/* utc2et.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* $Procedure      UTC2ET ( UTC to Ephemeris Time ) */
/* Subroutine */ int utc2et_(char *utcstr, doublereal *et, ftnlen utcstr_len)
{
    /* Builtin functions */
    /* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen);
    integer s_cmp(char *, char *, ftnlen, ftnlen), i_dnnt(doublereal *);

    /* Local variables */
    integer year;
    doublereal tvec[10];
    logical mods;
    char type__[8];
    extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
	     ftnlen, ftnlen), repmc_(char *, char *, char *, char *, ftnlen, 
	    ftnlen, ftnlen, ftnlen);
    integer ntvec;
    char error[480];
    logical ok;
    extern /* Subroutine */ int tcheck_(doublereal *, char *, logical *, char 
	    *, logical *, char *, ftnlen, ftnlen, ftnlen);
    logical succes, yabbrv;
    char modify[8*5];
    extern /* Subroutine */ int sigerr_(char *, ftnlen), chkout_(char *, 
	    ftnlen), setmsg_(char *, ftnlen);
    char pictur[80];
    extern /* Subroutine */ int ttrans_(char *, char *, doublereal *, ftnlen, 
	    ftnlen);
    extern logical return_(void);
    extern /* Subroutine */ int tpartv_(char *, doublereal *, integer *, char 
	    *, char *, logical *, logical *, logical *, char *, char *, 
	    ftnlen, ftnlen, ftnlen, ftnlen, ftnlen), texpyr_(integer *);

/* $ Abstract */

/*      Convert an input time from Calendar or Julian Date format, UTC, */
/*      to ephemeris seconds past J2000. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*      TIME, KERNEL */

/* $ Keywords */

/*      TIME */

/* $ Declarations */
/* $ Brief_I/O */

/*      VARIABLE  I/O  DESCRIPTION */
/*      --------  ---  -------------------------------------------------- */
/*      UTCSTR     I   Input time string, UTC. */
/*      ET         O   Output epoch, ephemeris seconds past J2000. */

/* $ Detailed_Input */

/*      UTCSTR      is an input time string, containing a Calendar or */
/*                  Julian Date, UTC. Any input string acceptable to the */
/*                  routine TPARTV are acceptable to UTC2ET. The length */
/*                  of UTCSTR should not exceed 80 characters. */

/* $ Detailed_Output */

/*      ET          is the equivalent of UTCSTR, expressed in ephemeris */
/*                  seconds past J2000. If an error occurs, or if the */
/*                  input string is ambiguous, ET is not changed. */


/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*      1) If the input time string is ambiguous, the error */
/*         SPICE(INVALIDTIMESTRING) is signalled. */

/*      2) This routine does not attempt to account for variations */
/*         in the length of the second that were in effect prior */
/*         to Jan 1, 1972.  For days prior to that date, we assume */
/*         there are exactly 86400 ephemeris seconds. */

/* $ Files */

/*      None. */

/* $ Particulars */

/*      This routine handles that task of converting strings */
/*      representing epochs in the UTC system to ephemeris seconds */
/*      (TDB) past the epoch of the J2000 frame. */

/*      Although this routine is intended primarily for the */
/*      conversion of epochs during the "space age" it may also */
/*      be used to convert much earlier epochs.  However, before */
/*      using this routine to convert epochs prior to 1972 */
/*      you must be sure that the assumptions made by in the */
/*      implementation are consistent with the accuracy of */
/*      the input calendar string. */

/*      As noted in the "Exceptions" section above, this routine */
/*      does not attempt to account for variations in the */
/*      length of the second that were used prior to Jan 1, 1972. */
/*      Instead each "UTC" day prior to Jan 1, 1972 is assumed */
/*      to have exactly 86400 TDT seconds. */

