from django.conf import settings
from rest_framework.settings import perform_import

SWAGGER_DEFAULTS = {
    'DEFAULT_GENERATOR_CLASS': 'drf_yasg.generators.OpenAPISchemaGenerator',
    'DEFAULT_AUTO_SCHEMA_CLASS': 'drf_yasg.inspectors.SwaggerAutoSchema',

    'DEFAULT_FIELD_INSPECTORS': [
        'drf_yasg.inspectors.CamelCaseJSONFilter',
        'drf_yasg.inspectors.RecursiveFieldInspector',
        'drf_yasg.inspectors.ReferencingSerializerInspector',
        'drf_yasg.inspectors.ChoiceFieldInspector',
        'drf_yasg.inspectors.FileFieldInspector',
        'drf_yasg.inspectors.DictFieldInspector',
        'drf_yasg.inspectors.HiddenFieldInspector',
        'drf_yasg.inspectors.RelatedFieldInspector',
        'drf_yasg.inspectors.SerializerMethodFieldInspector',
        'drf_yasg.inspectors.SimpleFieldInspector',
        'drf_yasg.inspectors.StringDefaultFieldInspector',
    ],
    'DEFAULT_FILTER_INSPECTORS': [
        'drf_yasg.inspectors.CoreAPICompatInspector',
    ],
    'DEFAULT_PAGINATOR_INSPECTORS': [
        'drf_yasg.inspectors.DjangoRestResponsePagination',
        'drf_yasg.inspectors.CoreAPICompatInspector',
    ],

    'EXCLUDED_MEDIA_TYPES': ['html'],

    'DEFAULT_INFO': None,
    'DEFAULT_API_URL': None,

    'USE_SESSION_AUTH': True,
    'SECURITY_DEFINITIONS': {
        'basic': {
            'type': 'basic'
        }
    },
    'SECURITY_REQUIREMENTS': None,
    'LOGIN_URL': getattr(settings, 'LOGIN_URL', None),
    'LOGOUT_URL': getattr(settings, 'LOGOUT_URL', None),
    'SPEC_URL': None,
    'VALIDATOR_URL': '',

    'OPERATIONS_SORTER': None,
    'TAGS_SORTER': None,
    'DOC_EXPANSION': 'list',
    'DEEP_LINKING': False,
    'SHOW_EXTENSIONS': True,
    'DEFAULT_MODEL_RENDERING': 'model',
    'DEFAULT_MODEL_DEPTH': 3,
    'SHOW_COMMON_EXTENSIONS': True,
    'OAUTH2_REDIRECT_URL': None,
    'OAUTH2_CONFIG': {},
    'SUPPORTED_SUBMIT_METHODS': [
        'get',
        'put',
        'post',
        'delete',
        'options',
        'head',
        'patch',
        'trace'
    ],
    'DISPLAY_OPERATION_ID': True,
}

REDOC_DEFAULTS = {
    'SPEC_URL': None,
    'LAZY_RENDERING': False,
    'HIDE_HOSTNAME': False,
    'EXPAND_RESPONSES': 'all',
    'PATH_IN_MIDDLE': False,
    'NATIVE_SCROLLBARS': False,
    'REQUIRED_PROPS_FIRST': False,
}

IMPORT_STRINGS = [
    'DEFAULT_GENERATOR_CLASS',
    'DEFAULT_AUTO_SCHEMA_CLASS',
    'DEFAULT_FIELD_INSPECTORS',
    'DEFAULT_FILTER_INSPECTORS',
    'DEFAULT_PAGINATOR_INSPECTORS',
    'DEFAULT_INFO',
]


class AppSettings(object):
    """
    Stolen from Django Rest Framework, removed caching for easier testing
    """

    def __init__(self, user_settings, defaults, import_strings=None):
        self._user_settings = user_settings
        self.defaults = defaults
        self.import_strings = import_strings or []

    @property
    def user_settings(self):
        return getattr(settings, self._user_settings, {})

    def __getattr__(self, attr):
        if attr not in self.defaults:
            raise AttributeError("Invalid setting: '%s'" % attr)  # pragma: no cover

        try:
            # Check if present in user settings
            val = self.user_settings[attr]
        except KeyError:
            # Fall back to defaults
            val = self.defaults[attr]

        # Coerce import strings into classes
        if attr in self.import_strings:
            val = perform_import(val, attr)

        return val


#:
swagger_settings = AppSettings(
    user_settings='SWAGGER_SETTINGS',
    defaults=SWAGGER_DEFAULTS,
    import_strings=IMPORT_STRINGS,
)

#:
redoc_settings = AppSettings(
    user_settings='REDOC_SETTINGS',
    defaults=REDOC_DEFAULTS,
    import_strings=IMPORT_STRINGS,
)
