"""System administration (spec sections 29, 41, 46).

Broker status and restart through the control sidecar. The restart
primitive is SIGTERM to PID 1 in the broker's (shared) PID namespace —
the broker shuts down gracefully (persistence saved) and Docker's
`restart: unless-stopped` policy brings the container back. No Docker
socket is involved (spec section 29).
"""

from __future__ import annotations

from typing import Annotated

from fastapi import APIRouter, Depends, Request
from sqlalchemy.orm import Session

from app import audit
from app.db import get_db
from app.deps import CurrentUser, require_roles
from app.models import ManagementRole
from app.routers.broker import _call_control, restart_required

router = APIRouter(prefix="/api/v1/system", tags=["system"])

BrokerAdmin = Annotated[CurrentUser, Depends(require_roles(ManagementRole.BROKER_ADMIN))]
AnyReader = Annotated[
    CurrentUser,
    Depends(
        require_roles(
            ManagementRole.BROKER_ADMIN,
            ManagementRole.OPERATOR,
            ManagementRole.AUDITOR,
        )
    ),
]
DbDep = Annotated[Session, Depends(get_db)]


@router.get("/status")
def system_status(db: DbDep, _user: AnyReader):
    """Broker process state + pending-restart flag (spec section 46).

    Used by the sidebar indicator (polls lightly) and the System page.
    The control call is allowed to fail — an unreachable sidecar is a
    status, not an error.
    """
    try:
        control = _call_control("/status", method="GET")
        broker_alive = bool(control.get("broker_pid_alive"))
    except Exception:  # noqa: BLE001 - status endpoint must not 500
        broker_alive = False
    return {
        "broker_alive": broker_alive,
        "restart_required": restart_required(db),
    }


@router.post("/broker/restart")
def restart_broker(request: Request, db: DbDep, user: BrokerAdmin):
    """Restart the broker via the control sidecar (spec section 29).

    The sidecar acknowledges and then SIGTERMs PID 1; Docker restarts
    the container. The pending-restart flag is cleared here — the config
    on disk is what the broker will boot with, so listener changes take
    effect by definition once the restart completes.
    """
    from app.routers.broker import _set_restart_required

    response = _call_control("/restart")
    _set_restart_required(db, False)
    audit.record(
        db,
        "BROKER_RESTARTED",
        request=request,
        user=user.username,
        object_type="broker",
        object_id="mosquitto",
        result="initiated",
    )
    return {"status": "restarting", "broker_alive": False}