import os
import uuid
import pathlib

ALLOWED_EXTENSIONS = {'png', 'jpg', 'jpeg', 'gif'}


def allowed_file(filename) -> bool:
    """ Ensures only filenames ending with the correct extension are allowed.
        Note: This does not verify that the content inside of the file
        matches the type specified
    """
    return '.' in filename and \
           filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS


def save_image(file) -> str | None:
    """ Saves a given file to disk with a random UUID4 generated
        filename. Returns the filename as a string.
    """
    # Ensure that the correct file type is uploaded
    if file is None or not allowed_file(file.filename):
        return None

    # Create the product object and push to database
    filename = str(uuid.uuid4()) + pathlib.Path(file.filename).suffix

    path = os.environ.get('FILESTORE')
    file.save(os.path.join(path, filename))
    return filename


def create_directory(dir: str):
    """ Creates the given directory string is not alreay made """
    try:
        os.makedirs(dir)
    except FileExistsError:
        pass


def remove_file(dir: str):
    """ Removes a given file if it is present at the given dir """
    try:
        os.remove(dir)
    except FileNotFoundError:
        pass