from sqlalchemy.orm import Session, joinedload
from typing import Optional, List
from .models import LoanCalculation, AmortizationScheduleEntry


def get_by_id(db: Session, entity_id: str) -> Optional[LoanCalculation]:
    return db.query(LoanCalculation).filter(LoanCalculation.id == entity_id).first()


def list_all(db: Session, limit: int = 20, offset: int = 0, **filters) -> List[LoanCalculation]:
    q = db.query(LoanCalculation)
    if filters.get("session_id") is not None:
        q = q.filter(LoanCalculation.session_id == filters["session_id"])
    return q.order_by(LoanCalculation.created_at.desc()).limit(limit).offset(offset).all()


def count_all(db: Session, **filters) -> int:
    q = db.query(LoanCalculation.id)
    if filters.get("session_id") is not None:
        q = q.filter(LoanCalculation.session_id == filters["session_id"])
    return q.count()


def create(db: Session, data: dict) -> LoanCalculation:
    obj = LoanCalculation(**data)
    db.add(obj)
    db.flush()
    return obj


def update(db: Session, entity_id: str, data: dict) -> Optional[LoanCalculation]:
    obj = db.query(LoanCalculation).filter(LoanCalculation.id == entity_id).first()
    if not obj:
        return None
    for key, value in data.items():
        setattr(obj, key, value)
    db.flush()
    return obj


def delete(db: Session, entity_id: str) -> bool:
    obj = db.query(LoanCalculation).filter(LoanCalculation.id == entity_id).first()
    if not obj:
        return False
    db.delete(obj)
    db.flush()
    return True


def get_with_details(db: Session, entity_id: str) -> Optional[LoanCalculation]:
    return (
        db.query(LoanCalculation)
        .options(
            joinedload(LoanCalculation.amortization_schedule_entries)
        )
        .filter(LoanCalculation.id == entity_id)
        .first()
    )