"""Global search API endpoint with full search parity."""

import re
import ipaddress
import logging

from datetime import datetime, timezone
from flask import Blueprint, request, current_app
from flask_jwt_extended import jwt_required
from sqlalchemy.orm import joinedload

from shopdb.extensions import db
from shopdb.core.models import (
    Application, Setting,
    Asset, AssetType, Communication, Vendor, Model,
    CustomField, CustomFieldValue
)
from shopdb.core.api.settings import get_cached_settings
from shopdb.utils.responses import success_response

logger = logging.getLogger(__name__)

search_bp = Blueprint('search', __name__)


def _require_enabled(name):
    """Raise ImportError when the named plugin is disabled.

    Each plugin-scoped search block already catches ImportError and skips the
    domain, so a disabled plugin is treated exactly like an absent one: its rows
    drop out of search results. Honors runtime enable/disable.
    """
    pm = current_app.extensions.get('plugin_manager')
    if pm and not pm.registry.is_enabled(name):
        raise ImportError(f'{name} plugin disabled')

# Shipped GE defaults. Settings override these per-site; identical fallbacks
# live here so this consumer works even if the settings seed has not run.
SERVICENOW_URL_DEFAULT = (
    'https://geaerospaceqa.service-now.com/now/nav/ui/search/'
    '0f8b85d0c7922010099a308dc7c2606a/params/search-term/{ticket}/'
    'global-search-data-config-id/c861cea2c7022010099a308dc7c26041/'
)
SERVICENOW_PREFIXES_DEFAULT = 'GEINC,GECHG,GERIT,GESCT'
EMPLOYEEID_PATTERN_DEFAULT = r'^\d{9}$'


def _get_search_integrations():
    """Resolve the settings-driven search integration config.

    Reads employeeid_pattern, servicenow_ticket_prefixes, servicenow_enabled
    and servicenow_search_url from cached settings, falling back to the shipped
    GE defaults for any missing key. An invalid employeeid_pattern regex falls
    back to the default rather than raising (search must never 500 on bad
    config). ServiceNow is inactive when disabled, when the URL is blank, or
    when no ticket prefixes are configured.
    """
    settings = get_cached_settings()

    # Employee-ID pattern. Bad regex falls back so search never 500s.
    pattern = settings.get('employeeid_pattern') or EMPLOYEEID_PATTERN_DEFAULT
    try:
        employeeid_re = re.compile(pattern)
    except re.error:
        employeeid_re = re.compile(EMPLOYEEID_PATTERN_DEFAULT)

    # Ticket prefixes -> case-insensitive alternation built at request time.
    prefixes_raw = settings.get('servicenow_ticket_prefixes')
    if prefixes_raw is None:
        prefixes_raw = SERVICENOW_PREFIXES_DEFAULT
    prefixes = [p.strip() for p in str(prefixes_raw).split(',') if p.strip()]

    servicenow_enabled = settings.get('servicenow_enabled')
    if servicenow_enabled is None:
        servicenow_enabled = True

    servicenow_url = settings.get('servicenow_search_url')
    if servicenow_url is None:
        servicenow_url = SERVICENOW_URL_DEFAULT

    servicenow_active = bool(servicenow_enabled) and bool(servicenow_url) and bool(prefixes)

    prefix_re = None
    if servicenow_active:
        alternation = '|'.join(re.escape(p) for p in prefixes)
        prefix_re = re.compile(r'^(' + alternation + r')\d+', re.IGNORECASE)

    return {
        'employeeid_re': employeeid_re,
        'prefix_re': prefix_re,
        'servicenow_active': servicenow_active,
        'servicenow_url': servicenow_url,
    }


def _classify_query(query, integrations):
    """Analyze the query string to determine its nature."""
    prefix_re = integrations['prefix_re']
    sn_match = prefix_re.match(query) if prefix_re else None
    return {
        'is_ip': bool(re.match(r'^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$', query)),
        'is_sso': bool(integrations['employeeid_re'].match(query)),
        'is_servicenow': bool(sn_match),
        'servicenow_prefix': sn_match.group(1) if sn_match else None,
        'is_fqdn': bool(re.match(r'^[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+$', query)),
    }


