from fastapi import APIRouter, Depends, Security
from sqlalchemy import desc, distinct, func, over
from sqlalchemy.orm import Session

from ..core.security import get_current_active_user as get_user
from ..db.session import SessionLocal
from ..models import Attendance
from ..schemas.auth import UserToken


router = APIRouter()


# Dependency
def get_db() -> Session:
    try:
        db = SessionLocal()
        yield db
    finally:
        db.close()


@router.post("")
def post_check_db(db: Session = Depends(get_db), user: UserToken = Security(get_user)):
    info = {}

    duplicate_attendances = get_duplicate_attendances(db)
    if duplicate_attendances > 0:
        fix_duplicate_attendances(db)
        info["Duplicate Attendances Fixed"] = duplicate_attendances
    db.commit()
    return info


def get_duplicate_attendances(db):
    sub_query = (
        db.query(
            over(
                distinct(func.first_value(Attendance.id)),
                partition_by=[Attendance.employee_id, Attendance.date],
            )
        )
        .filter(Attendance.is_valid == True)
        .subquery()
    )
    query = (
        db.query(func.count(Attendance.id))
        .filter(~Attendance.id.in_(sub_query))
        .filter(Attendance.is_valid == True)
    )
    return query.scalar()


def fix_duplicate_attendances(db):
    sub = (
        db.query(
            over(
                distinct(func.first_value(Attendance.id)),
                partition_by=[Attendance.employee_id, Attendance.date],
                order_by=desc(Attendance.creation_date),
            )
        )
        .filter(Attendance.is_valid == True)
        .subquery()
    )
    db.query(Attendance).filter(~Attendance.id.in_(sub)).filter(
        Attendance.is_valid == True
    ).delete(False)