/*
** dtimep.lex exceeds the default table capacities for some old versions
** of lex (and the minimum defaults as specified by POSIX).  The following
** choices meet or exceed the lex defaults for older SunOS4.x, Solaris,
** HPUX, and AIX.
*/
%e4000
%p7000
%n2500
%a5000
%{
#include <time.h>
#include <ctype.h>
#include <h/tws.h>

/*
** Since we're looking at a string at a time, don't worry about
** wrapping to the next buffer.
*/
#define yywrap() 1
#define YY_SKIP_YYWRAP

#define YY_NO_INPUT

/*
** This is the tricky thing that makes this function cool.  We
** replace the traditional int yylex(void) declaration with our
** dparsetime() declaration, essentially piggy-backing off the
** utility of the yylex() function and adding what we need to make
** the parsing function useful to us.
*/
#define YY_DECL struct tws *dparsetime(char *lexstr)

/*
** yyerminate() is called after the input string is matched to
** completion (actually, when the lexer reaches an EOF).  The only
** thing that really needs to be in this macro function is the
** return call, which must be substituted inline into dparsetime.
*/

#define yyterminate() (void)yy_delete_buffer(lexhandle); \
	if(!(tw.tw_flags & TW_SUCC)) { \
		return (struct tws *)NULL; \
	} \
	if(tw.tw_year < 1970) \
		tw.tw_year += 1900; \
	if(tw.tw_year < 1970) \
		tw.tw_year += 100; \
	return(&tw)

/*
** Patchable flag that says how to interpret NN/NN/NN dates. When
** true, we do it European style: DD/MM/YY. When false, we do it
** American style: MM/DD/YY.  Of course, these are all non-RFC822
** compliant.
*/
int europeandate = 0;

/*
** Table to convert month names to numeric month.  We use the
** fact that the low order 5 bits of the sum of the 2nd & 3rd
** characters of the name is a hash with no collisions for the 12
** valid month names.  (The mask to 5 bits maps any combination of
** upper and lower case into the same hash value).
*/
static int month_map[] = {
	0,
	6,	/* 1 - Jul */
	3,	/* 2 - Apr */
	5,	/* 3 - Jun */
	0,
	10,	/* 5 - Nov */
	0,
	1,	/* 7 - Feb */
	11,	/* 8 - Dec */
	0,
	0,
	0,
	0,
	0,
	0,
	0,	/*15 - Jan */
	0,
	0,
	0,
	2,	/*19 - Mar */
	0,
	8,	/*21 - Sep */
	0,
	9,	/*23 - Oct */
	0,
	0,
	4,	/*26 - May */
	0,
	7	/*28 - Aug */
};

/*
** Lookup table for day-of-week using the same hash trick as for above
** name-of-month table, but using the first and second character, not
** second and third.
**
** Compute index into table using: (day_name[0] & 7) + (day_name[1] & 4)
*/
static int day_map[] = {
	0,
	0,
	0,
	6,	/* 3 - Sat */
	4,	/* 4 - Thu */
	0,
	5,	/* 6 - Fri */
	0,	/* 7 - Sun */
	2,	/* 8 - Tue */
	1	/* 9 - Mon */,
	0,
	3	/*11 - Wed */
};

/*
** The SET* macros will parse for the appropriate field, and leave the
** cp pointer at the first character after the desired field. Be
** careful with variable-length fields or alpha-num mixes.
**
** The SKIP* macros skip over characters of a particular class and
** leave cp at the position of the first character that doesn't match
** that class. Correspondingly, SKIPTO* skips until it reaches a
** character of a particular class.
*/

