use super::{IauAstrom, apco13, atciq, atioq};

///  ICRS −> observed

///

///  ICRS RA,Dec to observed place.  The caller supplies UTC, site

///  coordinates, ambient air conditions and observing wavelength.

///

///  SOFA models are used for the Earth ephemeris, bias-precession-

///  nutation, Earth orientation and refraction.

///

///  This function is part of the International Astronomical Union's

///  SOFA (Standards of Fundamental Astronomy) software collection.

///

///  Status:  support function.

///

///  Given:

///  ```

///     rc,dc  double   ICRS right ascension at J2000.0 (radians, Note 1)

///     pr     double   RA proper motion (radians/year, Note 2)

///     pd     double   Dec proper motion (radians/year)

///     px     double   parallax (arcsec)

///     rv     double   radial velocity (km/s, +ve if receding)

///     utc1   double   UTC as a 2-part...

///     utc2   double   ...quasi Julian Date (Notes 3-4)

///     dut1   double   UT1-UTC (seconds, Note 5)

///     elong  double   longitude (radians, east +ve, Note 6)

///     phi    double   latitude (geodetic, radians, Note 6)

///     hm     double   height above ellipsoid (m, geodetic, Notes 6,8)

///     xp,yp  double   polar motion coordinates (radians, Note 7)

///     phpa   double   pressure at the observer (hPa = mB, Note 8)

///     tc     double   ambient temperature at the observer (deg C)

///     rh     double   relative humidity at the observer (range 0-1)

///     wl     double   wavelength (micrometers, Note 9)

///  ```

///  Returned

///  ```

///     aob    double*  observed azimuth (radians: N=0,E=90)

///     zob    double*  observed zenith distance (radians)

///     hob    double*  observed hour angle (radians)

///     dob    double*  observed declination (radians)

///     rob    double*  observed right ascension (CIO-based, radians)

///     eo     double*  equation of the origins (ERA-GST, radians)

///  ```

///  Returned (function value):

///  ```

///            int      status: +1 = dubious year (Note 4)

///                              0 = OK

///                             -1 = unacceptable date

///  ```

///

///  Notes:

///

///  1)  Star data for an epoch other than J2000.0 (for example from the

///      Hipparcos catalog, which has an epoch of J1991.25) will require

///      a preliminary call to iauPmsafe before use.

///

///  2)  The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt.

///

///  3)  utc1+utc2 is quasi Julian Date (see Note 2), apportioned in any

///      convenient way between the two arguments, for example where utc1

///      is the Julian Day Number and utc2 is the fraction of a day.

///

///      However, JD cannot unambiguously represent UTC during a leap

///      second unless special measures are taken.  The convention in the

///      present function is that the JD day represents UTC days whether

///      the length is 86399, 86400 or 86401 SI seconds.

///

///      Applications should use the function iauDtf2d to convert from

///      calendar date and time of day into 2-part quasi Julian Date, as

///      it implements the leap-second-ambiguity convention just

///      described.

///

///  4)  The warning status "dubious year" flags UTCs that predate the

///      introduction of the time scale or that are too far in the

///      future to be trusted.  See iauDat for further details.

///

///  5)  UT1-UTC is tabulated in IERS bulletins.  It increases by exactly

///      one second at the end of each positive UTC leap second,

///      introduced in order to keep UT1-UTC within +/- 0.9s.  n.b. This

///      practice is under review, and in the future UT1-UTC may grow

///      essentially without limit.

///

///  6)  The geographical coordinates are with respect to the WGS84

///      reference ellipsoid.  TAKE CARE WITH THE LONGITUDE SIGN:  the

///      longitude required by the present function is east-positive

///      (i.e. right-handed), in accordance with geographical convention.

///

///  7)  The polar motion xp,yp can be obtained from IERS bulletins.  The

///      values are the coordinates (in radians) of the Celestial

///      Intermediate Pole with respect to the International Terrestrial

///      Reference System (see IERS Conventions 2003), measured along the

///      meridians 0 and 90 deg west respectively.  For many

///      applications, xp and yp can be set to zero.