def _get_asset_result(asset, query, relevance=None):
    """Build a search result dict from an Asset object."""
    asset_type_name = asset.assettype.assettype if asset.assettype else 'asset'

    plugin_id = asset.assetid
    if asset_type_name == 'machine' and hasattr(asset, 'machine') and asset.machine:
        plugin_id = asset.machine.machineid
    elif asset_type_name == 'computer' and hasattr(asset, 'computer') and asset.computer:
        plugin_id = asset.computer.computerid
    elif asset_type_name == 'network_device' and hasattr(asset, 'network_device') and asset.network_device:
        plugin_id = asset.network_device.networkdeviceid
    elif asset_type_name == 'printer' and hasattr(asset, 'printer') and asset.printer:
        plugin_id = asset.printer.printerid
    elif asset_type_name == 'measuring_tool' and hasattr(asset, 'measuringtool') and asset.measuringtool:
        plugin_id = asset.measuringtool.measuringtoolid

    url_map = {
        'machine': f"/machines/{plugin_id}",
        'computer': f"/pcs/{plugin_id}",
        'network_device': f"/network/{plugin_id}",
        'printer': f"/printers/{plugin_id}",
        'measuring_tool': f"/measuringtools/{plugin_id}",
    }
    url = url_map.get(asset_type_name, f"/assets/{asset.assetid}")

    display_name = asset.display_name
    subtitle = None
    if asset.name and asset.assetnumber != asset.name:
        subtitle = asset.assetnumber

    location_name = asset.location.locationname if asset.location else None

    if relevance is None:
        relevance = 15

    return {
        'type': asset_type_name,
        'id': plugin_id,
        'title': display_name,
        'subtitle': subtitle,
        'location': location_name,
        'url': url,
        'relevance': relevance
    }


def _search_applications(query, search_term):
    """Search Applications by name and description."""
    results = []
    try:
        apps = Application.query.filter(
            Application.isactive == True,
            db.or_(
                Application.appname.ilike(search_term),
                Application.appdescription.ilike(search_term)
            )
        ).limit(10).all()

        for app in apps:
            relevance = 20
            if query.lower() == app.appname.lower():
                relevance = 100
            elif query.lower() in app.appname.lower():
                relevance = 50

            results.append({
                'type': 'application',
                'id': app.appid,
                'title': app.appname,
                'subtitle': app.appdescription[:100] if app.appdescription else None,
                'url': f"/applications/{app.appid}",
                'relevance': relevance
            })
    except Exception as e:
        logger.error(f"Application search failed: {e}")
    return results


def _search_knowledgebase(query, search_term):
    """Search Knowledge Base by description and keywords."""
    results = []
    try:
        _require_enabled('knowledgebase')
        from plugins.knowledgebase.models import KnowledgeBase
        kb_articles = KnowledgeBase.query.filter(
            KnowledgeBase.isactive == True,
            db.or_(
                KnowledgeBase.shortdescription.ilike(search_term),
                KnowledgeBase.keywords.ilike(search_term)
            )
        ).limit(20).all()

        for kb in kb_articles:
            relevance = 10 + (kb.clicks or 0) * 0.1
            if kb.keywords and query.lower() in kb.keywords.lower():
                relevance += 15

            results.append({
                'type': 'knowledgebase',
                'id': kb.linkid,
                'title': kb.shortdescription,
                'subtitle': kb.application.appname if kb.application else None,
                'url': f"/knowledgebase/{kb.linkid}",
                'linkurl': kb.linkurl,
                'relevance': relevance
            })
    except ImportError:
        pass  # knowledgebase plugin absent or disabled
    except Exception as e:
        logger.error(f"KnowledgeBase search failed: {e}")
    return results


