"""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 date, datetime, timedelta
from decimal import Decimal

from aiounifi.interfaces.api_handlers import ItemEvent
from aiounifi.interfaces.clients import Clients
from aiounifi.interfaces.devices import Devices
from aiounifi.interfaces.outlets import Outlets
from aiounifi.interfaces.ports import Ports
from aiounifi.interfaces.wlans import Wlans
from aiounifi.models.api import ApiItemT
from aiounifi.models.client import Client
from aiounifi.models.device import Device
from aiounifi.models.outlet import Outlet
from aiounifi.models.port import Port
from aiounifi.models.wlan import Wlan

from homeassistant.components.sensor import (
    SensorDeviceClass,
    SensorEntity,
    SensorEntityDescription,
    SensorStateClass,
    UnitOfTemperature,
)
from homeassistant.config_entries import ConfigEntry
from homeassistant.const import EntityCategory, UnitOfDataRate, UnitOfPower
from homeassistant.core import Event as core_Event, HomeAssistant, callback
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.typing import StateType
import homeassistant.util.dt as dt_util

from .const import DEVICE_STATES
from .entity import (
    HandlerT,
    UnifiEntity,
    UnifiEntityDescription,
    async_client_device_info_fn,
    async_device_available_fn,
    async_device_device_info_fn,
    async_wlan_available_fn,
    async_wlan_device_info_fn,
)
from .hub import UnifiHub


@callback
def async_bandwidth_sensor_allowed_fn(hub: UnifiHub, obj_id: str) -> bool:
    """Check if client is allowed."""
    if obj_id in hub.config.option_supported_clients:
        return True
    return hub.config.option_allow_bandwidth_sensors


@callback
def async_uptime_sensor_allowed_fn(hub: UnifiHub, obj_id: str) -> bool:
    """Check if client is allowed."""
    if obj_id in hub.config.option_supported_clients:
        return True
    return hub.config.option_allow_uptime_sensors


@callback
def async_client_rx_value_fn(hub: UnifiHub, client: Client) -> float:
    """Calculate receiving data transfer value."""
    if hub.entity_loader.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(hub: UnifiHub, client: Client) -> float:
    """Calculate transmission data transfer value."""
    if hub.entity_loader.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(hub: UnifiHub, 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_wlan_client_value_fn(hub: UnifiHub, wlan: Wlan) -> int:
    """Calculate the amount of clients connected to a wlan."""
    return len(
        [
            client.mac
            for client in hub.api.clients.values()
            if client.essid == wlan.name
            and dt_util.utcnow() - dt_util.utc_from_timestamp(client.last_seen or 0)
            < hub.config.option_detection_time
        ]
    )


@callback
def async_device_uptime_value_fn(hub: UnifiHub, device: Device) -> datetime | None:
    """Calculate the approximate time the device started (based on uptime returned from API, in seconds)."""
    if device.uptime <= 0:
        # Library defaults to 0 if uptime is not provided, e.g. when offline
        return None
    return (dt_util.now() - timedelta(seconds=device.uptime)).replace(microsecond=0)


@callback
def async_device_uptime_value_changed_fn(
    old: StateType | date | datetime | Decimal, new: datetime | float | str | None
) -> bool:
    """Reject the new uptime value if it's too similar to the old one. Avoids unwanted fluctuation."""
    if isinstance(old, datetime) and isinstance(new, datetime):
        return new != old and abs((new - old).total_seconds()) > 120
    return old is None or (new != old)


@callback
def async_device_outlet_power_supported_fn(hub: UnifiHub, obj_id: str) -> bool:
    """Determine if an outlet has the power property."""
    # At this time, an outlet_caps value of 3 is expected to indicate that the outlet
    # supports metering
    return hub.api.outlets[obj_id].caps == 3


@callback
def async_device_outlet_supported_fn(hub: UnifiHub, obj_id: str) -> bool:
    """Determine if a device supports reading overall power metrics."""
    return hub.api.devices[obj_id].outlet_ac_power_budget is not None


@callback
def async_client_is_connected_fn(hub: UnifiHub, obj_id: str) -> bool:
    """Check if client was last seen recently."""
    client = hub.api.clients[obj_id]

    if (
        dt_util.utcnow() - dt_util.utc_from_timestamp(client.last_seen or 0)
        > hub.config.option_detection_time
    ):
        return False

    return True


@callback
def async_device_state_value_fn(hub: UnifiHub, device: Device) -> str:
    """Retrieve the state of the device."""
    return DEVICE_STATES[device.state]


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

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

    # Optional
    is_connected_fn: Callable[[UnifiHub, str], bool] | None = None
    """Calculate if source is connected."""
    value_changed_fn: Callable[
        [StateType | date | datetime | Decimal, datetime | float | str | None],
        bool,
    ] = lambda old, new: old != new
    """Calculate whether a state change should be recorded."""