/*  Ancient Epochs */
/*  -------------- */

/*      The calendar used today, the Gregorian calendar, has its */
/*      initial epoch on 15 October, 1582.  Prior to that epoch the */
/*      Julian calendar was used for the recording of epochs. */
/*      October 15, 1582 (Gregorian) corresponds to */
/*      October 05, 1582 (Julian).  From the point of view of the */
/*      implementation of this routine, all epochs belong to the */
/*      Gregorian calendar extended indefinitely backward in time. */
/*      If you need to obtain ephemeris seconds past the J2000 epoch */
/*      from Julian Calendar strings, we suggest that */
/*      you make use of the SPICE routine STR2ET. */

/* $ Examples */

/*      Below is a sampling of some of the time formats that */
/*      are acceptable as inputs to UTC2ET.  A complete discussion */
/*      of permissible formats is given in the SPICE routine */
/*      TPARTV as well as the User's reference file time.req */
/*      located in the "doc" directory of the toolkit. */

/*      ISO (T) Formats. */

/*      String                        Year Mon  DOY DOM  HR Min Sec */
/*      ----------------------------  ---- ---  --- ---  -- --- ------ */
/*      1996-12-18T12:28:28           1996 Dec   na  18  12  28 28 */
/*      1986-01-18T12                 1986 Jan   na  18  12  00 00 */
/*      1986-01-18T12:19              1986 Jan   na  18  12  19 00 */
/*      1986-01-18T12:19:52.18        1986 Jan   na  18  12  19 52.18 */
/*      1995-08T18:28:12              1995  na  008  na  18  28 12 */
/*      1995-18T                      1995  na  018  na  00  00 00 */


/*      Calendar Formats. */

/*      String                        Year   Mon DOM  HR Min  Sec */
/*      ----------------------------  ----   --- ---  -- ---  ------ */
/*      Tue Aug  6 11:10:57  1996     1996   Aug  06  11  10  57 */
/*      1 DEC 1997 12:28:29.192       1997   Dec  01  12  28  29.192 */
/*      2/3/1996 17:18:12.002         1996   Feb  03  17  18  12.002 */
/*      Mar 2 12:18:17.287 1993       1993   Mar  02  12  18  17.287 */
/*      1992 11:18:28  3 Jul          1992   Jul  03  11  18  28 */
/*      June 12, 1989 01:21           1989   Jun  12  01  21  00 */
/*      1978/3/12 23:28:59.29         1978   Mar  12  23  28  59.29 */
/*      17JUN1982 18:28:28            1982   Jun  17  18  28  28 */
/*      13:28:28.128 1992 27 Jun      1992   Jun  27  13  28  28.128 */
/*      1972 27 jun 12:29             1972   Jun  27  12  29  00 */
/*      '93 Jan 23 12:29:47.289       1993*  Jan  23  12  29  47.289 */
/*      27 Jan 3, 19:12:28.182        2027*  Jan  03  19  12  28.182 */
/*      23 A.D. APR 4, 18:28:29.29    0023** Apr  04  18  28  29.29 */
/*      18 B.C. Jun 3, 12:29:28.291   -017** Jun  03  12  29  28.291 */
/*      29 Jun  30 12:29:29.298       2029+  Jun  30  12  29  29.298 */
/*      29 Jun '30 12:29:29.298       2030*  Jun  29  12  29  29.298 */

/*      Day of Year Formats */

/*      String                        Year  DOY HR Min Sec */
/*      ----------------------------  ----  --- -- --- ------ */
/*      1997-162::12:18:28.827        1997  162 12  18 28.827 */
/*      162-1996/12:28:28.287         1996  162 12  28 28.287 */
/*      1993-321/12:28:28.287         1993  231 12  28 28.287 */
/*      1992 183// 12 18 19           1992  183 12  18 19 */
/*      17:28:01.287 1992-272//       1992  272 17  28 01.287 */
/*      17:28:01.282 272-1994//       1994  272 17  28 01.282 */
/*      '92-271/ 12:28:30.291         1992* 271 12  28 30.291 */
/*      92-182/ 18:28:28.281          1992* 182 18  28 28.281 */
/*      182-92/ 12:29:29.192          0182+ 092 12  29 29.192 */
/*      182-'92/ 12:28:29.182         1992  182 12  28 29.182 */