def _search_employees(query, search_term):
    """Search Employees in separate wjf_employees database."""
    results = []
    try:
        # Use the shared env-backed connection helper; never hardcode creds.
        from shopdb.utils.employee_db import employee_connection
        emp_conn = employee_connection()

        with emp_conn.cursor() as cur:
            cur.execute('''
                SELECT SSO, First_Name, Last_Name, Team, Role
                FROM employees
                WHERE First_Name LIKE %s
                   OR Last_Name LIKE %s
                   OR CAST(SSO AS CHAR) LIKE %s
                ORDER BY Last_Name, First_Name
                LIMIT 10
            ''', (search_term, search_term, search_term))
            employees = cur.fetchall()

        emp_conn.close()

        for emp in employees:
            full_name = f"{emp['First_Name'].strip()} {emp['Last_Name'].strip()}"
            sso_str = str(emp['SSO'])

            relevance = 20
            if query == sso_str:
                relevance = 100
            elif query.lower() == full_name.lower():
                relevance = 95
            elif query.lower() in full_name.lower():
                relevance = 60

            results.append({
                'type': 'employee',
                'id': emp['SSO'],
                'title': full_name,
                'subtitle': emp.get('Team') or emp.get('Role') or f"SSO: {sso_str}",
                'url': f"/employees/{emp['SSO']}",
                'relevance': relevance
            })
    except Exception as e:
        logger.error(f"Employee search failed: {e}")
    return results


def _search_assets(query, search_term):
    """Search unified Assets table by number, name, serial, notes."""
    results = []
    try:
        assets = Asset.query.join(AssetType).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            db.or_(
                Asset.assetnumber.ilike(search_term),
                Asset.name.ilike(search_term),
                Asset.serialnumber.ilike(search_term),
                Asset.notes.ilike(search_term)
            )
        ).limit(15).all()

        for asset in assets:
            relevance = 15
            if asset.assetnumber and query.lower() == asset.assetnumber.lower():
                relevance = 100
            elif asset.name and query.lower() == asset.name.lower():
                relevance = 90
            elif asset.serialnumber and query.lower() == asset.serialnumber.lower():
                relevance = 85
            elif asset.name and query.lower() in asset.name.lower():
                relevance = 50

            results.append(_get_asset_result(asset, query, relevance))
    except Exception as e:
        logger.error(f"Asset search failed: {e}")
    return results


def _search_measuringtools(query, search_term):
    """Search measuring tools, including the gaugelabreference identifier.

    The generic asset search already matches number/name/serial across all asset
    types; this gated searcher adds gaugelabreference (the gage tag the gage lab
    searches by) and drops out when the measuringtools plugin is disabled.
    """
    results = []
    try:
        _require_enabled('measuringtools')
        from plugins.measuringtools.models import MeasuringTool
        assets = db.session.query(Asset).join(
            MeasuringTool, MeasuringTool.assetid == Asset.assetid
        ).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            db.or_(
                Asset.assetnumber.ilike(search_term),
                Asset.name.ilike(search_term),
                Asset.serialnumber.ilike(search_term),
                Asset.gaugelabreference.ilike(search_term),
            )
        ).limit(15).all()

        for asset in assets:
            relevance = 15
            if asset.assetnumber and query.lower() == asset.assetnumber.lower():
                relevance = 100
            elif asset.gaugelabreference and query.lower() == asset.gaugelabreference.lower():
                relevance = 90
            elif asset.serialnumber and query.lower() == asset.serialnumber.lower():
                relevance = 85
            elif asset.name and query.lower() in asset.name.lower():
                relevance = 50
            results.append(_get_asset_result(asset, query, relevance))
    except ImportError:
        pass  # measuringtools plugin absent or disabled
    except Exception as e:
        logger.error(f"Measuring tool search failed: {e}")
    return results


def _search_customfields(query, search_term):
    """Search custom-field VALUES for fields flagged searchable.

