# -*- mode: python; coding: utf-8 -*-
# Copyright (c) 2019 Radio Astronomy Software Group
# Licensed under the 2-clause BSD License

"""Testing environment setup and teardown for pytest."""
import os

import pytest
from astropy.utils import iers
from astropy.time import Time
import numpy as np

from pyuvdata.data import DATA_PATH
from pyuvdata import UVData, UVBeam

filenames = ["HERA_NicCST_150MHz.txt", "HERA_NicCST_123MHz.txt"]
cst_folder = "NicCSTbeams"
cst_files = [os.path.join(DATA_PATH, cst_folder, f) for f in filenames]
casa_tutorial_uvfits = os.path.join(
    DATA_PATH, "day2_TDEM0003_10s_norx_1src_1spw.uvfits"
)
paper_miriad_file = os.path.join(DATA_PATH, "zen.2456865.60537.xy.uvcRREAA")


@pytest.fixture(autouse=True, scope="session")
def setup_and_teardown_package():
    """Handle possible IERS issues."""
    # Do a calculation that requires a current IERS table. This will trigger
    # automatic downloading of the IERS table if needed, including trying the
    # mirror site in python 3 (but won't redownload if a current one exists).
    # If there's not a current IERS table and it can't be downloaded, turn off
    # auto downloading for the tests and turn it back on once all tests are
    # completed (done by extending auto_max_age).
    # Also, the check_warnings function will ignore IERS-related warnings.
    try:
        t1 = Time.now()
        t1.ut1
    except (Exception):
        iers.conf.auto_max_age = None

    yield

    iers.conf.auto_max_age = 30


@pytest.fixture(scope="session")
def casa_uvfits_main():
    """Read in CASA tutorial uvfits file."""
    uv_in = UVData()
    uv_in.read(casa_tutorial_uvfits)

    return uv_in


@pytest.fixture(scope="function")
def casa_uvfits(casa_uvfits_main):
    """Make function level CASA tutorial uvfits object."""
    casa_uvfits = casa_uvfits_main.copy()
    yield casa_uvfits

    # clean up when done
    del casa_uvfits

    return


@pytest.fixture(scope="session")
def paper_miriad_main():
    """Read in PAPER miriad file."""
    pytest.importorskip("pyuvdata.uvdata.aipy_extracts")
    uv_in = UVData()
    uv_in.read(paper_miriad_file)

    return uv_in


@pytest.fixture(scope="function")
def paper_miriad(paper_miriad_main):
    """Make function level PAPER miriad object."""
    uv_in = paper_miriad_main.copy()

    yield uv_in

    # cleanup
    del uv_in


def make_cst_beam(beam_type, nfreq):
    """Make the default CST testing beam."""
    extra_keywords = {
        "software": "CST 2016",
        "sim_type": "E-farfield",
        "layout": "1 antenna",
        "port_num": 1,
    }

    beam = UVBeam()
    beam.read_cst_beam(
        cst_files,
        beam_type=beam_type,
        frequency=[150e6, 123e6],
        telescope_name="HERA",
        feed_name="Dipole",
        feed_version="1.0",
        feed_pol=["x"],
        model_name="Dipole - Rigging height 4.9 m",
        model_version="1.0",
        x_orientation="east",
        reference_impedance=100,
        history=(
            "Derived from https://github.com/Nicolas-Fagnoni/Simulations."
            "\nOnly 2 files included to keep test data volume low."
        ),
        extra_keywords=extra_keywords,
    )
    return beam


def cut_beam(beam):
    """Downselect a beam to a small sky area to speed tests up."""
    za_max = np.deg2rad(10.0)
    za_inds_use = np.nonzero(beam.axis2_array <= za_max)[0]
    beam.select(axis2_inds=za_inds_use)
    return beam


def single_freq_version(beam):
    """Make a single freq version with expected history."""
    history_use = beam.history[: beam.history.find(" Combined data")]
    beam.select(freq_chans=1)
    beam.history = history_use
    return beam


@pytest.fixture(scope="session")
def cst_efield_2freq_main():
    """Make session level 2-freq efield beam."""
    return make_cst_beam("efield", 2)


@pytest.fixture(scope="function")
def cst_efield_2freq(cst_efield_2freq_main):
    """Make function level 2-freq efield beam."""
    return cst_efield_2freq_main.copy()


@pytest.fixture(scope="session")
def cst_efield_2freq_cut_main(cst_efield_2freq_main):
    """Make session level cut down 2-freq efield beam."""
    return cut_beam(cst_efield_2freq_main.copy())


@pytest.fixture(scope="function")
def cst_efield_2freq_cut(cst_efield_2freq_cut_main):
    """Make function level cut down 2-freq efield beam."""
    return cst_efield_2freq_cut_main.copy()


