/*
    (C) 1995-96 AROS - The Amiga Replacement OS
    $Id: strtodate.c,v 1.3 1997/02/18 15:42:44 digulla Exp $

    Desc: Converts a string into a date
    Lang: english
*/
#include <string.h>
#include "dos_intern.h"

#ifdef TEST
#include <proto/dos.h>
#include <stdio.h>
#undef AROS_LH1
#undef StrToDate
#undef AROS_LHA
#define AROS_LH1(ret,name,arg,type,base,offset,libname) \
    ret name (arg)
#define AROS_LHA(type,name,reg) type name

const ULONG Dos_DayTable[]=
{
    0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335
};

const char *const Dos_MonthTable[]=
{
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};

const char *const Dos_WeekTable[]=
{
    "Sunday", "Monday", "Tuesday", "Wednesday",
    "Thursday", "Friday", "Saturday"
};

const char *const Dos_SubstDateTable[]=
{
    "Tomorrow", "Today", "Yesterday"
};
#else
#include "date.h"
#endif

/*****************************************************************************

    NAME */
#include <dos/datetime.h>
#include <proto/dos.h>

	AROS_LH1(LONG, StrToDate,

/*  SYNOPSIS */
	AROS_LHA(struct DateTime *, datetime, D1),

/*  LOCATION */
	struct DosLibrary *, DOSBase, 125, Dos)

/*  FUNCTION
	Converts a human readable ASCII string into an AmigaDOS
	DateStamp.

    INPUTS
	DateTime - a pointer to an initialized DateTime structure.
		The structure should be initialized as follows:

		\begin{description}
		\item{dat_Stamp} The converted date will be written here

		\item{dat_Format} How to convert the datestamp into
		    dat_StrDate. Can be any of the following:

		    \begin{description}
		    \item{FORMAT_DOS} AmigaDOS format (dd-mmm-yy). This
			    is the default if you specify something other
			    than any entry in this list.

		    \item{FORMAT_INT} International format (yy-mmm-dd).

		    \item{FORMAT_USA} American format (mm-dd-yy).

		    \item{FORMAT_CDN} Canadian format (dd-mm-yy).

		    \item{FORMAT_DEF} default format for locale.

		    \end{description}

		\item{dat_Flags} Modifies dat_Format. The only flag
		    used by this function is DTF_FUTURE. If set, then
		    a string like "Monday" refers to the next monday.
		    Otherwise it refers to the last monday.

		\item{dat_StrDay} Ignored.

		\item{dat_StrDate} Pointer to valid string representing the
			date. This can be a "DTF_SUBST" style string such
			as "Today" "Tomorrow" "Monday", or it may be a
			string as specified by the dat_Format byte. This
			will be converted to the ds_Days portion of the
			DateStamp. If this pointer is NULL,
			DateStamp->ds_Days will not be affected.

		\item{dat_StrTime} Pointer to a buffer which contains the
			time in the ASCII format hh:mm:ss. This will be
			converted to the ds_Minutes and ds_Ticks portions
			of the DateStamp.  If this pointer is NULL,
			ds_Minutes and ds_Ticks will be unchanged.

		\end{description}

    RESULT
	A zero return indicates that a conversion could not be performed. A
	non-zero return indicates that the DateTime.dat_Stamp variable
	contains the converted values.

    NOTES

    EXAMPLE

    BUGS

    SEE ALSO
	DateStamp(), DateToStr()

    INTERNALS

    HISTORY

*****************************************************************************/
{
    AROS_LIBFUNC_INIT
    AROS_LIBBASE_EXT_DECL(struct DosLibrary *,DOSBase)
    struct DateStamp curr;
    LONG days, min, tick, len, t, year, month;
    BOOL leap;
    UBYTE * ptr, * format;

    if ((ptr = datetime->dat_StrDate))
    {
	DateStamp (&curr);

	for (t=0; t<3; t++)
	{
	    if (!strncasecmp (Dos_SubstDateTable[t], ptr, strlen (Dos_SubstDateTable[t])))
		break;
	}

	if (t != 3)
	    days = curr.ds_Days + t - 1;
	else
	{
	    for (t=0; t<7; t++)
	    {
		if (!strncasecmp (Dos_WeekTable[t], ptr, strlen (Dos_WeekTable[t])))
		    break;
	    }

	    if (t != 7)
	    {
		days = curr.ds_Days;

		if ((days % 7) == 0)
		    days -= 7;
		else
		    days -= (days % 7);

		days += t;

		if (datetime->dat_Flags & DTF_FUTURE)
		    days += 7;
	    }
	    else
	    {
		switch (datetime->dat_Format)
		{
		case FORMAT_INT: format = "y-m-d"; break;
		case FORMAT_USA: format = "M-d-y"; break;
		case FORMAT_CDN: format = "d-M-y"; break;
		case FORMAT_DEF: format = "d.M.y"; break;
		default:	 format = "d-m-y"; break;
		}

