"""
Bambu Lab printer discovery service using SSDP and subnet scanning.

Bambu Lab printers advertise themselves via SSDP (Simple Service Discovery Protocol)
on the local network. This service listens for these advertisements and provides
a list of discovered printers.

For Docker environments where SSDP multicast doesn't work, subnet scanning is
available as an alternative discovery method.
"""

import asyncio
import ipaddress
import logging
import os
import re
import socket
import struct
from dataclasses import dataclass
from datetime import datetime
from pathlib import Path

logger = logging.getLogger(__name__)


def is_running_in_docker() -> bool:
    """Detect if we're running inside a Docker container."""
    # Check for .dockerenv file
    if Path("/.dockerenv").exists():
        return True

    # Check cgroup for docker/containerd
    try:
        with open("/proc/1/cgroup") as f:
            content = f.read()
            if "docker" in content or "containerd" in content or "kubepods" in content:
                return True
    except (FileNotFoundError, PermissionError):
        pass

    # Check for container environment variable
    return bool(os.environ.get("CONTAINER") or os.environ.get("DOCKER_CONTAINER"))


# SSDP multicast address - Bambu uses port 2021, not standard 1900
SSDP_ADDR = "239.255.255.250"
SSDP_PORT = 2021  # Bambu Lab uses non-standard port

# Bambu Lab SSDP search target
BAMBU_SEARCH_TARGET = "urn:bambulab-com:device:3dprinter:1"

# SSDP M-SEARCH message
SSDP_MSEARCH = (
    "M-SEARCH * HTTP/1.1\r\n"
    f"HOST: {SSDP_ADDR}:{SSDP_PORT}\r\n"
    'MAN: "ssdp:discover"\r\n'
    "MX: 3\r\n"
    f"ST: {BAMBU_SEARCH_TARGET}\r\n"
    "\r\n"
)


@dataclass
class DiscoveredPrinter:
    """Represents a discovered Bambu Lab printer."""

    serial: str
    name: str
    ip_address: str
    model: str | None = None
    discovered_at: str | None = None

    def to_dict(self) -> dict:
        return {
            "serial": self.serial,
            "name": self.name,
            "ip_address": self.ip_address,
            "model": self.model,
            "discovered_at": self.discovered_at,
        }


class PrinterDiscoveryService:
    """Service for discovering Bambu Lab printers on the network."""

    def __init__(self):
        self._discovered: dict[str, DiscoveredPrinter] = {}
        self._running = False
        self._task: asyncio.Task | None = None

    @property
    def is_running(self) -> bool:
        return self._running

    @property
    def discovered_printers(self) -> list[DiscoveredPrinter]:
        return list(self._discovered.values())

    def clear(self):
        """Clear discovered printers."""
        self._discovered.clear()

    async def start(self, duration: float = 10.0):
        """Start discovery for a specified duration."""
        if self._running:
            return

        self._running = True
        self._discovered.clear()
        self._task = asyncio.create_task(self._discover(duration))

    async def stop(self):
        """Stop discovery."""
        self._running = False
        if self._task and not self._task.done():
            self._task.cancel()
            try:
                await self._task
            except asyncio.CancelledError:
                pass
        self._task = None

    async def _discover(self, duration: float):
        """Run discovery for the specified duration.

        Bambu printers broadcast NOTIFY messages periodically on port 2021.
        We need to bind to that port and listen for broadcasts.
        """
        sock = None
        try:
            # Create UDP socket for SSDP
            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

            # Try to set SO_REUSEPORT if available (Linux/macOS)
            try:
                sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
            except (AttributeError, OSError):
                pass

            # Set non-blocking mode
            sock.setblocking(False)

            # Bind to the SSDP port to receive NOTIFY broadcasts from printers
            sock.bind(("", SSDP_PORT))

            # Join multicast group to receive multicast messages
            mreq = struct.pack("4sl", socket.inet_aton(SSDP_ADDR), socket.INADDR_ANY)
            sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)

            # Enable broadcast
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

            logger.info(f"Starting SSDP discovery on port {SSDP_PORT} for Bambu Lab printers...")

            # Send initial M-SEARCH request to trigger responses
            try:
                sock.sendto(SSDP_MSEARCH.encode(), (SSDP_ADDR, SSDP_PORT))
            except Exception as e:
                logger.debug(f"M-SEARCH send error: {e}")

            start_time = asyncio.get_event_loop().time()
            last_send = start_time

            while self._running and (asyncio.get_event_loop().time() - start_time) < duration:
                # Try to receive data
                try:
                    data, addr = sock.recvfrom(4096)
                    message = data.decode("utf-8", errors="ignore")
                    logger.debug(f"Received from {addr[0]}: {message[:100]}...")
                    self._handle_response(message, addr[0])
                except BlockingIOError:
                    # No data available, that's fine
                    pass
                except Exception as e:
                    logger.debug(f"SSDP receive error: {e}")

