"""Pytest plugin: marker-based changed-lambda filtering for integration tests.

Registered as a ``pytest11`` entry point, so any repo that installs
``test_fixtures`` gets it automatically. It registers the ``lambda_name`` marker
and deselects tests whose lambda is not named in the ``LAMBDA_FUNCTION_NAMES``
environment variable — the changed-lambda CI filter — without each repo
hand-writing ``pytest_collection_modifyitems`` in its ``conftest.py``.

Per-repo configuration is a single pytest ini option:

    [tool.pytest.ini_options]
    always_deselect_lambdas = ['state-machine']

Tags listed there only run when explicitly named in ``LAMBDA_FUNCTION_NAMES``
(e.g. a slow step-function suite). When no ``lambda_name`` markers are present
the plugin is a no-op, so it is safe for non-integration suites too.
"""

import os

import pytest

from test_fixtures.pytest_markers import deselect_items_by_tag

MARKER_NAME = 'lambda_name'
ENV_VAR = 'LAMBDA_FUNCTION_NAMES'
INI_ALWAYS_DESELECT = 'always_deselect_lambdas'


def pytest_configure(config: pytest.Config) -> None:
    config.addinivalue_line(
        'markers',
        f'{MARKER_NAME}(name): the lambda function directory name this test '
        "covers (e.g. 'finalize-job').",
    )


def pytest_addoption(parser: pytest.Parser) -> None:
    parser.addini(
        INI_ALWAYS_DESELECT,
        type='args',
        default=[],
        help=(
            'lambda_name tags that only run when explicitly named in '
            f'{ENV_VAR} (e.g. a step-function suite that needs a live state '
            'machine).'
        ),
    )


def active_tags_from_env() -> set[str]:
    """Parse ``LAMBDA_FUNCTION_NAMES`` into a set of tags (empty = run all)."""
    raw = os.environ.get(ENV_VAR, '').strip()
    if not raw:
        return set()
    return {name.strip() for name in raw.split(',') if name.strip()}


def pytest_collection_modifyitems(
    config: pytest.Config, items: list[pytest.Item]
) -> None:
    deselect_items_by_tag(
        config=config,
        items=items,
        marker_name=MARKER_NAME,
        active_tags=active_tags_from_env(),
        always_deselect_when_missing=set(config.getini(INI_ALWAYS_DESELECT)),
    )