from typing import Sequence
from sqlalchemy import select, desc, func
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import joinedload
from datetime import date

from app.domain.models import ScheduledAppointment


class ScheduledAppointmentsRepository:
    def __init__(self, db: AsyncSession):
        self.db = db

    async def get_all(self, start_date: date | None = None, end_date: date | None = None) -> Sequence[
        ScheduledAppointment]:
        stmt = (
            select(ScheduledAppointment)
            .options(joinedload(ScheduledAppointment.type))
            .options(joinedload(ScheduledAppointment.patient))
            .options(joinedload(ScheduledAppointment.doctor))
            .filter_by(is_canceled=False)
            .order_by(desc(ScheduledAppointment.scheduled_datetime))
        )
        if start_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime >= start_date)
        if end_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime <= end_date)
        result = await self.db.execute(stmt)
        return result.scalars().all()

    async def get_by_doctor_id(self, doctor_id: int, start_date: date | None = None, end_date: date | None = None) -> \
            Sequence[ScheduledAppointment]:
        stmt = (
            select(ScheduledAppointment)
            .options(joinedload(ScheduledAppointment.type))
            .options(joinedload(ScheduledAppointment.patient))
            .options(joinedload(ScheduledAppointment.doctor))
            .filter_by(doctor_id=doctor_id, is_canceled=False)
            .order_by(desc(ScheduledAppointment.scheduled_datetime))
        )
        if start_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime >= start_date)
        if end_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime <= end_date)
        result = await self.db.execute(stmt)
        return result.scalars().all()

    async def get_upcoming_by_doctor_id(self, doctor_id: int) -> Sequence[ScheduledAppointment]:
        stmt = (
            select(ScheduledAppointment)
            .options(joinedload(ScheduledAppointment.type))
            .options(joinedload(ScheduledAppointment.patient))
            .options(joinedload(ScheduledAppointment.doctor))
            .filter_by(doctor_id=doctor_id, is_canceled=False)
            .filter(ScheduledAppointment.scheduled_datetime >= func.now())
            .order_by(ScheduledAppointment.scheduled_datetime)
            .limit(5)
        )
        result = await self.db.execute(stmt)
        return result.scalars().all()

    async def get_by_patient_id(self, patient_id: int, start_date: date | None = None, end_date: date | None = None) -> \
            Sequence[ScheduledAppointment]:
        stmt = (
            select(ScheduledAppointment)
            .options(joinedload(ScheduledAppointment.type))
            .options(joinedload(ScheduledAppointment.patient))
            .options(joinedload(ScheduledAppointment.doctor))
            .filter_by(patient_id=patient_id, is_canceled=False)
            .order_by(desc(ScheduledAppointment.scheduled_datetime))
        )
        if start_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime >= start_date)
        if end_date:
            stmt = stmt.filter(ScheduledAppointment.scheduled_datetime <= end_date)
        result = await self.db.execute(stmt)
        return result.scalars().all()

    async def get_by_id(self, scheduled_appointment_id: int) -> ScheduledAppointment:
        stmt = (
            select(ScheduledAppointment)
            .options(joinedload(ScheduledAppointment.type))
            .options(joinedload(ScheduledAppointment.patient))
            .options(joinedload(ScheduledAppointment.doctor))
            .filter_by(id=scheduled_appointment_id, is_canceled=False)
        )
        result = await self.db.execute(stmt)
        return result.scalars().first()

    async def create(self, scheduled_appointment: ScheduledAppointment) -> ScheduledAppointment:
        self.db.add(scheduled_appointment)
        await self.db.commit()
        await self.db.refresh(scheduled_appointment)
        return scheduled_appointment

    async def update(self, scheduled_appointment: ScheduledAppointment) -> ScheduledAppointment:
        await self.db.merge(scheduled_appointment)
        await self.db.commit()
        return scheduled_appointment

    async def delete(self, scheduled_appointment: ScheduledAppointment) -> ScheduledAppointment:
        await self.db.delete(scheduled_appointment)
        await self.db.commit()
        return scheduled_appointment