"""The machine's power state and the power actions AMT accepts.

``CIM_AssociatedPowerManagementService.PowerState`` uses the CIM power state codes, and
``AvailableRequestedPowerStates`` lists the codes AMT accepts now. AMT lists the graceful
ones (12, 14) only where the host can honour them.
"""

from __future__ import annotations

from typing import Any

from napalm_device_types.models import POWER_ACTIONS

from napalm_amt.parsers.common import as_list, to_int

_Instance = dict[str, Any]

#: Role power action -> the CIM power state AMT is asked for. 8 is "Power Off - Hard" and
#: 10 "Master Bus Reset" (a hard reset); Intel verified both, and 2 and 5, on AMT.
POWER_REQUESTS: dict[str, int] = {
    "On": 2,
    "GracefulShutdown": 12,
    "ForceOff": 8,
    "GracefulRestart": 14,
    "ForceRestart": 10,
    "PowerCycle": 5,
}
_ON = {2}
#: Off, but also asleep (3, 4) and hibernating (7): the OS is not running, and On wakes it.
_OFF = {3, 4, 6, 7, 8, 12, 13}


def parse_power_state(service: _Instance) -> dict[str, Any]:
    """``{"state": "On" | "Off" | "", "available": [CIM power state codes]}``."""
    code = to_int(service.get("PowerState"))
    state = "On" if code in _ON else "Off" if code in _OFF else ""
    available = [
        n
        for n in (to_int(v) for v in as_list(service.get("AvailableRequestedPowerStates")))
        if n is not None
    ]
    return {"state": state, "available": available}


def accepted_actions(state: str, available: list[int]) -> list[str]:
    """The role actions that make sense in ``state`` and that AMT offers.

    A machine that is off accepts On (AMT may leave 2 out of its list then). A machine that
    is on accepts every other action whose state AMT lists.
    """
    if state == "Off":
        return ["On"] if not available or POWER_REQUESTS["On"] in available else []
    if state == "On":
        return [a for a in POWER_ACTIONS if a != "On" and POWER_REQUESTS[a] in available]
    return []