"""Virtual Printer Manager - coordinates SSDP, MQTT, and FTP services.

Supports multiple modes:
- immediate: Archive uploads immediately
- review: Queue uploads for user review before archiving
- print_queue: Archive and add to print queue (unassigned)
- proxy: Transparent TCP proxy to a real printer (for remote slicer access)
"""

import asyncio
import logging
from collections.abc import Callable
from datetime import datetime, timezone
from pathlib import Path

from backend.app.core.config import settings as app_settings
from backend.app.services.virtual_printer.certificate import CertificateService
from backend.app.services.virtual_printer.ftp_server import VirtualPrinterFTPServer
from backend.app.services.virtual_printer.mqtt_server import SimpleMQTTServer
from backend.app.services.virtual_printer.ssdp_server import SSDPProxy, VirtualPrinterSSDPServer
from backend.app.services.virtual_printer.tcp_proxy import SlicerProxyManager

logger = logging.getLogger(__name__)


# Mapping of SSDP model codes to display names
# These are the codes that slicers expect during discovery
# Sources:
#   - https://gist.github.com/Alex-Schaefer/72a9e2491a42da2ef99fb87601955cc3
#   - https://github.com/psychoticbeef/BambuLabOrcaSlicerDiscovery
VIRTUAL_PRINTER_MODELS = {
    # X1 Series
    "3DPrinter-X1-Carbon": "X1C",  # X1 Carbon
    "3DPrinter-X1": "X1",  # X1
    "C13": "X1E",  # X1E
    # P Series
    "C11": "P1P",  # P1P
    "C12": "P1S",  # P1S
    "N7": "P2S",  # P2S
    # A1 Series
    "N2S": "A1",  # A1
    "N1": "A1 Mini",  # A1 Mini
    # H2 Series
    "O1D": "H2D",  # H2D
    "O1C": "H2C",  # H2C
    "O1S": "H2S",  # H2S
}

# Serial number prefixes for each model (based on Bambu Lab serial number format)
# Format: MMM??RYMDDUUUUU (15 chars total)
#   MMM = Model prefix (3 chars)
#   ?? = Unknown/revision code (2 chars)
#   R = Revision letter (1 char)
#   Y = Year digit (1 char)
#   M = Month (1 char, hex: 1-9, A=Oct, B=Nov, C=Dec)
#   DD = Day (2 chars)
#   UUUUU = Unit number (5 chars)
MODEL_SERIAL_PREFIXES = {
    # X1 Series
    "3DPrinter-X1-Carbon": "00M00A",  # X1C
    "3DPrinter-X1": "00M00A",  # X1
    "C13": "03W00A",  # X1E
    # P Series
    "C11": "01S00A",  # P1P
    "C12": "01P00A",  # P1S
    "N7": "22E00A",  # P2S
    # A1 Series
    "N2S": "03900A",  # A1
    "N1": "03000A",  # A1 Mini
    # H2 Series
    "O1D": "09400A",  # H2D
    "O1C": "09400A",  # H2C
    "O1S": "09400A",  # H2S
}

# Default model
DEFAULT_VIRTUAL_PRINTER_MODEL = "3DPrinter-X1-Carbon"  # X1C


class VirtualPrinterManager:
    """Manages the virtual printer lifecycle and coordinates all services."""

    # Fixed configuration
    PRINTER_NAME = "Bambuddy"
    SERIAL_SUFFIX = "391800001"  # Fixed suffix for virtual printer

    def __init__(self):
        """Initialize the virtual printer manager."""
        self._session_factory: Callable | None = None
        self._enabled = False
        self._access_code = ""
        self._mode = "immediate"
        self._model = DEFAULT_VIRTUAL_PRINTER_MODEL
        self._target_printer_ip = ""  # For proxy mode
        self._target_printer_serial = ""  # For proxy mode (real printer's serial)
        self._remote_interface_ip = ""  # For proxy mode SSDP (LAN B - slicer network)

