from __future__ import unicode_literals
from oauthlib.oauth2.rfc6749 import tokens
from oauthlib.oauth2.rfc6749.clients.web_application import WebApplicationClient
from flask_dance.consumer import OAuth2ConsumerBlueprint
from functools import partial
from flask.globals import LocalProxy, _lookup_app_object
try:
    from flask import _app_ctx_stack as stack
except ImportError:
    from flask import _request_ctx_stack as stack

__maintainer__ = "Ryan Schaffer <schaffer.ry@gmail.com>"

AUTH_HEADER = 'auth_header'
URI_QUERY = 'query'
BODY = 'body'
ZOHO_TOKEN_HEADER = 'Zoho-oauthtoken'


def make_zoho_blueprint(
        client_id=None, client_secret=None, scope=None, redirect_url=None, offline=False,
        redirect_to=None, login_url=None, session_class=None, backend=None, reprompt_consent=False):
    """
    Make a blueprint for authenticating with Zoho using OAuth 2. This requires
    a client ID and client secret from Zoho. You should either pass them to
    this constructor, or make sure that your Flask application config defines
    them, using the variables ZOHO_OAUTH_CLIENT_ID and ZOHO_OAUTH_CLIENT_SECRET.
    IMPORTANT: Configuring the base_url is not supported in this config.

    Args:
        client_id (str): The client ID for your application on Zoho.
        client_secret (str): The client secret for your application on Zoho
        scope (list, optional): list of scopes (str) for the OAuth token
        redirect_url (str): the URL to redirect to after the authentication
            dance is complete
        redirect_to (str): if ``redirect_url`` is not defined, the name of the
            view to redirect to after the authentication dance is complete.
            The actual URL will be determined by :func:`flask.url_for`
        login_url (str, optional): the URL path for the ``login`` view.
            Defaults to ``/zoho``
        authorized_url (str, optional): the URL path for the ``authorized`` view.
            Defaults to ``/zoho/authorized``.
        session_class (class, optional): The class to use for creating a
            Requests session. Defaults to
            :class:`~flask_dance.consumer.requests.OAuth2Session`.
        backend: A storage backend class, or an instance of a storage
                backend class, to use for this blueprint. Defaults to
                :class:`~flask_dance.consumer.backend.session.SessionBackend`.
        offline (bool): Whether to request `offline access`
            for the OAuth token. Defaults to False
        reprompt_consent (bool): If True, force Zoho to re-prompt the user
            for their consent, even if the user has already given their
            consent. Defaults to False
    :rtype: :class:`~flask_dance.consumer.OAuth2ConsumerBlueprint`
    :returns: A :ref:`blueprint <flask:blueprints>` to attach to your Flask app.
    """
    scope = scope or ['ZohoCRM.users.all']
    base_url = "https://www.zohoapis.com/"
    client = ZohoWebClient(client_id, token_type=ZOHO_TOKEN_HEADER)
    authorization_url_params = {}
    authorization_url_params['access_type'] = 'offline' if offline else 'online'
    if reprompt_consent:
        authorization_url_params["prompt"] = "consent"
    zoho_bp = OAuth2ConsumerBlueprint('zoho', __name__,
                                      client_id=client_id,
                                      client_secret=client_secret,
                                      client=client,
                                      scope=scope,
                                      base_url=base_url,
                                      token_url="https://accounts.zoho.com/oauth/v2/token",
                                      authorization_url="https://accounts.zoho.com/oauth/v2/auth",
                                      authorization_url_params=authorization_url_params,
                                      redirect_url=redirect_url,
                                      redirect_to=redirect_to,
                                      login_url=login_url,
                                      session_class=session_class,
                                      backend=backend
                                      )
    if not client_id:
        zoho_bp.from_config["client_id"] = "ZOHO_OAUTH_CLIENT_ID"
    if not client_secret:
        zoho_bp.from_config["client_secret"] = "ZOHO_OAUTH_CLIENT_SECRET"


    @zoho_bp.before_app_request
    def set_applocal_session():
        ctx = stack.top
        ctx.zoho_oauth = zoho_bp.session

    return zoho_bp


zoho = LocalProxy(partial(_lookup_app_object, "zoho_oauth"))


class ZohoWebClient(WebApplicationClient):
    """
    Remove the requirement that token_types adhere to OAuth Standard
    """
    @property
    def token_types(self):
        return {
            'Bearer': self._add_bearer_token,
            'MAC': self._add_mac_token,
            ZOHO_TOKEN_HEADER: self._add_zoho_token
        }

    def _add_zoho_token(self, uri, http_method='GET', body=None,
                          headers=None, token_placement=None):
        """Add a zoho token to the request uri, body or authorization header. follows bearer pattern"""
        headers = self.prepare_zoho_headers(self.access_token, headers)
        return uri, headers, body

    @staticmethod
    def prepare_zoho_headers(token, headers=None):
        """Add a `Zoho Token`_ to the request URI.
        Recommended method of passing bearer tokens.

        Authorization: Zoho-oauthtoken h480djs93hd8

        .. _`Zoho-oauthtoken Token`: custom zoho token
        """
        headers = headers or {}
        headers['Authorization'] = '{token_header} {token}'.format(token_header=ZOHO_TOKEN_HEADER, token=token)
        return headers
