# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# 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.

from oslo_config import cfg
from oslo_log import log
from pecan import hooks
from six.moves import http_client

from iotronic.common import context
from iotronic.common import policy
from iotronic.conductor import rpcapi
from iotronic.db import api as dbapi

LOG = log.getLogger(__name__)

CHECKED_DEPRECATED_POLICY_ARGS = False


class ConfigHook(hooks.PecanHook):
    """Attach the config object to the request so controllers can get to it."""

    def before(self, state):
        state.request.cfg = cfg.CONF


class DBHook(hooks.PecanHook):
    """Attach the dbapi object to the request so controllers can get to it."""

    def before(self, state):
        state.request.dbapi = dbapi.get_instance()


class ContextHook(hooks.PecanHook):
    """Configures a request context and attaches it to the request."""

    def __init__(self, public_api_routes):
        self.public_api_routes = public_api_routes
        super(ContextHook, self).__init__()

    def before(self, state):
        headers = state.request.headers

        is_public_api = state.request.environ.get(
            'is_public_api', False)
        ctx = context.RequestContext.from_environ(
            state.request.environ,
            is_public_api=is_public_api,
            project_id=headers.get('X-Project-Id'),
            user_id=headers.get('X-User-Id'),
            )

        # Do not pass any token with context for noauth mode
        if cfg.CONF.auth_strategy == 'noauth':
            ctx.auth_token = None

        creds = ctx.to_policy_values()

        is_admin = policy.check('is_admin', creds, creds)
        ctx.is_admin = is_admin

        state.request.context = ctx

    def after(self, state):
        if state.request.context == {}:
            # An incorrect url path will not create RequestContext
            return
        # NOTE(lintan): RequestContext will generate a request_id if no one
        # passing outside, so it always contain a request_id.
        request_id = state.request.context.request_id
        state.response.headers['Openstack-Request-Id'] = request_id


class RPCHook(hooks.PecanHook):
    """Attach the rpcapi object to the request so controllers can get to it."""

    def before(self, state):
        state.request.rpcapi = rpcapi.ConductorAPI()


class NoExceptionTracebackHook(hooks.PecanHook):
    """Workaround rpc.common: deserialize_remote_exception.

    deserialize_remote_exception builds rpc exception traceback into error
    message which is then sent to the client. Such behavior is a security
    concern so this hook is aimed to cut-off traceback from the error message.

    """

    # NOTE(max_lobur): 'after' hook used instead of 'on_error' because
    # 'on_error' never fired for wsme+pecan pair. wsme @wsexpose decorator
    # catches and handles all the errors, so 'on_error' dedicated for unhandled
    # exceptions never fired.
    def after(self, state):
        # Omit empty body. Some errors may not have body at this level yet.
        if not state.response.body:
            return

        # Do nothing if there is no error.
        # Status codes in the range 200 (OK) to 399 (400 = BAD_REQUEST) are not
        # an error.
        if (http_client.OK <= state.response.status_int <
                http_client.BAD_REQUEST):
            return

        json_body = state.response.json
        # Do not remove traceback when traceback config is set
        if cfg.CONF.debug_tracebacks_in_api:
            return

        faultstring = json_body.get('faultstring')
        traceback_marker = 'Traceback (most recent call last):'
        if faultstring and traceback_marker in faultstring:
            # Cut-off traceback.
            faultstring = faultstring.split(traceback_marker, 1)[0]
            # Remove trailing newlines and spaces if any.
            json_body['faultstring'] = faultstring.rstrip()
            # Replace the whole json. Cannot change original one because it's
            # generated on the fly.
            state.response.json = json_body


class PublicUrlHook(hooks.PecanHook):
    """Attach the right public_url to the request.

    Attach the right public_url to the request so resources can create
    links even when the API service is behind a proxy or SSL terminator.

    """

    def before(self, state):
        state.request.public_url = (cfg.CONF.api.public_endpoint or
                                    state.request.host_url)