#define INIT() { cp = yytext;}
#define SETWDAY()  { tw.tw_wday= day_map[(cp[0] & 7) + (cp[1] & 4)]; \
	tw.tw_flags &= ~TW_SDAY; tw.tw_flags |= TW_SEXP; SKIPA(); }
#define SETMON()  { cp++; tw.tw_mon = month_map[(cp[0] + cp[1]) & 0x1f]; \
	SKIPA(); }
#define SETMON_NUM()  { tw.tw_mon = atoi(cp)-1; SKIPD(); }
#define SETYEAR()  { tw.tw_year = atoi(cp); SKIPD(); }
#define SETDAY()  { tw.tw_mday = atoi(cp); tw.tw_flags |= TW_YES; SKIPD(); }
#define SETTIME()  { tw.tw_hour = atoi(cp); cp += 2; SKIPTOD(); \
	tw.tw_min = atoi(cp); cp += 2; if(*cp == ':') { \
	tw.tw_sec = atoi(++cp); SKIPD(); } }
#define SETZONE(x)  { tw.tw_zone = ((x)/100)*60+(x)%100; \
	tw.tw_flags |= TW_SZEXP; SKIPD(); }
#define SETDST()  { tw.tw_flags |= TW_DST; }
#define SKIPD()  { while ( isdigit(*cp++) ) ; --cp; }
#define SKIPTOD()  { while ( !isdigit(*cp++) ) ; --cp; }
#define SKIPA()  { while ( isalpha(*cp++) ) ; --cp; }
#define SKIPTOA()  { while ( !isalpha(*cp++) ) ; --cp; }
#define SKIPSP()  { while ( isspace(*cp++) ) ; --cp; }
#define SKIPTOSP()  { while ( !isspace(*cp++) ) ; --cp; }

#ifdef ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST
# ifdef HAVE_SYS_TIME_H
#  include <sys/time.h>
# endif
#include <time.h>

static void
zonehack (struct tws *tw)
{
	struct tm *tm;

	if (dmktime (tw) == (time_t) -1)
		return;

	tm = localtime (&tw->tw_clock);
	if (tm->tm_isdst) {
		tw->tw_flags |= TW_DST;
		tw->tw_zone -= 60;
	}
}
#endif /* ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST */
%}

sun	([Ss]un(day)?)
mon	([Mm]on(day)?)
tue	([Tt]ue(sday)?)
wed	([Ww]ed(nesday)?)
thu	([Tt]hu(rsday)?)
fri	([Ff]ri(day)?)
sat	([Ss]at(urday)?)

DAY	({sun}|{mon}|{tue}|{wed}|{thu}|{fri}|{sat})

jan	([Jj]an(uary)?)
feb	([Ff]eb(ruary)?)
mar	([Mm]ar(ch)?)
apr	([Aa]pr(il)?)
may	([Mm]ay)
jun	([Jj]un(e)?)
jul	([Jj]ul(y)?)
aug	([Aa]ug(ust)?)
sep	([Ss]ep(tember)?)
oct	([Oo]ct(ober)?)
nov	([Nn]ov(ember)?)
dec	([Dd]ec(ember)?)

MONTH	({jan}|{feb}|{mar}|{apr}|{may}|{jun}|{jul}|{aug}|{sep}|{oct}|{nov}|{dec})

TIME	({D}:{d}{d}(:{d}{d})?)

/*
** The year can either be 2 digits, or 4. However, after
** Y2K, we found that some MUA were reporting the year 100, hence
** the middle term here. yyterminate() resolves the actual
** issues with 2-digit years.
*/

YEAR	(({d}{d})|(1{d}{d})|({d}{4}))

w	([ \t]*)
W	([ \t]+)
D	([0-9]?[0-9])
d	[0-9]
nl	[ \t\n()]

%%
%{
	/*
	** This section begins the definition of dparsetime().
	** Put here any local variable definitions and initializations
	*/
	YY_BUFFER_STATE lexhandle;

	unsigned char *cp;
	static struct tws tw;

	memset(&tw,0,sizeof(struct tws));

	lexhandle = yy_scan_string(lexstr);
%}

{DAY}","?{W}{MONTH}{W}{D}{W}{TIME}{W}{YEAR}  {
	INIT();
	SETWDAY();
	SKIPTOA();
	SETMON();
	SKIPTOD();
	SETDAY();
	SKIPTOD();
	SETTIME();
	SKIPTOD();
	SETYEAR();
}