ENTITY_DESCRIPTIONS: tuple[UnifiSensorEntityDescription, ...] = (
    UnifiSensorEntityDescription[Clients, Client](
        key="Bandwidth sensor RX",
        device_class=SensorDeviceClass.DATA_RATE,
        entity_category=EntityCategory.DIAGNOSTIC,
        state_class=SensorStateClass.MEASUREMENT,
        native_unit_of_measurement=UnitOfDataRate.MEGABYTES_PER_SECOND,
        icon="mdi:upload",
        allowed_fn=async_bandwidth_sensor_allowed_fn,
        api_handler_fn=lambda api: api.clients,
        device_info_fn=async_client_device_info_fn,
        is_connected_fn=async_client_is_connected_fn,
        name_fn=lambda _: "RX",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda hub, _: hub.config.option_allow_bandwidth_sensors,
        unique_id_fn=lambda hub, obj_id: f"rx-{obj_id}",
        value_fn=async_client_rx_value_fn,
    ),
    UnifiSensorEntityDescription[Clients, Client](
        key="Bandwidth sensor TX",
        device_class=SensorDeviceClass.DATA_RATE,
        entity_category=EntityCategory.DIAGNOSTIC,
        state_class=SensorStateClass.MEASUREMENT,
        native_unit_of_measurement=UnitOfDataRate.MEGABYTES_PER_SECOND,
        icon="mdi:download",
        allowed_fn=async_bandwidth_sensor_allowed_fn,
        api_handler_fn=lambda api: api.clients,
        device_info_fn=async_client_device_info_fn,
        is_connected_fn=async_client_is_connected_fn,
        name_fn=lambda _: "TX",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda hub, _: hub.config.option_allow_bandwidth_sensors,
        unique_id_fn=lambda hub, 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,
        entity_registry_enabled_default=False,
        api_handler_fn=lambda api: api.ports,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda port: f"{port.name} PoE Power",
        object_fn=lambda api, obj_id: api.ports[obj_id],
        supported_fn=lambda hub, obj_id: bool(hub.api.ports[obj_id].port_poe),
        unique_id_fn=lambda hub, 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="Client uptime",
        device_class=SensorDeviceClass.TIMESTAMP,
        entity_category=EntityCategory.DIAGNOSTIC,
        entity_registry_enabled_default=False,
        allowed_fn=async_uptime_sensor_allowed_fn,
        api_handler_fn=lambda api: api.clients,
        device_info_fn=async_client_device_info_fn,
        name_fn=lambda client: "Uptime",
        object_fn=lambda api, obj_id: api.clients[obj_id],
        supported_fn=lambda hub, _: hub.config.option_allow_uptime_sensors,
        unique_id_fn=lambda hub, obj_id: f"uptime-{obj_id}",
        value_fn=async_client_uptime_value_fn,
    ),
    UnifiSensorEntityDescription[Wlans, Wlan](
        key="WLAN clients",
        entity_category=EntityCategory.DIAGNOSTIC,
        state_class=SensorStateClass.MEASUREMENT,
        api_handler_fn=lambda api: api.wlans,
        available_fn=async_wlan_available_fn,
        device_info_fn=async_wlan_device_info_fn,
        object_fn=lambda api, obj_id: api.wlans[obj_id],
        should_poll=True,
        unique_id_fn=lambda hub, obj_id: f"wlan_clients-{obj_id}",
        value_fn=async_wlan_client_value_fn,
    ),
    UnifiSensorEntityDescription[Outlets, Outlet](
        key="Outlet power metering",
        device_class=SensorDeviceClass.POWER,
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfPower.WATT,
        api_handler_fn=lambda api: api.outlets,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda outlet: f"{outlet.name} Outlet Power",
        object_fn=lambda api, obj_id: api.outlets[obj_id],
        should_poll=True,
        supported_fn=async_device_outlet_power_supported_fn,
        unique_id_fn=lambda hub, obj_id: f"outlet_power-{obj_id}",
        value_fn=lambda _, obj: obj.power if obj.relay_state else "0",
    ),
    UnifiSensorEntityDescription[Devices, Device](
        key="SmartPower AC power budget",
        device_class=SensorDeviceClass.POWER,
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfPower.WATT,
        suggested_display_precision=1,
        api_handler_fn=lambda api: api.devices,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda device: "AC Power Budget",
        object_fn=lambda api, obj_id: api.devices[obj_id],
        supported_fn=async_device_outlet_supported_fn,
        unique_id_fn=lambda hub, obj_id: f"ac_power_budget-{obj_id}",
        value_fn=lambda hub, device: device.outlet_ac_power_budget,
    ),
    UnifiSensorEntityDescription[Devices, Device](
        key="SmartPower AC power consumption",
        device_class=SensorDeviceClass.POWER,
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfPower.WATT,
        suggested_display_precision=1,
        api_handler_fn=lambda api: api.devices,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda device: "AC Power Consumption",
        object_fn=lambda api, obj_id: api.devices[obj_id],
        supported_fn=async_device_outlet_supported_fn,
        unique_id_fn=lambda hub, obj_id: f"ac_power_conumption-{obj_id}",
        value_fn=lambda hub, device: device.outlet_ac_power_consumption,
    ),
    UnifiSensorEntityDescription[Devices, Device](
        key="Device uptime",
        device_class=SensorDeviceClass.TIMESTAMP,
        entity_category=EntityCategory.DIAGNOSTIC,
        api_handler_fn=lambda api: api.devices,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda device: "Uptime",
        object_fn=lambda api, obj_id: api.devices[obj_id],
        unique_id_fn=lambda hub, obj_id: f"device_uptime-{obj_id}",
        value_fn=async_device_uptime_value_fn,
        value_changed_fn=async_device_uptime_value_changed_fn,
    ),
    UnifiSensorEntityDescription[Devices, Device](
        key="Device temperature",
        device_class=SensorDeviceClass.TEMPERATURE,
        entity_category=EntityCategory.DIAGNOSTIC,
        native_unit_of_measurement=UnitOfTemperature.CELSIUS,
        api_handler_fn=lambda api: api.devices,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda device: "Temperature",
        object_fn=lambda api, obj_id: api.devices[obj_id],
        supported_fn=lambda hub, obj_id: hub.api.devices[obj_id].has_temperature,
        unique_id_fn=lambda hub, obj_id: f"device_temperature-{obj_id}",
        value_fn=lambda hub, device: device.general_temperature,
    ),
    UnifiSensorEntityDescription[Devices, Device](
        key="Device State",
        device_class=SensorDeviceClass.ENUM,
        entity_category=EntityCategory.DIAGNOSTIC,
        api_handler_fn=lambda api: api.devices,
        available_fn=async_device_available_fn,
        device_info_fn=async_device_device_info_fn,
        name_fn=lambda device: "State",
        object_fn=lambda api, obj_id: api.devices[obj_id],
        unique_id_fn=lambda hub, obj_id: f"device_state-{obj_id}",
        value_fn=async_device_state_value_fn,
        options=list(DEVICE_STATES.values()),
    ),
)


