/*
Copyright (c) 2015, 2016 Saurav Sachidanand

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

//! Corrections for aberration

use angle;
use time;
use coords;

/**
Computes solar aberration in ecliptic longitude

# Returns

* `abrr`: Solar aberration in ecliptic
          longitude *| in radians*

# Arguments

* `R`: Sun-Earth distance *| in AU*
**/
#[inline(always)]
pub fn sol_aberr(R: f64) -> f64 {

    -angle::deg_frm_dms(0, 0, 20.4898).to_radians() / R

}

/**
Computes stellar aberration in equatorial coordinates

# Returns

`(abrr_in_asc, abrr_in_dec)`

* `abrr_in_asc`: Aberration in right ascension *| in radians*
* `abrr_in_dec`: Aberration in declination *| in radians*

# Arguments

* `stell_eq_point`: Equatorial coordinates of the star *| in radians*
* `JD`            : Julian (Ephemeris) day
**/
pub fn stell_aberr_in_eq_coords(stell_eq_point: &coords::EqPoint, JD: f64) -> (f64, f64) {

    let t = time::julian_cent(JD);

    let l2 = 3.1761467 + 1021.3285546*t;
    let l3 = 1.7534703 +  628.3075849*t;
    let l4 = 6.2034809 +  334.0612431*t;
    let l5 = 0.5995465 +   52.9690965*t;
    let l6 = 0.8740168 +   21.3299095*t;
    let l7 = 5.4812939 +    7.4781599*t;
    let l8 = 5.3118863 +    3.8133036*t;
    let l1 = 3.8103444 + 8399.6847337*t;
    let d  = 5.1984667 + 7771.3771486*t;
    let m1 = 2.3555559 + 8328.6914289*t;
    let f  = 1.6279052 + 8433.4661601*t;

    let mut x = 0.0;
    let mut y = 0.0;
    let mut z = 0.0;

    let mut A;
    let mut sinA;
    let mut cosA;

    // ROW 1
    A = l3;
    sinA = A.sin(); cosA = A.cos();
    x += (-1719914.0 - 2.0*t)*sinA - 25.0*cosA;
    y += (25.0 - 13.0*t)*sinA + (1578089.0 + 156.0*t)*cosA;
    z += (10.0 + 32.0*t)*sinA + (684185.0 - 358.0*t)*cosA;

    // ROW 2
    A = 2.0 * l3;
    sinA = A.sin(); cosA = A.cos();
    x += (6434.0 + 141.0*t)*sinA + (28007.0 - 107.0*t)*cosA;
    y += (25697.0 - 95.0*t)*sinA + (-5904.0 - 130.0*t)*cosA;
    z += (11141.0 - 48.0*t)*sinA + (-2559.0 - 55.0*t)*cosA;

    // ROW 3
    A = l5;
    sinA = A.sin(); cosA = A.cos();
    x += 715.0*sinA;
    y += 6.0*sinA - 657.0*cosA;
    z += -15.0*sinA - 282.0*cosA;

    // ROW 4
    A = l1;
    sinA = A.sin(); cosA = A.cos();
    x += 715.0*sinA;
    y += -656.0*cosA;
    z += -285.0*cosA;

    // ROW 5
    A = 3.0 * l3;
    sinA = A.sin(); cosA = A.cos();
    x += (486.0 - 5.0*t)*sinA + (-236.0 - 4.0*t)*cosA;
    y += (-216.0 - 4.0*t)*sinA + (-446.0 + 5.0*t)*cosA;
    z += -94.0*sinA - 193.0*cosA;

    // ROW 6
    A = l6;
    sinA = A.sin(); cosA = A.cos();
    x += 159.0*sinA;
    y += 2.0*sinA - 147.0*cosA;
    z += -6.0*sinA - 61.0*cosA;

    // ROW 7
    A = f;
    cosA = A.cos();
    y += 26.0*cosA;
    z += -59.0*cosA;

    // ROW 8
    A = l1 + m1;
    sinA = A.sin(); cosA = A.cos();
    x += 39.0*sinA;
    y += -36.0*cosA;
    z += -16.0*cosA;

    // ROW 9
    A = 2.0 * l5;
    sinA = A.sin(); cosA = A.cos();
    x += 33.0*sinA - 10.0*cosA;
    y += -9.0*sinA - 30.0*cosA;
    z += -5.0*sinA - 13.0*cosA;

    // ROW 10
    A = 2.0*l3 - l5;
    sinA = A.sin(); cosA = A.cos();
    x += 31.0*sinA + cosA;
    y += sinA - 28.0*cosA;
    z += -12.0*cosA;

    // ROW 11
    A = 3.0*l3 - 8.0*l4 + 3.0*l5;
    sinA = A.sin(); cosA = A.cos();
    x += 8.0*sinA - 28.0*cosA;
    y += 25.0*sinA + 8.0*cosA;
    z += 11.0*sinA + 3.0*cosA;

    // ROW 12
    A = 5.0*l3 - 8.0*l4 + 3.0*l5;
    sinA = A.sin(); cosA = A.cos();
    x += 8.0*sinA - 28.0*cosA;
    y += -25.0*sinA - 8.0*cosA;
    z += -11.0*sinA - 3.0*cosA;

    // ROW 13
    A = 2.0*l2 - l3;
    sinA = A.sin(); cosA = A.cos();
    x += 21.0*sinA;
    y += -19.0*cosA;
    z += -8.0*cosA;