///

///  8)  If hm, the height above the ellipsoid of the observing station

///      in meters, is not known but phpa, the pressure in hPa (=mB),

///      is available, an adequate estimate of hm can be obtained from

///      the expression

///

///            hm = -29.3 * tsl * log ( phpa / 1013.25 );

///

///      where tsl is the approximate sea-level air temperature in K

///      (See Astrophysical Quantities, C.W.Allen, 3rd edition, section

///      52).  Similarly, if the pressure phpa is not known, it can be

///      estimated from the height of the observing station, hm, as

///      follows:

///

///            phpa = 1013.25 * exp ( -hm / ( 29.3 * tsl ) );

///

///      Note, however, that the refraction is nearly proportional to

///      the pressure and that an accurate phpa value is important for

///      precise work.

///

///  9)  The argument wl specifies the observing wavelength in

///      micrometers.  The transition from optical to radio is assumed to

///      occur at 100 micrometers (about 3000 GHz).

///

///  10) The accuracy of the result is limited by the corrections for

///      refraction, which use a simple A*tan(z) + B*tan^3(z) model.

///      Providing the meteorological parameters are known accurately and

///      there are no gross local effects, the predicted observed

///      coordinates should be within 0.05 arcsec (optical) or 1 arcsec

///      (radio) for a zenith distance of less than 70 degrees, better

///      than 30 arcsec (optical or radio) at 85 degrees and better

///      than 20 arcmin (optical) or 30 arcmin (radio) at the horizon.

///

///      Without refraction, the complementary functions iauAtco13 and

///      iauAtoc13 are self-consistent to better than 1 microarcsecond

///      all over the celestial sphere.  With refraction included,

///      consistency falls off at high zenith distances, but is still

///      better than 0.05 arcsec at 85 degrees.

///

///  11) "Observed" Az,ZD means the position that would be seen by a

///      perfect geodetically aligned theodolite.  (Zenith distance is

///      used rather than altitude in order to reflect the fact that no

///      allowance is made for depression of the horizon.)  This is

///      related to the observed HA,Dec via the standard rotation, using

///      the geodetic latitude (corrected for polar motion), while the

///      observed HA and RA are related simply through the Earth rotation

///      angle and the site longitude.  "Observed" RA,Dec or HA,Dec thus

///      means the position that would be seen by a perfect equatorial

///      with its polar axis aligned to the Earth's axis of rotation.

///

///  12) It is advisable to take great care with units, as even unlikely

///      values of the input parameters are accepted and processed in

///      accordance with the models used.

///

///  Called:

///  ```

///     iauApco13    astrometry parameters, ICRS-observed, 2013

///     iauAtciq     quick ICRS to CIRS

///     iauAtioq     quick CIRS to observed

///  ```

pub fn atco13(

    rc: f64,

    dc: f64,

    pr: f64,

    pd: f64,

    px: f64,

    rv: f64,

    utc1: f64,

    utc2: f64,

    dut1: f64,

    elong: f64,

    phi: f64,

    hm: f64,

    xp: f64,

    yp: f64,

    phpa: f64,

    tc: f64,

    rh: f64,

    wl: f64,

) -> Result<(f64, f64, f64, f64, f64, f64), i32> {

    let astrom = &mut IauAstrom::default();

    let eo = &mut 0.0;

    /* Star-independent astrometry parameters. */

    let j = apco13(

        utc1, utc2, dut1, elong, phi, hm, xp, yp, phpa, tc, rh, wl, astrom, eo,

    );

    /* Abort if bad UTC. */

    if j.is_err() {

        return Err(j.unwrap_err());

    };

    /* Transform ICRS to CIRS. */

    let (ri, di) = atciq(rc, dc, pr, pd, px, rv, astrom);

    /* Transform CIRS to observed. */

    let (aob, zob, hob, dob, rob) = atioq(ri, di, astrom);

    /* Return values */

    Ok((aob, zob, hob, dob, rob, *eo))

}