    Joins CustomFieldValue -> CustomField (searchable + active) -> Asset (active)
    and emits a normal asset result routed to that asset's detail page. Results
    are deduped against built-in-field asset matches by the shared (type, id) key
    in global_search, and the asset's search_<type>_enabled domain toggle is
    applied by the same end-of-request domain filter. The matched field label is
    put in the subtitle so a value hit reads sensibly.
    """
    results = []
    try:
        rows = db.session.query(Asset, CustomField).join(
            CustomFieldValue, CustomFieldValue.assetid == Asset.assetid
        ).join(
            CustomField, CustomField.fieldid == CustomFieldValue.fieldid
        ).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            CustomField.searchable == True,
            CustomField.isactive == True,
            CustomFieldValue.value.ilike(search_term),
        ).limit(15).all()

        for asset, field in rows:
            result = _get_asset_result(asset, query, relevance=40)
            result['subtitle'] = field.label
            results.append(result)
    except Exception as e:
        logger.error(f"Custom field search failed: {e}")
    return results


def _search_by_ip(query, search_term):
    """Search Communications table for IP address matches."""
    results = []
    try:
        comms = Communication.query.filter(
            Communication.ipaddress.ilike(search_term)
        ).options(
            joinedload(Communication.asset).joinedload(Asset.assettype),
            joinedload(Communication.asset).joinedload(Asset.location),
        ).limit(10).all()

        seen_assets = set()
        for comm in comms:
            asset = comm.asset
            if not asset or not asset.isactive or asset.assetid in seen_assets:
                continue
            seen_assets.add(asset.assetid)

            relevance = 80 if query == comm.ipaddress else 40
            result = _get_asset_result(asset, query, relevance)
            result['subtitle'] = comm.ipaddress
            results.append(result)
    except Exception as e:
        logger.error(f"IP search failed: {e}")
    return results


def _search_subnets(query):
    """Find which subnet an IP address belongs to."""
    results = []
    try:
        _require_enabled('network')
        from plugins.network.models import Subnet
        ip_obj = ipaddress.ip_address(query)
        subnets = Subnet.query.filter(Subnet.isactive == True).all()
        for subnet in subnets:
            try:
                network = ipaddress.ip_network(subnet.cidr, strict=False)
                if ip_obj in network:
                    results.append({
                        'type': 'subnet',
                        'id': subnet.subnetid,
                        'title': f'{subnet.name} ({subnet.cidr})',
                        'subtitle': subnet.description or subnet.subnettype,
                        'url': f'/network',
                        'relevance': 70
                    })
            except ValueError:
                continue
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Subnet search failed: {e}")
    return results


def _search_hostnames(query, search_term):
    """Search hostname fields across Computer, Printer, NetworkDevice."""
    results = []

    # Search Computers
    try:
        _require_enabled('computers')
        from plugins.computers.models import Computer
        computers = Computer.query.filter(
            Computer.hostname.ilike(search_term)
        ).options(
            joinedload(Computer.asset).joinedload(Asset.assettype),
            joinedload(Computer.asset).joinedload(Asset.location),
        ).limit(10).all()

        for comp in computers:
            if comp.asset and comp.asset.isactive:
                relevance = 85 if query.lower() == (comp.hostname or '').lower() else 40
                result = _get_asset_result(comp.asset, query, relevance)
                result['subtitle'] = comp.hostname
                results.append(result)
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Computer hostname search failed: {e}")

    # Search Printers
    try:
        _require_enabled('printers')
        from plugins.printers.models import Printer
        printers = Printer.query.filter(
            db.or_(
                Printer.hostname.ilike(search_term),
                Printer.sharename.ilike(search_term),
                Printer.windowsname.ilike(search_term),
            )
        ).options(
            joinedload(Printer.asset).joinedload(Asset.assettype),
            joinedload(Printer.asset).joinedload(Asset.location),
        ).limit(10).all()

        for printer in printers:
            if printer.asset and printer.asset.isactive:
                match_field = printer.hostname or printer.sharename or ''
                relevance = 85 if query.lower() == match_field.lower() else 40
                result = _get_asset_result(printer.asset, query, relevance)
                result['subtitle'] = printer.hostname or printer.sharename
                results.append(result)
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Printer hostname search failed: {e}")

