"""Support UPNP discovery method that mimics Hue hubs."""

import asyncio
from contextlib import suppress
import logging
import socket
from typing import cast, override

from aiohttp import web

from homeassistant import core
from homeassistant.components.http import HomeAssistantView

from .config import Config
from .const import HUE_SERIAL_NUMBER, HUE_UUID

_LOGGER = logging.getLogger(__name__)

BROADCAST_PORT = 1900
BROADCAST_ADDR = "239.255.255.250"


class DescriptionXmlView(HomeAssistantView):
    """Handles requests for the description.xml file."""

    url = "/description.xml"
    name = "description:xml"
    requires_auth = False

    def __init__(self, config: Config) -> None:
        """Initialize the instance of the view."""
        self.config = config

    @core.callback
    def get(self, request: web.Request) -> web.Response:
        """Handle a GET request."""
        resp_text = f"""<?xml version="1.0" encoding="UTF-8" ?>
<root xmlns="urn:schemas-upnp-org:device-1-0">
<specVersion>
<major>1</major>
<minor>0</minor>
</specVersion>
<URLBase>http://{self.config.advertise_ip}:{self.config.advertise_port}/</URLBase>
<device>
<deviceType>urn:schemas-upnp-org:device:Basic:1</deviceType>
<friendlyName>Home Assistant Bridge ({self.config.advertise_ip})</friendlyName>
<manufacturer>Royal Philips Electronics</manufacturer>
<manufacturerURL>http://www.philips.com</manufacturerURL>
<modelDescription>Philips hue Personal Wireless Lighting</modelDescription>
<modelName>Philips hue bridge 2015</modelName>
<modelNumber>BSB002</modelNumber>
<modelURL>http://www.meethue.com</modelURL>
<serialNumber>{HUE_SERIAL_NUMBER}</serialNumber>
<UDN>uuid:{HUE_UUID}</UDN>
</device>
</root>
"""

        return web.Response(text=resp_text, content_type="text/xml")


class UPNPResponderProtocol(asyncio.Protocol):
    """Handle responding to UPNP/SSDP discovery requests."""

    def __init__(
        self,
        loop: asyncio.AbstractEventLoop,
        ssdp_socket: socket.socket,
        advertise_ip: str,
        advertise_port: int,
    ) -> None:
        """Initialize the class."""
        self.transport: asyncio.DatagramTransport | None = None
        self._loop = loop
        self._sock = ssdp_socket
        self.advertise_ip = advertise_ip
        self.advertise_port = advertise_port
        self._upnp_root_response = self._prepare_response(
            "upnp:rootdevice", f"uuid:{HUE_UUID}::upnp:rootdevice"
        )
        self._upnp_device_response = self._prepare_response(
            "urn:schemas-upnp-org:device:basic:1", f"uuid:{HUE_UUID}"
        )

    @override
    def connection_made(self, transport: asyncio.BaseTransport) -> None:
        """Set the transport."""
        self.transport = cast(asyncio.DatagramTransport, transport)

    @override
    def connection_lost(self, exc: Exception | None) -> None:
        """Handle connection lost."""

    def datagram_received(self, data: bytes, addr: tuple[str, int]) -> None:
        """Respond to msearch packets."""
        decoded_data = data.decode("utf-8", errors="ignore")

        if "M-SEARCH" not in decoded_data:
            return

        _LOGGER.debug("UPNP Responder M-SEARCH method received: %s", data)
        # SSDP M-SEARCH method received, respond to it with our info
        response = self._handle_request(decoded_data)
        _LOGGER.debug("UPNP Responder responding with: %s", response)
        assert self.transport is not None
        self.transport.sendto(response, addr)

    def error_received(self, exc: Exception) -> None:
        """Log UPNP errors."""
        _LOGGER.error("UPNP Error received: %s", exc)

    def close(self) -> None:
        """Stop the server."""
        _LOGGER.info("UPNP responder shutting down")
        if self.transport:
            self.transport.close()
        self._loop.remove_writer(self._sock.fileno())
        self._loop.remove_reader(self._sock.fileno())
        self._sock.close()

    def _handle_request(self, decoded_data: str) -> bytes:
        if "upnp:rootdevice" in decoded_data:
            return self._upnp_root_response

        return self._upnp_device_response

    def _prepare_response(self, search_target: str, unique_service_name: str) -> bytes:
        # Note that the double newline at the end of
        # this string is required per the SSDP spec
        response = f"""HTTP/1.1 200 OK
CACHE-CONTROL: max-age=60
EXT:
LOCATION: http://{self.advertise_ip}:{self.advertise_port}/description.xml
SERVER: FreeRTOS/6.0.5, UPnP/1.0, IpBridge/1.16.0
hue-bridgeid: {HUE_SERIAL_NUMBER}
ST: {search_target}
USN: {unique_service_name}

"""
        return response.replace("\n", "\r\n").encode("utf-8")


async def async_create_upnp_datagram_endpoint(
    host_ip_addr: str,
    upnp_bind_multicast: bool,
    advertise_ip: str,
    advertise_port: int,
) -> UPNPResponderProtocol:
    """Create the UPNP socket and protocol."""
    # Listen for UDP port 1900 packets sent to SSDP multicast address
    ssdp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    ssdp_socket.setblocking(False)

    # Required for receiving multicast
    # Note: some code duplication from async_upnp_client/ssdp.py here.
    ssdp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    with suppress(AttributeError):
        ssdp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)

    ssdp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

    ssdp_socket.setsockopt(
        socket.SOL_IP, socket.IP_MULTICAST_IF, socket.inet_aton(host_ip_addr)
    )

    ssdp_socket.setsockopt(
        socket.SOL_IP,
        socket.IP_ADD_MEMBERSHIP,
        socket.inet_aton(BROADCAST_ADDR) + socket.inet_aton(host_ip_addr),
    )

    ssdp_socket.bind(("" if upnp_bind_multicast else host_ip_addr, BROADCAST_PORT))

    loop = asyncio.get_running_loop()

    transport_protocol = await loop.create_datagram_endpoint(
        lambda: UPNPResponderProtocol(loop, ssdp_socket, advertise_ip, advertise_port),
        sock=ssdp_socket,
    )
    return transport_protocol[1]
