import os

from .confirmation import TRUTHY


def env(key, default=None, parser=None):
    value = os.environ.get(key)

    if value is None:
        return default

    if parser is None:
        if default is None:
            return value
        else:
            parser = type(default)

    if parser is bool:
        return truthy(value, default)

    return parser(value)


def truthy(value, default=False):
    return TRUTHY.get(value, default)


def password_validators(*validators):
    return list(_parse_password_validators(validators))


def _parse_password_validators(validators):
    for validator in validators:
        if isinstance(validator, (tuple, list)):
            validator, options = validator
        else:
            validator, options = validator, {}

        if '.' not in validator:
            validator = 'django.contrib.auth.password_validation.%s' % validator

        yield dict(NAME=validator, OPTIONS=options)