import datetime
import os

import pytest

from suvi import paths

GOOD = "dr_suvi-l2-ci171_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits"


def test_parses_a_real_filename():
    frame = paths.parse_frame_filename(GOOD)
    assert frame.satellite == 16
    assert frame.wavelength == 171
    assert frame.version == "1-0-2"
    assert frame.label is None
    assert frame.t_end - frame.t_start == paths.CADENCE
    assert frame.t_start == int(
        datetime.datetime(2024, 5, 10, tzinfo=datetime.timezone.utc).timestamp()
    )


@pytest.mark.parametrize("label", [None, "f", "e"])
def test_filename_round_trips(label):
    name = GOOD if label is None else GOOD.replace(".fits", f"_{label}.fits")
    frame = paths.parse_frame_filename(name)
    assert frame.label == label
    assert frame.filename(label) == name


def test_double_suffix_keeps_outermost_label():
    """Re-processing an already-labelled file produced '..._f_f.fits' in the archive."""
    frame = paths.parse_frame_filename(GOOD.replace(".fits", "_f_e.fits"))
    assert frame.label == "e"
    assert frame.filename() == GOOD


def test_relpath_files_under_the_start_date():
    """A frame opening at 23:58 belongs to that day, not the day it ends on."""
    name = "dr_suvi-l2-ci304_g18_s20241231T235800Z_e20250101T000200Z_v1-0-2.fits"
    frame = paths.parse_frame_filename(name)
    assert frame.relpath() == (
        "goes18/l2/data/suvi-l2-ci304/2024/12/31/" + name
    )


def test_slot_identifies_the_observation():
    frame = paths.parse_frame_filename(GOOD)
    labelled = paths.parse_frame_filename(GOOD.replace(".fits", "_e.fits"))
    assert frame.slot == labelled.slot == (16, 171, frame.t_start)


def test_error_plot_name_matches_legacy_filter_output():
    frame = paths.parse_frame_filename(GOOD)
    assert frame.error_plot_name() == GOOD.replace(".fits", "_e.jpg")


@pytest.mark.parametrize(
    "name",
    [
        "",
        "x" * 300,
        "README.txt",
        "dr_suvi-l2-ci171_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits.bak",
        "dr_suvi-l2-ci999_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits",  # bad band
        "dr_suvi-l2-ci171_g17_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits",  # excluded sat
        "dr_suvi-l2-ci171_g16_s20241310T000000Z_e20240510T000400Z_v1-0-2.fits",  # month 13
        "dr_suvi-l2-ci171_g16_s20240510T000400Z_e20240510T000000Z_v1-0-2.fits",  # end <= start
        "dr_suvi-l2-ci171_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2_x.fits",  # bad label
        "../dr_suvi-l2-ci171_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits",
        "sub/dr_suvi-l2-ci171_g16_s20240510T000000Z_e20240510T000400Z_v1-0-2.fits",
    ],
)
def test_rejects_malformed_names(name):
    assert paths.parse_frame_filename(name) is None


def test_rejects_non_string_input():
    for value in (None, 42, b"bytes", ["list"]):
        assert paths.parse_frame_filename(value) is None


def test_filename_rejects_unknown_label():
    frame = paths.parse_frame_filename(GOOD)
    with pytest.raises(ValueError):
        frame.filename("q")


def test_abspath_resolves_within_the_root(tmp_path):
    frame = paths.parse_frame_filename(GOOD)
    resolved = paths.abspath(frame.relpath(), root=str(tmp_path))
    assert resolved.startswith(str(tmp_path) + os.sep)
    assert resolved.endswith(GOOD)


@pytest.mark.parametrize("hostile", ["../../etc/passwd", "goes16/../../../etc/passwd"])
def test_abspath_refuses_to_escape_the_root(tmp_path, hostile):
    with pytest.raises(ValueError):
        paths.abspath(hostile, root=str(tmp_path))


def test_data_root_honours_the_environment(archive):
    assert paths.data_root() == str(archive)


def test_default_db_path_honours_the_environment(monkeypatch, tmp_path):
    target = tmp_path / "scratch.sqlite"
    monkeypatch.setenv("SUVI_DB", str(target))
    assert paths.default_db_path() == str(target)


def test_wavelength_dirs_covers_every_combination(tmp_path):
    dirs = paths.wavelength_dirs(str(tmp_path))
    assert len(dirs) == len(paths.SATELLITES) * len(paths.WAVELENGTHS)
    assert len(set(dirs)) == len(dirs)