@pytest.fixture(scope="session")
def cst_efield_2freq_cut_healpix_main(cst_efield_2freq_cut_main):
    """Make session level cut down HEALPix 2-freq efield beam."""
    pytest.importorskip("astropy_healpix")
    beam = cst_efield_2freq_cut_main.copy()
    beam.interpolation_function = "az_za_simple"
    beam.to_healpix()
    return beam


@pytest.fixture(scope="function")
def cst_efield_2freq_cut_healpix(cst_efield_2freq_cut_healpix_main):
    """Make function level cut down HEALPix 2-freq efield beam."""
    return cst_efield_2freq_cut_healpix_main.copy()


@pytest.fixture(scope="session")
def cst_efield_1freq_main(cst_efield_2freq_main):
    """Make session level single freq efield beam."""
    return single_freq_version(cst_efield_2freq_main.copy())


@pytest.fixture(scope="function")
def cst_efield_1freq(cst_efield_1freq_main):
    """Make function level single freq efield beam."""
    return cst_efield_1freq_main.copy()


@pytest.fixture(scope="session")
def cst_efield_1freq_cut_main(cst_efield_2freq_cut_main):
    """Make session level cut down single freq efield beam."""
    return single_freq_version(cst_efield_2freq_cut_main.copy())


@pytest.fixture(scope="function")
def cst_efield_1freq_cut(cst_efield_1freq_cut_main):
    """Make function level cut down single freq efield beam."""
    return cst_efield_1freq_cut_main.copy()


@pytest.fixture(scope="session")
def cst_efield_1freq_cut_healpix_main(cst_efield_2freq_cut_healpix_main):
    """Make session level HEALPix cut down single freq efield beam."""
    return single_freq_version(cst_efield_2freq_cut_healpix_main.copy())


@pytest.fixture(scope="function")
def cst_efield_1freq_cut_healpix(cst_efield_1freq_cut_healpix_main):
    """Make function level HEALPix cut down single freq efield beam."""
    return cst_efield_1freq_cut_healpix_main.copy()


@pytest.fixture(scope="session")
def cst_power_2freq_main():
    """Make session level 2-freq power beam."""
    return make_cst_beam("power", 2)


@pytest.fixture(scope="function")
def cst_power_2freq(cst_power_2freq_main):
    """Make function level 2-freq efield beam."""
    return cst_power_2freq_main.copy()


@pytest.fixture(scope="session")
def cst_power_2freq_cut_main(cst_power_2freq_main):
    """Make session level cut down 2-freq power beam."""
    return cut_beam(cst_power_2freq_main.copy())


@pytest.fixture(scope="function")
def cst_power_2freq_cut(cst_power_2freq_cut_main):
    """Make function level cut down 2-freq power beam."""
    return cst_power_2freq_cut_main.copy()


@pytest.fixture(scope="session")
def cst_power_2freq_cut_healpix_main(cst_power_2freq_cut_main):
    """Make session level HEALPix cut down 2-freq power beam."""
    pytest.importorskip("astropy_healpix")
    beam = cst_power_2freq_cut_main.copy()
    beam.interpolation_function = "az_za_simple"
    beam.to_healpix()
    return beam


@pytest.fixture(scope="function")
def cst_power_2freq_cut_healpix(cst_power_2freq_cut_healpix_main):
    """Make function level HEALPix cut down 2-freq power beam."""
    return cst_power_2freq_cut_healpix_main.copy()


@pytest.fixture(scope="session")
def cst_power_1freq_main(cst_power_2freq_main):
    """Make session level single freq power beam."""
    return single_freq_version(cst_power_2freq_main.copy())


@pytest.fixture(scope="function")
def cst_power_1freq(cst_power_1freq_main):
    """Make function level single freq power beam."""
    return cst_power_1freq_main.copy()


@pytest.fixture(scope="session")
def cst_power_1freq_cut_main(cst_power_2freq_cut_main):
    """Make session level cut down single freq power beam."""
    return single_freq_version(cst_power_2freq_cut_main.copy())


@pytest.fixture(scope="function")
def cst_power_1freq_cut(cst_power_1freq_cut_main):
    """Make function level cut down single freq power beam."""
    return cst_power_1freq_cut_main.copy()


@pytest.fixture(scope="session")
def cst_power_1freq_cut_healpix_main(cst_power_2freq_cut_healpix_main):
    """Make session level HEALPix cut down single freq power beam."""
    return single_freq_version(cst_power_2freq_cut_healpix_main.copy())


@pytest.fixture(scope="function")
def cst_power_1freq_cut_healpix(cst_power_1freq_cut_healpix_main):
    """Make function level HEALPix cut down single freq power beam."""
    return cst_power_1freq_cut_healpix_main.copy()