/*      Julian Date Strings */

/*      jd 28272.291                  Julian Date   28272.291 */
/*      2451515.2981 (JD)             Julian Date 2451515.2981 */
/*      2451515.2981 JD               Julian Date 2451515.2981 */

/*                                   Abbreviations Used in Tables */

/*                                      na    --- Not Applicable */
/*                                      Mon   --- Month */
/*                                      DOY   --- Day of Year */
/*                                      DOM   --- Day of Month */
/*                                      Wkday --- Weekday */
/*                                      Hr    --- Hour */
/*                                      Min   --- Minutes */
/*                                      Sec   --- Sec */

/*      * The default interpretation of a year that has been abbreviated */
/*      with a leading quote as in 'xy (such as '92) is to treat */
/*      the year as 19xy if xy > 68 and to treat it is 20xy otherwise. */
/*      Thus '70 is interpreted as 1970 and '47 is treated as 2047. */
/*      However, you may change the "split point" and centuries through */
/*      use of the SPICE routine TSETYR which is an entry point in */
/*      the SPICE module TEXPYR.  See that routine for a discussion of */
/*      how you may reset the split point. */

/*      ** All epochs are regarded as belonging to the Gregorian */
/*      calendar.  We formally extend the Gregorian calendar backward */
/*      and forward in time for all epochs.  If you have epochs belonging */
/*      to the Julian Calendar, consult the routines TPARTV and JUL2GR */
/*      for a discussion concerning conversions to the Gregorian */
/*      calendar and ET. */

/*      +  When a day of year format or calendar format string is */
/*      input and neither of integer components of the date */
/*      is greater than 1000, the first integer */
/*      is regarded as being the year. */


/* $ Restrictions */

/*      The conversion between ET and UTC depends on the values in the */
/*      input kernel pool. The kernel pool should be loaded prior to */
/*      calling this routine. */

/*      Before using this routine for epochs prior to Jan 1, 1972 */
/*      be sure to check the "Particulars" section to make sure */
/*      that the assumptions made in this routine are consistent */
/*      with the accuracy you require for your application. */

/* $ Literature_References */

/*      Jesperson and Fitz-Randolph, From Sundials to Atomic Clocks, */
/*      Dover Publications, New York, 1977. */

/* $ Author_and_Institution */

/*      W.L. Taber      (JPL) */
/*      W.M. Owen       (JPL) */
/*      I.M. Underwood  (JPL) */

/* $ Version */

/* -      SPICELIB Version 2.1.0, 05-JAN-1998  (WLT) */

/*          Comments concerning the default century for abbreviated */
/*          years were updated to reflect changes to TEXPYR. */

/* -      SPICELIB Version 2.0.0, 20-NOV-1996  (WLT) */

/*          About the only thing that is the same in this routine */
/*          from the previous editions, is that the interface is */
/*          unchanged.  Nearly everything else has been modified. */
/*          The routine was modified to make use of TPARTV */
/*          and TTRANS to handle the task of parsing and */
/*          computing seconds past 2000 TDB.  This version */
/*          now handles leap seconds correctly. */

/* -      SPICELIB Version 1.0.1, 10-MAR-1992 (WLT) */

/*          Comment section for permuted index source lines was added */
/*          following the header. */

/* -      SPICELIB Version 1.0.0, 31-JAN-1990 (WMO) (IMU) */

/* -& */
/* $ Index_Entries */

/*     utc to ephemeris time */

/* -& */

/*     SPICELIB functions */


/*     Parameters */


/*     Local variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	return 0;
    }
    chkin_("UTC2ET", (ftnlen)6);

/*     So far we have no errors, the type of input is unknown. */

    s_copy(error, " ", (ftnlen)480, (ftnlen)1);
    s_copy(type__, " ", (ftnlen)8, (ftnlen)1);

/*     First parse the string and perform the various tests on */
/*     the validity of its components. */

    tpartv_(utcstr, tvec, &ntvec, type__, modify, &mods, &yabbrv, &succes, 
	    pictur, error, utcstr_len, (ftnlen)8, (ftnlen)8, (ftnlen)80, (
	    ftnlen)480);
    if (! succes) {
	setmsg_(error, (ftnlen)480);
	sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	chkout_("UTC2ET", (ftnlen)6);
	return 0;
    }

