/* utils.c */
/* $Id: utils.c,v 1.4 1993/08/16 01:57:27 nils Exp $ */

#include <sys/types.h>
#include <time.h>
#include <ctype.h>

#include "externs.h"
#include "db.h"
#include "config.h"

extern long get_timezone()
{
  struct timeval tv;
  struct timezone tz;
  gettimeofday(&tv,&tz);
  return tz.tz_minuteswest * 60;
}

/* added 12/1/90 by jstanley to locate entrance of an exit */
dbref find_entrance(door)
     dbref door;
{
  /*    dbref room;
	dbref thing;
	
	for ( room = 0; room < db_top; room++ )
	if ( Typeof(room) == TYPE_ROOM )  {
	thing = Exits(room);
	while ( thing != NOTHING )  {
	if ( thing == door )
	return room;
	thing = db[thing].next;
	}
	}
	
	return NOTHING; */
  return db[door].location;
}

/* remove the first occurence of what in list headed by first */
dbref remove_first(first,what)
     dbref first;
     dbref what;
{
  dbref prev;
  
  /* special case if it's the first one */
  if(first == what) {
    return db[first].next;
  } else {
    /* have to find it */
    DOLIST(prev, first) {
      if(db[prev].next == what) {
	db[prev].next = db[what].next;
	return first;
      }
    }
    return first;
  }
}

int member(thing,list)
     dbref thing;
     dbref list;
{
  DOLIST(list, list) {
    if(list == thing) return 1;
  }
  
  return 0;
}

dbref reverse(list)
     dbref list;
{
  dbref newlist;
  dbref rest;
  
  newlist = NOTHING;
  while(list != NOTHING) {
    rest = db[list].next;
    PUSH(list, newlist);
    list = rest;
  }
  return newlist;
}

void get_tz(tz, tzp, lyp)
char *tz;
char **tzp;
int *lyp;
{
  char *s;

  *lyp = 0;
  *tzp = tz;
  if ( *tzp != NULL )
    if ( **tzp != '\0' )
      if ( (s = strchr(*tzp, ':')) != NULL )  {
	++s;
        if ( *s == 'Y' || *s == 'y' )
          *lyp = 1;
      }
}

void get_thing_tz(thing, tzp, lyp)
     dbref thing;
     char **tzp;
     int *lyp;
{
  char *s;

  *tzp = atr_get(thing, A_TZ);
  if ( **tzp == '\0' )
    *tzp = atr_get(db[thing].owner, A_TZ);

  if ( **tzp == '\0' )
    *lyp = 0;
  else if ( (s = strchr(*tzp, ':')) == NULL )
    *lyp = 0;
  else {
    ++s;
    if ( *s == 'Y' || *s == 'y' )
      *lyp = 1;
  }
}

char *mktm(cl, tz, thing)
     time_t cl;
     char *tz;
     dbref thing;
{
  int ly;
  char *s;
  struct tm *tmp;
  long adjust, utcdiff;

  if ( tz == NULL )
    tz = "";
  if ( *tz == 'D' || *tz == '\0' )
    get_thing_tz(thing, &tz, &ly);
  else
    get_tz(tz, &tz, &ly);

  /* determine time diff between gmt and local standard time */
  utcdiff = get_timezone();
  tmp = localtime(&cl);
  if ( tmp )
    if ( tmp->tm_isdst )
      utcdiff -= 3600L;

  /* get or calculate timezone adjustment */
  if ( *tz == '\0' )
    adjust = utcdiff;
  else  {
    adjust = 0L - atol(tz) * 3600L;
    if ( ly && tmp->tm_isdst > 0 )
      adjust -= 3600L;
  }

  /* adjust for timezone */
  cl += (utcdiff - adjust);

  /* generate ascii string */
  s = ctime(&cl);
  s[strlen(s)-1]='\0';
  return s;
}