    // ROW 14
    A = l2;
    sinA = A.sin(); cosA = A.cos();
    x += -19.0*sinA;
    y += 17.0*cosA;
    z += 8.0*cosA;

    // ROW 15
    A = l7;
    sinA = A.sin(); cosA = A.cos();
    x += 17.0*sinA;
    y += -16.0*cosA;
    z += -7.0*cosA;

    // ROW 16
    A = l3 - 2.0*l5;
    sinA = A.sin(); cosA = A.cos();
    x += 16.0*sinA;
    y += 15.0*cosA;
    z += sinA + 7.0*cosA;

    // ROW 17
    A = l8;
    sinA = A.sin(); cosA = A.cos();
    x += 16.0*sinA;
    y += sinA - 15.0*cosA;
    z += -3.0*sinA - 6.0*cosA;

    // ROW 18
    A = l3 + l5;
    sinA = A.sin(); cosA = A.cos();
    x += 11.0*sinA - cosA;
    y += -1.0*sinA - 10.0*cosA;
    z += -1.0*sinA - 5.0*cosA;

    // ROW 19
    A = 2.0 * (l2 - l3);
    sinA = A.sin(); cosA = A.cos();
    x += -11.0*cosA;
    y += -10.0*sinA;
    z += -4.0*sinA;

    // ROW 20
    A = l3 - l5;
    sinA = A.sin(); cosA = A.cos();
    x += -11.0*sinA - 2.0*cosA;
    y += -2.0*sinA + 9.0*cosA;
    z += -1.0*sinA + 4.0*cosA;

    // ROW 21
    A = 4.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -7.0*sinA - 8.0*cosA;
    y += -8.0*sinA + 6.0*cosA;
    z += 3.0 * (cosA - sinA);

    // ROW 22
    A = 3.0*l3 - 2.0*l5;
    sinA = A.sin(); cosA = A.cos();
    x += -10.0*sinA;
    y += 9.0*cosA;
    z += 4.0*cosA;

    // ROW 23
    A = l2 - 2.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -9.0*sinA;
    y += -9.0*cosA;
    z += -4.0*cosA;

    // ROW 24
    A = 2.0*l2 - 3.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -9.0*sinA;
    y += -8.0*cosA;
    z += -4.0*cosA;

    // ROW 25
    A = 2.0*l6;
    sinA = A.sin(); cosA = A.cos();
    x += -9.0*cosA;
    y += -8.0*sinA;
    z += -3.0*sinA;

    // ROW 26
    A = 2.0*l2 - 4.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -9.0*cosA;
    y += 8.0*sinA;
    z += 3.0*sinA;

    // ROW 27
    A = 3.0*l3 - 2.0*l4;
    sinA = A.sin(); cosA = A.cos();
    x += 8.0*sinA;
    y += -8.0*cosA;
    z += -3.0*cosA;

    // ROW 28
    A = l1 + 2.0*d - m1;
    sinA = A.sin(); cosA = A.cos();
    x += 8.0*sinA;
    y += -7.0*cosA;
    z += -3.0*cosA;

    // ROW 29
    A = 8.0*l2 - 12.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -4.0*sinA - 7.0*cosA;
    y += -6.0*sinA + 4.0*cosA;
    z += -3.0*sinA + 2.0*cosA;

    // ROW 30
    A = 8.0*l2 - 14.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -4.0*sinA - 7.0*cosA;
    y += 6.0*sinA - 4.0*cosA;
    z += 3.0*sinA - 2.0*cosA;

    // ROW 31
    A = 2.0*l4;
    sinA = A.sin(); cosA = A.cos();
    x += -6.0*sinA - 5.0*cosA;
    y += -4.0*sinA + 5.0*cosA;
    z += 2.0 * (cosA - sinA);

    // ROW 32
    A = 3.0*l2 - 4.0*l3;
    sinA = A.sin(); cosA = A.cos();
    x += -1.0 * (sinA + cosA);
    y += -2.0*sinA - 7.0*cosA;
    z += sinA - 4.0*cosA;

    // ROW 33
    A = 2.0 * (l3 - l5);
    sinA = A.sin(); cosA = A.cos();
    x += 4.0*sinA - 6.0*cosA;
    y += -5.0*sinA - 4.0*cosA;
    z += -2.0 * (sinA + cosA);

    // ROW 34
    A = 3.0 * (l2 - l3);
    sinA = A.sin(); cosA = A.cos();
    x += -7.0*cosA;
    y += -6.0*sinA;
    z += -3.0*sinA;

    // ROW 35
    A = 2.0 * (l3 - l4);
    sinA = A.sin(); cosA = A.cos();
    x += 5.0 * (sinA - cosA);
    y += -4.0*sinA - 5.0*cosA;
    z += -2.0 * (sinA + cosA);

    // ROW 36
    A = l1 - 2.0*d;
    sinA = A.sin(); cosA = A.cos();
    x += 5.0*sinA;
    y += -5.0*cosA;
    z += -2.0*cosA;

    let c = 17314463350.0;

    let (asc, dec) = (stell_eq_point.asc, stell_eq_point.dec);

    let delta_asc = (y*asc.cos() - x*asc.sin()) / (c*dec.cos());
    let delta_dec = -(((x*asc.cos() + y*asc.sin())*dec.sin() - z*dec.cos())) / c;

    (delta_asc, delta_dec)

}