        # Service instances
        self._ssdp: VirtualPrinterSSDPServer | None = None
        self._ssdp_proxy: SSDPProxy | None = None
        self._ftp: VirtualPrinterFTPServer | None = None
        self._mqtt: SimpleMQTTServer | None = None
        self._proxy: SlicerProxyManager | None = None  # For proxy mode

        # Background tasks
        self._tasks: list[asyncio.Task] = []

        # Directories
        self._base_dir = app_settings.base_dir / "virtual_printer"
        self._upload_dir = self._base_dir / "uploads"
        self._cert_dir = self._base_dir / "certs"

        # Create directories early to avoid permission issues later
        # If running in Docker, these need to be on a writable volume
        self._ensure_directories()

        # Certificate service
        self._cert_service = CertificateService(self._cert_dir)

        # Track pending uploads for MQTT correlation
        self._pending_files: dict[str, Path] = {}

    def _ensure_directories(self) -> None:
        """Create and verify virtual printer directories are writable.

        Creates all required directories at startup to catch permission
        issues early rather than when the user tries to enable features.
        """
        dirs_to_create = [
            self._base_dir,
            self._upload_dir,
            self._upload_dir / "cache",
            self._cert_dir,
        ]

        logger.info("Checking virtual printer directories in %s", self._base_dir)

        for dir_path in dirs_to_create:
            try:
                dir_path.mkdir(parents=True, exist_ok=True)
            except PermissionError:
                logger.error(
                    f"Cannot create directory {dir_path}: Permission denied. "
                    f"For Docker: ensure the data volume is writable by the container user. "
                    f"For bare metal: run 'sudo chown -R $(whoami) {self._base_dir}'"
                )
                continue

            # Verify directory is writable by attempting to create a test file
            test_file = dir_path / ".write_test"
            try:
                test_file.touch()
                test_file.unlink(missing_ok=True)
            except PermissionError:
                logger.error(
                    f"Directory {dir_path} exists but is not writable. "
                    f"For Docker: ensure the data volume is writable by the container user (uid/gid). "
                    f"For bare metal: run 'sudo chown -R $(whoami) {self._base_dir}'"
                )

    def _get_serial_for_model(self, model: str) -> str:
        """Get appropriate serial number for the given model.

        Args:
            model: SSDP model code (e.g., 'BL-P001', 'C11')

        Returns:
            Serial number with correct prefix for the model
        """
        prefix = MODEL_SERIAL_PREFIXES.get(model, "00M09A")
        return f"{prefix}{self.SERIAL_SUFFIX}"

    @property
    def printer_serial(self) -> str:
        """Get the current printer serial number based on model."""
        return self._get_serial_for_model(self._model)

    def set_session_factory(self, session_factory: Callable) -> None:
        """Set the database session factory.

        Args:
            session_factory: Async context manager for database sessions
        """
        self._session_factory = session_factory

    @property
    def is_enabled(self) -> bool:
        """Check if virtual printer is enabled."""
        return self._enabled

    @property
    def is_running(self) -> bool:
        """Check if virtual printer services are running."""
        return len(self._tasks) > 0 and all(not t.done() for t in self._tasks)

    async def configure(
        self,
        enabled: bool,
        access_code: str = "",
        mode: str = "immediate",
        model: str = "",
        target_printer_ip: str = "",
        target_printer_serial: str = "",
        remote_interface_ip: str = "",
    ) -> None:
        """Configure and start/stop virtual printer.

        Args:
            enabled: Whether to enable the virtual printer
            access_code: Authentication password for slicer connections
            mode: Archive mode - 'immediate', 'review', 'print_queue', or 'proxy'
            model: SSDP model code (e.g., 'BL-P001' for X1C)
            target_printer_ip: Target printer IP for proxy mode
            target_printer_serial: Target printer serial for proxy mode
            remote_interface_ip: IP of interface on slicer network (LAN B) for SSDP proxy
        """
        # Proxy mode has different requirements
        if mode == "proxy":
            if enabled and not target_printer_ip:
                raise ValueError("Target printer IP is required for proxy mode")
            # Access code not required for proxy mode (uses printer's credentials)
        else:
            if enabled and not access_code:
                raise ValueError("Access code is required when enabling virtual printer")

