"""libtmux pytest plugin."""

from __future__ import annotations

import contextlib
import functools
import getpass
import logging
import os
import pathlib
import typing as t

import pytest

from libtmux import exc
from libtmux.server import Server
from libtmux.test.constants import TEST_SESSION_PREFIX
from libtmux.test.random import get_test_session_name, namer

if t.TYPE_CHECKING:
    from libtmux.session import Session

logger = logging.getLogger(__name__)
USING_ZSH = "zsh" in os.getenv("SHELL", "")


def _reap_test_server(socket_name: str | None) -> None:
    """Kill the tmux daemon on ``socket_name`` and unlink the socket file.

    Invoked from the :func:`server` and :func:`TestServer` fixture
    finalizers to guarantee teardown even when the daemon has already
    exited (``kill`` is a no-op then) and the socket file was left on
    disk. tmux does not reliably ``unlink(2)`` its socket on
    non-graceful exit, so ``/tmp/tmux-<uid>/`` otherwise accumulates
    stale entries across test runs.

    Conservative: suppresses ``LibTmuxException`` / ``OSError`` on both
    the kill and the unlink. A finalizer that raises replaces the real
    test failure with a cleanup error, and cleanup failures are not
    actionable (socket already gone, permissions changed, race with a
    concurrent pytest-xdist worker).
    """
    if not socket_name:
        return

    with contextlib.suppress(exc.LibTmuxException, OSError):
        srv = Server(socket_name=socket_name)
        if srv.is_alive():
            srv.kill()

    # ``Server(socket_name=...)`` does not populate ``socket_path`` —
    # the Server class only derives the path when neither ``socket_name``
    # nor ``socket_path`` was supplied. Recompute the location tmux uses
    # so we can unlink the file regardless of daemon state.
    tmux_tmpdir = pathlib.Path(os.environ.get("TMUX_TMPDIR", "/tmp"))
    socket_path = tmux_tmpdir / f"tmux-{os.geteuid()}" / socket_name
    with contextlib.suppress(OSError):
        socket_path.unlink(missing_ok=True)


@pytest.fixture(scope="session")
def home_path(tmp_path_factory: pytest.TempPathFactory) -> pathlib.Path:
    """Temporary `/home/` path."""
    return tmp_path_factory.mktemp("home")


@pytest.fixture(scope="session")
def home_user_name() -> str:
    """Return default username to set for :fixture:`user_path` fixture."""
    return getpass.getuser()


@pytest.fixture(scope="session")
def user_path(home_path: pathlib.Path, home_user_name: str) -> pathlib.Path:
    """Ensure and return temporary user directory.

    Note: You will need to set the home directory, see :ref:`set_home`.
    """
    p = home_path / home_user_name
    p.mkdir()
    return p


@pytest.mark.skipif(USING_ZSH, reason="Using ZSH")
@pytest.fixture(scope="session")
def zshrc(user_path: pathlib.Path) -> pathlib.Path:
    """Suppress ZSH default message.

    Needs a startup file .zshenv, .zprofile, .zshrc, .zlogin.
    """
    p = user_path / ".zshrc"
    p.touch()
    return p


@pytest.fixture(scope="session")
def config_file(user_path: pathlib.Path) -> pathlib.Path:
    """Return fixture for ``.tmux.conf`` configuration.

    - ``base-index -g 1``

    These guarantee pane and windows targets can be reliably referenced and asserted.

    Note: You will need to set the home directory, see :ref:`set_home`.
    """
    c = user_path / ".tmux.conf"
    c.write_text(
        """
set -g base-index 1
    """,
        encoding="utf-8",
    )
    return c


@pytest.fixture
def clear_env(monkeypatch: pytest.MonkeyPatch) -> None:
    """Clear out any unnecessary environment variables that could interrupt tests.

    tmux show-environment tests were being interrupted due to a lot of crazy env vars.
    """
    for k in os.environ:
        if not any(
            needle in k.lower()
            for needle in [
                "window",
                "tmux",
                "pane",
                "session",
                "pytest",
                "path",
                "pwd",
                "shell",
                "home",
                "xdg",
                "disable_auto_title",
                "lang",
                "term",
            ]
        ):
            monkeypatch.delenv(k)


@pytest.fixture
def server(
    request: pytest.FixtureRequest,
    monkeypatch: pytest.MonkeyPatch,
    config_file: pathlib.Path,
) -> Server:
    """Return new, temporary :class:`libtmux.Server`.

    >>> from libtmux.server import Server

    >>> def test_example(server: Server) -> None:
    ...     assert isinstance(server, Server)
    ...     session = server.new_session('my session')
    ...     assert len(server.sessions) == 1
    ...     assert [session.name.startswith('my') for session in server.sessions]

    .. ::
        >>> locals().keys()
        dict_keys(...)

