#-----------------------------------------------------------------------------
# Copyright (c) Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Provide a mixin class to add authorization hooks to a request handler.

'''

#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

# Standard library imports
from urllib.parse import urljoin

# External imports
from tornado.web import RequestHandler

#-----------------------------------------------------------------------------
# Globals and constants
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__all__ = (
    'AuthRequestHandler',
)

#-----------------------------------------------------------------------------
# General API
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#-----------------------------------------------------------------------------
# Dev API
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class AuthRequestHandler(RequestHandler):
    ''' This mixin adds the expected Tornado authorization hooks:

    * get_login_url
    * get_current_user
    * prepare

    All of these delegate to the a :class:`~bokeh.serve.auth_provider.AuthProvider`
    configured on the Bokeh tornado application.

    '''

    def get_login_url(self):
        ''' Delegates to``get_login_url`` method of the auth provider, or the
        ``login_url`` attribute.

        '''
        auth_provider = self.application.auth_provider
        if auth_provider.get_login_url is not None:
            return auth_provider.get_login_url(self)
        if auth_provider.login_url is not None:
            # second arg must be lstrip'd to avoid dropping the prefix
            # (urljoin treats a leading-slash second arg as an absolute path and discards the base)
            return urljoin(self.application.prefix + "/", auth_provider.login_url.lstrip("/"))
        raise RuntimeError('login_url or get_login_url() must be supplied when authentication hooks are enabled')

    def get_current_user(self):
        ''' Delegate to the synchronous ``get_user`` method of the auth
        provider

        '''
        if self.application.auth_provider.get_user is not None:
            return self.application.auth_provider.get_user(self)
        return "default_user"

    async def prepare(self):
        ''' Async counterpart to ``get_current_user``

        '''
        if self.application.auth_provider.get_user_async is not None:
            self.current_user = await self.application.auth_provider.get_user_async(self)

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# Private API
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#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