        # Validate model if provided
        new_model = model if model and model in VIRTUAL_PRINTER_MODELS else self._model
        model_changed = new_model != self._model
        mode_changed = mode != self._mode
        target_changed = target_printer_ip != self._target_printer_ip
        serial_changed = target_printer_serial != self._target_printer_serial
        remote_iface_changed = remote_interface_ip != self._remote_interface_ip
        old_mode = self._mode

        logger.debug(
            f"configure() called: enabled={enabled}, self._enabled={self._enabled}, "
            f"mode={mode}, old_mode={old_mode}, model={model}, new_model={new_model}, "
            f"target_printer_ip={target_printer_ip}, target_printer_serial={target_printer_serial}, "
            f"remote_interface_ip={remote_interface_ip}"
        )

        self._access_code = access_code
        self._mode = mode
        self._model = new_model
        self._target_printer_ip = target_printer_ip
        self._target_printer_serial = target_printer_serial
        self._remote_interface_ip = remote_interface_ip

        needs_restart = (
            model_changed
            or mode_changed
            or (mode == "proxy" and (target_changed or serial_changed or remote_iface_changed))
        )

        if enabled and not self._enabled:
            logger.info("Starting virtual printer (was disabled)")
            await self._start()
        elif not enabled and self._enabled:
            logger.info("Stopping virtual printer (was enabled)")
            await self._stop()
        elif enabled and self._enabled and needs_restart:
            # Configuration changed while running - restart services
            logger.info("Configuration changed (mode=%s→%s), restarting...", old_mode, mode)
            await self._stop()
            # Give time for ports to be released
            await asyncio.sleep(0.5)
            await self._start()
            logger.info("Virtual printer restarted with new configuration")
        else:
            logger.debug("No state change needed (enabled=%s, self._enabled=%s)", enabled, self._enabled)

        self._enabled = enabled

    async def _start(self) -> None:
        """Start all virtual printer services."""
        logger.info("Starting virtual printer services (mode=%s)...", self._mode)

        # Proxy mode uses different services
        if self._mode == "proxy":
            await self._start_proxy_mode()
            return

        # Standard modes (immediate, review, print_queue) use FTP/MQTT servers
        await self._start_server_mode()

    async def _start_proxy_mode(self) -> None:
        """Start virtual printer in proxy mode (TLS terminating relay)."""
        logger.info("Starting proxy mode to %s", self._target_printer_ip)

        # In proxy mode, use the REAL printer's serial number
        # This ensures MQTT topic subscriptions match the real printer's topics
        proxy_serial = self._target_printer_serial or self.printer_serial
        logger.info("Proxy mode using serial: %s", proxy_serial)

        # Update certificate service with the real printer's serial
        self._cert_service.serial = proxy_serial

        # Regenerate printer cert if needed (CA is preserved)
        self._cert_service.delete_printer_certificate()
        cert_path, key_path = self._cert_service.generate_certificates()
        logger.info("Generated certificate for proxy serial: %s", proxy_serial)

        # Initialize TLS proxy with our certificates
        self._proxy = SlicerProxyManager(
            target_host=self._target_printer_ip,
            cert_path=cert_path,
            key_path=key_path,
            on_activity=self._on_proxy_activity,
        )

        # Start services as background tasks
        async def run_with_logging(coro, name):
            try:
                await coro
            except Exception as e:
                logger.error("Virtual printer %s failed: %s", name, e)

        self._tasks = []