                # Re-send M-SEARCH every 3 seconds
                now = asyncio.get_event_loop().time()
                if now - last_send >= 3.0:
                    try:
                        sock.sendto(SSDP_MSEARCH.encode(), (SSDP_ADDR, SSDP_PORT))
                        last_send = now
                    except Exception as e:
                        logger.debug(f"SSDP send error: {e}")

                await asyncio.sleep(0.1)

            logger.info(f"Discovery complete. Found {len(self._discovered)} printers.")

        except OSError as e:
            if e.errno == 98:  # Address already in use
                logger.warning(f"Port {SSDP_PORT} is in use, trying alternative discovery...")
                await self._discover_alternative(duration)
            else:
                logger.error(f"Discovery error: {e}")
        except Exception as e:
            logger.error(f"Discovery error: {e}")
        finally:
            self._running = False
            if sock:
                try:
                    sock.close()
                except Exception:
                    pass

    async def _discover_alternative(self, duration: float):
        """Alternative discovery using a random port (less reliable)."""
        sock = None
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
            sock.setblocking(False)
            sock.bind(("", 0))

            # Join multicast group
            mreq = struct.pack("4sl", socket.inet_aton(SSDP_ADDR), socket.INADDR_ANY)
            sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

            logger.info("Using alternative discovery method...")

            start_time = asyncio.get_event_loop().time()
            last_send = start_time

            while self._running and (asyncio.get_event_loop().time() - start_time) < duration:
                try:
                    data, addr = sock.recvfrom(4096)
                    self._handle_response(data.decode("utf-8", errors="ignore"), addr[0])
                except BlockingIOError:
                    pass
                except Exception as e:
                    logger.debug(f"SSDP receive error: {e}")

                now = asyncio.get_event_loop().time()
                if now - last_send >= 2.0:
                    try:
                        sock.sendto(SSDP_MSEARCH.encode(), (SSDP_ADDR, SSDP_PORT))
                        last_send = now
                    except Exception:
                        pass

                await asyncio.sleep(0.1)

            logger.info(f"Alternative discovery complete. Found {len(self._discovered)} printers.")
        except Exception as e:
            logger.error(f"Alternative discovery error: {e}")
        finally:
            if sock:
                try:
                    sock.close()
                except Exception:
                    pass

    def _handle_response(self, response: str, ip_address: str):
        """Parse SSDP response and extract printer info."""
        # Check if it's a Bambu Lab printer response
        if BAMBU_SEARCH_TARGET not in response and "bambulab" not in response.lower():
            logger.debug(f"Ignoring non-Bambu response from {ip_address}")
            return

        # Extract USN (Unique Service Name) which contains the serial
        # Bambu format is just "USN: SERIALNUMBER" (no uuid: prefix)
        usn_match = re.search(r"USN:\s*(?:uuid:)?([^\s\r\n]+)", response, re.IGNORECASE)
        if not usn_match:
            logger.debug(f"No USN found in response from {ip_address}")
            return

        serial = usn_match.group(1).strip()

        # Extract device name from LOCATION or DevName header
        name = serial  # Default to serial if no name found
        name_match = re.search(r"DevName\.bambu\.com:\s*(.+?)(?:\r\n|\n|$)", response, re.IGNORECASE)
        if name_match:
            name = name_match.group(1).strip()

        # Try to extract model from DevModel header
        model = None
        model_match = re.search(r"DevModel\.bambu\.com:\s*(.+?)(?:\r\n|\n|$)", response, re.IGNORECASE)
        if model_match:
            model = model_match.group(1).strip()

        # Also try NT header for model
        if not model:
            nt_match = re.search(r"NT:\s*urn:bambulab-com:device:([^:]+)", response, re.IGNORECASE)
            if nt_match:
                model = nt_match.group(1).strip()

        # Skip if already discovered
        if serial in self._discovered:
            return

        printer = DiscoveredPrinter(
            serial=serial,
            name=name,
            ip_address=ip_address,
            model=model,
            discovered_at=datetime.now().isoformat(),
        )

        self._discovered[serial] = printer
        logger.info(f"Discovered printer: {name} ({serial}) at {ip_address}")


class SubnetScanner:
    """Scanner for discovering Bambu printers by probing IP addresses."""

    # Bambu printer ports
    MQTT_PORT = 8883
    FTP_PORT = 990

    def __init__(self):
        self._discovered: dict[str, DiscoveredPrinter] = {}
        self._running = False
        self._scanned = 0
        self._total = 0

    @property
    def is_running(self) -> bool:
        return self._running

    @property
    def discovered_printers(self) -> list[DiscoveredPrinter]:
        return list(self._discovered.values())

    @property
    def progress(self) -> tuple[int, int]:
        """Return (scanned, total) counts."""
        return self._scanned, self._total

    async def scan_subnet(self, subnet: str, timeout: float = 1.0) -> list[DiscoveredPrinter]:
        """Scan a subnet for Bambu printers.

