# encoding: utf-8
from __future__ import absolute_import, division, print_function

from datetime import timedelta as _timedelta

from scipy.constants import kilo as _kilo

# IAU 2009 System of Astronomical Constants
# Updated as of 2014

constant_of_gravitation = 6.67428e-11  # m^3 kg^-1 s^-2
solar_mass_parameter    = 1.32712440041e20  # m^3 s^-2

sun_mass = solar_mass_parameter / constant_of_gravitation
geocentric_gravitational_constant = earth_mu = 3.986004415e14  # m^3 s^-2

earth_mass = geocentric_gravitational_constant / constant_of_gravitation

mercury_mass = sun_mass / 6.0236e6
venus_mass   = sun_mass / 4.08523710e5
mars_mass    = sun_mass / 3.09870359e6
jupiter_mass = sun_mass / 1.047348644e3
saturn_mass  = sun_mass / 3.4979018e3
uranus_mass  = sun_mass / 2.290298e4
neptune_mass = sun_mass / 1.941226e4
moon_mass    = sun_mass / 27082754.423010625

sun_radius_equatorial     = 696000    * _kilo
mercury_radius_equatorial = 2439.7    * _kilo
venus_radius_equatorial   = 6051.8    * _kilo
earth_radius_equatorial   = 6378.1366 * _kilo
mars_radius_equatorial    = 3396.19   * _kilo
jupiter_radius_equatorial = 71492     * _kilo
saturn_radius_equatorial  = 60268     * _kilo
uranus_radius_equatorial  = 25559     * _kilo
neptune_radius_equatorial = 24764     * _kilo
moon_radius_equatorial    = 1738.1    * _kilo

mercury_mu = mercury_mass * constant_of_gravitation
venus_mu   = venus_mass   * constant_of_gravitation
mars_mu    = mars_mass    * constant_of_gravitation
jupiter_mu = jupiter_mass * constant_of_gravitation
saturn_mu  = saturn_mass  * constant_of_gravitation
uranus_mu  = uranus_mass  * constant_of_gravitation
neptune_mu = neptune_mass * constant_of_gravitation
moon_mu    = moon_mass * constant_of_gravitation

mercury_radius_polar = mercury_radius_mean = mercury_radius_equatorial
venus_radius_polar = venus_radius_mean = venus_radius_equatorial

# The following constants are not from IAU
earth_radius_mean    = 6371.0 * _kilo
earth_radius_polar   = 6356.8 * _kilo

mars_radius_mean     = 3389.5 * _kilo
mars_radius_polar    = 3376.2 * _kilo

jupiter_radius_mean  = 69911 * _kilo
jupiter_radius_polar = 66854 * _kilo

saturn_radius_mean   = 58232 * _kilo
saturn_radius_polar  = 54364 * _kilo

uranus_radius_mean   = 25362 * _kilo
uranus_radius_polar  = 24973 * _kilo

neptune_radius_mean  = 24622 * _kilo
neptune_radius_polar = 24341 * _kilo

moon_radius_mean     = 1737.4* _kilo
moon_radius_polar    = 1736.0* _kilo

# 4.1 s, 56 minutes, 23 hours
earth_sidereal_day = _timedelta(hours=23, minutes=56, seconds=4.1).total_seconds()
