"""Tests for the tomo_type-4 angle file parser (OMNY_shared/angle_file.py)."""

import pytest

from csaxs_bec.bec_ipython_client.plugins.OMNY_shared.angle_file import (
    AngleFileError,
    describe_opposite_pairs,
    describe_summary,
    read_angle_file,
    summarize_angles,
)


def _write(tmp_path, text, name="angles.txt"):
    path = tmp_path / name
    path.write_text(text)
    return str(path)


def test_one_column_defaults_to_subtomo_1(tmp_path):
    path = _write(tmp_path, "0\n45.5\n360\n")
    assert read_angle_file(path) == [(0.0, 1), (45.5, 1), (360.0, 1)]


def test_two_columns_whitespace_and_comma_separators(tmp_path):
    path = _write(tmp_path, "0 1\n10\t1\n190.5, 2\n270,3\n")
    assert read_angle_file(path) == [(0.0, 1), (10.0, 1), (190.5, 2), (270.0, 3)]


def test_comments_and_blank_lines_ignored_and_order_kept(tmp_path):
    path = _write(tmp_path, "# header\n\n90  2  # trailing comment\n   \n30 1\n")
    assert read_angle_file(path) == [(90.0, 2), (30.0, 1)]


def test_tilde_expansion(tmp_path, monkeypatch):
    monkeypatch.setenv("HOME", str(tmp_path))
    _write(tmp_path, "12\n")
    assert read_angle_file("~/angles.txt") == [(12.0, 1)]


@pytest.mark.parametrize(
    "text, match",
    [
        ("-0.1\n", "outside"),
        ("360.01\n", "outside"),
        ("abc\n", "invalid angle"),
        ("10 x\n", "invalid sub-tomogram"),
        ("10 0\n", ">= 1"),
        ("10 1 5\n", "expected"),
        ("# only comments\n\n", "no angles"),
    ],
)
def test_invalid_content_raises_with_reason(tmp_path, text, match):
    path = _write(tmp_path, text)
    with pytest.raises(AngleFileError, match=match):
        read_angle_file(path)


def test_error_reports_line_number(tmp_path):
    path = _write(tmp_path, "# c\n10\nbad\n")
    with pytest.raises(AngleFileError, match="line 3"):
        read_angle_file(path)


def test_missing_file_and_empty_path_raise(tmp_path):
    with pytest.raises(AngleFileError, match="Cannot read"):
        read_angle_file(str(tmp_path / "nope.txt"))
    with pytest.raises(AngleFileError, match="No angle file"):
        read_angle_file("")


def test_angle_file_error_is_a_value_error():
    assert issubclass(AngleFileError, ValueError)


def test_summary_counts():
    summary = summarize_angles([(0.0, 1), (45.0, 1), (100.0, 3)])
    assert summary["n"] == 3
    assert summary["min"] == 0.0
    assert summary["max"] == 100.0
    assert summary["n_subtomos"] == 2
    assert summary["opposite_pairs"] == []
    assert describe_summary(summary) == "3 angles, 0.00-100.00 deg, 2 sub-tomograms"
    assert describe_opposite_pairs(summary) is None


def test_summary_detects_180_opposite_and_exact_duplicates():
    entries = [(10.0, 1), (190.0, 1), (50.0, 1), (50.0, 2), (120.0, 1)]
    pairs = summarize_angles(entries)["opposite_pairs"]
    assert [(a, b) for a, b, _, _ in pairs] == [(0, 1), (2, 3)]


def test_summary_detects_pair_across_the_mod_180_wrap():
    # 179.99 and 0.0 are 0.01 apart mod 180; so are 359.99 and 0.0
    pairs = summarize_angles([(0.0, 1), (90.0, 1), (359.99, 1)])["opposite_pairs"]
    assert [(a, b) for a, b, _, _ in pairs] == [(0, 2)]


def test_summary_no_false_positives_for_equally_spaced_360():
    # 0, 7, 14, ... 353: 360/7 is not an integer, so no 180-degree pairs
    entries = [(float(a), 1) for a in range(0, 360, 7)]
    assert summarize_angles(entries)["opposite_pairs"] == []


def test_summary_flags_every_pair_for_equally_spaced_360_with_even_count():
    entries = [(float(a), 1) for a in range(0, 360, 10)]
    assert len(summarize_angles(entries)["opposite_pairs"]) == 18