from typing import Optional, List
from sqlalchemy.orm import Session
from uuid import UUID

from models.book import Book
from schemas.book import BookCreate, BookUpdate

def create_book(db: Session, book_data: BookCreate) -> Book:
    """
    Creates a new book in the database.

    Args:
        db (Session): The database session.
        book_data (BookCreate): The data for the book to create.

    Returns:
        Book: The newly created book object.
    """
    db_book = Book(**book_data.dict())
    db.add(db_book)
    db.commit()
    db.refresh(db_book)
    return db_book

def update_book(db: Session, book_id: UUID, book_data: BookUpdate) -> Optional[Book]:
    """
    Updates an existing book in the database.

    Args:
        db (Session): The database session.
        book_id (UUID): The ID of the book to update.
        book_data (BookUpdate): The data to update the book with.

    Returns:
        Optional[Book]: The updated book object if found, otherwise None.
    """
    book = db.query(Book).filter(Book.id == book_id).first()
    if not book:
        return None
        
    update_data = book_data.dict(exclude_unset=True)
    for key, value in update_data.items():
        setattr(book, key, value)
        
    db.commit()
    db.refresh(book)
    return book

def delete_book(db: Session, book_id: UUID) -> bool:
    """
    Deletes a book from the database.

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

    Returns:
        bool: True if the book was successfully deleted, False if the book was not found.
    """
    book = db.query(Book).filter(Book.id == book_id).first()
    if not book:
        return False
        
    db.delete(book)
    db.commit()
    return True

def get_book_by_id(db: Session, book_id: UUID) -> Optional[Book]:
    """
    Retrieves a book by its ID.

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

    Returns:
        Optional[Book]: The book object if found, otherwise None.
    """
    return db.query(Book).filter(Book.id == book_id).first()

def get_books_by_author(db: Session, author: str, skip: int = 0, limit: int = 100) -> List[Book]:
    """
    Retrieves books by a specific author.

    Args:
        db (Session): The database session.
        author (str): The author name to filter by.
        skip (int, optional): Number of records to skip for pagination. Defaults to 0.
        limit (int, optional): Maximum number of records to return. Defaults to 100.

    Returns:
        List[Book]: A list of books by the specified author.
    """
    return db.query(Book).filter(Book.author == author).offset(skip).limit(limit).all()

def get_books_by_title(db: Session, title: str, skip: int = 0, limit: int = 100) -> List[Book]:
    """
    Retrieves books by a specific title or partial title match.

    Args:
        db (Session): The database session.
        title (str): The title or partial title to search for.
        skip (int, optional): Number of records to skip for pagination. Defaults to 0.
        limit (int, optional): Maximum number of records to return. Defaults to 100.

    Returns:
        List[Book]: A list of books matching the title search.
    """
    return db.query(Book).filter(Book.title.ilike(f"%{title}%")).offset(skip).limit(limit).all()

def get_all_books(db: Session, author: Optional[str] = None, title: Optional[str] = None, skip: int = 0, limit: int = 100) -> List[Book]:
    """
    Retrieves all books with optional filtering by author or title and pagination.

    Args:
        db (Session): The database session.
        author (Optional[str], optional): The author name to filter by. Defaults to None.
        title (Optional[str], optional): The title or partial title to search for. Defaults to None.
        skip (int, optional): Number of records to skip for pagination. Defaults to 0.
        limit (int, optional): Maximum number of records to return. Defaults to 100.

    Returns:
        List[Book]: A list of book objects matching the filters.
    """
    query = db.query(Book)
    
    if author:
        query = query.filter(Book.author == author)
    
    if title:
        query = query.filter(Book.title.ilike(f"%{title}%"))
        
    return query.offset(skip).limit(limit).all()