] == '-')
			com_cachedir[0] = 0;
		else
			strcpy (com_cachedir, com_argv[i+1]);
	}
	else if (host_parms.cachedir)
		strcpy (com_cachedir, host_parms.cachedir);
	else
		com_cachedir[0] = 0;

//
// start up with GAMENAME by default (id1)
//
	COM_AddGameDirectory (va("%s/"GAMENAME, basedir) );

	if (COM_CheckParm ("-rogue"))
		COM_AddGameDirectory (va("%s/rogue", basedir) );
	if (COM_CheckParm ("-hipnotic"))
		COM_AddGameDirectory (va("%s/hipnotic", basedir) );

//
// -game <gamedir>
// Adds basedir/gamedir as an override game
//
	i = COM_CheckParm ("-game");
	if (i && i < com_argc-1)
	{
		com_modified = true;
		COM_AddGameDirectory (va("%s/%s", basedir, com_argv[i+1]));
	}

//
// -path <dir or packfile> [<dir or packfile>] ...
// Fully specifies the exact serach path, overriding the generated one
//
	i = COM_CheckParm ("-path");
	if (i)
	{
		com_modified = true;
		com_searchpaths = NULL;
		while (++i < com_argc)
		{
			if (!com_argv[i] || com_argv[i][0] == '+' || com_argv[i][0] == '-')
				break;

			search = (searchpath_t*) Hunk_Alloc (sizeof(searchpath_t));
			if ( !strcmp(COM_FileExtension(com_argv[i]), "pak") )
			{
				search->pack = COM_LoadPackFile (com_argv[i]);
				if (!search->pack)
					Sys_Error ("Couldn't load packfile: %s", com_argv[i]);
			}
			else
				strcpy (search->filename, com_argv[i]);
			search->next = com_searchpaths;
			com_searchpaths = search;
		}
	}

	if (COM_CheckParm ("-proghack"))
		proghack = true;
}


