python source code of redirect_uri

#   Copyright 2020 Samuel Gulliksson
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0

#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
import warnings
from urllib.parse import urlparse


class RedirectUriConfig:
    def __init__(self, config):
        if 'OIDC_REDIRECT_URI' in config:
            self._parse_redirect_uri(config['OIDC_REDIRECT_URI'])
        else:
            self._parse_legacy_config(config)

    def _parse_redirect_uri(self, redirect_uri):
        parsed = urlparse(redirect_uri)
        self.full_uri = redirect_uri
        self.endpoint = parsed.path.lstrip('/')

    def _parse_legacy_config(self, config):
        redirect_domain = config.get('OIDC_REDIRECT_DOMAIN', config.get('SERVER_NAME'))
        if not redirect_domain:
            raise ValueError("'OIDC_REDIRECT_URI' must be configured.")

        scheme = config.get('PREFERRED_URL_SCHEME', 'http')
        self.endpoint = config.get('OIDC_REDIRECT_ENDPOINT', 'redirect_uri').lstrip('/')
        self.full_uri = scheme + '://' + redirect_domain + '/'  + self.endpoint

        warnings.warn(
            "Please use 'OIDC_REDIRECT_URI' to configure the redirect_uri for flask-pyoidc. 'OIDC_REDIRECT_DOMAIN' and 'OIDC_REDIRECT_ENDPOINT' have been deprecated.",
            DeprecationWarning,
            stacklevel=2
        )