"""Private anndata pytest plugin.

This file exists
1. to allow ignoring warnings without test collection failing on CI
2. as a pytest plugin/config that applies to doctests as well

It lives outside of the anndata package in order to avoid importing anndata too early.
"""

from __future__ import annotations

import re
import warnings
from importlib.util import find_spec
from typing import TYPE_CHECKING, cast

import pytest

import anndata

if TYPE_CHECKING:
    from collections.abc import Generator, Iterable
    from pathlib import Path


@pytest.fixture(autouse=True)
def _anndata_test_env(request: pytest.FixtureRequest) -> None:

    if isinstance(request.node, pytest.DoctestItem):
        request.getfixturevalue("_doctest_env")

    anndata.settings.reset(anndata.settings._registered_options.keys())


@pytest.fixture
def _doctest_env(
    request: pytest.FixtureRequest, cache: pytest.Cache, tmp_path: Path
) -> Generator[None, None, None]:
    from contextlib import chdir

    from scanpy import settings

    from anndata.utils import import_name

    assert isinstance(request.node.parent, pytest.Module)
    # request.node.parent is either a DoctestModule or a DoctestTextFile.
    # Only DoctestModule has a .obj attribute (the imported module).
    if request.node.parent.obj:
        func = import_name(request.node.name)
        warning_detail: tuple[type[Warning], str, bool] | None
        if warning_detail := getattr(func, "__deprecated", None):
            cat, msg, _ = warning_detail
            warnings.filterwarnings("ignore", category=cat, message=re.escape(msg))
        if (mod := getattr(func, "_doctest_needs", None)) is not None and not find_spec(
            mod
        ):
            request.applymarker(pytest.skip(reason=f"doctest needs {mod} to run"))
    old_dd, settings.datasetdir = settings.datasetdir, cache.mkdir("scanpy-data")
    with chdir(tmp_path):
        yield
    settings.datasetdir = old_dd


def pytest_itemcollected(item: pytest.Item) -> None:
    """Define behavior of pytest.mark.gpu."""
    is_gpu = len(list(item.iter_markers(name="gpu"))) > 0
    if is_gpu:
        item.add_marker(
            pytest.mark.skipif(not find_spec("cupy"), reason="Cupy not installed.")
        )


def pytest_addoption(parser: pytest.Parser) -> None:
    """Hook to register custom CLI options and config values"""
    parser.addoption(
        "--strict-warnings",
        action="store_true",
        default=False,
        help="Turn warnings into errors that are not overridden by `filterwarnings` or `filterwarnings_when_strict`.",
    )

    parser.addini(
        "filterwarnings_when_strict",
        "Filters to apply after `-Werror` when --strict-warnings is active",
        type="linelist",
        default=[],
    )


def pytest_collection_modifyitems(
    session: pytest.Session, config: pytest.Config, items: Iterable[pytest.Item]
):
    for item in items:
        if "zarr" in item.name:
            item.add_marker("zarr_io")

    if not config.getoption("--strict-warnings"):
        return

    warning_filters = [
        "error",
        *_config_get_strlist(config, "filterwarnings"),
        *_config_get_strlist(config, "filterwarnings_when_strict"),
    ]
    warning_marks = [pytest.mark.filterwarnings(f) for f in warning_filters]

    # Add warning filters defined in the config to all tests items.
    # Test items might already have @pytest.mark.filterwarnings applied,
    # so we prepend ours to ensure that an item’s explicit filters override these.
    # Reversing then individually prepending ensures that the order is preserved.
    for item in items:
        for mark in reversed(warning_marks):
            item.add_marker(mark, append=False)


def _config_get_strlist(config: pytest.Config, name: str) -> list[str]:
    if strs := config.getini(name):
        assert isinstance(strs, list)
        assert all(isinstance(item, str) for item in strs)
        return cast("list[str]", strs)
    return []