# --------------------
# Asset Editing Views
# --------------------

import json
import os
from django.http import JsonResponse, Http404
from django.shortcuts import get_object_or_404
from django.urls import reverse
from django.views.decorators.http import require_GET, require_POST
from django.contrib.contenttypes.models import ContentType
from django.contrib.gis.geos import Point, GEOSGeometry
from django.db import transaction
from django.db.models import Q
from django.utils import timezone
from django.utils.translation import gettext as _

from assets.permissions import (
    can_edit_asset,
    get_allowed_update_fields_for_asset,
    get_allowed_actions_for_asset,
    get_allowed_actions_for_thematic,
    get_user_asset_thematic_access,
)
from assets.models import AssetCategory, ASSET_STATUS_CHOICES
from assets.models.core import ASSET_VALIDATION_STATUS_CHOICES
from common.models import Thematic
from interventions.models import Intervention, InterventionAsset
from assets.views.locations import ASSETS_LOCATION_REGISTRY


# -----------------------------------------------------------------------
# Asset Document API
# -----------------------------------------------------------------------

@require_POST
def asset_add_document(request, asset_model, asset_id):
    """
    Upload a new file, create a ManagedDocument + DocumentVersion and attach
    it to the asset via DocumentAttachment.
    Expects multipart/form-data with:
      - file  : the file to upload
      - title : document title (optional, defaults to filename)
    """
    asset, model_class, content_type = _get_asset_by_ct(asset_model, asset_id)

    if not can_edit_asset(request.user, asset):
        return JsonResponse(
            {'success': False, 'error': _("Permission refusée")}, status=403
        )

    uploaded_file = request.FILES.get('file')
    if not uploaded_file:
        return JsonResponse(
            {'success': False, 'error': _("Aucun fichier fourni")}, status=400
        )

    title = request.POST.get('title', '').strip()
    if not title:
        title = os.path.splitext(uploaded_file.name)[0]

    from documents.models import ManagedDocument, DocumentVersion, DocumentAttachment

    tag_ids = request.POST.getlist('tag_ids')

    with transaction.atomic():
        doc = ManagedDocument.objects.create(
            title=title,
            created_by=request.user,
        )
        if tag_ids:
            from documents.models import DocumentTag
            valid_tags = DocumentTag.objects.filter(pk__in=tag_ids)
            doc.tags.set(valid_tags)

        version = DocumentVersion(
            document=doc,
            uploaded_by=request.user,
            version_number=1,
        )
        version.file.save(uploaded_file.name, uploaded_file, save=True)

        DocumentAttachment.objects.create(
            document=doc,
            content_type=content_type,
            object_id=asset.pk,
            attached_by=request.user,
        )

    return JsonResponse({'success': True})


@require_GET
def asset_document_list_html(request, asset_model, asset_id):
    """
    Returns the rendered document-viewer HTML for the #documents-list div.
    Used after AJAX uploads to refresh the thumbnail grid without a full page reload.
    """
    from django.http import HttpResponse
    from django.template.loader import render_to_string
    from documents.models import DocumentAttachment

    asset, _model_class, content_type = _get_asset_by_ct(asset_model, asset_id)

    documents = DocumentAttachment.objects.select_related(
        "document",
        "document__current_version",
    ).filter(
        content_type=content_type,
        object_id=asset.pk,
    ).order_by("-attached_at")

    html = render_to_string(
        "assets/components/_documents_inner.html",
        {"documents": documents},
        request=request,
    )
    return HttpResponse(html)


@require_POST
def asset_delete_document(request, asset_model, asset_id, document_id):
    """
    Detach (and optionally delete) a document from an asset.
    Only removes the DocumentAttachment; the ManagedDocument itself is preserved
    unless it has no other attachments, in which case it is deleted too.
    """
    asset, model_class, content_type = _get_asset_by_ct(asset_model, asset_id)

    if not can_edit_asset(request.user, asset):
        return JsonResponse(
            {'success': False, 'error': _("Permission refusée")}, status=403
        )

    from documents.models import DocumentAttachment

    try:
        attachment = DocumentAttachment.objects.get(
            document_id=document_id,
            content_type=content_type,
            object_id=asset.pk,
        )
    except DocumentAttachment.DoesNotExist:
        return JsonResponse(
            {'success': False, 'error': _("Document non trouvé")}, status=404
        )

    with transaction.atomic():
        doc = attachment.document
        attachment.delete()
        # Delete the document itself if it is now orphaned
        if not doc.attachments.exists():
            doc.delete()

    return JsonResponse({'success': True})


# Constants for code generation
MAX_REPLACEMENT_ATTEMPTS = 100
MAX_CODE_GENERATION_ATTEMPTS = 1000


def _get_asset_by_ct(content_type_model, asset_id):
    """Get asset by content type model name and id."""
    try:
        content_type = ContentType.objects.get(app_label='assets', model=content_type_model.lower())
        model_class = content_type.model_class()
        return get_object_or_404(model_class, pk=asset_id), model_class, content_type
    except ContentType.DoesNotExist:
        raise Http404(_("Type d'asset inconnu"))


def _get_model_class_for_asset(asset_model_name):
    """Get the model class for an asset type."""
    try:
        content_type = ContentType.objects.get(app_label='assets', model=asset_model_name.lower())
        return content_type.model_class()
    except ContentType.DoesNotExist:
        return None


def _update_lon_lat_from_geom(asset, geom):
    """Update lon/lat fields from geometry (in SRID 3812)."""
    # Clone and transform to WGS84 for lon/lat
    geom_wgs84 = geom.transform(4326, clone=True)
    
    if geom_wgs84.geom_type == 'Point':
        asset.lon = geom_wgs84.x
        asset.lat = geom_wgs84.y
    else:
        # Use centroid for non-point geometries
        centroid = geom_wgs84.centroid
        asset.lon = centroid.x
        asset.lat = centroid.y


def _assign_default_position(new_asset, location, thematic_code=None):
    """
    Assign default geometry, lon, lat, and geojson to the asset from its location/hierarchy.
    """
    from assets.models import AbstractGeoAsset
    if not isinstance(new_asset, AbstractGeoAsset):
        return

    # Check if the asset already has a geometry/coordinates assigned
    if new_asset.geom is not None or (new_asset.lon is not None and new_asset.lat is not None):
        # Already has coordinates/geometry, update geojson if needed
        if new_asset.geom is not None and not new_asset.geojson:
            try:
                geom_4326 = new_asset.geom.transform(4326, clone=True)
                new_asset.geojson = geom_4326.geojson
            except Exception:
                pass
        return

    if not location:
        return

    # Resolve geom and coordinates by walking up the hierarchy
    geom, lon, lat = None, None, None
    
    # Try the location itself
    if hasattr(location, 'geom') and location.geom is not None:
        geom = location.geom
    if hasattr(location, 'lon') and location.lon is not None:
        lon = location.lon
    if hasattr(location, 'lat') and location.lat is not None:
        lat = location.lat

    # Walk up parent locations if any
    current = location
    while (geom is None or lon is None or lat is None) and getattr(current, 'parent_location', None) is not None:
        current = current.parent_location
        if geom is None and hasattr(current, 'geom'):
            geom = getattr(current, 'geom', None)
        if lon is None and hasattr(current, 'lon'):
            lon = getattr(current, 'lon', None)
        if lat is None and hasattr(current, 'lat'):
            lat = getattr(current, 'lat', None)

    # Fall back to structure's main location if still None (for structures thematic)
    if (geom is None or lon is None or lat is None) and hasattr(location, 'structure') and location.structure:
        main_loc = getattr(location.structure, 'main_location', None)
        if main_loc:
            if geom is None and hasattr(main_loc, 'geom'):
                geom = getattr(main_loc, 'geom', None)
            if lon is None and hasattr(main_loc, 'lon'):
                lon = getattr(main_loc, 'lon', None)
            if lat is None and hasattr(main_loc, 'lat'):
                lat = getattr(main_loc, 'lat', None)

    # Assign resolved values
    if geom is not None:
        try:
            if geom.geom_type == 'Point':
                new_asset.geom = geom
            else:
                new_asset.geom = geom.centroid
        except Exception:
            pass

    if lon is not None:
        new_asset.lon = lon
    if lat is not None:
        new_asset.lat = lat

    # Ensure lon/lat are set if geom is set, and vice versa
    if new_asset.geom is not None and (new_asset.lon is None or new_asset.lat is None):
        try:
            _update_lon_lat_from_geom(new_asset, new_asset.geom)
        except Exception:
            pass

