"""Hub for communication with 1-Wire server or mount_dir."""
from __future__ import annotations

import logging
import os
from typing import TYPE_CHECKING

from pyownet import protocol

from homeassistant.config_entries import ConfigEntry
from homeassistant.const import (
    ATTR_IDENTIFIERS,
    ATTR_MANUFACTURER,
    ATTR_MODEL,
    ATTR_NAME,
    ATTR_VIA_DEVICE,
    CONF_HOST,
    CONF_PORT,
)
from homeassistant.core import HomeAssistant
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers import device_registry as dr
from homeassistant.helpers.entity import DeviceInfo

from .const import (
    DEVICE_SUPPORT,
    DOMAIN,
    MANUFACTURER_EDS,
    MANUFACTURER_HOBBYBOARDS,
    MANUFACTURER_MAXIM,
)
from .model import OWDeviceDescription

DEVICE_COUPLERS = {
    # Family : [branches]
    "1F": ["aux", "main"]
}

DEVICE_MANUFACTURER = {
    "7E": MANUFACTURER_EDS,
    "EF": MANUFACTURER_HOBBYBOARDS,
}

_LOGGER = logging.getLogger(__name__)


def _is_known_device(device_family: str, device_type: str) -> bool:
    """Check if device family/type is known to the library."""
    if device_family in ("7E", "EF"):  # EDS or HobbyBoard
        return device_type in DEVICE_SUPPORT[device_family]
    return device_family in DEVICE_SUPPORT


class OneWireHub:
    """Hub to communicate with server."""

    def __init__(self, hass: HomeAssistant) -> None:
        """Initialize."""
        self.hass = hass
        self.owproxy: protocol._Proxy | None = None
        self.devices: list[OWDeviceDescription] | None = None

    async def connect(self, host: str, port: int) -> None:
        """Connect to the server."""
        try:
            self.owproxy = await self.hass.async_add_executor_job(
                protocol.proxy, host, port
            )
        except protocol.ConnError as exc:
            raise CannotConnect from exc

    async def initialize(self, config_entry: ConfigEntry) -> None:
        """Initialize a config entry."""
        host = config_entry.data[CONF_HOST]
        port = config_entry.data[CONF_PORT]
        _LOGGER.debug("Initializing connection to %s:%s", host, port)
        await self.connect(host, port)
        await self.discover_devices()
        if TYPE_CHECKING:
            assert self.devices
        # Register discovered devices on Hub
        device_registry = dr.async_get(self.hass)
        for device in self.devices:
            device_info: DeviceInfo = device.device_info
            device_registry.async_get_or_create(
                config_entry_id=config_entry.entry_id,
                identifiers=device_info[ATTR_IDENTIFIERS],
                manufacturer=device_info[ATTR_MANUFACTURER],
                model=device_info[ATTR_MODEL],
                name=device_info[ATTR_NAME],
                via_device=device_info.get(ATTR_VIA_DEVICE),
            )

    async def discover_devices(self) -> None:
        """Discover all devices."""
        if self.devices is None:
            self.devices = await self.hass.async_add_executor_job(
                self._discover_devices
            )

    def _discover_devices(
        self, path: str = "/", parent_id: str | None = None
    ) -> list[OWDeviceDescription]:
        """Discover all server devices."""
        devices: list[OWDeviceDescription] = []
        assert self.owproxy
        for device_path in self.owproxy.dir(path):
            device_id = os.path.split(os.path.split(device_path)[0])[1]
            device_family = self.owproxy.read(f"{device_path}family").decode()
            _LOGGER.debug("read `%sfamily`: %s", device_path, device_family)
            device_type = self._get_device_type(device_path)
            if not _is_known_device(device_family, device_type):
                _LOGGER.warning(
                    "Ignoring unknown device family/type (%s/%s) found for device %s",
                    device_family,
                    device_type,
                    device_id,
                )
                continue
            device_info: DeviceInfo = {
                ATTR_IDENTIFIERS: {(DOMAIN, device_id)},
                ATTR_MANUFACTURER: DEVICE_MANUFACTURER.get(
                    device_family, MANUFACTURER_MAXIM
                ),
                ATTR_MODEL: device_type,
                ATTR_NAME: device_id,
            }
            if parent_id:
                device_info[ATTR_VIA_DEVICE] = (DOMAIN, parent_id)
            device = OWDeviceDescription(
                device_info=device_info,
                id=device_id,
                family=device_family,
                path=device_path,
                type=device_type,
            )
            devices.append(device)
            if device_branches := DEVICE_COUPLERS.get(device_family):
                for branch in device_branches:
                    devices += self._discover_devices(
                        f"{device_path}{branch}", device_id
                    )

        return devices

    def _get_device_type(self, device_path: str) -> str:
        """Get device model."""
        if TYPE_CHECKING:
            assert self.owproxy
        device_type = self.owproxy.read(f"{device_path}type").decode()
        _LOGGER.debug("read `%stype`: %s", device_path, device_type)
        if device_type == "EDS":
            device_type = self.owproxy.read(f"{device_path}device_type").decode()
            _LOGGER.debug("read `%sdevice_type`: %s", device_path, device_type)
        if TYPE_CHECKING:
            assert isinstance(device_type, str)
        return device_type


class CannotConnect(HomeAssistantError):
    """Error to indicate we cannot connect."""


class InvalidPath(HomeAssistantError):
    """Error to indicate the path is invalid."""