# --------------------------------------------------------------------------
#
# Copyright (c) Microsoft Corporation. All rights reserved.
#
# The MIT License (MIT)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the ""Software""), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
#
# --------------------------------------------------------------------------

import requests
from requests.auth import HTTPBasicAuth
import requests_oauthlib as oauth


class Authentication(object):
    """Default, simple auth object.
    Doesn't actually add any auth headers.
    """

    header = "Authorization"

    def signed_session(self):
        """Create requests session with any required auth headers
        applied.

        :rtype: requests.Session.
        """
        return requests.Session()


class BasicAuthentication(Authentication):
    """Implmentation of Basic Authentication.

    :param str username: Authentication username.
    :param str password: Authentication password.
    """

    def __init__(self, username, password):
        self.scheme = 'Basic'
        self.username = username
        self.password = password

    def signed_session(self):
        """Create requests session with any required auth headers
        applied.

        :rtype: requests.Session.
        """
        session = super(BasicAuthentication, self).signed_session()
        session.auth = HTTPBasicAuth(self.username, self.password)
        return session


class BasicTokenAuthentication(Authentication):
    """Simple Token Authentication.
    Does not adhere to OAuth, simply adds provided token as a header.

    :param dict token: Authentication token, must have 'access_token' key.
    """

    def __init__(self, token):
        self.scheme = 'Bearer'
        self.token = token

    def set_token(self):
        """Should be used to define the self.token attribute.

        In this implementation, does nothing since the token is statically provided
        at creation.
        """
        pass

    def signed_session(self):
        """Create requests session with any required auth headers
        applied.

        :rtype: requests.Session.
        """
        session = super(BasicTokenAuthentication, self).signed_session()
        header = "{} {}".format(self.scheme, self.token['access_token'])
        session.headers['Authorization'] = header
        return session


class OAuthTokenAuthentication(BasicTokenAuthentication):
    """OAuth Token Authentication.
    Requires that supplied token contains an expires_in field.

    :param str client_id: Account Client ID.
    :param dict token: OAuth2 token.
    """

    def __init__(self, client_id, token):
        self.scheme = 'Bearer'
        self.id = client_id
        self.token = token
        self.store_key = self.id

    def construct_auth(self):
        """Format token header.

        :rtype: str.
        """
        return "{} {}".format(self.scheme, self.token)

    def refresh_session(self):
        """Return updated session if token has expired, attempts to
        refresh using refresh token.

        :rtype: requests.Session.
        """
        return self.signed_session()

    def signed_session(self):
        """Create requests session with any required auth headers
        applied.

        :rtype: requests.Session.
        """
        return oauth.OAuth2Session(self.id, token=self.token)

class ApiKeyCredentials(Authentication):
    """Represent the ApiKey feature of Swagger.

    Dict should be dict[str, str] to be accepted by requests.

    :param dict[str, str] in_headers: Headers part of the ApiKey
    :param dict[str, str] in_query: ApiKey in the query as parameters.
    """
    def __init__(self, in_headers=None, in_query=None):
        if in_headers is None:
            in_headers = {}
        if in_query is None:
            in_query = {}

        if not in_headers and not in_query:
            raise ValueError("You need to define in_headers or in_query")

        self.in_headers = in_headers
        self.in_query = in_query

    def signed_session(self):
        """Create requests session with ApiKey.

        :rtype: requests.Session.
        """
        session = super(ApiKeyCredentials, self).signed_session()
        session.headers.update(self.in_headers)
        session.params.update(self.in_query)
        return session

class CognitiveServicesCredentials(ApiKeyCredentials):
    """Cognitive Services authentication.

    :param str subscription_key: The CS subscription key
    """

    _subscription_key_header = 'Ocp-Apim-Subscription-Key'

    def __init__(self, subscription_key):
        if not subscription_key:
            raise ValueError("Subscription key cannot be None")
        super(CognitiveServicesCredentials, self).__init__(
            in_headers={
                self._subscription_key_header: subscription_key,
                'X-BingApis-SDK-Client': 'Python-SDK'
            }
        )
