"""Device management service."""

import logging
import re

from gatehouse_app.extensions import db
from gatehouse_app.models import Device
from gatehouse_app.models.user import User
from gatehouse_app.services.audit_service import AuditService
from gatehouse_app.exceptions import (
    DeviceNotFoundError,
    DeviceAlreadyExistsError,
    InvalidNodeIdError,
    ValidationError,
)

logger = logging.getLogger(__name__)

_NODE_ID_RE = re.compile(r"^[0-9a-fA-F]{10}$")


def _validate_node_id(node_id: str) -> str:
    node_id = node_id.strip().lower()
    if not _NODE_ID_RE.match(node_id):
        raise InvalidNodeIdError(
            f"Invalid ZeroTier node ID '{node_id}' — must be exactly 10 hex characters."
        )
    return node_id


def register_device(
    user_id: str,
    organization_id: str,
    node_id: str,
    nickname: str | None = None,
    hostname: str | None = None,
    asset_tag: str | None = None,
    serial_number: str | None = None,
) -> Device:
    """Register a new device for a user in an organization.

    Args:
        user_id: ID of the owning user
        organization_id: ID of the organization
        node_id: 10-char hex ZeroTier node ID
        nickname: User-assigned friendly name
        hostname: Device hostname
        asset_tag: Corporate asset tag
        serial_number: Device serial number

    Returns:
        The created Device record
    """
    node_id = _validate_node_id(node_id)

    existing = Device.query.filter(
        Device.node_id == node_id,
        Device.deleted_at.is_(None),
    ).first()
    if existing:
        raise DeviceAlreadyExistsError(
            f"A device with node ID {node_id} is already registered."
        )

    device = Device(
        user_id=user_id,
        organization_id=organization_id,
        node_id=node_id,
        device_nickname=nickname,
        hostname=hostname,
        asset_tag=asset_tag,
        serial_number=serial_number,
    )
    device.save()

    AuditService.log_action(
        action="device.registered",
        user_id=user_id,
        organization_id=organization_id,
        resource_type="device",
        resource_id=device.id,
        metadata={"node_id": node_id, "nickname": nickname},
        description=f"Device {node_id} registered",
        success=True,
    )

    return device


def list_user_devices(user_id: str, organization_id: str) -> list[Device]:
    """List all active devices for a user in an organization."""
    return Device.query.filter(
        Device.user_id == user_id,
        Device.organization_id == organization_id,
        Device.deleted_at.is_(None),
    ).all()


def get_device(device_id: str, organization_id: str | None = None) -> Device:
    """Fetch a device by ID, optionally scoped to an organization."""
    q = Device.query.filter(
        Device.id == device_id,
        Device.deleted_at.is_(None),
    )
    if organization_id:
        q = q.filter(Device.organization_id == organization_id)

    device = q.first()
    if not device:
        raise DeviceNotFoundError(f"Device {device_id} not found.")
    return device


def get_device_by_node_id(node_id: str, organization_id: str | None = None) -> Device | None:
    """Find a device by its ZeroTier node ID, optionally scoped to org."""
    node_id = _validate_node_id(node_id)
    q = Device.query.filter(
        Device.node_id == node_id,
        Device.deleted_at.is_(None),
    )
    if organization_id:
        q = q.filter(Device.organization_id == organization_id)
    return q.first()


def update_device(
    device_id: str,
    user_id: str,
    **kwargs,
) -> Device:
    """Update device fields. Only allows nickname, hostname, asset_tag."""
    device = get_device(device_id)

    if device.user_id != user_id:
        raise DeviceNotFoundError("Device not found.")

    allowed = {"device_nickname", "hostname", "asset_tag", "serial_number"}
    for key in kwargs:
        if key not in allowed:
            raise ValidationError(f"Cannot update field: {key}")

    device.update(**kwargs)

    AuditService.log_action(
        action="device.updated",
        user_id=user_id,
        organization_id=device.organization_id,
        resource_type="device",
        resource_id=device.id,
        metadata=kwargs,
        description=f"Device {device.node_id} updated",
        success=True,
    )

    return device


def remove_device(device_id: str, user_id: str) -> None:
    """Soft-delete a device, deactivate its active memberships, and soft-delete all memberships.

    Since memberships are device-centric (tied to a specific device/node_id), removing a device
    means all its memberships are orphaned and must be cleaned up.
    """
    device = get_device(device_id)

    if device.user_id != user_id:
        raise DeviceNotFoundError("Device not found.")

    # Soft-delete all memberships (deactivates active ones first)
    for membership in device.memberships:
        if membership.deleted_at is None:
            from gatehouse_app.services.network_access_service import revoke_membership_soft
            revoke_membership_soft(membership.id, revoked_by_user_id=user_id)

    device.delete(soft=True)

    AuditService.log_action(
        action="device.removed",
        user_id=user_id,
        organization_id=device.organization_id,
        resource_type="device",
        resource_id=device.id,
        metadata={"node_id": device.node_id, "memberships_removed": len([m for m in device.memberships if m.deleted_at is None])},
        description=f"Device {device.node_id} removed",
        success=True,
    )