        # SSDP setup: use SSDPProxy if remote interface is configured
        # Local interface is auto-detected from target printer IP
        if self._remote_interface_ip:
            # Auto-detect local interface based on target printer IP
            from backend.app.services.network_utils import find_interface_for_ip

            local_iface = find_interface_for_ip(self._target_printer_ip)
            if local_iface:
                local_interface_ip = local_iface["ip"]
                logger.info(
                    f"SSDP proxy mode: LAN A ({local_interface_ip}, auto-detected) -> LAN B ({self._remote_interface_ip})"
                )
                self._ssdp_proxy = SSDPProxy(
                    local_interface_ip=local_interface_ip,
                    remote_interface_ip=self._remote_interface_ip,
                    target_printer_ip=self._target_printer_ip,
                )
                self._tasks.append(
                    asyncio.create_task(
                        run_with_logging(self._ssdp_proxy.start(), "SSDP Proxy"),
                        name="virtual_printer_ssdp_proxy",
                    )
                )
            else:
                logger.warning(
                    f"Could not auto-detect local interface for printer {self._target_printer_ip}, "
                    "falling back to single-interface SSDP"
                )
                self._start_fallback_ssdp(proxy_serial, run_with_logging)
        else:
            # Single interface: broadcast SSDP on same network (fallback)
            self._start_fallback_ssdp(proxy_serial, run_with_logging)

        # Add TLS proxy task
        self._tasks.append(
            asyncio.create_task(
                run_with_logging(self._proxy.start(), "Proxy"),
                name="virtual_printer_proxy",
            )
        )

        logger.info(
            f"Virtual printer proxy started: "
            f"FTP 0.0.0.0:{SlicerProxyManager.LOCAL_FTP_PORT} -> {self._target_printer_ip}:{SlicerProxyManager.PRINTER_FTP_PORT}, "
            f"MQTT 0.0.0.0:{SlicerProxyManager.LOCAL_MQTT_PORT} -> {self._target_printer_ip}:{SlicerProxyManager.PRINTER_MQTT_PORT}"
        )

    def _start_fallback_ssdp(self, proxy_serial: str, run_with_logging) -> None:
        """Start single-interface SSDP server as fallback."""
        logger.info("SSDP broadcast mode (single interface)")
        self._ssdp = VirtualPrinterSSDPServer(
            name=f"{self.PRINTER_NAME} (Proxy)",
            serial=proxy_serial,
            model=self._model,
        )
        self._tasks.append(
            asyncio.create_task(
                run_with_logging(self._ssdp.start(), "SSDP"),
                name="virtual_printer_ssdp",
            )
        )

    async def _start_server_mode(self) -> None:
        """Start virtual printer in server mode (FTP/MQTT servers)."""
        # Update certificate service with current serial (based on model)
        current_serial = self.printer_serial
        self._cert_service.serial = current_serial

        # Regenerate printer cert if serial changed (CA is preserved)
        self._cert_service.delete_printer_certificate()
        cert_path, key_path = self._cert_service.generate_certificates()
        logger.info("Generated certificate for serial: %s", current_serial)

        # Create directories
        self._upload_dir.mkdir(parents=True, exist_ok=True)
        (self._upload_dir / "cache").mkdir(exist_ok=True)

        # Initialize services
        self._ssdp = VirtualPrinterSSDPServer(
            name=self.PRINTER_NAME,
            serial=self.printer_serial,
            model=self._model,
        )

        self._ftp = VirtualPrinterFTPServer(
            upload_dir=self._upload_dir,
            access_code=self._access_code,
            cert_path=cert_path,
            key_path=key_path,
            on_file_received=self._on_file_received,
        )

        self._mqtt = SimpleMQTTServer(
            serial=self.printer_serial,
            access_code=self._access_code,
            cert_path=cert_path,
            key_path=key_path,
            on_print_command=self._on_print_command,
        )

        # Start services as background tasks
        # Wrap each in error handler so one failure doesn't stop others
        async def run_with_logging(coro, name):
            try:
                await coro
            except Exception as e:
                logger.error("Virtual printer %s failed: %s", name, e)

        self._tasks = [
            asyncio.create_task(run_with_logging(self._ssdp.start(), "SSDP"), name="virtual_printer_ssdp"),
            asyncio.create_task(run_with_logging(self._ftp.start(), "FTP"), name="virtual_printer_ftp"),
            asyncio.create_task(run_with_logging(self._mqtt.start(), "MQTT"), name="virtual_printer_mqtt"),
        ]

        logger.info("Virtual printer '%s' started (serial: %s)", self.PRINTER_NAME, self.printer_serial)

    def _on_proxy_activity(self, name: str, message: str) -> None:
        """Handle proxy activity for logging."""
        logger.info("Proxy %s: %s", name, message)

    async def _stop(self) -> None:
        """Stop all virtual printer services."""
        logger.info("Stopping virtual printer services...")

