@bp.route("/upload_data", methods=["GET", "POST"])
@auth.admin_required
def upload_data():
    """
    This is a flask function for the backend logic to upload a file to the database.
    """
    filename = None
    if request.method == "POST":
        if db.get_task(f"upload_and_process:{current_user.username}"):
            flash("A file is already being processed.")
            return redirect(request.url)
        minio_file = request.form.get("miniofile")
        if minio_file != "None" and minio_file is not None:
            logger.info(f"Using minio file: {minio_file}")
            filename = minio_file
        else:
            if 'data_file' not in request.files:
                flash('No file part')
                return redirect(request.url)
            file = request.files['data_file']
            if file.filename == '':
                flash('No selected file')
                return redirect(request.url)
            if file and not allowed_data_file(file.filename):
                flash("Invalid file type. Please upload a .csv, .xlsx, .json, .parquet, .pickle, .pkl, or .xml file.")
                return redirect(request.url)

            filename = f"uploaded_files/{secure_filename(file.filename)}"
            size = os.fstat(file.fileno()).st_size
            try:
                minio.put_object(g.bucket_name,
                                 filename,
                                 file,
                                 size)
                logger.info(f"File - {file.filename} uploaded successfully.")
                flash(f"{filename} uploaded successfully.")

            except Exception as e:
                filename = None
                flash(f"Failed to upload file: {str(e)}")
                return redirect(request.url)

        if filename:
            try:
                EMR_to_mongodb(filename)
                flash(f"Data from {filename} uploaded to the database.")
                return redirect(url_for('ops.upload_query'))
            except Exception as e:
                flash(f"Failed to upload data: {str(e)}")
                return redirect(request.url)
    try:
        files = [(obj.object_name, obj.size)
                 for obj in minio.list_objects(g.bucket_name,
                                               prefix="uploaded_files/")]
    except Exception as e:
        flash(f"Error listing files: {e}")
        files = []

    return render_template("ops/upload_file.html", files=files, **db.get_info())

def EMR_to_mongodb(filepath):  # pylint: disable=C0103
    """
    This function is used to open a csv file and load it's contents into the mongodb database.

    Args:
        filename (str) : The path to the file to load data from.
        For valid file extensions refer to the allowed_data_file function above.
    Returns:
        None
    """

    data_frame = load_pandas_dataframe(filepath)
    if data_frame is None:
        return

    logger.info(f"columns in dataframe:\n {data_frame.columns}")
    logger.debug(data_frame.head())
    id_list = data_frame["patient_id"].unique()
    logger.info("Starting document migration to mongodb database.")
    for i, p_id in enumerate(id_list):
        documents = data_frame[data_frame["patient_id"] == p_id]
        db.upload_notes(documents)
        if i+1 % 100 == 0:
            logger.info(f"Documents uploaded for patient #{i+1}")

    logger.info("Completed document migration to mongodb database.")