    # Populate geojson
    if new_asset.geom is not None:
        try:
            geom_4326 = new_asset.geom.transform(4326, clone=True)
            new_asset.geojson = geom_4326.geojson
        except Exception:
            pass


def _update_asset_field(asset, field_name, new_value, model_class):
    """
    Update a single field on an asset.
    Returns (success, error_message).
    """
    if not hasattr(asset, field_name):
        return False, _("Champ inconnu: %(field)s") % {"field": field_name}
    
    try:
        # Handle special field types
        if field_name in ('installation_date', 'uninstallation_date', 'last_inspection_date'):
            # Date field
            if new_value:
                from django.utils.dateparse import parse_datetime
                parsed = parse_datetime(new_value)
                if not parsed:
                    from datetime import datetime
                    try:
                        parsed = datetime.strptime(new_value, "%Y-%m-%d")
                    except ValueError:
                        return False, _("Format de date invalide pour %(field)s") % {"field": field_name}
                setattr(asset, field_name, parsed)
            else:
                setattr(asset, field_name, None)
        
        elif field_name == 'model':
            # ForeignKey to model
            if new_value:
                # Get the model's ForeignKey field to find the related model class
                field = model_class._meta.get_field('model')
                related_model = field.related_model
                try:
                    related_obj = related_model.objects.get(pk=int(new_value))
                    asset.model = related_obj
                except related_model.DoesNotExist:
                    return False, _("Modèle non trouvé")
            else:
                asset.model = None
        
        elif field_name == 'category':
            # ForeignKey to category
            if new_value:
                try:
                    category = AssetCategory.objects.get(pk=int(new_value))
                    asset.category = category
                except AssetCategory.DoesNotExist:
                    return False, _("Catégorie non trouvée")
            else:
                asset.category = None

        elif field_name in ('location_id', 'intersection_id'):
            # ForeignKey location/intersection — derive the actual field name from the suffix
            fk_field_name = field_name[:-3]  # 'location' or 'intersection'
            if not hasattr(asset, fk_field_name):
                # Field doesn't exist on this asset type — silently skip for compatibility
                return True, None
            if new_value:
                try:
                    field = model_class._meta.get_field(fk_field_name)
                    related_model = field.related_model
                    related_obj = related_model.objects.get(pk=int(new_value))
                    setattr(asset, fk_field_name, related_obj)
                except Exception:
                    return False, _("Localisation non trouvée")
            else:
                setattr(asset, fk_field_name, None)
        
        elif field_name == 'status':
            # Validate status
            if new_value in dict(ASSET_STATUS_CHOICES):
                asset.status = new_value
            else:
                return False, _("Statut invalide: %(status)s") % {"status": new_value}
        
        elif field_name == 'validation_status':
            # Validate validation status
            if new_value in dict(ASSET_VALIDATION_STATUS_CHOICES) or new_value in (None, ''):
                asset.validation_status = new_value if new_value else None
            else:
                return False, _("Statut de validation invalide: %(status)s") % {"status": new_value}
        
        elif field_name in ('lon', 'lat'):
            # Float field with geometry update
            if new_value:
                try:
                    float_value = float(new_value)
                    setattr(asset, field_name, float_value)
                    # Update geometry if both lon and lat are set
                    if hasattr(asset, 'geom') and asset.lon is not None and asset.lat is not None:
                        pt = Point(asset.lon, asset.lat, srid=4326)
                        pt.transform(3812)
                        asset.geom = pt
                except ValueError:
                    return False, _("Valeur numérique invalide pour %(field)s") % {"field": field_name}
            else:
                setattr(asset, field_name, None)
        
        elif field_name == 'geom':
            # Geometry field - expects GeoJSON
            if new_value:
                try:
                    if isinstance(new_value, str):
                        geom_data = json.loads(new_value)
                    else:
                        geom_data = new_value
                    
                    # Handle GeoJSON Feature or Geometry
                    if geom_data.get('type') == 'Feature':
                        geom_json = json.dumps(geom_data.get('geometry', {}))
                    else:
                        geom_json = json.dumps(geom_data)
                    
                    geom = GEOSGeometry(geom_json, srid=4326)
                    geom.transform(3812)
                    asset.geom = geom
                    
                    # Update lon/lat from geometry
                    if hasattr(asset, 'lon') and hasattr(asset, 'lat'):
                        _update_lon_lat_from_geom(asset, geom)
                except Exception as e:
                    return False, _("Géométrie invalide: %(error)s") % {"error": str(e)}
            else:
                asset.geom = None
        
        elif field_name in ('warranty_duration',):
            # Integer field
            if new_value:
                try:
                    asset.warranty_duration = int(new_value)
                except ValueError:
                    return False, _("Valeur numérique invalide pour %(field)s") % {"field": field_name}
            else:
                setattr(asset, field_name, None)
        
        else:
            # Use field introspection for proper type coercion
            from django.db.models import (FloatField, DecimalField, IntegerField,
                                           BooleanField, DateField, DateTimeField)
            try:
                field_obj = asset._meta.get_field(field_name)
            except Exception:
                field_obj = None

            if field_obj and isinstance(field_obj, (FloatField, DecimalField)):
                if new_value not in (None, ''):
                    try:
                        setattr(asset, field_name, float(str(new_value).replace(',', '.')))
                    except (ValueError, TypeError):
                        return False, _("Valeur numérique invalide pour %(field)s") % {"field": field_name}
                else:
                    setattr(asset, field_name, None)

            elif field_obj and isinstance(field_obj, IntegerField):
                if new_value not in (None, ''):
                    try:
                        setattr(asset, field_name, int(new_value))
                    except (ValueError, TypeError):
                        return False, _("Valeur numérique invalide pour %(field)s") % {"field": field_name}
                else:
                    setattr(asset, field_name, None)

            elif field_obj and isinstance(field_obj, BooleanField):
                if new_value in (None, '') and getattr(field_obj, 'null', False):
                    setattr(asset, field_name, None)
                else:
                    setattr(asset, field_name, new_value in (True, 'true', 'True', '1', 'on'))

            elif field_obj and isinstance(field_obj, (DateTimeField, DateField)):
                if new_value:
                    from django.utils.dateparse import parse_datetime, parse_date
                    parsed = parse_datetime(str(new_value)) or parse_date(str(new_value))
                    if not parsed:
                        from datetime import datetime
                        try:
                            parsed = datetime.strptime(str(new_value), "%Y-%m-%d")
                        except ValueError:
                            return False, _("Format de date invalide pour %(field)s") % {"field": field_name}
                    setattr(asset, field_name, parsed)
                else:
                    setattr(asset, field_name, None)

            else:
                # Char / Text field or fallback
                setattr(asset, field_name, new_value if new_value else None)

        return True, None
    
    except Exception as e:
        return False, str(e)


@require_POST
def update_asset(request, asset_model, asset_id):
    """
    Update asset fields via AJAX.
    Expects JSON body with field:value pairs.
    """
    asset, model_class, content_type = _get_asset_by_ct(asset_model, asset_id)
    
    if not can_edit_asset(request.user, asset):
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de modifier cet asset")
        }, status=403)
    
    allowed_fields = get_allowed_update_fields_for_asset(request.user, asset)
    
    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({
            'success': False,
            'error': _("Format JSON invalide")
        }, status=400)
    
    updated_fields = []
    errors = []
    
    with transaction.atomic():
        for field_name, new_value in data.items():
            if field_name not in allowed_fields:
                errors.append(_("Champ non modifiable: %(field)s") % {"field": field_name})
                continue
            
            success, error = _update_asset_field(asset, field_name, new_value, model_class)
            if success:
                updated_fields.append(field_name)
            else:
                errors.append(error)
        
        if updated_fields:
            # If the user is not internal, automatically set status to 'to_be_approved'
            # (unless the asset is already archived/removed, or the user explicitly set the status)
            if 'status' not in updated_fields and asset.status not in ('removed',):
                try:
                    from common.models import UserConfig
                    user_config = UserConfig.objects.get(user=request.user)
                    if not user_config.is_intern:
                        asset.status = 'to_be_approved'
                        updated_fields.append('status')
                except UserConfig.DoesNotExist:
                    pass

            # Set the user for history tracking
            asset._history_user = request.user
            asset.save()
    
    if errors and not updated_fields:
        return JsonResponse({
            'success': False,
            'errors': errors,
            'message': _("Aucun champ mis à jour")
        }, status=400)
    
    return JsonResponse({
        'success': True,
        'updated_fields': updated_fields,
        'errors': errors,
        'message': _("%(count)s champ(s) mis à jour") % {"count": len(updated_fields)}
    })


@require_POST
def archive_asset(request, asset_model, asset_id):
    """
    Archive an asset (set status to 'removed').
    """
    asset, model_class, content_type = _get_asset_by_ct(asset_model, asset_id)
    
    if not can_edit_asset(request.user, asset):
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de modifier cet asset")
        }, status=403)
    
    allowed_actions = get_allowed_actions_for_asset(request.user, asset)
    if 'archive' not in allowed_actions:
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission d'archiver cet asset")
        }, status=403)
    
    with transaction.atomic():
        asset.status = 'removed'
        asset.uninstallation_date = timezone.now()
        asset.save(update_fields=['status', 'uninstallation_date'])
    
    return JsonResponse({
        'success': True,
        'message': _("Asset archivé avec succès")
    })


@require_POST
def replace_asset(request, asset_model, asset_id):
    """
    Replace an asset: archive the old one and optionally create a new one.
    Expects JSON body with:
    - copy_attributes: boolean - whether to copy attributes from old asset
    - new_model_id: int - ID of the new asset model (optional, defaults to same)
    - new_data: dict - additional data for the new asset
    """
    asset, model_class, content_type = _get_asset_by_ct(asset_model, asset_id)
    
    if not can_edit_asset(request.user, asset):
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de modifier cet asset")
        }, status=403)
    
    allowed_actions = get_allowed_actions_for_asset(request.user, asset)
    if 'replace' not in allowed_actions:
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de remplacer cet asset")
        }, status=403)
    
    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({
            'success': False,
            'error': _("Format JSON invalide")
        }, status=400)
    
    copy_attributes = data.get('copy_attributes', True)
    new_model_id = data.get('new_model_id')
    new_data = data.get('new_data', {})
    intervention_id = data.get('intervention_id')  # ID de l'intervention si appelé depuis une intervention
    
    with transaction.atomic():
        # Create new asset first (before archiving old one)
        new_asset = model_class()
        
