from django.db import models
from django.core.files.storage import get_storage_class
import json

class UserStorage(models.Model):
    """ A user defined storage
    """
    owner = models.ForeignKey('auth.User', on_delete=models.CASCADE, null=True, blank=True)
    name = models.SlugField(max_length=20, help_text="Storage tag")
    storage = models.CharField(max_length=255, help_text="Storage class for this instance")
    settings_data = models.TextField(help_text="JSON dict with key/value settings")

    def instance(self):
        return get_storage_class(self.storage)(**self.settings)

    @property
    def settings(self):
        return json.loads(self.settings_data)