		while (*format)
		{
		    switch (*format)
		    {
		    case 'y':
			t = StrToLong (ptr, &year);

			if (t == -1)
			    return DOSFALSE;

			if (year < 100)
			    year += 1900;

			ptr += t;

			break;

		    case 'M':
			t = StrToLong (ptr, &month);

			if (t == -1)
			    return DOSFALSE;

			ptr += t;

			break;

		    case 'd':
			t = StrToLong (ptr, &days);

			if (t == -1)
			    return DOSFALSE;

			ptr += t;

			break;

		    case 'm':
			for (t=0; t<12; t++)
			{
			    if (!strncasecmp (Dos_MonthTable[t], ptr,
				    strlen (Dos_MonthTable[t])))
				break;
			}

			if (t == 12)
			    return DOSFALSE;

			month = t+1;

			ptr += strlen (Dos_MonthTable[t]);

			break;

		    default:
			if (*ptr != *format)
			    return DOSFALSE;

			ptr ++;

			break;

		    } /* switch */

		    format ++;
		} /* while */

		/* kprintf ("Year=%ld, Month=%ld, Days=%ld\n",
			year, month, days); */

		/* Days go from 1..x */
		days --;

		/* First year must be 1978 */
		if (year < 1978)
		    return DOSFALSE;

		/* Is this year a leap year ? */
		leap = (((year % 400) == 0) ||
		    (((year % 4) == 0) && !((year % 100) == 0)));

		/* Add the days for all years (without leap years) */
		days += (year - 1978) * 365;

		/* Add leap years */
		days += ((year / 4) - (year / 100) + (year / 400)
		    - (494 - 19 + 4));

		/* Add days of months */
		days += Dos_DayTable[month-1];

		/*
		    In Dos_DayTable, February has 29 days. Correct this in
		    non-leap years and if the day has not yet been reached.
		*/
		if (month >= 2 || (leap && month < 2))
		    days --;

	    } /* Normal date */
	} /* Not "Tomorrow", "Today" or "Yesterday" */
    } /* Convert date ? */
    else
	days = 0;

    if ((ptr = datetime->dat_StrTime))
    {
	len = StrToLong (ptr, &t);

	if (len == -1)
	    return DOSFALSE;

	min = t * 60;

	ptr += len;

	if (*ptr++ != ':')
	    return DOSFALSE;

	len = StrToLong (ptr, &t);

	if (len == -1)
	    return DOSFALSE;

	min += t;

	ptr += len;

	if (*ptr++ != ':')
	    return DOSFALSE;

	len = StrToLong (ptr, &t);

	if (len == -1)
	    return DOSFALSE;

	tick = t * TICKS_PER_SECOND;
    }
    else
    {
	min = 0;
	tick = 0;
    }

    datetime->dat_Stamp.ds_Days   = days;
    datetime->dat_Stamp.ds_Minute = min;
    datetime->dat_Stamp.ds_Tick   = tick;

    return DOSTRUE;
    AROS_LIBFUNC_EXIT
} /* StrToDate */

#ifdef TEST
#include <stdio.h>

int main (int argc, char ** argv)
{
    struct DateTime dt;
    char * date;
    char * time;
    char daybuf[LEN_DATSTRING];
    char datebuf[LEN_DATSTRING];
    char timebuf[LEN_DATSTRING];

    if (argc >= 2)
	date = argv[1];
    else
	date = NULL;

    if (argc >= 3)
	time = argv[2];
    else
	time = NULL;

    dt.dat_StrDate = date;
    dt.dat_StrTime = time;
    dt.dat_Flags   = 0;
    dt.dat_Format  = FORMAT_CDN;

    if (!StrToDate (&dt))
    {
	printf ("Cannot convert date/time\n");
	return 10;
    }
    else
    {
	printf ("Result: Days=%ld, Minute=%ld, Ticks=%ld\n"
	    , dt.dat_Stamp.ds_Days
	    , dt.dat_Stamp.ds_Minute
	    , dt.dat_Stamp.ds_Tick
	);

	dt.dat_StrDay  = daybuf;
	dt.dat_StrDate = datebuf;
	dt.dat_StrTime = timebuf;

	DateToStr (&dt);

	printf ("Gives: %s, %s %s\n", daybuf, datebuf, timebuf);

	dt.dat_Flags   = DTF_SUBST;

	DateToStr (&dt);

	printf ("(With DTF_SUBST): %s, %s %s\n", daybuf, datebuf, timebuf);

    }

    return 0;
} /* main */

#endif /* TEST */