"""Device metadata helpers for the HA Probe integration."""

from __future__ import annotations

from typing import Any

from homeassistant.core import HomeAssistant
from homeassistant.helpers import device_registry as dr
from homeassistant.helpers.device_registry import DeviceInfo

from .const import DOMAIN

DEFAULT_MANUFACTURER = "gerviba/systemmonitor"
DEFAULT_MODEL = "Probe"

# Probe payload key -> normalized metadata key.
_PAYLOAD_KEYS = {
    "manufacturer": "manufacturer",
    "model": "model",
    "configurationUrl": "configuration_url",
    "swVersion": "sw_version",
    "viaDevice": "via_device",
}


def parse_device_meta(device: dict[str, Any]) -> dict[str, str]:
    """Pick the optional metadata fields a probe device record carries."""
    return {
        key: value
        for payload_key, key in _PAYLOAD_KEYS.items()
        if isinstance(value := device.get(payload_key), str) and value
    }


def device_identifier(entry_id: str, device_ha_id: str) -> tuple[str, str]:
    """Registry identifier of a probe device."""
    return (DOMAIN, f"{entry_id}_{device_ha_id}")


def build_device_info(
    entry_id: str, device_ha_id: str, name: str, meta: dict[str, str]
) -> DeviceInfo:
    """DeviceInfo for a probe device, using whatever metadata is known."""
    info = DeviceInfo(
        identifiers={device_identifier(entry_id, device_ha_id)},
        name=name,
        manufacturer=meta.get("manufacturer") or DEFAULT_MANUFACTURER,
        model=meta.get("model") or DEFAULT_MODEL,
    )
    if sw_version := meta.get("sw_version"):
        info["sw_version"] = sw_version
    if configuration_url := meta.get("configuration_url"):
        info["configuration_url"] = configuration_url
    if via_device := meta.get("via_device"):
        info["via_device"] = device_identifier(entry_id, via_device)
    return info


def sync_device_registry(
    hass: HomeAssistant,
    entry_id: str,
    device_ha_id: str,
    meta: dict[str, str],
) -> None:
    """Push changed metadata (e.g. a new docker image) to an existing device.

    Entities only hand their DeviceInfo to HA when first created, so later
    changes from the probe have to be applied to the registry directly.
    """
    registry = dr.async_get(hass)
    device = registry.async_get_device(
        identifiers={device_identifier(entry_id, device_ha_id)}
    )
    if device is None:
        return

    changes: dict[str, Any] = {
        "manufacturer": meta.get("manufacturer") or DEFAULT_MANUFACTURER,
        "model": meta.get("model") or DEFAULT_MODEL,
    }
    if sw_version := meta.get("sw_version"):
        changes["sw_version"] = sw_version
    if configuration_url := meta.get("configuration_url"):
        changes["configuration_url"] = configuration_url
    if via_device := meta.get("via_device"):
        parent = registry.async_get_device(
            identifiers={device_identifier(entry_id, via_device)}
        )
        if parent is not None:
            changes["via_device_id"] = parent.id

    registry.async_update_device(device.id, **changes)