Global refactoring of the project to use poetry and implement tests,

fixing bugs, changing the handling of dto and db models, preparing to
add new functionality

library_service/routers/books.py

@@ -0,0 +1,77 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlmodel import Session, select
+from typing import Deque, List
+
+from library_service.settings import get_session
+from library_service.models.db import Book, Author, AuthorBookLink, BookWithAuthors
+from library_service.models.dto import (
+    BookCreate, BookUpdate, BookRead,
+    BookList, AuthorRead
+)
+
+router = APIRouter(prefix="/books", tags=["books"])
+
+# Create a book
+@router.post("/", response_model=Book)
+def create_book(book: BookCreate, session: Session = Depends(get_session)):
+    db_book = Book(**book.model_dump())
+    session.add(db_book)
+    session.commit()
+    session.refresh(db_book)
+    return BookRead(**db_book.model_dump())
+
+# Read books
+@router.get("/", response_model=BookList)
+def read_books(session: Session = Depends(get_session)):
+    books = session.exec(select(Book)).all()
+    return BookList(
+        books=[BookRead(**book.model_dump()) for book in books],
+        total=len(books)
+    )
+
+# Read a book
+@router.get("/{book_id}", response_model=BookWithAuthors)
+def get_book(book_id: int, session: Session = Depends(get_session)):
+    book = session.get(Book, book_id)
+    if not book:
+        raise HTTPException(status_code=404, detail="Book not found")
+    return BookWithAuthors(**book.model_dump())
+
+# Update a book
+@router.put("/{book_id}", response_model=Book)
+def update_book(book_id: int, book: BookUpdate, session: Session = Depends(get_session)):
+    db_book = session.get(Book, book_id)
+    if not db_book:
+        raise HTTPException(status_code=404, detail="Book not found")
+
+    db_book.title = book.title or db_book.title
+    db_book.description = book.description or db_book.description
+    session.commit()
+    session.refresh(db_book)
+    return db_book
+
+# Delete a book
+@router.delete("/{book_id}", response_model=BookRead)
+def delete_book(book_id: int, session: Session = Depends(get_session)):
+    book = session.get(Book, book_id)
+    if not book:
+        raise HTTPException(status_code=404, detail="Book not found")
+    book_read = BookRead(id=(book.id or 0), title=book.title, description=book.description)
+    session.delete(book)
+    session.commit()
+    return book_read
+
+# Get all authors for a book
+@router.get("/{book_id}/authors/", response_model=List[AuthorRead])
+def get_authors_for_book(book_id: int, session: Session = Depends(get_session)):
+    book = session.get(Book, book_id)
+    if not book:
+        raise HTTPException(status_code=404, detail="Book not found")
+
+    authors = session.exec(
+        select(Author)
+        .join(AuthorBookLink)
+        .where(AuthorBookLink.book_id == book_id)
+    ).all()
+
+    return [AuthorRead(**author.model_dump()) for author in authors]