from typing import List, Optional
from uuid import UUID
from sqlalchemy.orm import Session
from sqlalchemy.exc import SQLAlchemyError
from models.ship import Ship
from schemas.ship import ShipCreate, ShipUpdate

def get_all_ships(db: Session) -> List[Ship]:
    """
    Retrieves all ships from the database.

    Args:
        db (Session): The database session.

    Returns:
        List[Ship]: A list of all ship objects.
    """
    return db.query(Ship).all()

def get_ship_by_id(db: Session, ship_id: UUID) -> Optional[Ship]:
    """
    Retrieves a single ship by its ID.

    Args:
        db (Session): The database session.
        ship_id (UUID): The ID of the ship to retrieve.

    Returns:
        Optional[Ship]: The ship object if found, otherwise None.
    """
    return db.query(Ship).filter(Ship.id == ship_id).first()

def get_ship_names(db: Session) -> List[str]:
    """
    Retrieves a list of all ship names.
    
    Note: This function is deprecated. Use get_all_ships() instead to get full ship objects.

    Args:
        db (Session): The database session.

    Returns:
        List[str]: A list of ship names.
    """
    return [ship.name for ship in db.query(Ship.name).all()]

def create_ship(db: Session, ship_data: ShipCreate) -> Ship:
    """
    Creates a new ship in the database.

    Args:
        db (Session): The database session.
        ship_data (ShipCreate): The data for the ship to create.

    Returns:
        Ship: The newly created ship object.

    Raises:
        SQLAlchemyError: If there's an error creating the ship.
    """
    try:
        db_ship = Ship(**ship_data.dict())
        db.add(db_ship)
        db.commit()
        db.refresh(db_ship)
        return db_ship
    except SQLAlchemyError:
        db.rollback()
        raise

def update_ship(db: Session, ship_id: UUID, ship_data: ShipUpdate) -> Optional[Ship]:
    """
    Updates an existing ship in the database.

    Args:
        db (Session): The database session.
        ship_id (UUID): The ID of the ship to update.
        ship_data (ShipUpdate): The update data for the ship.

    Returns:
        Optional[Ship]: The updated ship object if found, otherwise None.

    Raises:
        SQLAlchemyError: If there's an error updating the ship.
    """
    try:
        db_ship = get_ship_by_id(db, ship_id)
        if not db_ship:
            return None

        update_data = ship_data.dict(exclude_unset=True)
        for field, value in update_data.items():
            setattr(db_ship, field, value)

        db.commit()
        db.refresh(db_ship)
        return db_ship
    except SQLAlchemyError:
        db.rollback()
        raise

def delete_ship(db: Session, ship_id: UUID) -> bool:
    """
    Deletes a ship from the database.

    Args:
        db (Session): The database session.
        ship_id (UUID): The ID of the ship to delete.

    Returns:
        bool: True if the ship was deleted, False if not found.

    Raises:
        SQLAlchemyError: If there's an error deleting the ship.
    """
    try:
        db_ship = get_ship_by_id(db, ship_id)
        if not db_ship:
            return False

        db.delete(db_ship)
        db.commit()
        return True
    except SQLAlchemyError:
        db.rollback()
        raise