        Args:
            subnet: CIDR notation subnet (e.g., "192.168.1.0/24")
            timeout: Connection timeout per host in seconds

        Returns:
            List of discovered printers
        """
        if self._running:
            return []

        self._running = True
        self._discovered.clear()
        self._scanned = 0

        try:
            network = ipaddress.ip_network(subnet, strict=False)
            hosts = list(network.hosts())
            self._total = len(hosts)

            if self._total > 1024:
                logger.warning(f"Subnet {subnet} has {self._total} hosts, limiting to /22 (1024 hosts)")
                self._total = 1024
                hosts = hosts[:1024]

            logger.info(f"Starting subnet scan of {subnet} ({self._total} hosts)")

            # Scan in batches to avoid overwhelming the network
            batch_size = 50
            for i in range(0, len(hosts), batch_size):
                if not self._running:
                    break

                batch = hosts[i : i + batch_size]
                tasks = [self._probe_host(str(ip), timeout) for ip in batch]
                await asyncio.gather(*tasks, return_exceptions=True)
                self._scanned = min(i + batch_size, len(hosts))

            logger.info(f"Subnet scan complete. Found {len(self._discovered)} printers.")
            return self.discovered_printers

        except ValueError as e:
            logger.error(f"Invalid subnet format: {e}")
            return []
        finally:
            self._running = False

    async def _probe_host(self, ip: str, timeout: float):
        """Probe a single host for Bambu printer ports."""
        # Check FTP port (990) - more reliable indicator
        ftp_open = await self._check_port(ip, self.FTP_PORT, timeout)
        if not ftp_open:
            return

        # Also check MQTT port (8883) for confirmation
        mqtt_open = await self._check_port(ip, self.MQTT_PORT, timeout)
        if not mqtt_open:
            return

        # Both ports open - likely a Bambu printer
        logger.info(f"Found potential Bambu printer at {ip}")

        # Try to get printer info via SSDP unicast
        serial, name, model = await self._get_printer_info_ssdp(ip, timeout)

        printer = DiscoveredPrinter(
            serial=serial or f"unknown-{ip.replace('.', '-')}",
            name=name or f"Printer at {ip}",
            ip_address=ip,
            model=model,
            discovered_at=datetime.now().isoformat(),
        )
        self._discovered[ip] = printer

    async def _get_printer_info_ssdp(self, ip: str, timeout: float) -> tuple[str | None, str | None, str | None]:
        """Try to get printer info via SSDP unicast query."""
        loop = asyncio.get_event_loop()

        def _query():
            try:
                sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
                sock.settimeout(timeout)
                sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

                # Send M-SEARCH directly to the printer
                msearch = (
                    "M-SEARCH * HTTP/1.1\r\n"
                    f"HOST: {ip}:{SSDP_PORT}\r\n"
                    'MAN: "ssdp:discover"\r\n'
                    "MX: 1\r\n"
                    f"ST: {BAMBU_SEARCH_TARGET}\r\n"
                    "\r\n"
                )
                sock.sendto(msearch.encode(), (ip, SSDP_PORT))

                # Wait for response
                data, _ = sock.recvfrom(4096)
                response = data.decode("utf-8", errors="ignore")
                sock.close()

                # Parse response
                serial = None
                name = None
                model = None

                usn_match = re.search(r"USN:\s*(?:uuid:)?([^\s\r\n]+)", response, re.IGNORECASE)
                if usn_match:
                    serial = usn_match.group(1).strip()

                name_match = re.search(r"DevName\.bambu\.com:\s*(.+?)(?:\r\n|\n|$)", response, re.IGNORECASE)
                if name_match:
                    name = name_match.group(1).strip()

                model_match = re.search(r"DevModel\.bambu\.com:\s*(.+?)(?:\r\n|\n|$)", response, re.IGNORECASE)
                if model_match:
                    model = model_match.group(1).strip()

                logger.debug(f"SSDP info from {ip}: serial={serial}, name={name}, model={model}")
                return serial, name, model

            except Exception as e:
                logger.debug(f"SSDP query to {ip} failed: {e}")
                return None, None, None

        return await loop.run_in_executor(None, _query)

    async def _check_port(self, ip: str, port: int, timeout: float) -> bool:
        """Check if a port is open on the given IP."""
        try:
            _, writer = await asyncio.wait_for(asyncio.open_connection(ip, port), timeout=timeout)
            writer.close()
            await writer.wait_closed()
            logger.debug(f"Port {port} open on {ip}")
            return True
        except TimeoutError:
            return False
        except ConnectionRefusedError:
            return False
        except OSError as e:
            # Log first few errors to help debug network issues
            if self._scanned < 5:
                logger.debug(f"OSError checking {ip}:{port}: {e}")
            return False

    def stop(self):
        """Stop the current scan."""
        self._running = False


# Global instances
discovery_service = PrinterDiscoveryService()
subnet_scanner = SubnetScanner()