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: ConfigEntry,
    async_add_entities: AddEntitiesCallback,
) -> None:
    """Set up sensors for UniFi Network integration."""
    UnifiHub.get_hub(hass, config_entry).entity_loader.register_platform(
        async_add_entities, UnifiSensorEntity, ENTITY_DESCRIPTIONS
    )


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

    entity_description: UnifiSensorEntityDescription[HandlerT, ApiItemT]

    @callback
    def _make_disconnected(self, *_: core_Event) -> None:
        """No heart beat by device.

        Set sensor as unavailable when client device is disconnected
        """
        if self._attr_available:
            self._attr_available = False
            self.async_write_ha_state()

    @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.hub.api, self._obj_id)
        # Update the value only if value is considered to have changed relative to its previous state
        if description.value_changed_fn(
            self.native_value, (value := description.value_fn(self.hub, obj))
        ):
            self._attr_native_value = value

        if description.is_connected_fn is not None:
            # Send heartbeat if client is connected
            if description.is_connected_fn(self.hub, self._obj_id):
                self.hub.async_heartbeat(
                    self._attr_unique_id,
                    dt_util.utcnow() + self.hub.config.option_detection_time,
                )

    async def async_added_to_hass(self) -> None:
        """Register callbacks."""
        await super().async_added_to_hass()

        if self.entity_description.is_connected_fn is not None:
            # Register callback for missed heartbeat
            self.async_on_remove(
                async_dispatcher_connect(
                    self.hass,
                    f"{self.hub.signal_heartbeat_missed}_{self.unique_id}",
                    self._make_disconnected,
                )
            )

    async def async_will_remove_from_hass(self) -> None:
        """Disconnect object when removed."""
        await super().async_will_remove_from_hass()

        if self.entity_description.is_connected_fn is not None:
            # Remove heartbeat registration
            self.hub.async_heartbeat(self._attr_unique_id)