        # Copy attributes if requested
        if copy_attributes:
            for field in model_class._meta.get_fields():
                if field.auto_created or field.name in ('id', 'code', 'replaced_by'):
                    continue
                if hasattr(asset, field.name):
                    setattr(new_asset, field.name, getattr(asset, field.name))
        
        # Set default values for new asset
        new_asset.status = 'active'
        new_asset.installation_date = timezone.now()
        new_asset.uninstallation_date = None
        
        # Override with new data
        for field_name, value in new_data.items():
            if hasattr(new_asset, field_name):
                setattr(new_asset, field_name, value)
        
        # Handle new model if specified
        if new_model_id and hasattr(new_asset, 'model'):
            try:
                model_field = model_class._meta.get_field('model')
                related_model = model_field.related_model
                new_asset.model = related_model.objects.get(pk=int(new_model_id))
            except Exception:
                pass

        # Generate new code for old asset
        new_asset.code = asset.code
        asset.code = _generate_archive_asset_code(asset)

        # Save new asset first
        new_asset.save()
        
        # Archive old asset and create the replacement link
        asset.status = 'removed'
        asset.uninstallation_date = timezone.now()
        asset.replaced_by = new_asset  # Create the replacement link
        asset.save(update_fields=['code', 'status', 'uninstallation_date', 'replaced_by'])
        
        # Si appelé depuis une intervention, créer le lien avec le nouvel asset
        if intervention_id:
            try:
                from interventions.models import Intervention, InterventionAsset
                from interventions.views import _create_equipment_operations_for_assets
                
                intervention = Intervention.objects.get(pk=intervention_id)
                InterventionAsset.objects.create(
                    intervention=intervention,
                    content_type=content_type,
                    object_id=new_asset.id
                )
                
                # Créer les opérations d'équipement pour le nouvel asset
                # basées sur les templates d'opération de l'intervention
                _create_equipment_operations_for_assets(
                    intervention,
                    [(content_type, new_asset)]
                )
            except Exception as e:
                # Log mais ne fait pas échouer le remplacement
                pass
    
    return JsonResponse({
        'success': True,
        'message': _("Asset remplacé avec succès"),
        'old_asset_id': asset.id,
        'new_asset_id': new_asset.id,
        'new_asset_code': new_asset.code
    })


def _generate_archive_asset_code(old_asset):
    """Generate a new unique code for an asset."""
    base_code = old_asset.code
    
    # new_code = base_code + "YYYY-MM-DD" format
    new_code = f"{base_code}_{timezone.now().strftime('%Y%m%d')}"

    # get location from old_asset
    location = None
    for field_name in ASSETS_LOCATION_REGISTRY:
        if hasattr(old_asset, field_name):
            location = getattr(old_asset, field_name, None)
            if location is not None:
                break

    # Ensure uniqueness for archived asset codes in this location
    if location and hasattr(location, 'get_direct_child_assets'):
        existing_codes = set()
        assets_dict = location.get_direct_child_assets()
        for key, queryset in assets_dict.items():
            for asset in queryset:
                existing_codes.add(asset.code)
        
        if new_code not in existing_codes:
            return new_code
        
        # Try appending a counter
        for i in range(1, MAX_REPLACEMENT_ATTEMPTS):
            candidate_code = f"{new_code}-{i:02d}"
            if candidate_code not in existing_codes:
                return candidate_code

    return new_code
    


@require_POST
def create_asset(request, thematic_code, location_type, location_id):
    """
    Create a new asset at a location.
    Expects JSON body with:
    - asset_type: string - the asset model name (e.g., 'trafficlightpole')
    - model_id: int - ID of the asset model
    - category_id: int - ID of the category
    - data: dict - additional data for the asset
    """
    # Get thematic and check permission
    try:
        thematic = Thematic.objects.get(code=thematic_code)
    except Thematic.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Thématique non trouvée")
        }, status=404)
    
    allowed_actions = get_allowed_actions_for_thematic(request.user, thematic)
    if 'create' not in allowed_actions:
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de créer des assets")
        }, status=403)
    
    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({
            'success': False,
            'error': _("Format JSON invalide")
        }, status=400)
    
    asset_type = data.get('asset_type')
    model_id = data.get('model_id')
    category_id = data.get('category_id')
    asset_data = data.get('data', {})
    
    # Convert model_id and category_id to int if they are strings
    if model_id and str(model_id).strip():
        try:
            model_id = int(model_id)
        except (ValueError, TypeError):
            model_id = None
    else:
        model_id = None
        
    if category_id and str(category_id).strip():
        try:
            category_id = int(category_id)
        except (ValueError, TypeError):
            category_id = None
    else:
        category_id = None
    
    # Try to resolve category to deduce asset_type
    category = None
    if category_id:
        try:
            category = AssetCategory.objects.get(pk=category_id)
        except AssetCategory.DoesNotExist:
            pass
            
    # Deduce asset_type from category if not specified
    if not asset_type and category:
        allowed_cts = category.allowed_models.all()
        if allowed_cts.exists():
            asset_type = allowed_cts.first().model
        else:
            classes = _get_asset_classes_for_category(thematic_code, category)
            if classes and classes[0]:
                asset_type = classes[0]._meta.model_name
                
    if not asset_type:
        return JsonResponse({
            'success': False,
            'error': _("Type d'asset requis")
        }, status=400)
    
    # Get asset model class
    model_class = _get_model_class_for_asset(asset_type)
    if not model_class:
        return JsonResponse({
            'success': False,
            'error': _("Type d'asset invalide: %(type)s") % {"type": asset_type}
        }, status=400)
    
    # Get location
    try:
        location_ct = ContentType.objects.get(app_label='assets', model=location_type.lower())
        location_model = location_ct.model_class()
        location = get_object_or_404(location_model, pk=location_id)
    except ContentType.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Type de localisation invalide")
        }, status=400)
    
    with transaction.atomic():
        new_asset = model_class()
        
        # Get location model name for comparison
        location_model_name = location_model._meta.model_name.lower()
        
        # Find the ForeignKey field that points to the location model
        location_set = False
        for field in model_class._meta.get_fields():
            if hasattr(field, 'related_model') and field.related_model:
                related_model_name = field.related_model._meta.model_name.lower()
                if related_model_name == location_model_name:
                    # This is a ForeignKey to the location model
                    setattr(new_asset, field.name, location)
                    location_set = True
                    break
        
        if not location_set:
            return JsonResponse({
                'success': False,
                'error': _("Impossible de lier l'asset à cette localisation")
            }, status=400)
        
        # Set model if specified or required
        if hasattr(model_class, '_meta'):
            try:
                model_field = model_class._meta.get_field('model')
                is_model_required = not model_field.null and not model_field.blank
                
                if model_id:
                    related_model = model_field.related_model
                    new_asset.model = related_model.objects.get(pk=model_id)
                elif is_model_required:
                    return JsonResponse({
                        'success': False,
                        'error': _("Le modèle d'asset est requis pour ce type d'asset")
                    }, status=400)
            except model_class._meta.get_field('model').related_model.DoesNotExist:
                return JsonResponse({
                    'success': False,
                    'error': _("Modèle d'asset non trouvé")
                }, status=400)
            except Exception:
                # No 'model' field on this asset type, that's OK
                pass
        
        # Set category if specified
        if category_id:
            try:
                new_asset.category = AssetCategory.objects.get(pk=int(category_id))
            except AssetCategory.DoesNotExist:
                pass
        
        # Set default values
        new_asset.status = 'active'
        new_asset.validation_status = 'to_be_validated'
        new_asset.installation_date = timezone.now()
        
        # Generate code
        new_asset.code = _generate_asset_code(model_class, location)
        
        # Set additional data
        for field_name, value in asset_data.items():
            if hasattr(new_asset, field_name) and field_name not in ('id', 'code'):
                setattr(new_asset, field_name, value)
        
        # Assign position from location / hierarchy
        _assign_default_position(new_asset, location, thematic_code)
        
        new_asset.save()
    
    return JsonResponse({
        'success': True,
        'message': _("Asset créé avec succès"),
        'asset_id': new_asset.id,
        'asset_code': new_asset.code
    })


def _generate_asset_code(model_class, location):
    """Generate a unique code for a new asset."""
    location_code = getattr(location, 'code', 'AST')
    
    # Get count of existing assets at this location
    model_name = model_class._meta.model_name.upper()[:3]
    base_code = f"{location_code}-{model_name}"
    
    # Find next available number
    for i in range(1, MAX_CODE_GENERATION_ATTEMPTS):
        new_code = f"{base_code}-{i:03d}"
        if not model_class.objects.filter(code=new_code).exists():
            return new_code
    
    # Fallback
    import time
    return f"{base_code}-{int(time.time())}"


@require_POST
def bulk_archive_assets(request, thematic_code, location_type, location_id):
    """
    Archive all active assets at a location.
    """
    # Get thematic and check permission
    try:
        thematic = Thematic.objects.get(code=thematic_code)
    except Thematic.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Thématique non trouvée")
        }, status=404)
    
    allowed_actions = get_allowed_actions_for_thematic(request.user, thematic)
    if 'bulk_archive' not in allowed_actions:
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission d'archiver en masse")
        }, status=403)
    
    # Get location
    try:
        location_ct = ContentType.objects.get(app_label='assets', model=location_type.lower())
        location_model = location_ct.model_class()
        location = get_object_or_404(location_model, pk=location_id)
    except ContentType.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Type de localisation invalide")
        }, status=400)
    
    # Get all active assets for this location
    if not hasattr(location, 'get_active_assets'):
        return JsonResponse({
            'success': False,
            'error': _("Cette localisation ne supporte pas la gestion des assets")
        }, status=400)
    
    archived_count = 0
    now = timezone.now()
    
    with transaction.atomic():
        assets_dict = location.get_active_assets()
        
