Add helper functions for Book

helpers/book_helpers.py

@@ -0,0 +1,78 @@
+from typing import Optional
+from datetime import datetime
+import re
+from pydantic import BaseModel, validator
+
+class Book(BaseModel):
+    title: str
+    author: str
+    description: Optional[str] = None
+    page_count: int
+    published_date: datetime
+    isbn: str
+
+    @validator('isbn')
+    def validate_isbn(cls, isbn):
+        """
+        Validate the ISBN format.
+        """
+        pattern = r'^[\d-]+$'
+        if not re.match(pattern, isbn):
+            raise ValueError('Invalid ISBN format')
+        return isbn
+
+def create_book(db, book_data):
+    """
+    Create a new book in the database.
+
+    Args:
+        db: Database session
+        book_data: Book data to create
+
+    Returns:
+        Book object if created successfully, None otherwise
+    """
+    try:
+        book = Book(**book_data.dict())
+    except ValueError as e:
+        return None
+
+    db_book = db.query(Book).filter(Book.isbn == book.isbn).first()
+    if db_book:
+        return None
+
+    db.add(book)
+    db.commit()
+    db.refresh(book)
+    return book
+
+def get_book_by_isbn(db, isbn):
+    """
+    Get a book by its ISBN.
+
+    Args:
+        db: Database session
+        isbn: ISBN to search for
+
+    Returns:
+        Book object if found, None otherwise
+    """
+    return db.query(Book).filter(Book.isbn == isbn).first()
+
+def search_books(db, query):
+    """
+    Search for books based on a query string.
+
+    Args:
+        db: Database session
+        query: Search query string
+
+    Returns:
+        List of Book objects matching the query
+    """
+    books = db.query(Book).filter(
+        Book.title.ilike(f'%{query}%') |
+        Book.author.ilike(f'%{query}%') |
+        Book.description.ilike(f'%{query}%')
+    ).all()
+    return books