from __future__ import annotations

import pwd
import subprocess


def user_exists(
    username: str,
) -> bool:
    try:
        pwd.getpwnam(
            username
        )
        return True
    except KeyError:
        return False


def _run(
    command: list[str],
) -> subprocess.CompletedProcess:
    return subprocess.run(
        command,
        capture_output=True,
        text=True,
        check=False,
    )


def is_locked(
    username: str,
) -> bool:
    if not user_exists(username):
        return False

    result = _run(
        [
            "passwd",
            "-S",
            username,
        ]
    )

    if result.returncode != 0:
        return False

    parts = result.stdout.strip().split()

    if len(parts) < 2:
        return False

    status = parts[1].upper()

    return status.startswith("L")


def lock_user(
    username: str,
) -> None:
    if not user_exists(username):
        raise RuntimeError(
            f"Linux user does not exist: {username}"
        )

    result = _run(
        [
            "passwd",
            "-l",
            username,
        ]
    )

    if result.returncode != 0:
        error = (
            result.stderr.strip()
            or result.stdout.strip()
            or "unknown error"
        )

        raise RuntimeError(
            f"Unable to lock {username}: {error}"
        )


def unlock_user(
    username: str,
) -> None:
    if not user_exists(username):
        raise RuntimeError(
            f"Linux user does not exist: {username}"
        )

    result = _run(
        [
            "passwd",
            "-u",
            username,
        ]
    )

    if result.returncode != 0:
        error = (
            result.stderr.strip()
            or result.stdout.strip()
            or "unknown error"
        )

        raise RuntimeError(
            f"Unable to unlock {username}: {error}"
        )


def terminate_user(
    username: str,
) -> None:
    if not user_exists(username):
        return

    result = _run(
        [
            "loginctl",
            "terminate-user",
            username,
        ]
    )

    if result.returncode != 0:
        error = (
            result.stderr.strip()
            or result.stdout.strip()
        )

        if error:
            raise RuntimeError(
                f"Unable to terminate "
                f"{username}: {error}"
            )


def get_uid(
    username: str,
) -> int | None:
    try:
        return pwd.getpwnam(
            username
        ).pw_uid
    except KeyError:
        return None


def get_home(
    username: str,
) -> str | None:
    try:
        return pwd.getpwnam(
            username
        ).pw_dir
    except KeyError:
        return None