use crate::consts::{DAS2R, TURNAS};

use std::ops::Rem;

/// Fundamental argument, IERS Conventions (2003):

/// mean anomaly of the Moon.

///

/// Status:  canonical model.

///

/// Given:

///    t     f64    TDB, Julian centuries since J2000.0 (Note 1)

///

/// Returned (function value):

///          f64    l, radians (Note 2)

///

/// Notes:

///

/// 1) Though t is strictly TDB, it is usually more convenient to use

///    TT, which makes no significant difference.

///

/// 2) The expression used is as adopted in IERS Conventions (2003) and

///    is from Simon et al. (1994).

///

/// References:

///

///    McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),

///    IERS Technical Note No. 32, BKG (2004)

///

///    Simon, J.-L., Bretagnon, P., Chapront, J., Chapront-Touze, M.,

///    Francou, G., Laskar, J. 1994, Astron.Astrophys. 282, 663-683

pub fn fal03(t: f64) -> f64 {

    /* Mean anomaly of the Moon (IERS Conventions 2003). */

    (485868.249036 + t * (1717915923.2178 + t * (31.8792 + t * (0.051635 + t * -0.00024470))))

        .rem(TURNAS)

        * DAS2R

}