        # Stop services first - this closes servers and cancels active sessions
        if self._ftp:
            await self._ftp.stop()
            self._ftp = None

        if self._mqtt:
            await self._mqtt.stop()
            self._mqtt = None

        if self._ssdp:
            await self._ssdp.stop()
            self._ssdp = None

        if self._ssdp_proxy:
            await self._ssdp_proxy.stop()
            self._ssdp_proxy = None

        if self._proxy:
            await self._proxy.stop()
            self._proxy = None

        # Cancel remaining tasks with short timeout
        for task in self._tasks:
            task.cancel()

        if self._tasks:
            try:
                await asyncio.wait_for(asyncio.gather(*self._tasks, return_exceptions=True), timeout=1.0)
            except TimeoutError:
                logger.debug("Some tasks didn't stop in time")

        self._tasks = []

        logger.info("Virtual printer stopped")

    async def _on_file_received(self, file_path: Path, source_ip: str) -> None:
        """Handle file upload completion from FTP.

        Args:
            file_path: Path to uploaded file
            source_ip: IP address of the uploading slicer
        """
        logger.info("Virtual printer received file: %s from %s", file_path.name, source_ip)

        # Store file reference for MQTT correlation
        self._pending_files[file_path.name] = file_path

        # Handle based on mode:
        # - immediate: archive right away
        # - review: create pending upload record for user review before archiving
        # - print_queue: archive and add to print queue (unassigned)
        if self._mode == "immediate":
            await self._archive_file(file_path, source_ip)
        elif self._mode == "print_queue":
            await self._add_to_print_queue(file_path, source_ip)
        else:
            # "review" mode (or legacy "queue" mode)
            await self._queue_file(file_path, source_ip)

    async def _on_print_command(self, filename: str, data: dict) -> None:
        """Handle print command from MQTT.

        In a real printer, this would start the print. For virtual printer,
        we just log it since archiving is handled by file upload.

        Args:
            filename: Name of the file to print
            data: Print command data (contains settings like timelapse, bed_leveling, etc.)
        """
        logger.info("Virtual printer received print command for: %s", filename)
        logger.debug("Print command data: %s", data)

        # The file should already be archived from FTP upload
        # This command just confirms the slicer's intent to "print"

    async def _archive_file(self, file_path: Path, source_ip: str) -> None:
        """Archive file immediately.

        Args:
            file_path: Path to the 3MF file
            source_ip: IP address of uploader
        """
        if not self._session_factory:
            logger.error("Cannot archive: no database session factory configured")
            return

        # Only archive 3MF files
        if file_path.suffix.lower() != ".3mf":
            logger.debug("Skipping non-3MF file: %s", file_path.name)
            # Remove from pending and clean up
            self._pending_files.pop(file_path.name, None)
            try:
                file_path.unlink()
            except OSError:
                pass
            return

        try:
            from backend.app.services.archive import ArchiveService

            async with self._session_factory() as db:
                service = ArchiveService(db)

                # Archive the print
                archive = await service.archive_print(
                    printer_id=None,  # No physical printer
                    source_file=file_path,
                    print_data={
                        "status": "archived",
                        "source": "virtual_printer",
                        "source_ip": source_ip,
                    },
                )

                if archive:
                    logger.info("Archived virtual printer upload: %s - %s", archive.id, archive.print_name)

                    # Clean up uploaded file (it's now copied to archive)
                    try:
                        file_path.unlink()
                    except OSError:
                        pass

                    # Remove from pending
                    self._pending_files.pop(file_path.name, None)
                else:
                    logger.error("Failed to archive file: %s", file_path.name)

        except Exception as e:  # Mixed async DB + archive operations
            logger.error("Error archiving file: %s", e)

    async def _queue_file(self, file_path: Path, source_ip: str) -> None:
        """Queue file for user review.

