"""doctor: validate host prerequisites for running bot-bottle."""

from __future__ import annotations

import argparse
import shutil
import subprocess
import sys
from pathlib import Path

from ._common import PROG


def _ok(label: str, detail: str) -> None:
    print(f"ok: {label}: {detail}")


def _fail(label: str, detail: str) -> None:
    print(f"fail: {label}: {detail}")


def _check_python() -> bool:
    version = sys.version_info
    detail = f"{version.major}.{version.minor}.{version.micro}"
    if version >= (3, 11):
        _ok("python", detail)
        return True
    _fail("python", f"{detail}; need 3.11 or newer")
    return False


def _check_docker() -> bool:
    docker = shutil.which("docker")
    if not docker:
        _fail("docker", "docker command not found")
        return False
    try:
        result = subprocess.run(
            [docker, "info"],
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
            check=False,
            timeout=10,
        )
    except (OSError, subprocess.TimeoutExpired) as exc:
        _fail("docker", f"daemon check failed: {exc}")
        return False
    if result.returncode == 0:
        _ok("docker", "daemon reachable")
        return True
    _fail("docker", "daemon not reachable")
    return False


def _check_config_dir() -> bool:
    config = Path.home() / ".bot-bottle"
    if config.is_dir():
        _ok("config", str(config))
        return True
    _fail("config", f"{config} does not exist")
    return False


def cmd_doctor(argv: list[str]) -> int:
    parser = argparse.ArgumentParser(prog=f"{PROG} doctor", add_help=True)
    parser.parse_args(argv)

    checks = (
        _check_python(),
        _check_docker(),
        _check_config_dir(),
    )
    return 0 if all(checks) else 1