from __future__ import annotations

import shutil
from typing import TYPE_CHECKING

from django.conf import settings
from django.core.checks import Tags
from django.core.checks import Warning as DjangoWarning
from django.core.checks import register

if TYPE_CHECKING:
    from django.core.checks import CheckMessage

REQUIRED_DEV_COMMANDS: tuple[str, ...] = (
    "uname",
    "curl",
    "basename",
    "grep",
    "sort",
    "tail",
    "wget",
    "unsquashfs",
    "ssh-keygen",
    "sudo",
    "chown",
    "truncate",
    "mkfs.ext4",
    "e2fsck",
)


@register(Tags.compatibility)
def check_required_dev_commands(*_: object, **__: object) -> list[CheckMessage]:
    """Warn in dev-like runtime when host tooling for init script is missing.

    Returns:
        A list of CheckMessage objects representing any issues found.
    """
    if not (settings.DEBUG or getattr(settings, "TESTING", False)):
        return []

    missing_commands: list[str] = [
        command for command in REQUIRED_DEV_COMMANDS if shutil.which(command) is None
    ]

    if not missing_commands:
        return []

    return [
        DjangoWarning(
            "Missing host commands used by get_rootfs.bash.",
            hint=(
                "Dev-only tooling missing: "
                f"{', '.join(missing_commands)}. "
                "These are required for local VM/rootfs setup during development, not production runtime."
            ),
            id="tussilago.W001",
        ),
    ]