        # Flatten all assets into a single list
        assets_to_archive = []
        if isinstance(assets_dict, dict):
            for val in assets_dict.values():
                if isinstance(val, (list, tuple)) or hasattr(val, '__iter__'):
                    assets_to_archive.extend(val)
                else:
                    assets_to_archive.append(val)
        elif isinstance(assets_dict, (list, tuple)) or hasattr(assets_dict, '__iter__'):
            assets_to_archive.extend(assets_dict)
        else:
            assets_to_archive.append(assets_dict)
            
        # Archive each asset individually to trigger signals and history logs
        for asset in assets_to_archive:
            if hasattr(asset, 'status') and asset.status == 'active':
                asset._history_user = request.user
                asset.status = 'removed'
                asset.uninstallation_date = now
                asset.save(update_fields=['status', 'uninstallation_date'])
                archived_count += 1
    
    return JsonResponse({
        'success': True,
        'message': _("%(count)s asset(s) archivé(s)") % {"count": archived_count},
        'archived_count': archived_count
    })


def _has_field(model_class, field_name):
    try:
        model_class._meta.get_field(field_name)
        return True
    except Exception:
        return False


@require_GET
def get_child_asset_form_fields(request, model_name):
    """
    Return field descriptors for building a dynamic creation form for a child asset.
    Excludes system-managed fields and the parent FK (field_on_child).
    Pre-fills FK fields where the value can be inferred from the parent asset context.
    Query params: field_on_child, parent_model, parent_id
    """
    from django.db.models import (
        ForeignKey, CharField, TextField, IntegerField,
        FloatField, DecimalField, BooleanField, DateTimeField, DateField,
    )

    field_on_child    = request.GET.get('field_on_child', '')
    parent_model_name = request.GET.get('parent_model', '')
    parent_id_str     = request.GET.get('parent_id', '')

    child_model_class = None
    try:
        cts = ContentType.objects.filter(model=model_name.lower())
        if not cts.exists():
            return JsonResponse({'fields': []})
        cts_sorted = sorted(cts, key=lambda ct: (0 if ct.app_label == 'assets' else 1))
        for ct in cts_sorted:
            mc = ct.model_class()
            if mc is not None:
                child_model_class = mc
                break
    except Exception:
        return JsonResponse({'fields': []})

    if child_model_class is None:
        return JsonResponse({'fields': []})

    # Fields always managed by the system — never shown in the creation form
    SYSTEM_FIELDS = {
        'id', 'code', 'status', 'installation_date', 'uninstallation_date',
        'serial_number', 'warranty_duration', 'last_inspection_date',
        'last_preventive_date', 'last_corrective_date', 'last_survey_date',
        'replaced_by', 'marked_as_removed_date', 'marked_as_removed_by',
        'obsolescence', 'note', 'category', 'name_fr', 'name_nl',
        'lon', 'lat', 'geom', 'geojson', 'brand',
    }

    # Load parent asset for context-based pre-filling
    parent_asset = None
    if parent_model_name and parent_id_str:
        try:
            parent_cts = ContentType.objects.filter(model=parent_model_name.lower())
            parent_cts_sorted = sorted(parent_cts, key=lambda ct: (0 if ct.app_label == 'assets' else 1))
            for pct in parent_cts_sorted:
                pmc = pct.model_class()
                if pmc is not None:
                    parent_asset = pmc.objects.get(pk=int(parent_id_str))
                    break
        except Exception:
            pass

    def _prefill_for_fk(field):
        """Return the raw PK to pre-select for a child FK field, or None."""
        if parent_asset is None:
            return None
        # Strategy 1: same field name on parent (e.g. child.intersection → parent.intersection_id)
        val = getattr(parent_asset, field.attname, None)
        if val is not None:
            return val
        # Strategy 2: any FK on parent that points to the same related model
        for pf in type(parent_asset)._meta.get_fields():
            if (hasattr(pf, 'attname') and hasattr(pf, 'related_model')
                    and pf.related_model == field.related_model):
                val = getattr(parent_asset, pf.attname, None)
                if val is not None:
                    return val
        return None

    fields_out = []
    for field in child_model_class._meta.get_fields():
        if not hasattr(field, 'column'):
            continue  # skip reverse relations / M2M
        fname = field.name
        if fname in SYSTEM_FIELDS or fname == field_on_child:
            continue
        required = not getattr(field, 'null', True) and not getattr(field, 'blank', True)
        verbose  = str(getattr(field, 'verbose_name', fname)).capitalize()

        if isinstance(field, ForeignKey):
            order_field = 'code' if _has_field(field.related_model, 'code') else 'pk'
            prefill_pk   = _prefill_for_fk(field)

            def _obj_label(obj):
                lbl = obj.code if hasattr(obj, 'code') else str(obj)
                if hasattr(obj, 'get_name'):
                    n = obj.get_name().strip()
                    if n and n != lbl:
                        lbl += ' — ' + n
                return lbl

            choices = []
            seen_ids = set()
            for obj in field.related_model.objects.order_by(order_field)[:500]:
                choices.append({'id': obj.pk, 'label': _obj_label(obj)})
                seen_ids.add(obj.pk)

            # Always include the pre-filled object, even if beyond the :500 limit
            if prefill_pk is not None and prefill_pk not in seen_ids:
                try:
                    prefill_obj = field.related_model.objects.get(pk=prefill_pk)
                    choices.insert(0, {'id': prefill_obj.pk, 'label': _obj_label(prefill_obj)})
                except field.related_model.DoesNotExist:
                    pass

            fields_out.append({
                'name': field.attname,  # e.g. "intersection_id"
                'label': verbose,
                'type': 'fk',
                'required': required,
                'choices': choices,
                'prefill': prefill_pk,
            })
        elif getattr(field, 'choices', None):
            fields_out.append({
                'name': fname,
                'label': verbose,
                'type': 'choice',
                'required': required,
                'choices': [{'id': str(k), 'label': str(v)} for k, v in field.choices],
                'prefill': None,
            })
        elif isinstance(field, BooleanField):
            fields_out.append({
                'name': fname,
                'label': verbose,
                'type': 'boolean',
                'required': False,
                'choices': [],
                'prefill': field.default if field.has_default() else False,
            })
        elif isinstance(field, DateTimeField):
            fields_out.append({
                'name': fname,
                'label': verbose,
                'type': 'datetime',
                'required': required,
                'choices': [],
                'prefill': None,
            })
        elif isinstance(field, (IntegerField, FloatField, DecimalField)):
            fields_out.append({
                'name': fname,
                'label': verbose,
                'type': 'number',
                'required': required,
                'choices': [],
                'prefill': None,
            })
        elif isinstance(field, (CharField, TextField)):
            fields_out.append({
                'name': fname,
                'label': verbose,
                'type': 'text',
                'required': required,
                'choices': [],
                'prefill': None,
            })
        # GeometryField, ArrayField, etc. are intentionally skipped

    return JsonResponse({'fields': fields_out})


@require_GET
def get_asset_models_for_category(request, thematic_code, category_id):
    """
    Get asset models available for a category.
    Asset models are like TrafficLightPoleModel, TrafficLightControllerModel, etc.
    """
    from django.apps import apps
    from assets.models.core import AbstractAssetModel
    
    try:
        category = AssetCategory.objects.get(pk=category_id)
    except AssetCategory.DoesNotExist:
        return JsonResponse({'models': []})
    
    # Find all concrete model classes that inherit from AbstractAssetModel
    # and query for instances that have the given category
    models_data = []
    
    for model in apps.get_models():
        # Skip abstract models
        if model._meta.abstract:
            continue
        
        # Check if this model has a category field and inherits from AbstractAssetModel
        try:
            if not issubclass(model, AbstractAssetModel):
                continue
        except TypeError:
            continue
        
        # Check if the model has a category field
        if not hasattr(model, 'category'):
            continue
        
        # Query for model instances with this category
        try:
            model_objects = model.objects.filter(category=category)
            for obj in model_objects:
                models_data.append({
                    'id': obj.id,
                    'code': obj.code,
                    'name': obj.get_name() if hasattr(obj, 'get_name') else str(obj),
                    'model_type': model._meta.model_name
                })
        except Exception:
            # Skip models that don't have a proper category FK
            continue
    
    return JsonResponse({'models': models_data})


def _is_model_required(model_class):
    if not model_class or not hasattr(model_class, '_meta'):
        return False
    try:
        field = model_class._meta.get_field('model')
        return field.is_relation and not field.null and not field.blank
    except Exception:
        return False


@require_GET
def get_asset_categories_for_thematic(request, thematic_code):
    """
    Get asset categories for a thematic.
    """
    try:
        thematic = Thematic.objects.get(code=thematic_code)
    except Thematic.DoesNotExist:
        return JsonResponse({'categories': []})
    
    categories = AssetCategory.objects.filter(thematic=thematic).order_by('name_fr')
    
    categories_data = []
    for cat in categories:
        allowed_cts = list(cat.allowed_models.all())
        
