from typing import Optional
from sqlalchemy.orm import Session
from sqlalchemy.exc import IntegrityError
from models.fruit import Fruit
from schemas.fruit import FruitCreate, FruitSchema

def create_fruit(db: Session, fruit_data: FruitCreate) -> Optional[Fruit]:
    """
    Creates a new fruit in the database.

    Args:
        db (Session): The database session.
        fruit_data (FruitCreate): The data for the fruit to create.

    Returns:
        Optional[Fruit]: The newly created fruit object, or None if creation fails.
    """
    try:
        db_fruit = Fruit(name=fruit_data.name)
        db.add(db_fruit)
        db.commit()
        db.refresh(db_fruit)
        return db_fruit
    except IntegrityError:
        db.rollback()
        return None

def get_fruit_by_name(db: Session, name: str) -> Optional[Fruit]:
    """
    Retrieves a fruit by its name.

    Args:
        db (Session): The database session.
        name (str): The name of the fruit to retrieve.

    Returns:
        Optional[Fruit]: The fruit object if found, otherwise None.
    """
    return db.query(Fruit).filter(Fruit.name == name).first()

def validate_fruit_name(name: str) -> bool:
    """
    Validates the fruit name according to business rules.

    Args:
        name (str): The fruit name to validate.

    Returns:
        bool: True if the name is valid, False otherwise.
    """
    if not name or not isinstance(name, str):
        return False
    
    # Remove whitespace and check length
    cleaned_name = name.strip()
    if len(cleaned_name) < 1:
        return False
    
    # Additional validation rules could be added here
    return True

def format_fruit_response(fruit: Fruit) -> FruitSchema:
    """
    Formats a fruit database object into a response schema.

    Args:
        fruit (Fruit): The fruit database object to format.

    Returns:
        FruitSchema: The formatted fruit response.
    """
    return FruitSchema(
        id=fruit.id,
        name=fruit.name,
        created_at=fruit.created_at,
        updated_at=fruit.updated_at
    )