"""PINT Is Not TEMPO3!

This package has many submodules, but useful starting places may be
:class:`pint.toa.TOAs`, :class:`pint.models.timing_model.TimingModel`, and
:class:`pint.residuals.Residuals`.

Below you will find a tree of submodules. The online documentation should also
provide a usable table of contents.

These docstrings contain reference documentation; for tutorials, explanations,
or how-to documentation, please see other sections of the online documentation.
"""

import astropy
import astropy.constants as c
import astropy.time as time
import astropy.units as u
import numpy as np
import pkg_resources
from astropy.units import si

from pint import logging
from pint.extern._version import get_versions
from pint.pulsar_ecliptic import PulsarEcliptic
from pint.pulsar_mjd import PulsarMJD, time_to_longdouble  # ensure always loaded


__all__ = [
    "__version__",
    "ls",
    "dmu",
    "light_second_equivalency",
    "hourangle_second",
    "pulsar_mjd",
    "GMsun",
    "Tsun",
    "Tmercury",
    "Tvenus",
    "Tearth",
    "Tmars",
    "Tjupiter",
    "Tsaturn",
    "Turanus",
    "Tneptune",
    "J2000",
    "J2000ld",
    "JD_MJD",
    "pint_units",
    # "PulsarEcliptic",
    # "PulsarMJD",
]

__version__ = get_versions()["version"]

# Define a few important constants

# light-second unit
ls = u.def_unit("ls", c.c * 1.0 * u.s)

# DM unit (pc cm^-3)
dmu = u.def_unit("dmu", u.pc * u.cm**-3)

# This value is cited from Duncan Lorimer, Michael Kramer, Handbook of Pulsar
# Astronomy, Second edition, Page 86, Note 1
DMconst = 1.0 / 2.41e-4 * u.MHz * u.MHz * u.s * u.cm**3 / u.pc

# define equivalency for astropy units
light_second_equivalency = [(ls, si.second, lambda x: x, lambda x: x)]
# hourangle_second unit
hourangle_second = u.def_unit("hourangle_second", u.hourangle / np.longdouble(3600.0))

# Following are from here:
# http://ssd.jpl.nasa.gov/?constants (grabbed on 30 Dec 2013)
GMsun = 1.32712440018e20 * u.m**3 / u.s**2

# Solar mass in time units (sec)
Tsun = (GMsun / c.c**3).to(u.s)

# Planet system(!) masses in time units
Tmercury = Tsun / 6023600.0
Tvenus = Tsun / 408523.71
Tearth = Tsun / 328900.56  # Includes Moon!
Tmars = Tsun / 3098708.0
Tjupiter = Tsun / 1047.3486
Tsaturn = Tsun / 3497.898
Turanus = Tsun / 22902.98
Tneptune = Tsun / 19412.24

# The Epoch J2000
J2000 = time.Time("2000-01-01 12:00:00", scale="utc")
J2000ld = time_to_longdouble(J2000)
JD_MJD = 2400000.5
# PINT special units list
pint_units = {
    "H:M:S": u.hourangle,
    "D:M:S": u.deg,
    "lt-s": ls,
    "ls": ls,
    "Tsun": Tsun,
    "GMsun": GMsun,
    "MJD": u.day,
    "pulse phase": u.dimensionless_unscaled,
    "hourangle_second": hourangle_second,
}

import astropy.version

if astropy.version.major < 4:
    raise ValueError(
        f"astropy version must be >=4 (currently it is {astropy.version.major})"
    )