        # Fallback to CATEGORY_ASSET_MAPPING if empty
        if not allowed_cts:
            asset_class, _ = _get_asset_classes_for_category(thematic_code, cat)
            if asset_class:
                from django.contrib.contenttypes.models import ContentType
                try:
                    ct = ContentType.objects.get_for_model(asset_class)
                    allowed_cts = [ct]
                except Exception:
                    pass
                    
        allowed_models_data = []
        for ct in allowed_cts:
            model_class = ct.model_class()
            if model_class:
                allowed_models_data.append({
                    'model_name': ct.model,
                    'verbose_name': str(model_class._meta.verbose_name).capitalize(),
                    'is_model_required': _is_model_required(model_class)
                })
                
        categories_data.append({
            'id': cat.id,
            'code': cat.code,
            'name': cat.get_name(),
            'allowed_models': allowed_models_data
        })
    
    return JsonResponse({'categories': categories_data})


# Mapping of thematic codes to default asset model classes
# For thematics with multiple asset types, we use category code to determine the right class
THEMATIC_ASSET_MAPPING = {
    'structures': 'StructureGeoAsset',
    'trafficlights': 'TrafficLightPole',  # Default, overridden by category
    'publiclighting': 'PublicLightingPole',  # Default, overridden by category
    'nature': 'NatureGeoAsset',
    'artworks': 'Fountain',  # or Monument depending on category
    'controlcenters': 'ControlCenterGeoAsset',
    'its': 'ITSGeoAsset',
    'sign': 'SignGeoAsset',
    'roads': 'RoadGeoAsset',
}

# Mapping of category codes to (asset_class, asset_model_class) tuples
# This allows different asset types per category within a thematic
CATEGORY_ASSET_MAPPING = {
    # Traffic Lights categories
    'trafficlights_pole': ('TrafficLightPole', 'TrafficLightPoleModel'),
    'trafficlights_cable': ('TrafficLightCable', 'TrafficLightCableModel'),
    'trafficlights_lantern': ('TrafficLightLantern', 'TrafficLightLanternModel'),
    'trafficlights_controller': ('TrafficLightController', 'TrafficLightControllerModel'),
    'trafficlights_detector': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'trafficlights_cabinet': ('TrafficLightElectricalCabinet', 'TrafficLightElectricalCabinetModel'),
    # Alias with simpler names
    'pole': ('TrafficLightPole', 'TrafficLightPoleModel'),
    'TL_POTEAU': ('TrafficLightPole', 'TrafficLightPoleModel'),
    'cable': ('TrafficLightCable', 'TrafficLightCableModel'),
    'TL_CABLE': ('TrafficLightCable', 'TrafficLightCableModel'),
    'lantern': ('TrafficLightLantern', 'TrafficLightLanternModel'),
    'TL_LANTERNE': ('TrafficLightLantern', 'TrafficLightLanternModel'),
    'controller': ('TrafficLightController', 'TrafficLightControllerModel'),
    'TL_REGELAAR': ('TrafficLightController', 'TrafficLightControllerModel'),
    'detector': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'cabinet': ('TrafficLightElectricalCabinet', 'TrafficLightElectricalCabinetModel'),
    'electrical_cabinet': ('TrafficLightElectricalCabinet', 'TrafficLightElectricalCabinetModel'),
    'TL_ARMOIRE': ('TrafficLightElectricalCabinet', 'TrafficLightElectricalCabinetModel'),
    'TL_RADAR_PREVENTIF': ('TrafficLightRadar', 'TrafficLightRadarModel'),
    'TL_RADAR_POLE': ('TrafficLightRadarPole', 'TrafficLightRadarPoleModel'),
    'TL_DETEC_BP': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'TL_DETEC_RADAR': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'TL_DETEC_VIDEO': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'TL_DETEC_OTHER': ('TrafficLightDetector', 'TrafficLightDetectorModel'),
    'TL_BORNIER': ('TrafficLightAccessory', 'TrafficLightAccessoryModel'),
    'TL_DIVERS': ('TrafficLightAccessory', 'TrafficLightAccessoryModel'),
    # Public Lighting categories
    'publiclighting_pole': ('PublicLightingPole', 'PublicLightingPoleModel'),
    'LI_poles': ('PublicLightingPole', 'PublicLightingPoleModel'),
    'publiclighting_luminaire': ('PublicLightingLuminaire', 'PublicLightingLuminaireModel'),
    'LI_lightfixtures': ('PublicLightingLightFixture', 'PublicLightingLightFixtureModel'),
}


def _get_asset_classes_for_category(thematic_code, category):
    """
    Get the appropriate asset class and model class based on the thematic and category.
    Returns (asset_class, asset_model_class) tuple.
    """
    if category:
        allowed_cts = category.allowed_models.all()
        if allowed_cts.exists():
            ct = allowed_cts.first()
            asset_class = ct.model_class()
            if asset_class:
                import importlib
                model_class_name = f"{asset_class.__name__}Model"
                try:
                    module = importlib.import_module(asset_class.__module__)
                    asset_model_class = getattr(module, model_class_name, None)
                except Exception:
                    asset_model_class = None
                return asset_class, asset_model_class

    category_code = category.code if category and category.code else None

    # First, try category-specific mapping (case-insensitive)
    if category_code:
        lower_map = {k.lower(): v for k, v in CATEGORY_ASSET_MAPPING.items()}

        # Try with thematic prefix
        prefixed_code = f"{thematic_code}_{category_code}".lower()
        if prefixed_code in lower_map:
            return _import_asset_classes(thematic_code, lower_map[prefixed_code])

        # Try category code directly
        if category_code.lower() in lower_map:
            return _import_asset_classes(thematic_code, lower_map[category_code.lower()])

    # Fallback to thematic-level default
    return _get_asset_model_class_for_thematic(thematic_code)


def _import_asset_classes(thematic_code, class_names):
    """Import asset classes dynamically based on thematic and class names."""
    asset_class_name, model_class_name = class_names
    
    # Map thematics to their modules
    thematic_module_map = {
        'structures': 'assets.models.structures',
        'trafficlights': 'assets.models.trafficlights',
        'publiclighting': 'assets.models.publiclighting',
        'nature': 'assets.models.nature',
        'controlcenters': 'assets.models.controlcenters',
        'its': 'assets.models.its',
        'artworks': 'assets.models.artworks',
        'sign': 'assets.models.sign',
        'roads': 'assets.models.roads',
    }
    
    module_name = thematic_module_map.get(thematic_code)
    if not module_name:
        return None, None
    
    try:
        import importlib
        module = importlib.import_module(module_name)
        asset_class = getattr(module, asset_class_name, None)
        model_class = getattr(module, model_class_name, None)
        return asset_class, model_class
    except (ImportError, AttributeError):
        return None, None


def _get_asset_model_class_for_thematic(thematic_code):
    """Get the appropriate asset model class for a thematic."""
    from django.apps import apps
    
    # Direct imports for known thematics
    if thematic_code == 'structures':
        from assets.models.structures import StructureGeoAsset, StructureAssetModel
        return StructureGeoAsset, StructureAssetModel
    elif thematic_code == 'trafficlights':
        from assets.models.trafficlights import TrafficLightPole, TrafficLightPoleModel
        return TrafficLightPole, TrafficLightPoleModel
    elif thematic_code == 'publiclighting':
        from assets.models.publiclighting import PublicLightingPole, PublicLightingPoleModel
        return PublicLightingPole, PublicLightingPoleModel
    elif thematic_code == 'nature':
        from assets.models.nature import NatureGreenSurface, NatureAssetModel
        return NatureGreenSurface, NatureAssetModel
    elif thematic_code == 'controlcenters':
        from assets.models.controlcenters import ControlCenterGeoAsset, ControlCenterAssetModel
        return ControlCenterGeoAsset, ControlCenterAssetModel
    elif thematic_code == 'its':
        from assets.models.its import ITSGeoAsset, ITSAssetModel
        return ITSGeoAsset, ITSAssetModel
    
    return None, None


def _get_asset_model_instance(thematic_code, model_id, category=None):
    """Get the asset model instance for a given thematic, model ID, and optionally category."""
    # Try category-specific lookup first
    if category:
        _, asset_model_class = _get_asset_classes_for_category(thematic_code, category)
    else:
        _, asset_model_class = _get_asset_model_class_for_thematic(thematic_code)
    
    if asset_model_class and model_id:
        try:
            return asset_model_class.objects.get(pk=model_id)
        except asset_model_class.DoesNotExist:
            return None
    return None


@require_POST
def create_asset_api(request):
    """
    API endpoint to create a new asset and optionally link it to an intervention.
    Expects JSON body with:
    - thematic_code: string - the thematic code (e.g., 'structures')
    - category_id: int - ID of the category
    - model_id: int - ID of the asset model
    - code: string - unique code for the asset
    - name_fr: string (optional) - French name
    - name_nl: string (optional) - Dutch name
    - location_id: int (optional) - ID of the location
    - structure_id: int (optional) - ID of the structure (for structures thematic)
    - intervention_id: int (optional) - ID of the intervention to link to
    """
    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({
            'success': False,
            'error': _("Format JSON invalide")
        }, status=400)
    
    thematic_code = data.get('thematic_code')
    category_id = data.get('category_id')
    model_id = data.get('model_id')
    code = data.get('code', '').strip()
    name_fr = data.get('name_fr', '').strip()
    name_nl = data.get('name_nl', '').strip()
    location_id = data.get('location_id')
    structure_id = data.get('structure_id')
    intervention_id = data.get('intervention_id')
    
    # Convert string IDs to integers
    try:
        if category_id:
            category_id = int(category_id)
        if model_id:
            model_id = int(model_id)
        if location_id:
            location_id = int(location_id)
        if structure_id:
            structure_id = int(structure_id)
        if intervention_id:
            intervention_id = int(intervention_id)
    except (ValueError, TypeError):
        return JsonResponse({
            'success': False,
            'error': _("Format d'ID invalide")
        }, status=400)
    
