boards/abstracts/sticker_factory.py

from boards.abstracts.settingsmanager import SessionSettingsManager
from boards.models import Attachment


class StickerFactory:
    def get_image(self, alias):
        pass


class SessionStickerFactory(StickerFactory):
    def __init__(self, session):
        self.session = session

    def get_image(self, alias):
        settings_manager = SessionSettingsManager(self.session)
        return settings_manager.get_attachment_by_alias(alias)


class ModelStickerFactory(StickerFactory):
    def get_image(self, alias):
        if alias.count('/') == 1:
            return Attachment.objects.get_by_alias(alias)


def get_attachment_by_alias(alias, session):
    """Gets attachment from a source (local or server/global) using an alias."""
    
    factories = [SessionStickerFactory(session), ModelStickerFactory()]
    for factory in factories:
        image = factory.get_image(alias)

        if image is not None:
            return image