/*     We are not going to allow most of the modifiers in strings. */

    if (mods) {
	if (s_cmp(modify + 32, " ", (ftnlen)8, (ftnlen)1) != 0 && s_cmp(
		modify + 32, "UTC", (ftnlen)8, (ftnlen)3) != 0) {
	    s_copy(error, "UTC2ET does not support the specification of a ti"
		    "me system in a string.  The time system # was specified."
		    " Try the routine STR2ET.", (ftnlen)480, (ftnlen)129);
	    repmc_(error, "#", modify + 32, error, (ftnlen)480, (ftnlen)1, (
		    ftnlen)8, (ftnlen)480);
	    setmsg_(error, (ftnlen)480);
	    sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	    chkout_("UTC2ET", (ftnlen)6);
	    return 0;
	} else if (s_cmp(modify + 16, " ", (ftnlen)8, (ftnlen)1) != 0) {
	    s_copy(error, "UTC2ET does not support the specification of a ti"
		    "me zone in a time string.  The time zone '#' was specifi"
		    "ed. Try the routine STR2ET.", (ftnlen)480, (ftnlen)132);
	    repmc_(error, "#", modify + 16, error, (ftnlen)480, (ftnlen)1, (
		    ftnlen)8, (ftnlen)480);
	    setmsg_(error, (ftnlen)480);
	    sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	    chkout_("UTC2ET", (ftnlen)6);
	    return 0;
	} else if (s_cmp(modify + 24, " ", (ftnlen)8, (ftnlen)1) != 0) {
	    s_copy(error, "UTC2ET does not support the AM/PM conventions for"
		    " time strings. Try the routine STR2ET.", (ftnlen)480, (
		    ftnlen)87);
	    setmsg_(error, (ftnlen)480);
	    sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	    chkout_("UTC2ET", (ftnlen)6);
	    return 0;
	}
    }

/*     If parsing the time string went well, we let TTRANS handle */
/*     the problem of transforming the time vector to TDB. */

    if (s_cmp(type__, "YMD", (ftnlen)8, (ftnlen)3) == 0 || s_cmp(type__, 
	    "YD", (ftnlen)8, (ftnlen)2) == 0) {

/*        Check the components of the time vector for reasonableness. */

	tcheck_(tvec, type__, &mods, modify, &ok, error, (ftnlen)8, (ftnlen)8,
		 (ftnlen)480);
	if (! ok) {
	    setmsg_(error, (ftnlen)480);
	    sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	}

/*        Fix up the year as needed. */

	year = i_dnnt(tvec);
	if (s_cmp(modify, "B.C.", (ftnlen)8, (ftnlen)4) == 0) {
	    year = 1 - year;
	} else if (s_cmp(modify, "A.D.", (ftnlen)8, (ftnlen)4) == 0) {

/*           Do nothing. */

	} else if (year < 100) {
	    texpyr_(&year);
	}
	tvec[0] = (doublereal) year;

/*        We are ready for launch, convert the time vector. */

	ttrans_(type__, "TDB", tvec, (ftnlen)8, (ftnlen)3);
	*et = tvec[0];
    } else if (s_cmp(type__, "JD", (ftnlen)8, (ftnlen)2) == 0) {
	ttrans_("JDUTC", "TDB", tvec, (ftnlen)5, (ftnlen)3);
	*et = tvec[0];
    } else {

/*        The only way to get here is if we got some unexpected */
/*        type of time string. Signal an error. */

	setmsg_("# time strings are not handled by UTC2ET. ", (ftnlen)42);
	errch_("#", type__, (ftnlen)1, (ftnlen)8);
	sigerr_("SPICE(INVALIDTIMESTRING)", (ftnlen)24);
	chkout_("UTC2ET", (ftnlen)6);
	return 0;
    }
    chkout_("UTC2ET", (ftnlen)6);
    return 0;
} /* utc2et_ */