        >>> source = ''.join([e.source for e in request._pyfuncitem.dtest.examples][:3])
        >>> pytester = request.getfixturevalue('pytester')

        >>> pytester.makepyfile(**{'whatever.py': source})
        PosixPath(...)

        >>> result = pytester.runpytest('whatever.py', '--disable-warnings')
        ===...

        >>> result.assert_outcomes(passed=1)
    """
    server = Server(socket_name=f"libtmux_test{next(namer)}")

    def fin() -> None:
        _reap_test_server(server.socket_name)

    request.addfinalizer(fin)

    return server


@pytest.fixture
def session_params() -> dict[str, t.Any]:
    """Return default session creation parameters.

    >>> import pytest
    >>> from libtmux.session import Session

    >>> @pytest.fixture
    ... def session_params(session_params):
    ...     return {
    ...         'x': 800,
    ...         'y': 600,
    ...     }

    >>> def test_example(session: "Session") -> None:
    ...     assert isinstance(session.name, str)
    ...     assert session.name.startswith('libtmux_')
    ...     window = session.new_window(window_name='new one')
    ...     assert window.name == 'new one'

    .. ::
        >>> locals().keys()
        dict_keys(...)

        >>> source = ''.join([e.source for e in request._pyfuncitem.dtest.examples][:4])
        >>> pytester = request.getfixturevalue('pytester')

        >>> pytester.makepyfile(**{'whatever.py': source})
        PosixPath(...)

        >>> result = pytester.runpytest('whatever.py', '--disable-warnings')
        ===...

        >>> result.assert_outcomes(passed=1)
    """
    return {}


@pytest.fixture
def session(
    request: pytest.FixtureRequest,
    session_params: dict[str, t.Any],
    server: Server,
) -> Session:
    """Return new, temporary :class:`libtmux.Session`.

    >>> from libtmux.session import Session

    >>> def test_example(session: "Session") -> None:
    ...     assert isinstance(session.name, str)
    ...     assert session.name.startswith('libtmux_')
    ...     window = session.new_window(window_name='new one')
    ...     assert window.name == 'new one'

    .. ::
        >>> locals().keys()
        dict_keys(...)

        >>> source = ''.join([e.source for e in request._pyfuncitem.dtest.examples][:3])
        >>> pytester = request.getfixturevalue('pytester')

        >>> pytester.makepyfile(**{'whatever.py': source})
        PosixPath(...)

        >>> result = pytester.runpytest('whatever.py', '--disable-warnings')
        ===...

        >>> result.assert_outcomes(passed=1)
    """
    session_name = "tmuxp"

    if not server.has_session(session_name):
        server.new_session(
            session_name=session_name,
        )

    # find current sessions prefixed with tmuxp
    old_test_sessions = []
    for s in server.sessions:
        old_name = s.session_name
        if old_name is not None and old_name.startswith(TEST_SESSION_PREFIX):
            old_test_sessions.append(old_name)

    TEST_SESSION_NAME = get_test_session_name(server=server)

    session = server.new_session(
        session_name=TEST_SESSION_NAME,
        **session_params,
    )

    """
    Make sure that tmuxp can :ref:`test_builder_visually` and switches to
    the newly created session for that testcase.
    """
    session_id = session.session_id
    assert session_id is not None

    with contextlib.suppress(exc.LibTmuxException):
        server.switch_client(target_session=session_id)

    for old_test_session in old_test_sessions:
        server.kill_session(old_test_session)
        logger.debug(
            "old test session killed",
            extra={
                "tmux_session": old_test_session,
                "tmux_subcommand": "kill-session",
            },
        )
    assert session.session_name == TEST_SESSION_NAME
    assert TEST_SESSION_NAME != "tmuxp"

    return session


@pytest.fixture
def TestServer(
    request: pytest.FixtureRequest,
) -> type[Server]:
    """Create a temporary tmux server that cleans up after itself.

    This is similar to the server pytest fixture, but can be used outside of pytest.
    The server will be killed when the test completes.

    Examples
    --------
    >>> server = Server()  # Create server instance
    >>> server.new_session()
    Session($... ...)
    >>> server.is_alive()
    True
    >>> # Each call creates a new server with unique socket
    >>> server2 = Server()
    >>> server2.socket_name != server.socket_name
    True
    """
    created_sockets: list[str] = []

    def on_init(server: Server) -> None:
        """Track created servers for cleanup."""
        created_sockets.append(server.socket_name or "default")

    def socket_name_factory() -> str:
        """Generate unique socket names."""
        return f"libtmux_test{next(namer)}"

    def fin() -> None:
        """Kill all servers created with these sockets and unlink their sockets."""
        for socket_name in created_sockets:
            _reap_test_server(socket_name)

    request.addfinalizer(fin)

    return t.cast(
        "type[Server]",
        functools.partial(
            Server,
            on_init=on_init,
            socket_name_factory=socket_name_factory,
        ),
    )
