"""Sensor platform for UniFi Network integration.

Support for bandwidth sensors of network clients.
Support for uptime sensors of network clients.
"""
from __future__ import annotations

from collections.abc import Callable
from dataclasses import dataclass
from datetime import datetime, timedelta
from typing import Generic

import aiounifi
from aiounifi.interfaces.api_handlers import ItemEvent
from aiounifi.interfaces.clients import Clients
from aiounifi.interfaces.ports import Ports
from aiounifi.models.api import ApiItemT
from aiounifi.models.client import Client
from aiounifi.models.port import Port

from homeassistant.components.sensor import (
    SensorDeviceClass,
    SensorEntity,
    SensorEntityDescription,
)
from homeassistant.config_entries import ConfigEntry
from homeassistant.const import EntityCategory, UnitOfInformation, UnitOfPower
from homeassistant.core import HomeAssistant, callback
from homeassistant.helpers.device_registry import CONNECTION_NETWORK_MAC
from homeassistant.helpers.entity import DeviceInfo
from homeassistant.helpers.entity_platform import AddEntitiesCallback
import homeassistant.util.dt as dt_util

from .const import DOMAIN as UNIFI_DOMAIN
from .controller import UniFiController
from .entity import (
    HandlerT,
    UnifiEntity,
    UnifiEntityDescription,
    async_device_available_fn,
    async_device_device_info_fn,
)


@callback
def async_client_rx_value_fn(controller: UniFiController, client: Client) -> float:
    """Calculate receiving data transfer value."""
    if controller.wireless_clients.is_wireless(client):
        return client.rx_bytes_r / 1000000
    return client.wired_rx_bytes_r / 1000000


@callback
def async_client_tx_value_fn(controller: UniFiController, client: Client) -> float:
    """Calculate transmission data transfer value."""
    if controller.wireless_clients.is_wireless(client):
        return client.tx_bytes_r / 1000000
    return client.wired_tx_bytes_r / 1000000


@callback
def async_client_uptime_value_fn(
    controller: UniFiController, client: Client
) -> datetime:
    """Calculate the uptime of the client."""
    if client.uptime < 1000000000:
        return dt_util.now() - timedelta(seconds=client.uptime)
    return dt_util.utc_from_timestamp(float(client.uptime))


@callback
def async_client_device_info_fn(api: aiounifi.Controller, obj_id: str) -> DeviceInfo:
    """Create device registry entry for client."""
    client = api.clients[obj_id]
    return DeviceInfo(
        connections={(CONNECTION_NETWORK_MAC, obj_id)},
        default_manufacturer=client.oui,
        default_name=client.name or client.hostname,
    )


@dataclass
class UnifiSensorEntityDescriptionMixin(Generic[HandlerT, ApiItemT]):
    """Validate and load entities from different UniFi handlers."""

    value_fn: Callable[[UniFiController, ApiItemT], datetime | float | str | None]


@dataclass
class UnifiSensorEntityDescription(
    SensorEntityDescription,
    UnifiEntityDescription[HandlerT, ApiItemT],
    UnifiSensorEntityDescriptionMixin[HandlerT, ApiItemT],
):
    """Class describing UniFi sensor entity."""


ENTITY_DESCRIPTIONS: tuple[UnifiSensorEntityDescription, ...] = (
    UnifiSensorEntityDescription[Clients, Client](
        key="Bandwidth sensor RX",
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfInformation.MEGABYTES,
        has_entity_name=True,
        allowed_fn=lambda controller, _: controller.option_allow_bandwidth_sensors,
        api_handler_fn=lambda api: api.clients,
        available_fn=lambda controller, _: controller.available,
        device_info_fn=async_client_device_info_fn,
        event_is_on=None,
        event_to_subscribe=None,
        name_fn=lambda _: "RX",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda controller, _: controller.option_allow_bandwidth_sensors,
        unique_id_fn=lambda controller, obj_id: f"rx-{obj_id}",
        value_fn=async_client_rx_value_fn,
    ),
    UnifiSensorEntityDescription[Clients, Client](
        key="Bandwidth sensor TX",
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfInformation.MEGABYTES,
        has_entity_name=True,
        allowed_fn=lambda controller, _: controller.option_allow_bandwidth_sensors,
        api_handler_fn=lambda api: api.clients,
        available_fn=lambda controller, _: controller.available,
        device_info_fn=async_client_device_info_fn,
        event_is_on=None,
        event_to_subscribe=None,
        name_fn=lambda _: "TX",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda controller, _: controller.option_allow_bandwidth_sensors,
        unique_id_fn=lambda controller, obj_id: f"tx-{obj_id}",
        value_fn=async_client_tx_value_fn,
    ),
    UnifiSensorEntityDescription[Ports, Port](
        key="PoE port power sensor",
        device_class=SensorDeviceClass.POWER,
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfPower.WATT,
        has_entity_name=True,
        entity_registry_enabled_default=False,
        allowed_fn=lambda controller, obj_id: True,
        api_handler_fn=lambda api: api.ports,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        event_is_on=None,
        event_to_subscribe=None,
        name_fn=lambda port: f"{port.name} PoE Power",
        object_fn=lambda api, obj_id: api.ports[obj_id],
        supported_fn=lambda controller, obj_id: controller.api.ports[obj_id].port_poe,
        unique_id_fn=lambda controller, obj_id: f"poe_power-{obj_id}",
        value_fn=lambda _, obj: obj.poe_power if obj.poe_mode != "off" else "0",
    ),
    UnifiSensorEntityDescription[Clients, Client](
        key="Uptime sensor",
        device_class=SensorDeviceClass.TIMESTAMP,
        entity_category=EntityCategory.DIAGNOSTIC,
        has_entity_name=True,
        entity_registry_enabled_default=False,
        allowed_fn=lambda controller, _: controller.option_allow_uptime_sensors,
        api_handler_fn=lambda api: api.clients,
        available_fn=lambda controller, obj_id: controller.available,
        device_info_fn=async_client_device_info_fn,
        event_is_on=None,
        event_to_subscribe=None,
        name_fn=lambda client: "Uptime",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda controller, _: controller.option_allow_uptime_sensors,
        unique_id_fn=lambda controller, obj_id: f"uptime-{obj_id}",
        value_fn=async_client_uptime_value_fn,
    ),
)


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: ConfigEntry,
    async_add_entities: AddEntitiesCallback,
) -> None:
    """Set up sensors for UniFi Network integration."""
    controller: UniFiController = hass.data[UNIFI_DOMAIN][config_entry.entry_id]
    controller.register_platform_add_entities(
        UnifiSensorEntity, ENTITY_DESCRIPTIONS, async_add_entities
    )


class UnifiSensorEntity(UnifiEntity[HandlerT, ApiItemT], SensorEntity):
    """Base representation of a UniFi sensor."""

    entity_description: UnifiSensorEntityDescription[HandlerT, ApiItemT]

    @callback
    def async_update_state(self, event: ItemEvent, obj_id: str) -> None:
        """Update entity state.

        Update native_value.
        """
        description = self.entity_description
        obj = description.object_fn(self.controller.api, self._obj_id)
        if (value := description.value_fn(self.controller, obj)) != self.native_value:
            self._attr_native_value = value