        Args:
            file_path: Path to the 3MF file
            source_ip: IP address of uploader
        """
        if not self._session_factory:
            logger.error("Cannot queue: no database session factory configured")
            return

        # Only queue 3MF files
        if file_path.suffix.lower() != ".3mf":
            logger.warning("Skipping non-3MF file: %s", file_path.name)
            return

        try:
            from backend.app.models.pending_upload import PendingUpload

            async with self._session_factory() as db:
                pending = PendingUpload(
                    filename=file_path.name,
                    file_path=str(file_path),
                    file_size=file_path.stat().st_size,
                    source_ip=source_ip,
                    status="pending",
                    uploaded_at=datetime.now(timezone.utc),
                )
                db.add(pending)
                await db.commit()

                logger.info("Queued virtual printer upload: %s - %s", pending.id, file_path.name)

                # Remove from pending files dict
                self._pending_files.pop(file_path.name, None)

        except Exception as e:
            logger.error("Error queueing file: %s", e)

    async def _add_to_print_queue(self, file_path: Path, source_ip: str) -> None:
        """Archive file and add to print queue (unassigned).

        Args:
            file_path: Path to the 3MF file
            source_ip: IP address of uploader
        """
        if not self._session_factory:
            logger.error("Cannot add to print queue: no database session factory configured")
            return

        # Only process 3MF files
        if file_path.suffix.lower() != ".3mf":
            logger.debug("Skipping non-3MF file: %s", file_path.name)
            self._pending_files.pop(file_path.name, None)
            try:
                file_path.unlink()
            except OSError:
                pass
            return

        try:
            from backend.app.models.print_queue import PrintQueueItem
            from backend.app.services.archive import ArchiveService

            async with self._session_factory() as db:
                service = ArchiveService(db)

                # First, archive the print
                archive = await service.archive_print(
                    printer_id=None,  # No physical printer
                    source_file=file_path,
                    print_data={
                        "status": "archived",
                        "source": "virtual_printer",
                        "source_ip": source_ip,
                    },
                )

                if archive:
                    logger.info("Archived virtual printer upload: %s - %s", archive.id, archive.print_name)

                    # Now add to print queue (unassigned)
                    queue_item = PrintQueueItem(
                        printer_id=None,  # Unassigned - user will assign later
                        archive_id=archive.id,
                        position=1,  # Will be adjusted when assigned to a printer
                        status="pending",
                    )
                    db.add(queue_item)
                    await db.commit()

                    logger.info(
                        "Added to print queue (unassigned): queue_id=%s, archive_id=%s", queue_item.id, archive.id
                    )

                    # Clean up uploaded file (it's now copied to archive)
                    try:
                        file_path.unlink()
                    except OSError:
                        pass

                    # Remove from pending
                    self._pending_files.pop(file_path.name, None)
                else:
                    logger.error("Failed to archive file: %s", file_path.name)

        except Exception as e:  # Mixed async DB + archive + queue operations
            logger.error("Error adding to print queue: %s", e)

    def get_status(self) -> dict:
        """Get virtual printer status.

        Returns:
            Status dictionary with enabled, running, mode, etc.
        """
        status = {
            "enabled": self._enabled,
            "running": self.is_running,
            "mode": self._mode,
            "name": self.PRINTER_NAME,
            "serial": self.printer_serial,
            "model": self._model,
            "model_name": VIRTUAL_PRINTER_MODELS.get(self._model, self._model),
            "pending_files": len(self._pending_files),
        }

        # Add proxy-specific status
        if self._mode == "proxy":
            status["target_printer_ip"] = self._target_printer_ip
            if self._proxy:
                proxy_status = self._proxy.get_status()
                status["proxy"] = proxy_status

        return status


# Global instance
virtual_printer_manager = VirtualPrinterManager()