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

#include "quakedef.h"

#define MAX_NUM_ARGVS	50
#define NUM_SAFE_ARGVS	6

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

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

cvar_t registered = { "registered", "0" };

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

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

void COM_InitFilesystem(void);

// if a packfile directory differs from this, it is assumed to be hacked
#define	PAK0_COUNT		339
#define	PAK0_CRC		62751

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

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

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

int Q_strlen(char *str)
{
    int count;

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

    return count;
}

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

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

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

int Q_atoi(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(char *str)
{
    float 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 = 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 = 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 = SZ_GetSpace(sb, 2);
    buf[0] = c & 0xff;
    buf[1] = c >> 8;
}

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

    buf = 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, 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 < 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 = 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, void *data, int length)
{
    Q_memcpy(SZ_GetSpace(buf, length), data, length);
}

void SZ_Print(sizebuf_t * buf, 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
============
*/
char *COM_SkipPath(char *pathname)
{
    char *last;

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

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

/*
============
COM_FileExtension
============
*/
char *COM_FileExtension(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(char *in, char *out)
{
    char *s, *s2;

    s = in + strlen(in) - 1;

    while (s != in && *s != '.')
	s--;

    for (s2 = s; *s2 && *s2 != '/'; s2--);

    if (s - s2 < 2)
	strcpy(out, "?model?");
    else {
	s--;
	strncpy(out, s2 + 1, s - s2);
	out[s - s2] = 0;
    }
}


/*
==================
COM_DefaultExtension
==================
*/
void COM_DefaultExtension(char *path, 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);
}

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

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


/*
==============
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(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) {
	Con_Printf("Playing shareware version.\n");
//              if (com_modified)
//                      Sys_Error ("You must have the registered version to use modified games");
//              /*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("registered", "1");
    static_registered = 1;
    Con_Printf("Playing registered version.\n");
}


void COM_Path_f(void);


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

    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;
}


/*
================
COM_Init
================
*/
void COM_Init(char *basedir)
{
    byte swaptest[2] = { 1, 0 };

// set the byte swapping variables in a portable manner 
    if (*(short *) swaptest == 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);
    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(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(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;

/*
============
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(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(char *path)
{
    char *ofs;

    for (ofs = 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(char *netpath, 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 < 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
===========
*/
int COM_FindFile(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
//
    for (search = com_searchpaths; 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 {
		sprintf(cachepath, "%s/%s", com_cachedir, netpath);
		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(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(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(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);

    if (usehunk == 1)
	buf = Hunk_AllocName(len + 1, base);
    else if (usehunk == 2)
	buf = Hunk_TempAlloc(len + 1);
    else if (usehunk == 0)
	buf = Z_Malloc(len + 1);
    else if (usehunk == 3)
	buf = Cache_Alloc(loadcache, len + 1, base);
    else if (usehunk == 4) {
	if (len + 1 > loadsize)
	    buf = 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(char *path)
{
    return COM_LoadFile(path, 1);
}

byte *COM_LoadTempFile(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(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(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 =
	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);
	newfiles[i].filepos = LittleLong(info[i].filepos);
	newfiles[i].filelen = LittleLong(info[i].filelen);
    }

    pack = 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 = 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 = 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;
    char basedir[MAX_OSPATH];
    searchpath_t *search;

//
// -basedir <path>
// Overrides the system supplied base directory (under id1)
//
    i = COM_CheckParm("-basedir");
    if (i && i < com_argc - 1)
	strcpy(basedir, com_argv[i + 1]);
    else
	strcpy(basedir, host_parms.basedir);

//
// -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 id1 by default
//
    COM_AddGameDirectory(va("%s/id1", 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 = 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;
	}
    }
}