    # Search Network Devices
    try:
        _require_enabled('network')
        from plugins.network.models import NetworkDevice
        devices = NetworkDevice.query.filter(
            NetworkDevice.hostname.ilike(search_term)
        ).options(
            joinedload(NetworkDevice.asset).joinedload(Asset.assettype),
            joinedload(NetworkDevice.asset).joinedload(Asset.location),
        ).limit(10).all()

        for device in devices:
            if device.asset and device.asset.isactive:
                relevance = 85 if query.lower() == (device.hostname or '').lower() else 40
                result = _get_asset_result(device.asset, query, relevance)
                result['subtitle'] = device.hostname
                results.append(result)
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Network device hostname search failed: {e}")

    return results


def _search_notifications(query, search_term):
    """Search notifications with time-weighted relevance."""
    results = []
    try:
        _require_enabled('notifications')
        from plugins.notifications.models import Notification

        notifications = Notification.query.options(
            joinedload(Notification.notificationtype)
        ).filter(
            db.or_(
                Notification.notification.ilike(search_term),
                Notification.ticketnumber.ilike(search_term)
            )
        ).order_by(Notification.starttime.desc()).limit(15).all()

        now = datetime.now(timezone.utc).replace(tzinfo=None)
        for notif in notifications:
            base_relevance = 20
            if notif.ticketnumber and query.lower() == notif.ticketnumber.lower():
                base_relevance = 85

            # Time-weighted relevance
            if notif.is_current:
                base_relevance *= 3
            elif notif.starttime and notif.starttime > now:
                base_relevance *= 2
            elif notif.endtime and (now - notif.endtime).days < 7:
                base_relevance = int(base_relevance * 1.5)

            results.append({
                'type': 'notification',
                'id': notif.notificationid,
                'title': notif.title,
                'subtitle': notif.notificationtype.typename if notif.notificationtype else None,
                'url': f'/notifications',
                'relevance': min(int(base_relevance), 100),
                'ticketnumber': notif.ticketnumber,
                'iscurrent': notif.is_current
            })
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Notification search failed: {e}")
    return results


def _search_vendor_model_type(query, search_term):
    """Search assets by vendor name, model name, or machine/device type name."""
    results = []

    # Machines: vendor, model, machinetype
    try:
        _require_enabled('machines')
        from plugins.machines.models import Machine, MachineType
        machine_assets = db.session.query(Asset).join(
            Machine, Machine.assetid == Asset.assetid
        ).outerjoin(
            Vendor, Machine.vendorid == Vendor.vendorid
        ).outerjoin(
            Model, Machine.modelnumberid == Model.modelnumberid
        ).outerjoin(
            MachineType, Machine.machinetypeid == MachineType.machinetypeid
        ).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            db.or_(
                Vendor.vendor.ilike(search_term),
                Model.modelnumber.ilike(search_term),
                MachineType.machinetype.ilike(search_term)
            )
        ).limit(10).all()

        for asset in machine_assets:
            results.append(_get_asset_result(asset, query, 30))
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Machine vendor/model/type search failed: {e}")

    # Printers: vendor, model, printertype
    try:
        _require_enabled('printers')
        from plugins.printers.models import Printer, PrinterType
        printer_assets = db.session.query(Asset).join(
            Printer, Printer.assetid == Asset.assetid
        ).outerjoin(
            Vendor, Printer.vendorid == Vendor.vendorid
        ).outerjoin(
            Model, Printer.modelnumberid == Model.modelnumberid
        ).outerjoin(
            PrinterType, Printer.printertypeid == PrinterType.printertypeid
        ).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            db.or_(
                Vendor.vendor.ilike(search_term),
                Model.modelnumber.ilike(search_term),
                PrinterType.printertype.ilike(search_term)
            )
        ).limit(10).all()

        for asset in printer_assets:
            results.append(_get_asset_result(asset, query, 30))
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Printer vendor/model/type search failed: {e}")

