from django.conf import settings


class AliyunVideoSettings:

    all_settings = [
        'ACCESS_KEY_ID',
        'ACCESS_KEY_SECRET',
        'WORKFLOW_ID',
        'CDN_URL_PREFIX',
        'CDN_ACCESS_TOKEN'
    ]

    default_settings = {}

    def __init__(self):
        self.user_settings = getattr(settings, "ALIYUN_VIDEO", {})

    def check(self):
        for st in self.all_settings:
            getattr(self, st)

    def __getattr__(self, attr):
        try:
            val = self.user_settings[attr]
        except KeyError:
            try:
                val = self.default_settings[attr]
            except KeyError as exc:
                raise KeyError(
                    "ALIYUN_VIDEO missed required settings: %s, "
                    "please defined `ALIYUN_VIDEO = {'%s': ..}` "
                    "in your settings." % (attr, attr)) from exc

        # Cache result
        setattr(self, attr, val)
        return val


video_settings = AliyunVideoSettings()