{DAY}","?{W}{D}{W}{MONTH}{W}{YEAR}{W}{TIME}  {
	INIT();
	SETWDAY();
	SKIPTOD();
	SETDAY();
	SKIPTOA();
	SETMON();
	SKIPTOD();
	SETYEAR();
	SKIPTOD();
	SETTIME();
}
{D}{W}{MONTH}{W}{YEAR}{W}{TIME}  {
	INIT();
	SETDAY();
	SKIPTOA();
	SETMON();
	SKIPTOD();
	SETYEAR();
	SKIPTOD();
	SETTIME();
}
{DAY}","?{W}{MONTH}{W}{D}","?{W}{YEAR}","?{W}{TIME}  {
	INIT();
	SETWDAY();
	SKIPTOA();
	SETMON();
	SKIPTOD();
	SETDAY();
	SKIPTOD();
	SETYEAR();
	SKIPTOD();
	SETTIME();
}
{DAY}","?{W}{MONTH}{W}{D}","?{W}{YEAR}  {
	INIT();
	SETWDAY();
	SKIPTOA();
	SETMON();
	SKIPTOD();
	SETDAY();
	SKIPTOD();
	SETYEAR();
}
{MONTH}{W}{D}","?{W}{YEAR}","?{W}{DAY}  {
	INIT();
	SETMON();
	SKIPTOD();
	SETDAY();
	SKIPTOD();
	SETYEAR();
	SKIPTOA();
	SETWDAY();
}
{MONTH}{W}{D}","?{W}{YEAR}  {
	INIT();
	SETMON();
	SKIPTOD();
	SETDAY();
	SKIPTOD();
	SETYEAR();
}
{D}("-"|"/"){D}("-"|"/"){YEAR}{W}{TIME}  {
	INIT();
	if(europeandate) {
		/* DD/MM/YY */
		SETDAY();
		SKIPTOD();
		SETMON_NUM();
	} else {
		/* MM/DD/YY */
		SETMON_NUM();
		SKIPTOD();
		SETDAY();
	}
	SKIPTOD();
	SETYEAR();
	SKIPTOD();
	SETTIME();
}
{D}("-"|"/"){D}("-"|"/"){YEAR}  {
	INIT();
	if(europeandate) {
		/* DD/MM/YY */
		SETDAY();
		SKIPTOD();
		SETMON_NUM();
	} else {
		/* MM/DD/YY */
		SETMON_NUM();
		SKIPTOD();
		SETDAY();
	}
	SKIPTOD();
	SETYEAR();
}

"[Aa][Mm]"
"[Pp][Mm]"  tw.tw_hour += 12;

"+"{D}{d}{d}  {
	INIT();
	SKIPTOD();
	SETZONE(atoi(cp));
#ifdef ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST
	zonehack (&tw);
#endif /* ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST */
	yyterminate();
}
"-"{D}{d}{d}  {
	INIT();
	SKIPTOD();
	SETZONE(-atoi(cp));
#ifdef ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST
	zonehack (&tw);
#endif /* ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST */
	yyterminate();

}
{nl}("ut"|"UT")		INIT(); SETZONE(0); yyterminate();
{nl}("gmt"|"GMT")	INIT(); SETZONE(0); yyterminate();
{nl}("est"|"EST")	INIT(); SETZONE(-500); yyterminate();
{nl}("edt"|"EDT")	{ INIT(); SETDST(); SETZONE(-500); yyterminate(); }
{nl}("cst"|"CST")	INIT(); SETZONE(-600); yyterminate();
{nl}("cdt"|"CDT")	{ INIT(); SETDST(); SETZONE(-600); yyterminate(); }
{nl}("mst"|"MST")	INIT(); SETZONE(-700); yyterminate();
{nl}("mdt"|"MDT")	{ INIT(); SETDST(); SETZONE(-700); yyterminate(); }
{nl}("pst"|"PST")	INIT(); SETZONE(-800); yyterminate();
{nl}("pdt"|"PDT")	{ INIT(); SETDST(); SETZONE(-800); yyterminate(); }
{nl}("nst"|"NST")	INIT(); SETZONE(-330); yyterminate();
{nl}("ast"|"AST")	INIT(); SETZONE(-400); yyterminate();
{nl}("adt"|"ADT")	{ INIT(); SETDST(); SETZONE(-400); yyterminate(); }
{nl}("hst"|"HST")	INIT(); SETZONE(-1000); yyterminate();
{nl}("hdt"|"HDT")	{ INIT(); SETDST(); SETZONE(-1000); yyterminate(); }
.|\n

%%
/*
** This is a portable way to squash a warning about the yyunput()
** function being static but never used. It costs us a tiny amount
** of extra code in the binary but the other options are:
** "%option nounput" which is flex-specific
** makefile hackery just to compile dtimep.c with different flags
*/
void dtimep_yyunput(int c)
{
	unput(c);
}