    # Validate required fields
    if not thematic_code:
        return JsonResponse({
            'success': False,
            'error': _("Thématique requise")
        }, status=400)
    
    if not category_id:
        return JsonResponse({
            'success': False,
            'error': _("Catégorie requise")
        }, status=400)
    
    if not code:
        return JsonResponse({
            'success': False,
            'error': _("Code requis")
        }, status=400)
    
    # Get thematic and check permission
    try:
        thematic = Thematic.objects.get(code=thematic_code)
    except Thematic.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Thématique non trouvée")
        }, status=404)
    
    allowed_actions = get_allowed_actions_for_thematic(request.user, thematic)
    if 'create' not in allowed_actions:
        return JsonResponse({
            'success': False,
            'error': _("Vous n'avez pas la permission de créer des équipements")
        }, status=403)
    
    # Get category first (needed to determine the correct asset class)
    try:
        category = AssetCategory.objects.get(pk=category_id)
    except AssetCategory.DoesNotExist:
        return JsonResponse({
            'success': False,
            'error': _("Catégorie non trouvée")
        }, status=400)
    
    # Get the appropriate asset class based on thematic AND category
    asset_class, asset_model_class = _get_asset_classes_for_category(thematic_code, category)
    if not asset_class:
        # Fallback to thematic-level default
        asset_class, asset_model_class = _get_asset_model_class_for_thematic(thematic_code)
    
    if not asset_class:
        return JsonResponse({
            'success': False,
            'error': _("Type d'asset non supporté pour cette thématique/catégorie")
        }, status=400)
    
    # Check if code already exists
    if asset_class.objects.filter(code=code).exists():
        return JsonResponse({
            'success': False,
            'error': _("Un équipement avec ce code existe déjà")
        }, status=400)
    
    # Get asset model using category-aware function
    asset_model_instance = None
    if model_id:
        asset_model_instance = _get_asset_model_instance(thematic_code, model_id, category)
        if not asset_model_instance:
            return JsonResponse({
                'success': False,
                'error': _("Modèle d'équipement non trouvé")
            }, status=400)
    elif _is_model_required(asset_class):
        return JsonResponse({
            'success': False,
            'error': _("Modèle requis")
        }, status=400)
    
    # If creating from an intervention without explicit location, get the first location from intervention
    intervention = None
    if intervention_id:
        try:
            intervention = Intervention.objects.get(pk=intervention_id)

            # If no location_id specified, try to get first location from intervention
            if not location_id and not structure_id:
                from interventions.models import InterventionLocation
                first_location_link = intervention.locations.first()

                if first_location_link:
                    # Set location_id or structure_id based on what we find
                    location_id = first_location_link.object_id
                    # We'll use the location's content type to determine what to set
        except Intervention.DoesNotExist:
            intervention = None
    
    with transaction.atomic():
        # Create the new asset
        new_asset = asset_class()
        new_asset.code = code
        
        # Only set name fields if the model has them
        if hasattr(new_asset, 'name_fr'):
            new_asset.name_fr = name_fr if name_fr else None
        if hasattr(new_asset, 'name_nl'):
            new_asset.name_nl = name_nl if name_nl else None
        
        # Only set category if the model has it
        if hasattr(new_asset, 'category'):
            new_asset.category = category
        
        new_asset.model = asset_model_instance
        new_asset.status = 'active'
        new_asset.validation_status = 'to_be_validated'
        new_asset.installation_date = timezone.now()
        
        # Handle location based on thematic
        if thematic_code == 'structures':
            if location_id:
                from assets.models.structures import StructureLocation
                try:
                    location = StructureLocation.objects.get(pk=location_id)
                    new_asset.location = location
                    if not structure_id and getattr(location, 'structure', None):
                        new_asset.structure = location.structure
                except StructureLocation.DoesNotExist:
                    pass
            
            # Handle structure (for structures)
            if structure_id:
                from assets.models.structures import Structure
                try:
                    structure = Structure.objects.get(pk=structure_id)
                    new_asset.structure = structure
                except Structure.DoesNotExist:
                    pass
        
        # Handle intersection (for trafficlights)
        if thematic_code == 'trafficlights':
            intersection_id = data.get('intersection_id') or location_id

            if not intersection_id:
                return JsonResponse({
                    'success': False,
                    'error': _("Une localisation est requise pour créer cet asset.")
                }, status=400)

            from assets.models.trafficlights import TrafficLightIntersection
            try:
                intersection = TrafficLightIntersection.objects.get(pk=intersection_id)
                new_asset.intersection = intersection
            except TrafficLightIntersection.DoesNotExist:
                return JsonResponse({
                    'success': False,
                    'error': _("Localisation introuvable")
                }, status=400)
            
            # Handle pole (for trafficlight lanterns and detectors)
            pole_id = data.get('pole_id')
            if pole_id:
                from assets.models.trafficlights import TrafficLightPole
                try:
                    pole = TrafficLightPole.objects.get(pk=pole_id)
                    if hasattr(new_asset, 'pole'):
                        new_asset.pole = pole
                except TrafficLightPole.DoesNotExist:
                    pass
        
        # Assign position from location / hierarchy
        location = getattr(new_asset, 'location', None) or getattr(new_asset, 'intersection', None)
        _assign_default_position(new_asset, location, thematic_code)

        new_asset.save()
        
        # Link to intervention if specified
        intervention_linked = False
        operations_created = 0
        if intervention:
            try:
                content_type = ContentType.objects.get_for_model(asset_class)
                
                # Create the link
                InterventionAsset.objects.create(
                    intervention=intervention,
                    content_type=content_type,
                    object_id=new_asset.id
                )
                intervention_linked = True
                
                # For preventive interventions, don't create operations automatically
                # Let the user choose which templates to apply via the modal
                # This is handled by the JavaScript frontend
                
            except Exception as e:
                # Log the error but don't fail the asset creation
                import logging
                logger = logging.getLogger(__name__)
                logger.error(f"Error linking asset to intervention or creating operations: {str(e)}", exc_info=True)
    
    # Prepare response message
    success_message = _("Équipement créé avec succès")
    if intervention_linked and operations_created > 0:
        success_message += _(" • %(count)d opération(s) ajoutée(s)") % {'count': operations_created}
    
    response_data = {
        'success': True,
        'message': success_message,
        'asset_id': new_asset.id,
        'asset_code': new_asset.code,
        'intervention_linked': intervention_linked,
        'operations_created': operations_created,
        'needs_template_selection': intervention_linked and intervention and intervention.maintain_type == 'preventive'
    }
    
    # Add redirect URL
    if intervention_id and intervention_linked:
        response_data['redirect_url'] = reverse('interventions:intervention_detail', kwargs={'intervention_id': intervention_id})
    elif hasattr(new_asset, 'get_absolute_url'):
        response_data['redirect_url'] = new_asset.get_absolute_url()
    
    return JsonResponse(response_data)


@require_GET
def get_available_locations_for_asset(request, thematic_code, asset_id):
    """
    Get available locations for an asset based on its thematic.
    Used for changing the location of an asset in edit mode.
    """
    from django.contrib.contenttypes.models import ContentType

    query = (request.GET.get('q') or '').strip()
    try:
        limit = int(request.GET.get('limit', 100))
    except (TypeError, ValueError):
        limit = 100
    limit = max(1, min(limit, 500))
    
    # Get the base asset class for the thematic to find all possible content types
    asset_class, _ = _get_asset_model_class_for_thematic(thematic_code)
    if not asset_class:
        return JsonResponse({'locations': []})
    
    # Try to find the asset in any of the possible concrete classes
    asset = None
    
    if thematic_code == 'structures':
        from assets.models.structures import StructureGeoAsset
        try:
            asset = StructureGeoAsset.objects.get(pk=asset_id)
        except StructureGeoAsset.DoesNotExist:
            return JsonResponse({'locations': []})
    
    elif thematic_code == 'trafficlights':
        from assets.models.trafficlights import (
            TrafficLightPole, TrafficLightCable, TrafficLightLantern,
            TrafficLightController, TrafficLightDetector, TrafficLightElectricalCabinet
        )
        # Try each possible class
        for cls in [TrafficLightPole, TrafficLightCable, TrafficLightLantern,
                    TrafficLightController, TrafficLightDetector, TrafficLightElectricalCabinet]:
            try:
                asset = cls.objects.get(pk=asset_id)
                break
            except cls.DoesNotExist:
                continue
        
        if not asset:
            return JsonResponse({'locations': []})
    
    else:
        # For other thematics, try the base class
        try:
            asset = asset_class.objects.get(pk=asset_id)
        except asset_class.DoesNotExist:
            return JsonResponse({'locations': []})
    
    locations = []
    has_more = False
    
    if thematic_code == 'structures':
        from assets.models.structures import StructureLocation
        # Get locations from the same structure when available; otherwise
        # fall back to all structure locations so unlinked assets can be associated.
        structure = getattr(asset, 'structure', None)
        if not structure and getattr(asset, 'location', None):
            structure = getattr(asset.location, 'structure', None)

        if structure:
            structure_locations_qs = StructureLocation.objects.filter(structure=structure)
        else:
            structure_locations_qs = StructureLocation.objects.all()

        if query:
            structure_locations_qs = structure_locations_qs.filter(
                Q(code__icontains=query) |
                Q(name_fr__icontains=query) |
                Q(name_nl__icontains=query)
            )

        structure_locations = list(structure_locations_qs.order_by('code')[:limit + 1])
        has_more = len(structure_locations) > limit

        for loc in structure_locations[:limit]:
            locations.append({
                'id': loc.id,
                'code': loc.code,
                'name': loc.get_name() if hasattr(loc, 'get_name') else str(loc)
            })
    
    elif thematic_code == 'trafficlights':
        from assets.models.trafficlights import TrafficLightIntersection
        # Get all intersections (or filtered if necessary)
        intersections_qs = TrafficLightIntersection.objects.all()
        if query:
            intersections_qs = intersections_qs.filter(
                Q(code__icontains=query) |
                Q(name_fr__icontains=query) |
                Q(name_nl__icontains=query)
            )

        intersections = list(intersections_qs.order_by('code')[:limit + 1])
        has_more = len(intersections) > limit

        for intersection in intersections[:limit]:
            locations.append({
                'id': intersection.id,
                'code': intersection.code,
                'name': intersection.get_name() if hasattr(intersection, 'get_name') else str(intersection)
            })
    
