Refactored 'endpoints' module: added support of MongoDB to 'show_book…

…s' and 'delete_book' endpoints

backend/endpoints.py

@@ -320,7 +320,14 @@ def show_books(
         "Detected incoming GET request to /books endpoint from the"
         "client with IP %s ...", client_host
     )
-    return list(default_book_shelf.values())[: limit]
+    # find and retrieve each book in the collection
+    cursor = ma_books_collection.find()
+    # convert the cursor to the list with Book models, considering the limit
+    all_books = []
+    for book_in_db in cursor:
+        book = Book(*book_in_db)
+        all_books.append(book)
+    return all_books[: limit]
 
 
 @app.post(
@@ -412,7 +419,7 @@ def add_book(
 
     except Exception as e:
         TB = traceback.format_exc()
-        logger.exception(f"Exception occurred: {e}\ntraceback: {TB}")
+        logger.exception("Exception occurred: %s\ntraceback: %x", e, TB)
         return JSONResponse(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             content=Error(
@@ -435,9 +442,9 @@ def add_book(
     dependencies=[Depends(oauth2_scheme)]
 )
 def delete_book(
-    request: Request, 
+    request: Request,
     book_name: str = Path(..., title="Required book name to be deleted", example="Shantaram")
-) -> Union[Message, NoReturn]:
+) -> Union[Message, JSONResponse]:
     """
     Deletes a book from the book shelf by given book name
 
@@ -447,29 +454,45 @@ def delete_book(
     :type token: Annotated[str, Depends(oauth2_scheme)]
     :param book_name: Path parameter, book name gotten from the route
     :type book_name: str, optional
-    :raises HTTPException: exception with status_code HTTP_404_NOT_FOUND raised in case the given book name does not exist on the book shelf
+    :raises HTTPException: exception with status_code HTTP_404_NOT_FOUND
+            raised in case the given book name does not exist on the book shelf
     :return: message about successful book deletion from the book shelf
-    :rtype: Union[NoReturn, Message]
+    :rtype: Union[JSONResponse, Message]
     """
     client_host = request.client.host
     logger.debug(
         "Detected incoming DELETE request to /books/delete endpoint"
         "from the client with IP %s ...", client_host
         )
-    # todo add authorization via JWT token            
-    # todo add working with MongoDB
-    if book_name not in [book.book_name for book in default_book_shelf.values()]:
-        raise HTTPException(
+    # todo add authorization via JWT token
+
+    logger.debug(
+        "Book with book_name %s is requested to be deleted from the DB",
+        book_name
+    )
+    # delete returnable key-value pair deletion after extraction from DB
+    deletion_result = ma_books_collection.delete_db_entry(
+        index_name="book_name",
+        entry_id=book_name
+    )
+    # deletable_entry can be either valid data entry by the key "issue_id"
+    # from the DB or None if entry is not found
+    if deletion_result.deleted_count == 0:
+        logger.warning(
+            "The book %s was not found in the book shelf!",
+            book_name
+        )
+        return JSONResponse(
             status_code=status.HTTP_404_NOT_FOUND,
-            detail=f"The book {book_name} was not found in the book shelf!"
+            content=Error(
+                message=f"No data entry found with book_name {book_name}!",
+                status_code=status.HTTP_404_NOT_FOUND
+            ).dict()
         )
-    for book_id, book in default_book_shelf.items():
-        if book_name == book.book_name:
-            logger.debug(
-                "Book %s with assigned book ID %x is found on the book"
-                "shelf and is to be deleted ...", book_name, book_id
-            )
-            del default_book_shelf[book_id]
-            return Message(
-                message=f"Book {book_name} was successfully deleted from the book shelf!"
-            )
+    logger.info(
+        "Book %s is found on the book shelf and is to be deleted ...", 
+        book_name
+    )
+    return Message(
+        message=f"Book {book_name} was successfully deleted from the book shelf!"
+    )