    # Network Devices: vendor, networkdevicetype
    try:
        _require_enabled('network')
        from plugins.network.models import NetworkDevice, NetworkDeviceType
        netdev_assets = db.session.query(Asset).join(
            NetworkDevice, NetworkDevice.assetid == Asset.assetid
        ).outerjoin(
            Vendor, NetworkDevice.vendorid == Vendor.vendorid
        ).outerjoin(
            NetworkDeviceType, NetworkDevice.networkdevicetypeid == NetworkDeviceType.networkdevicetypeid
        ).options(
            joinedload(Asset.assettype),
            joinedload(Asset.location),
        ).filter(
            Asset.isactive == True,
            db.or_(
                Vendor.vendor.ilike(search_term),
                NetworkDeviceType.networkdevicetype.ilike(search_term)
            )
        ).limit(10).all()

        for asset in netdev_assets:
            results.append(_get_asset_result(asset, query, 30))
    except ImportError:
        pass
    except Exception as e:
        logger.error(f"Network device vendor/type search failed: {e}")

    return results


def _check_smart_redirect(query, classification):
    """Check if query exactly matches a single entity for smart redirect."""
    # Exact SSO match
    if classification['is_sso']:
        try:
            # Shared env-backed connection helper; never hardcode creds.
            from shopdb.utils.employee_db import employee_connection
            emp_conn = employee_connection()
            with emp_conn.cursor() as cur:
                cur.execute(
                    'SELECT SSO, First_Name, Last_Name FROM employees WHERE SSO = %s LIMIT 1',
                    (query,)
                )
                emp = cur.fetchone()
            emp_conn.close()
            if emp:
                name = f"{emp['First_Name'].strip()} {emp['Last_Name'].strip()}"
                return {
                    'type': 'employee',
                    'url': f"/employees/{emp['SSO']}",
                    'label': name
                }
        except Exception:
            pass

    # Exact asset number match
    try:
        asset = Asset.query.options(
            joinedload(Asset.assettype),
        ).filter(
            Asset.assetnumber == query,
            Asset.isactive == True
        ).first()
        if asset:
            result = _get_asset_result(asset, query)
            return {
                'type': result['type'],
                'url': result['url'],
                'label': asset.display_name
            }
    except Exception:
        pass

    # Exact printer CSF/share name
    try:
        _require_enabled('printers')
        from plugins.printers.models import Printer
        printer = Printer.query.options(
            joinedload(Printer.asset).joinedload(Asset.assettype),
        ).filter(
            db.or_(
                Printer.sharename == query,
                Printer.windowsname == query
            )
        ).first()
        if printer and printer.asset and printer.asset.isactive:
            return {
                'type': 'printer',
                'url': f"/printers/{printer.printerid}",
                'label': printer.sharename or printer.asset.display_name
            }
    except ImportError:
        pass
    except Exception:
        pass

    # Exact hostname match (FQDN or bare hostname)
    hostname_plugins = []
    try:
        _require_enabled('computers')
        from plugins.computers.models import Computer
        hostname_plugins.append(('computer', Computer, 'computerid', '/pcs'))
    except ImportError:
        pass
    try:
        _require_enabled('printers')
        from plugins.printers.models import Printer
        hostname_plugins.append(('printer', Printer, 'printerid', '/printers'))
    except ImportError:
        pass
    try:
        _require_enabled('network')
        from plugins.network.models import NetworkDevice
        hostname_plugins.append(('network_device', NetworkDevice, 'networkdeviceid', '/network'))
    except ImportError:
        pass

    for type_name, PluginModel, id_field, url_prefix in hostname_plugins:
        try:
            device = PluginModel.query.options(
                joinedload(PluginModel.asset)
            ).filter(
                PluginModel.hostname == query
            ).first()
            if device and device.asset and device.asset.isactive:
                return {
                    'type': type_name,
                    'url': f"{url_prefix}/{getattr(device, id_field)}",
                    'label': device.hostname
                }
        except Exception:
            pass

