from datetime import datetime, time, timedelta, timezone
from rest_framework import status
from rest_framework.exceptions import ValidationError

from api.models import EsExamActivity, EsExamRequirementStudent, EsInvigilator, EsSession, EsStudent
from api.translation import __
from api.utils import log_critical_error, get_exception_detail
from api.validator import BaseValidator
from api.views.admin.base import AdminApiBase
from api.views.admin.exam_activity_list import ExamActivityList

class StudentTimetable(AdminApiBase):
    def validate_request(self,request):
        rules = {
            "student_id": "required|exists:api.EsStudent,id",
            "exam_period_id": "required|exists:api.EsExamPeriod,id",
        }

        # if need rename field, can put here
        attribute = {
            # "email": __("attr.email"),
        }

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

    def post(self, request):
        try:
            self.validate_request(request)

            data = self.get_data(request)
            response = {
                "data": 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)

    def get_data(self, request):
        exam_requirement_ids = list(
            EsExamRequirementStudent.objects.filter(student_id=request.data["student_id"]).values_list("exam_requirement_id", flat=True)
        )

        exam_activities = (
            EsExamActivity.objects
            .filter(exam_requirement__exam_period_id=request.data["exam_period_id"], exam_requirement_id__in=exam_requirement_ids)
            .distinct()
        )

        return_data = []

        for val in exam_activities:
            data = {}
            data["id"] = val.id
            data["location_id"] = val.location_id
            data["location"] = val.location.name if val.location else None
            data["session_id"] = val.session_id
            data["session"] = val.session.name if val.session else None
            data["code"] = val.code
            data["name"] = val.name
            data["time_slot"] = val.time_slot
            data["is_scheduled"] = val.is_scheduled
            duration = ExamActivityList.build_duration(val.exam_requirement.writing_time, val.exam_requirement.reading_time)
            data["duration"] = duration
            duration_slots = ExamActivityList.build_duration_slots(val.exam_requirement.writing_time, val.exam_requirement.reading_time)
            scheduled_start_at = ExamActivityList.slot_to_datetime(val.time_slot)
            scheduled_end_at = scheduled_start_at + timedelta(minutes=duration_slots * 30) if scheduled_start_at else None
            data["scheduled_start_at"] = scheduled_start_at
            data["scheduled_end_at"] = scheduled_end_at

            data["exam_requirement_id"] = val.exam_requirement_id
            data["exam_requirement_code"] = val.exam_requirement.code
            data["exam_requirement_name"] = val.exam_requirement.name
            data["exam_period_id"] = val.exam_requirement.exam_period_id
            data["exam_period"] = val.exam_requirement.exam_period.name if val.exam_requirement.exam_period else None
            data["planned_size"] = val.exam_requirement.planned_size
            data["writing_time"] = val.exam_requirement.writing_time
            data["fixed_start_date"] = val.exam_requirement.fixed_start_date
            data["reading_time"] = val.exam_requirement.reading_time
            data["fixed_start_time"] = val.exam_requirement.fixed_start_time
            data["location_required"] = val.exam_requirement.location_required
            data["exclusive_use"] = val.exam_requirement.exclusive_use
            data["minimum_split_size"] = val.exam_requirement.minimum_split_size
            data["earliest_start"] = val.exam_requirement.earliest_start
            data["latest_end"] = val.exam_requirement.latest_end
            
            data["invigilator"] = [];

            if val.session:
                invigilators = (
                    EsInvigilator.objects
                    .filter(
                        status=EsInvigilator.STATUS_TO_CODE["active"],
                        essessioninvigilator__session_id=val.session_id
                    )
                    .order_by("name")
                    .all()
                )

                for invigilator in invigilators:
                    data["invigilator"].append({
                        "id": invigilator.id,
                        "code": invigilator.code,
                        "name": invigilator.name,
                        "desc": invigilator.desc,
                        "email": invigilator.email,
                        "phone": invigilator.phone,
                        "engagement_date": invigilator.engagement_date,
                        "termination_date": invigilator.termination_date,
                        "status": invigilator.status,
                    })

            return_data.append(data)

        return return_data