    # Add similar logic for other thematics as needed
    
    return JsonResponse({'locations': locations, 'has_more': has_more})


# ---------------------------------------------------------------------------
# Linked Assets API
# ---------------------------------------------------------------------------

@require_GET
def get_linked_asset_types(request, asset_model, asset_id):
    """
    Returns metadata about the child asset types linkable to this asset
    (reverse FK relations) and the parent FK fields it has.
    Used to populate the "link / create asset" modal.
    """
    from django.db.models import ManyToOneRel, ForeignKey
    from assets.models import AbstractAsset

    asset, model_class, _ct = _get_asset_by_ct(asset_model, asset_id)

    if not can_edit_asset(request.user, asset):
        return JsonResponse({'success': False, 'error': _("Permission refusée")}, status=403)

    EXCLUDED_CHILD_FIELDS = {'replaced_by'}
    EXCLUDED_PARENT_FIELDS = {
        'model', 'category', 'replaced_by', 'marked_as_removed_by',
        'controller_maintenance_contract',
    }

    # Child asset types (reverse FK relations)
    child_types = []
    for rel in type(asset)._meta.get_fields():
        if not isinstance(rel, ManyToOneRel):
            continue
        related_model = rel.related_model
        try:
            if not issubclass(related_model, AbstractAsset):
                continue
        except TypeError:
            continue
        if rel.field.name in EXCLUDED_CHILD_FIELDS and related_model == type(asset):
            continue
        child_types.append({
            'model_name': related_model._meta.model_name,
            'verbose_name': str(related_model._meta.verbose_name).capitalize(),
            'verbose_name_plural': str(related_model._meta.verbose_name_plural).capitalize(),
            'field_on_child': rel.field.name,
        })

    # Parent FK fields on this asset
    parent_types = []
    for field in type(asset)._meta.get_fields():
        if not isinstance(field, ForeignKey):
            continue
        if field.name in EXCLUDED_PARENT_FIELDS:
            continue
        related_model = field.related_model
        try:
            if not issubclass(related_model, AbstractAsset):
                continue
        except TypeError:
            continue
        current_parent = getattr(asset, field.name, None)
        parent_types.append({
            'field_name': field.name,
            'model_name': related_model._meta.model_name,
            'verbose_name': str(field.verbose_name).capitalize(),
            'current_id': current_parent.pk if current_parent else None,
            'current_code': current_parent.code if current_parent else None,
        })

    return JsonResponse({
        'success': True,
        'child_types': child_types,
        'parent_types': parent_types,
    })


@require_GET
def search_assets_by_model(request, model_name):
    """
    Autocomplete search for assets of a given model type.
    Query params:
      q             – search string (matches code / name_fr / name_nl)
      limit         – max results (default 10, max 50)
      field_on_child – FK field name on the child model (used to optionallyfilter: only unlinked or already linked to parent_id)
      parent_id     – current parent ID
    """
    from assets.models import AbstractAsset
    from django.db.models import Q

    model_class = None
    try:
        cts = ContentType.objects.filter(model=model_name.lower())
        if not cts.exists():
            return JsonResponse({'results': []})
        # Prefer the ContentType from the 'assets' app, then fall back to any matching one
        cts_sorted = sorted(cts, key=lambda ct: (0 if ct.app_label == 'assets' else 1))
        for ct in cts_sorted:
            mc = ct.model_class()
            try:
                if mc is not None and issubclass(mc, AbstractAsset):
                    model_class = mc
                    break
            except TypeError:
                continue
    except Exception:
        return JsonResponse({'results': []})

    if model_class is None:
        return JsonResponse({'results': []})

    q = request.GET.get('q', '').strip()
    limit = min(int(request.GET.get('limit', 10)), 50)
    field_on_child = request.GET.get('field_on_child', '')
    parent_id = request.GET.get('parent_id', '')

    qs = model_class.objects.all()

    if q:
        qs = qs.filter(
            Q(code__icontains=q) | Q(name_fr__icontains=q) | Q(name_nl__icontains=q)
        )

    # Show: assets where FK is NULL  OR  already linked to this parent
    if field_on_child and parent_id:
        try:
            pid = int(parent_id)
            qs = qs.filter(
                Q(**{f'{field_on_child}__isnull': True}) |
                Q(**{field_on_child: pid})
            )
        except (ValueError, TypeError):
            pass

    qs = qs[:limit]

    results = []
    for a in qs:
        results.append({
            'id': a.pk,
            'code': a.code,
            'name': getattr(a, 'name_fr', None) or getattr(a, 'name_nl', None) or '',
            'status': getattr(a, 'status', ''),
        })

    return JsonResponse({'results': results})


@require_POST
def link_child_asset(request, parent_model, parent_id):
    """
    Link an existing child asset to this parent by setting the FK on the child.
    Body JSON: {child_model, child_id, field_on_child}
    """
    from assets.models import AbstractAsset

    parent_asset, parent_model_class, _ct = _get_asset_by_ct(parent_model, parent_id)

    if not can_edit_asset(request.user, parent_asset):
        return JsonResponse({'success': False, 'error': _("Permission refusée")}, status=403)

    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({'success': False, 'error': _("Format JSON invalide")}, status=400)

    child_model_name = data.get('child_model', '')
    child_id = data.get('child_id')
    field_on_child = data.get('field_on_child', '')

    try:
        child_ct = ContentType.objects.get(app_label='assets', model=child_model_name.lower())
        child_model_class = child_ct.model_class()
    except ContentType.DoesNotExist:
        return JsonResponse({'success': False, 'error': _("Type d'asset inconnu")}, status=400)

    child_asset = get_object_or_404(child_model_class, pk=child_id)

    # Validate that field_on_child is a FK pointing to parent's model
    try:
        field_obj = child_model_class._meta.get_field(field_on_child)
        if field_obj.related_model != parent_model_class:
            return JsonResponse({'success': False, 'error': _("Champ de liaison invalide")}, status=400)
    except Exception:
        return JsonResponse({'success': False, 'error': _("Champ de liaison inconnu")}, status=400)

    with transaction.atomic():
        setattr(child_asset, field_on_child, parent_asset)
        child_asset._history_user = request.user
        child_asset.save()

    child_url = child_asset.get_absolute_url() if hasattr(child_asset, 'get_absolute_url') else None
    return JsonResponse({
        'success': True,
        'message': _("Asset lié avec succès"),
        'child_id': child_asset.pk,
        'child_code': child_asset.code,
        'child_name': child_asset.get_name() if hasattr(child_asset, 'get_name') else '',
        'child_url': child_url,
        'child_model_name': child_model_name,
        'field_on_child': field_on_child,
    })


@require_POST
def unlink_child_asset(request, parent_model, parent_id):
    """
    Unlink a child asset from this parent (clear the FK on the child).
    Body JSON: {child_model, child_id, field_on_child}
    """
    parent_asset, parent_model_class, _ct = _get_asset_by_ct(parent_model, parent_id)

    if not can_edit_asset(request.user, parent_asset):
        return JsonResponse({'success': False, 'error': _("Permission refusée")}, status=403)

    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({'success': False, 'error': _("Format JSON invalide")}, status=400)

    child_model_name = data.get('child_model', '')
    child_id = data.get('child_id')
    field_on_child = data.get('field_on_child', '')

    try:
        child_ct = ContentType.objects.get(app_label='assets', model=child_model_name.lower())
        child_model_class = child_ct.model_class()
    except ContentType.DoesNotExist:
        return JsonResponse({'success': False, 'error': _("Type d'asset inconnu")}, status=400)

    child_asset = get_object_or_404(child_model_class, pk=child_id)

    # Verify child currently points to this parent
    current_parent_id = getattr(child_asset, field_on_child + '_id', None)
    if current_parent_id != parent_asset.pk:
        return JsonResponse(
            {'success': False, 'error': _("Cet asset n'est pas lié à ce parent")}, status=400
        )

    # Validate field is nullable
    try:
        field_obj = child_model_class._meta.get_field(field_on_child)
        if not field_obj.null:
            return JsonResponse(
                {'success': False, 'error': _("Ce champ est obligatoire et ne peut pas être vidé")},
                status=400
            )
    except Exception:
        return JsonResponse({'success': False, 'error': _("Champ de liaison inconnu")}, status=400)

    with transaction.atomic():
        setattr(child_asset, field_on_child, None)
        child_asset._history_user = request.user
        child_asset.save()

    return JsonResponse({'success': True, 'message': _("Asset délié avec succès")})


