from typing import Optional, List
from datetime import datetime, date, time
from sqlalchemy.orm import joinedload
from sqlalchemy import and_, or_
from app.models.reservation import Reservation, ReservationStatus
from app.repositories.base_repository import BaseRepository
from app import db

class ReservationRepository(BaseRepository[Reservation]):
    """Repositorio para la persistencia y consulta de reservas de aulas."""

    def __init__(self):
        super().__init__(Reservation)

    def find_conflicts(self, classroom_id: int, start_time: datetime, end_time: datetime,
                       exclude_reservation_id: Optional[int] = None) -> List[Reservation]:
        """
        Encuentra reservas activas que se solapan en el mismo aula y franja horaria.
        Condición de solapamiento: (start_time < existing.end_time) AND (end_time > existing.start_time).
        """
        query = Reservation.query.filter(
            Reservation.classroom_id == classroom_id,
            Reservation.status != ReservationStatus.CANCELLED.value,
            Reservation.start_time < end_time,
            Reservation.end_time > start_time
        )

        if exclude_reservation_id:
            query = query.filter(Reservation.id != exclude_reservation_id)

        return query.all()

    def get_by_date_range(self, start_dt: datetime, end_dt: datetime,
                          classroom_id: Optional[int] = None) -> List[Reservation]:
        """Obtiene reservas dentro de una ventana temporal con carga ansiosa de relaciones."""
        query = Reservation.query.options(
            joinedload(Reservation.classroom),
            joinedload(Reservation.commission),
            joinedload(Reservation.user)
        ).filter(
            Reservation.start_time >= start_dt,
            Reservation.start_time <= end_dt,
            Reservation.status != ReservationStatus.CANCELLED.value
        )

        if classroom_id:
            query = query.filter(Reservation.classroom_id == classroom_id)

        return query.order_by(Reservation.start_time.asc()).all()

    def get_by_teacher(self, teacher_id: int) -> List[Reservation]:
        """Obtiene reservas asignadas a un docente."""
        return Reservation.query.filter_by(
            user_id=teacher_id
        ).order_by(Reservation.start_time.desc()).all()

    def get_by_commission(self, commission_id: int) -> List[Reservation]:
        """Obtiene todas las reservas asociadas a una comisión."""
        return Reservation.query.filter_by(
            commission_id=commission_id
        ).order_by(Reservation.start_time.asc()).all()