    # Exact IP match
    if classification['is_ip']:
        try:
            comm = Communication.query.options(
                joinedload(Communication.asset).joinedload(Asset.assettype)
            ).filter(
                Communication.ipaddress == query
            ).first()
            if comm and comm.asset and comm.asset.isactive:
                result = _get_asset_result(comm.asset, query)
                return {
                    'type': result['type'],
                    'url': result['url'],
                    'label': f"{comm.asset.display_name} ({comm.ipaddress})"
                }
        except Exception:
            pass

    return None


@search_bp.route('', methods=['GET'])
@jwt_required(optional=True)
def global_search():
    """
    Global search across multiple entity types.

    Returns combined results from assets, applications, knowledge base,
    employees, notifications, IP addresses, hostnames, and vendor/model/type.
    Supports smart redirects and ServiceNOW ticket detection.
    """
    query = request.args.get('q', '').strip()

    if not query or len(query) < 2:
        return success_response({
            'results': [],
            'query': query,
            'message': 'Search query must be at least 2 characters'
        })

    if len(query) > 200:
        return success_response({
            'results': [],
            'query': query[:200],
            'message': 'Search query too long'
        })

    integrations = _get_search_integrations()
    classification = _classify_query(query, integrations)

    # ServiceNOW prefix detection - return redirect immediately
    if classification['is_servicenow']:
        from urllib.parse import quote
        servicenow_url = integrations['servicenow_url'].format(ticket=quote(query))
        return success_response({
            'results': [],
            'query': query,
            'total': 0,
            'counts': {},
            'redirect': {
                'type': 'servicenow',
                'url': servicenow_url,
                'label': f'Open {query} in ServiceNOW'
            }
        })

    results = []
    search_term = f'%{query}%'

    # Run all search domains
    results.extend(_search_applications(query, search_term))
    results.extend(_search_knowledgebase(query, search_term))
    results.extend(_search_employees(query, search_term))
    results.extend(_search_assets(query, search_term))
    results.extend(_search_measuringtools(query, search_term))
    results.extend(_search_customfields(query, search_term))
    results.extend(_search_notifications(query, search_term))
    results.extend(_search_hostnames(query, search_term))
    results.extend(_search_vendor_model_type(query, search_term))

    # IP-specific searches
    if classification['is_ip']:
        results.extend(_search_by_ip(query, search_term))
        results.extend(_search_subnets(query))

    # Sort by relevance (highest first)
    results.sort(key=lambda x: x['relevance'], reverse=True)

    # Remove duplicates (prefer higher relevance)
    seen_ids = {}
    unique_results = []
    for r in results:
        key = (r['type'], r['id'])
        if key not in seen_ids:
            seen_ids[key] = True
            unique_results.append(r)

    # Drop result types disabled in Settings > Search (search_<type>_enabled).
    # Missing key = enabled. One query, default-on.
    disabled_types = {
        s.key[len('search_'):-len('_enabled')]
        for s in Setting.query.filter_by(category='search').all()
        if s.get_typed_value() is False
    }
    if disabled_types:
        unique_results = [r for r in unique_results if r['type'] not in disabled_types]

    # Compute type counts before truncation
    type_counts = {}
    for r in unique_results:
        t = r['type']
        type_counts[t] = type_counts.get(t, 0) + 1

    total_all = len(unique_results)

    # Limit total results
    unique_results = unique_results[:50]

    # Check for smart redirect
    response_data = {
        'results': unique_results,
        'query': query,
        'total': len(unique_results),
        'total_all': total_all,
        'counts': type_counts,
    }

    redirect = _check_smart_redirect(query, classification)
    if redirect:
        response_data['redirect'] = redirect

    return success_response(response_data)