@require_POST
def set_parent_asset(request, asset_model, asset_id):
    """
    Set (or clear) a parent FK field on the current asset.
    Body JSON: {field_name, parent_model, parent_id}
      - If parent_id is null/empty → clears the field (sets it to None).
      - Otherwise → sets the FK to the given parent asset.
    """
    from assets.models import AbstractAsset

    asset, model_class, _ct = _get_asset_by_ct(asset_model, asset_id)

    if not can_edit_asset(request.user, asset):
        return JsonResponse({'success': False, 'error': _("Permission refusée")}, status=403)

    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({'success': False, 'error': _("Format JSON invalide")}, status=400)

    field_name = data.get('field_name', '')
    parent_model_name = data.get('parent_model', '')
    new_parent_id = data.get('parent_id')  # may be None to clear

    # Validate that field_name is indeed a FK on this asset pointing to an AbstractAsset subclass
    try:
        from django.db.models import ForeignKey
        field_obj = model_class._meta.get_field(field_name)
        if not isinstance(field_obj, ForeignKey):
            return JsonResponse({'success': False, 'error': _("Champ de liaison invalide")}, status=400)
        related_model = field_obj.related_model
        if not issubclass(related_model, AbstractAsset):
            return JsonResponse({'success': False, 'error': _("Champ de liaison invalide")}, status=400)
    except Exception:
        return JsonResponse({'success': False, 'error': _("Champ de liaison inconnu")}, status=400)

    if new_parent_id:
        # Resolve parent asset
        try:
            parent_ct = ContentType.objects.get(app_label='assets', model=parent_model_name.lower())
            parent_model_class = parent_ct.model_class()
        except ContentType.DoesNotExist:
            return JsonResponse({'success': False, 'error': _("Type d'asset inconnu")}, status=400)

        # Make sure the field actually points to this parent model
        if field_obj.related_model != parent_model_class:
            return JsonResponse({'success': False, 'error': _("Champ de liaison invalide")}, status=400)

        parent_asset = get_object_or_404(parent_model_class, pk=new_parent_id)

        with transaction.atomic():
            setattr(asset, field_name, parent_asset)
            asset._history_user = request.user
            asset.save()

        parent_url = parent_asset.get_absolute_url() if hasattr(parent_asset, 'get_absolute_url') else None
        return JsonResponse({
            'success': True,
            'message': _("Parent lié avec succès"),
            'parent_id': parent_asset.pk,
            'parent_code': parent_asset.code,
            'parent_name': parent_asset.get_name() if hasattr(parent_asset, 'get_name') else '',
            'parent_url': parent_url,
            'field_name': field_name,
        })
    else:
        # Clear the field
        if not field_obj.null:
            return JsonResponse(
                {'success': False, 'error': _("Ce champ est obligatoire et ne peut pas être vidé")},
                status=400
            )
        with transaction.atomic():
            setattr(asset, field_name, None)
            asset._history_user = request.user
            asset.save()

        return JsonResponse({'success': True, 'message': _("Parent délié avec succès"), 'field_name': field_name})


@require_POST
def create_and_link_child_asset(request, parent_model, parent_id):
    """
    Create a new child asset and link it to this parent.
    Body JSON: {child_model, field_on_child, category_id (opt), model_id (opt), data (opt)}
    """
    parent_asset, parent_model_class, _ct = _get_asset_by_ct(parent_model, parent_id)

    if not can_edit_asset(request.user, parent_asset):
        return JsonResponse({'success': False, 'error': _("Permission refusée")}, status=403)

    # Check create permission at thematic level
    thematic = None
    if hasattr(parent_asset, 'category') and parent_asset.category and parent_asset.category.thematic:
        thematic = parent_asset.category.thematic
    elif (hasattr(parent_asset, 'model') and parent_asset.model
          and getattr(parent_asset.model, 'category', None)
          and parent_asset.model.category.thematic):
        thematic = parent_asset.model.category.thematic

    if thematic:
        thematic_actions = get_allowed_actions_for_thematic(request.user, thematic)
        if 'create' not in thematic_actions:
            return JsonResponse(
                {'success': False, 'error': _("Vous n'avez pas la permission de créer des assets")},
                status=403
            )

    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({'success': False, 'error': _("Format JSON invalide")}, status=400)

    child_model_name = data.get('child_model', '')
    field_on_child = data.get('field_on_child', '')
    category_id = data.get('category_id')
    model_id = data.get('model_id')
    extra_data = data.get('data', {})

    try:
        child_ct = ContentType.objects.get(app_label='assets', model=child_model_name.lower())
        child_model_class = child_ct.model_class()
    except ContentType.DoesNotExist:
        return JsonResponse({'success': False, 'error': _("Type d'asset inconnu")}, status=400)

    # Validate field
    try:
        field_obj = child_model_class._meta.get_field(field_on_child)
        if field_obj.related_model != parent_model_class:
            return JsonResponse({'success': False, 'error': _("Champ de liaison invalide")}, status=400)
    except Exception:
        return JsonResponse({'success': False, 'error': _("Champ de liaison inconnu")}, status=400)

    from django.db import IntegrityError as DBIntegrityError
    from django.db.models import ForeignKey as DjangoForeignKey

    with transaction.atomic():
        new_child = child_model_class()

        # Set parent FK
        setattr(new_child, field_on_child, parent_asset)

        # Defaults set before extra_data so user values can override if needed
        new_child.status = 'active'
        new_child.installation_date = timezone.now()

        # Set category if provided at top level (backward compat)
        if category_id:
            try:
                new_child.category_id = int(category_id)
            except (ValueError, TypeError):
                pass

        # Apply all extra form data (includes model_id, intersection_id, etc.)
        # field_name_id fields (FK raw IDs) are set directly to avoid DB lookups
        SKIP_KEYS = {'id', 'code'}
        for k, v in extra_data.items():
            if k in SKIP_KEYS or v is None or v == '':
                continue
            if not hasattr(new_child, k):
                continue
            # Coerce FK _id values to int
            if k.endswith('_id'):
                try:
                    v = int(v)
                except (ValueError, TypeError):
                    continue
            setattr(new_child, k, v)

        # Backward-compat: top-level model_id (used by old frontend)
        if model_id and not extra_data.get('model_id'):
            try:
                mf = child_model_class._meta.get_field('model')
                new_child.model_id = int(model_id)
            except Exception:
                pass

        # Generate code using parent as "location"
        new_child.code = _generate_asset_code(child_model_class, parent_asset)

        new_child._history_user = request.user
        try:
            new_child.save()
        except DBIntegrityError as exc:
            # Parse the violated column from the DB error to give a user-friendly message
            import re as _re
            m = _re.search(r'colonne\s+[«\"]([\w]+)[»\"]', str(exc)) \
                or _re.search(r'column\s+"([\w]+)"', str(exc))
            if m:
                col = m.group(1)
                # Try to get verbose name from the model field
                try:
                    bad_field = child_model_class._meta.get_field(col.removesuffix('_id'))
                    col = str(getattr(bad_field, 'verbose_name', col)).capitalize()
                except Exception:
                    pass
                msg = _("Le champ « %(field)s » est obligatoire.") % {'field': col}
            else:
                msg = _("Impossible de créer l'asset : un champ obligatoire est manquant.")
            return JsonResponse({'success': False, 'error': msg}, status=400)

    child_url = new_child.get_absolute_url() if hasattr(new_child, 'get_absolute_url') else None
    return JsonResponse({
        'success': True,
        'message': _("Asset créé et lié avec succès"),
        'child_id': new_child.pk,
        'child_code': new_child.code,
        'child_name': new_child.get_name() if hasattr(new_child, 'get_name') else '',
        'child_url': child_url,
        'child_model_name': child_model_name,
        'field_on_child': field_on_child,
    })


@require_POST
def bulk_edit_assets(request):
    """
    Bulk update status or validation_status of assets.
    Expects JSON body:
    {
        "assets": [{"model": "...", "object_id": 123}, ...],
        "field_name": "status" | "validation_status",
        "new_value": "..."
    }
    """
    from django.db import transaction
    from assets.permissions import can_edit_asset, can_validate_asset
    
    try:
        data = json.loads(request.body)
    except json.JSONDecodeError:
        return JsonResponse({'success': False, 'error': _("Format JSON invalide")}, status=400)

    assets_data = data.get('assets', [])
    field_name = data.get('field_name')
    new_value = data.get('new_value')

    if field_name not in ('status', 'validation_status'):
        return JsonResponse({'success': False, 'error': _("Champ non modifiable en masse")}, status=400)

    updated_count = 0
    skipped_count = 0
    errors = []

    with transaction.atomic():
        for item in assets_data:
            model_name = item.get('model')
            object_id = item.get('object_id')
            if not model_name or not object_id:
                continue

            try:
                ct = ContentType.objects.get(app_label='assets', model=model_name)
                asset = ct.get_object_for_this_type(pk=object_id)
            except Exception:
                skipped_count += 1
                continue

            # Permission check
            if field_name == 'status':
                has_perm = can_edit_asset(request.user, asset)
            elif field_name == 'validation_status':
                has_perm = can_validate_asset(request.user, asset)
            else:
                has_perm = False

            if not has_perm:
                skipped_count += 1
                continue

            success, error = _update_asset_field(asset, field_name, new_value, ct.model_class())
            if success:
                asset._history_user = request.user
                asset.save(update_fields=[field_name])
                updated_count += 1
            else:
                errors.append(error)
                skipped_count += 1

    return JsonResponse({
        'success': True,
        'updated_count': updated_count,
        'skipped_count': skipped_count,
        'errors': errors,
        'message': _("%(updated)s équipement(s) mis à jour, %(skipped)s ignoré(s).") % {
            'updated': updated_count,
            'skipped': skipped_count
        }
    })