/* this routine is designed to interpret a wide variety of time string
   formats converting them all to a longint x-value time representation */
long mkxtime(s, thing, tz)
     char *s;
     dbref thing;
     char *tz;
{
  int i, j, ly;
  long cl, adjust, utcdiff;
  char *p, *q=s, *dayp, *yearp=NULL;
  int seconds, minutes, hours, day, month, year;
  struct tm tmbuf;
  static int tadjust[] = {
       0,    -4,    -5,    -5,    -6,    -6,    -7,    -7,    -8
  };
  static char *tname[] = {
    "gmt", "edt", "est", "cdt", "cst", "mdt", "mst", "pdt", "pst", NULL
  };
  static char *mname[] = {
    "jan", "feb", "mar", "apr", "may", "jun",
    "jul", "aug", "sep", "oct", "nov", "dec", NULL
  };

  /* Locate month if present */
  month = -1;
  for ( p = s; month < 0 && *p != '\0'; p++ )  {
    if ( isalpha(*p) )
      for ( i = 0; mname[i] != NULL; i++ )  {
	j = 0, q = p;
	while ( mname[i][j] != '\0' && mname[i][j] == to_lower(*q) )
	  ++j, ++q;
	if ( mname[i][j] == '\0' )  {
	  month = i;
	  break;
	}
      }
  }
  if ( month < 0 )
    return -1L;

  /* skip remaining string and whitespace */
  for ( p = q; isalpha(*p); p++ )
    ;
  for ( ; isspace(*p); p++ )
    ;

  /* get day */
  day = -1;
  if ( isdigit(*p) )
    day = atoi(p);
  if ( day < 1 || day > 31)
    return -1L;
  dayp = p;

  /* get year */
  year = -1;
  for ( p = s; *p != '\0'; p++ )
    if ( isdigit(*p) )  {
      year = atoi(p);
      if ( year < 1900 )  {
	year = -1;
	for ( ; isdigit(*p); p++ )
	  ;
	continue;
      }
      yearp = p;
      break;
    }
  if ( year < 0 )
    return -1L;

  /* get hours */
  hours = -1;
  for ( p = s; *p != '\0'; p++ )
    if ( isdigit(*p) )  {
      hours = atoi(p);
      if ( p == dayp || p == yearp || hours < 0 || hours > 59 )  {
	hours = -1;
	for ( ; isdigit(*p); p++ )
	  ;
	continue;
      }
      break;
    }
  if ( hours < 0 )
    return -1L;
  for ( ; isdigit(*p); p++ )
    ;

  /* get minutes */
  minutes = -1;
  if ( *p == ':' )
    minutes = atoi(++p);
  if ( minutes < 0 || minutes > 59 )
    return -1L;
  for ( ; isdigit(*p); p++ )
    ;

  /* get seconds */
  seconds = -1;
  if ( *p == ':' )
    seconds = atoi(++p);
  if ( seconds < 0 || seconds > 59 )
    return -1L;

  tmbuf.tm_sec   = seconds;
  tmbuf.tm_min   = minutes;
  tmbuf.tm_hour  = hours;
  tmbuf.tm_mday  = day;
  tmbuf.tm_mon   = month;
  tmbuf.tm_year  = year - 1900;
  tmbuf.tm_isdst = -1;
  cl = mktime(&tmbuf);

  /* determine time diff between gmt and local standard time */
  /* (for the time calculated) */
  utcdiff = ( tmbuf.tm_isdst > 0 ) ? get_timezone() - 3600L : get_timezone();

  /* calculate timezone adjustment */
  if ( tz == NULL )
    tz = "";
  if ( *tz == 'D' || *tz == '\0' )
    get_thing_tz(thing, &tz, &ly);
  else
    get_tz(tz, &tz, &ly);
  if ( *tz == '\0' )
    adjust = utcdiff;
  else  {
    adjust = 0L - atol(tz) * 3600L;
    if ( ly && tmbuf.tm_isdst > 0 )
      adjust -= 3600L;
  }

  /* check for timezone override in string specification */
  for ( p = s; *p != '\0'; p++ )
    if ( isalpha(*p) )  {
      for ( i = 0; tname[i] != NULL; i++ )  {
	j = 0; q = p;
	while ( tname[i][j] != '\0' && tname[i][j] == to_lower(*q) )
	  ++j, ++q;
	if ( tname[i][j] == '\0' )  {
	  adjust = 0L - (3600L * (long) (tadjust[i]));
	  goto OUT;
	}
      }
    }
OUT:

  cl += (adjust - utcdiff);
  return cl;
}