from rest_framework import status
from rest_framework.exceptions import ValidationError

from api.models import EsInvigilator, EsSession
from api.translation import __
from api.utils import get_exception_detail, log_critical_error
from api.validator import BaseValidator
from api.views.admin.base import AdminApiBase


class SessionUpdateInvigilatorRules(AdminApiBase):
    list_default_order_column = "id"

    def validate_request(self, request):
        rules = {
            "id": "nullable|array|exists:api.EsSession,id",
        }
        attribute = {}

        validator = BaseValidator(request.data, rules, attribute)
        error = validator.validate()
        if error:
            raise ValidationError(error)

    def custom_listing_filter(self, request, model):
        filters = request.data.get("filter")
        if filters:
            for key, val in filters.items():
                if val == "" or val is None:
                    continue
                match key:
                    case "desc" | "email" | "phone":
                        filter_kwargs = {f"{key}__icontains": val}
                        model = model.filter(**filter_kwargs)
                    case "status":
                        if isinstance(val, (list, tuple)):
                            model = model.filter(status__in=val)
                        else:
                            model = model.filter(status=val)
                    case "tag_id":
                        if isinstance(val, (list, tuple)):
                            model = model.filter(tag__tag_id__in=val)
                        else:
                            model = model.filter(tag__tag_id=val)
                    case "role_id":
                        if isinstance(val, (list, tuple)):
                            model = model.filter(role__in=val)
                        else:
                            model = model.filter(role__id=val)
                    case "suitability":
                        if isinstance(val, (list, tuple)):
                            model = model.filter(suitability__in=val)
                        else:
                            model = model.filter(suitability__id=val)
                    case "engagement_date_from" | "termination_date_from":
                        db_field = "engagement_date" if key == "engagement_date_from" else "termination_date"
                        to_key = f"{db_field}_to"
                        if not filters.get(to_key):
                            model = model.filter(**{f"{db_field}": val})
                        else:
                            model = model.filter(**{f"{db_field}__gte": val})
                    case "engagement_date_to" | "termination_date_to":
                        db_field = "engagement_date" if key == "engagement_date_to" else "termination_date"
                        from_key = f"{db_field}_from"
                        if not filters.get(from_key):
                            model = model.filter(**{f"{db_field}": val})
                        else:
                            model = model.filter(**{f"{db_field}__lte": val})
        return model

    def post(self, request):
        try:
            self.api_log_skip_outgoing_data = True
            self.validate_request(request)

            ids = request.data.get("id")
            if not ids:
                ids = []

            obj = None
            if isinstance(ids, (list, tuple)) and len(ids) == 1:
                obj = (
                    EsSession.objects
                    .select_related("location")
                    .prefetch_related("essessioninvigilator_set__invigilator__department", "essessioninvigilator_set__invigilator__role", "essessioninvigilator_set__invigilator__tag__tag")
                    .filter(id__in=ids)
                    .first()
                )

            info = None
            if obj:
                info = {
                    # "id": obj.id,
                    "name": obj.name,
                    # "location_id": obj.location_id,
                    # "location": obj.location.name if obj.location else None,
                    # "description": obj.description,
                    # "start_time": obj.start_time,
                    # "duration": obj.duration,
                    # "students_enrolled": obj.students_enrolled,
                    # "invigilators_required": obj.invigilators_required,
                    "invigilator": [
                        relation.invigilator_id
                        for relation in obj.essessioninvigilator_set.all()
                        if relation.invigilator_id is not None and not relation.is_floating
                    ],
                    "floating_invigilator": [
                        relation.invigilator_id
                        for relation in obj.essessioninvigilator_set.all()
                        if relation.invigilator_id is not None and relation.is_floating
                    ],
                }

            invigilators_query = (
                EsInvigilator.objects
                .select_related("department")
                .prefetch_related("role", "tag__tag", "suitability")
                .filter(status=EsInvigilator.STATUS_TO_CODE["active"])
            )

            invigilators_query = self.listing_filter(request, invigilators_query)
            invigilators_query = self.custom_listing_filter(request, invigilators_query)
            paginated_details = self.listing_pagination(request, invigilators_query)

            invigilator_list = []
            for invigilator in paginated_details["paginated_data"]:
                invigilator_list.append({
                    "id": invigilator.id,
                    "code": invigilator.code,
                    "name": invigilator.name,
                    "desc": invigilator.desc,
                    "department_id": invigilator.department_id,
                    "department": invigilator.department.name if invigilator.department else None,
                    "email": invigilator.email,
                    "phone": invigilator.phone,
                    "engagement_date": invigilator.engagement_date,
                    "termination_date": invigilator.termination_date,
                    "status": invigilator.status,
                    "status_text": "Active" if invigilator.status == EsInvigilator.STATUS_TO_CODE.get("active", 1) else "Inactive",
                    "role": list(invigilator.role.values("id", "name", "color")),
                    "suitability": [
                        {"id": suitability.id, "name": suitability.name}
                        for suitability in invigilator.suitability.all()
                    ],
                    "tag": [
                        {"id": tag.tag.id, "name": tag.tag.name}
                        for tag in invigilator.tag.all()
                    ],
                })

            data = {
                "delete_confirmation_api": False,
                "allow_remove": [
                    "invigilator_id",
                    "floating_invigilator_id",
                ],
                "invigilator": invigilator_list,
                "page": paginated_details["page"],
                "per_page": request.data.get("per_page") or self.default_per_page,
                "total": paginated_details["total"],
            }

            response = {
                "info": info,
                "rules": data,
            }

            return self.api_response(data=response)
        except ValidationError as e:
            first_message = e.detail["error"]
            errors = e.detail["errors"]
            return self.api_response(error=first_message, errors=errors, code=status.HTTP_400_BAD_REQUEST)
        except Exception as e:
            e_details = get_exception_detail(e)
            log_critical_error(user_id=None, descr=e_details["descr"], url=e_details["url"], trace=e_details["trace"])
            return self.api_response(error=__("message.internal_server_error"), code=status.HTTP_500_INTERNAL_SERVER_ERROR)