from __future__ import annotations

import asyncio
import os
from dataclasses import dataclass

from app.core.config import get_settings


@dataclass(slots=True)
class SystemCommandResult:
    accepted: bool
    action: str
    status: str
    detail: str

    def as_dict(self) -> dict[str, object]:
        return {
            "accepted": self.accepted,
            "action": self.action,
            "status": self.status,
            "detail": self.detail,
        }


class SystemControlService:
    def __init__(self) -> None:
        settings = get_settings()
        self._enabled = settings.system_control_enabled
        self._platform = os.name
        self._helper = settings.system_control_helper

    async def restart_service(self) -> dict[str, object]:
        return (await self._run_helper(
            action="restart-service",
            helper_action="restart-service",
        )).as_dict()

    async def reboot_host(self) -> dict[str, object]:
        return (await self._run_helper(
            action="reboot-host",
            helper_action="reboot-host",
        )).as_dict()

    async def _run_helper(
        self,
        *,
        action: str,
        helper_action: str,
    ) -> SystemCommandResult:
        if not self._enabled:
            return SystemCommandResult(
                accepted=False,
                action=action,
                status="disabled",
                detail="Systemkontrol er deaktiveret i serverkonfigurationen.",
            )
        if self._platform != "posix":
            return SystemCommandResult(
                accepted=False,
                action=action,
                status="unsupported-platform",
                detail="Systemkontrol understoettes kun paa Linux/systemd-installationer.",
            )
        if not os.path.exists(self._helper):
            return SystemCommandResult(
                accepted=False,
                action=action,
                status="helper-missing",
                detail="Systemkontrol-helperen findes ikke paa maskinen.",
            )

        process = await asyncio.create_subprocess_exec(
            "sudo",
            "-n",
            self._helper,
            helper_action,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )
        stdout, stderr = await process.communicate()
        if process.returncode != 0:
            error_output = (stderr or stdout).decode("utf-8", errors="ignore").strip() or "Ukendt fejl"
            return SystemCommandResult(
                accepted=False,
                action=action,
                status="command-failed",
                detail=f"Kunne ikke planlaegge handlingen: {error_output}",
            )

        return SystemCommandResult(
            accepted=True,
            action=action,
            status="scheduled",
            detail="Handling planlagt. Serveren kan blive utilgaengelig et kort oeje.",
        )