from datetime import datetime


def _delete_event_trigger_file(blob_service_client, trigger_file_path, container_name):
    """Helper function that delete event trigger file from target container of storage account.
    Warning! If target deleting file is not there, BlobNotFound exception will be raised.

    Args:
        blob_service_client (BlobServiceClient): Azure Storage Account service client
        trigger_file_path (str): Path of trigger file in storage account container
        container_name (str): Name of target container to upload the trigger file.

    Returns:
        blob_properties, including last modified time
    """
    container_client = blob_service_client.get_container_client(container_name)

    # Delete target event trigger file from storage account
    container_client.delete_blob(trigger_file_path)
    deleted_time = datetime.utcnow()
    blob_properties = {
        "etag": "",
        "last_modified": deleted_time
    }

    return blob_properties