static char rcsid[] = "@(#)$Id: realfrom.c,v 1.2 1995/09/29 17:41:31 wfp5p Exp $";

/*******************************************************************************
 *  The Elm Mail System  -  $Revision: 1.2 $   $State: Exp $
 *
 *                      Copyright (c) 1988-1995 USENET Community Trust
 *******************************************************************************
 * Bug reports, patches, comments, suggestions should be sent to:
 *
 *      Bill Pemberton, Elm Coordinator
 *      flash@virginia.edu
 *
 *******************************************************************************
 * $Log: realfrom.c,v $
 * Revision 1.2  1995/09/29  17:41:31  wfp5p
 * Alpha 8 (Chip's big changes)
 *
 * Revision 1.1.1.1  1995/04/19  20:38:33  wfp5p
 * Initial import of elm 2.4 PL0 as base for elm 2.5.
 *
 ******************************************************************************/


#include "elm_defs.h"


extern long make_gmttime();


int
real_from(buffer, entry)
const char *buffer;
struct header_rec *entry;
{

    /*
     * Breakup and validate the "From_" line in the "buffer".  If "entry"
     * is not NULL then the structure is filled in with sender and time
     * information.  Returns TRUE if the "From_" line is valid, otherwise
     * FALSE.
     *
     * A valid from line will be in the following format:
     *
     *	From <user> <weekday> <month> <day> <hr:min:sec>
     *	    [TZ1 [TZ2]] <year> [remote from sitelist]
     *
     * We insist that all of the <angle bracket> fields are present.
     * If two timezone fields are present, the first is used for date
     * information.  We do not look at anything beyond the <year> field.
     * We just insist that everything up to the <year> field is present
     * and valid.
     */

    char field[STRING];		/* buffer for current field of line	*/
    char field2[STRING];		/* buffer for current field of line	*/
    char field3[STRING];		/* buffer for current field of line	*/
    char save_tz[STRING];	/* extracted time zone field		*/
    int len;			/* length of current field		*/
    int month, day, year, hours, mins, secs, tz, i;

    /*
     * Zero out the portions of the record we fill in.
     */
    if (entry != NULL) {
	entry->time_zone[0] = '\0';
	entry->from[0] = '\0';
	entry->time_sent = 0;
	entry->received_time = 0;
	entry->tz_offset = 0;
    }

    /* From */
    if (strncmp(buffer, "From ", 5) != 0) {
	(void) strcpy(field, "From_");
	len = 1;
	goto failed;
    }
    buffer += 5;
    dprint(7, (debugfile, "real_from parsing %s", buffer));

    /* <user> or <weekday> */
    if ((len = get_word(buffer, 0, field, sizeof(field))) < 0)
	goto failed;
    buffer += len;

    /* <weekday> or <month> */
    if ((len = get_word(buffer, 0, field2, sizeof(field2))) < 0)
	goto failed;
    buffer += len;

    /* <month> or <day> */
    if ((len = get_word(buffer, 0, field3, sizeof(field3))) < 0 )
	goto failed;
    buffer += len;

    /* is <month> in field2 or field3? */
    if (!cvt_monthname_to_monthnum(field3, &month))
      if (!cvt_monthname_to_monthnum(field2, &month))
	goto failed;
      else
	{
	  /*  field2 is month, field3 is day  */
          /* <user> */
          if (entry != NULL)
	      *( entry->from ) = '\0';
          dprint(7, (debugfile, "  user=\n"));

          /* <day> */
          if ((day = atonum(field3)) < 0 || day < 1 || day > 31)
	      goto failed;
	}
    else
      {
        /* <user> */
        if (entry != NULL)
	    strfcpy(entry->from, field, sizeof(field));
        dprint(7, (debugfile, "  user=%s\n", field));

        /* <day> */
        if ((len = get_word(buffer, 0, field, sizeof(field))) < 0 ||
	        (day = atonum(field)) < 0 || day < 1 || day > 31)
	    goto failed;
        buffer += len;
      }

    /* <hr:min:sec> */
    if ((len = get_word(buffer, 0, field, sizeof(field))) < 0 ||
	    !cvt_timestr_to_hhmmss(field, &hours, &mins, &secs))
	goto failed;
    buffer += len;
    dprint(7, (debugfile, "  hours=%d mins=%d secs=%d\n", hours, mins, secs));

    /*
     * [ <tz> ... ] <year>
     *
     * This is messy.  Not only is the timezone field optional, there
     * might be multiple fields (e.g. "MET DST"), or it might be entirely
     * bogus (e.g. some MTAs produce "0600" instead of "+0600".
     */
    tz = 0;
    save_tz[0] = save_tz[1] = '\0';
    for (;;) {

	if ((len = get_word(buffer, 0, field, sizeof(field))) < 0)
	    goto failed;
	buffer += len;

	/*
	 * First check if this is a TZ field.  If so, pull in the info
	 * and continue onto the next field.
	 */
	if (cvt_timezone_to_offset(field, &i)) {
	    tz += i;
	    i = strlen(save_tz);
	    (void) strfcpy(save_tz+i, " ", sizeof(save_tz)-i);
	    ++i;
	    (void) strfcpy(save_tz+i, field, sizeof(save_tz)-i);
	    continue;
	}

	/*
	 * If this isn't a valid TZ then it should be a year.  If so
	 * then save off the year info and break out of this loop.
	 */
	if (cvt_yearstr_to_yearnum(field, &year))
	    break;

	/*
	 * This isn't either a valid TZ or year.  Assume it is a bogus
	 * timezone we don't understand, and continue processing the line.
	 */
	dprint(7, (debugfile,
	    "  assuming \"%s\" is a bogus timezone - skipping it\n", field));

    }
    if (entry != NULL) {
	entry->tz_offset = tz * 60;
	(void) strfcpy(entry->time_zone, save_tz+1, sizeof(entry->time_zone));
	entry->received_time = entry->time_sent =
	    make_gmttime(year, month, day, hours, mins-tz, secs);
    }
    dprint(7, (debugfile, "  tz=%s tz_offset=%d\n", save_tz+1, tz));
    dprint(7, (debugfile, "  month=%d day=%d year=%d\n", month, day, year));

    /*
     * The line is parsed and valid.  There might be more but we don't care.
     */
    dprint(7, (debugfile, "  return success\n"));
    return TRUE;

failed:
    dprint(4, (debugfile, "real_from failed at \"%s\"\n", 
	(len <= 0 ? "<premature eol>" : field)));
    return FALSE;
}


#ifdef _TEST
int debug = 9999;
FILE *debugfile = stdout;
main()
{
    struct header_rec hdr;
    char buf[1024];

    while (gets(buf) != NULL) {
	if (!real_from(buf, &hdr))
	    printf("FAIL %s\n", buf);
	else {
	    printf("OK %s\n", buf);
	    printf("from=%s time_zone=%s tz_offset=%d\n",
		hdr.from, hdr.time_zone, hdr.tz_offset);
	    printf("time_sent=%ld received_time=%ld %s",
		hdr.time_sent, hdr.received_time, ctime(&hdr.received_time));
	}
	putchar('\n');
    }
    exit(0);
}
#endif