# Copyright 2011, OpenStack Foundation
# Copyright 2012, Red Hat, Inc.
# Copyright 2013 IBM Corp.
#
#    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 glance_store
from oslo.config import cfg
from oslo import messaging
from oslo.utils import excutils
from oslo.utils import timeutils
import webob

from glance.common import exception
from glance.common import utils
import glance.domain.proxy
import glance.openstack.common.log as logging

notifier_opts = [
    cfg.StrOpt('default_publisher_id', default="image.localhost",
               help='Default publisher_id for outgoing notifications.'),
]

CONF = cfg.CONF
CONF.register_opts(notifier_opts)

LOG = logging.getLogger(__name__)

_ALIASES = {
    'glance.openstack.common.rpc.impl_kombu': 'rabbit',
    'glance.openstack.common.rpc.impl_qpid': 'qpid',
    'glance.openstack.common.rpc.impl_zmq': 'zmq',
}


def get_transport():
    return messaging.get_transport(CONF, aliases=_ALIASES)


class Notifier(object):
    """Uses a notification strategy to send out messages about events."""

    def __init__(self):
        publisher_id = CONF.default_publisher_id
        self._transport = get_transport()
        self._notifier = messaging.Notifier(self._transport,
                                            publisher_id=publisher_id)

    def warn(self, event_type, payload):
        self._notifier.warn({}, event_type, payload)

    def info(self, event_type, payload):
        self._notifier.info({}, event_type, payload)

    def error(self, event_type, payload):
        self._notifier.error({}, event_type, payload)


def format_image_notification(image):
    """
    Given a glance.domain.Image object, return a dictionary of relevant
    notification information. We purposely do not include 'location'
    as it may contain credentials.
    """
    return {
        'id': image.image_id,
        'name': image.name,
        'status': image.status,
        'created_at': timeutils.isotime(image.created_at),
        'updated_at': timeutils.isotime(image.updated_at),
        'min_disk': image.min_disk,
        'min_ram': image.min_ram,
        'protected': image.protected,
        'checksum': image.checksum,
        'owner': image.owner,
        'disk_format': image.disk_format,
        'container_format': image.container_format,
        'size': image.size,
        'is_public': image.visibility == 'public',
        'properties': dict(image.extra_properties),
        'tags': list(image.tags),
        'deleted': False,
        'deleted_at': None,
    }


def format_task_notification(task):
    # NOTE(nikhil): input is not passed to the notifier payload as it may
    # contain sensitive info.
    return {'id': task.task_id,
            'type': task.type,
            'status': task.status,
            'result': None,
            'owner': task.owner,
            'message': None,
            'expires_at': timeutils.isotime(task.expires_at),
            'created_at': timeutils.isotime(task.created_at),
            'updated_at': timeutils.isotime(task.updated_at),
            'deleted': False,
            'deleted_at': None,
            }


class ImageRepoProxy(glance.domain.proxy.Repo):

    def __init__(self, image_repo, context, notifier):
        self.image_repo = image_repo
        self.context = context
        self.notifier = notifier
        proxy_kwargs = {'context': self.context, 'notifier': self.notifier}
        super(ImageRepoProxy, self).__init__(image_repo,
                                             item_proxy_class=ImageProxy,
                                             item_proxy_kwargs=proxy_kwargs)

    def save(self, image):
        super(ImageRepoProxy, self).save(image)
        self.notifier.info('image.update',
                           format_image_notification(image))

    def add(self, image):
        super(ImageRepoProxy, self).add(image)
        self.notifier.info('image.create',
                           format_image_notification(image))

    def remove(self, image):
        super(ImageRepoProxy, self).remove(image)
        payload = format_image_notification(image)
        payload['deleted'] = True
        payload['deleted_at'] = timeutils.isotime()
        self.notifier.info('image.delete', payload)


class ImageFactoryProxy(glance.domain.proxy.ImageFactory):
    def __init__(self, factory, context, notifier):
        kwargs = {'context': context, 'notifier': notifier}
        super(ImageFactoryProxy, self).__init__(factory,
                                                proxy_class=ImageProxy,
                                                proxy_kwargs=kwargs)


class ImageProxy(glance.domain.proxy.Image):

    def __init__(self, image, context, notifier):
        self.image = image
        self.context = context
        self.notifier = notifier
        super(ImageProxy, self).__init__(image)

    def _format_image_send(self, bytes_sent):
        return {
            'bytes_sent': bytes_sent,
            'image_id': self.image.image_id,
            'owner_id': self.image.owner,
            'receiver_tenant_id': self.context.tenant,
            'receiver_user_id': self.context.user,
        }

    def _get_chunk_data_iterator(self, data, chunk_size=None):
        sent = 0
        for chunk in data:
            yield chunk
            sent += len(chunk)

        if sent != (chunk_size or self.image.size):
            notify = self.notifier.error
        else:
            notify = self.notifier.info

        try:
            notify('image.send',
                   self._format_image_send(sent))
        except Exception as err:
            msg = (_("An error occurred during image.send"
                     " notification: %(err)s") % {'err': err})
            LOG.error(msg)

    def get_data(self, offset=0, chunk_size=None):
        # Due to the need of evaluating subsequent proxies, this one
        # should return a generator, the call should be done before
        # generator creation
        data = self.image.get_data(offset=offset, chunk_size=chunk_size)
        return self._get_chunk_data_iterator(data, chunk_size=chunk_size)

    def set_data(self, data, size=None):
        payload = format_image_notification(self.image)
        self.notifier.info('image.prepare', payload)
        try:
            self.image.set_data(data, size)
        except glance_store.StorageFull as e:
            msg = (_("Image storage media is full: %s") %
                   utils.exception_to_str(e))
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPRequestEntityTooLarge(explanation=msg)
        except glance_store.StorageWriteDenied as e:
            msg = (_("Insufficient permissions on image storage media: %s")
                   % utils.exception_to_str(e))
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPServiceUnavailable(explanation=msg)
        except ValueError as e:
            msg = (_("Cannot save data for image %(image_id)s: %(error)s") %
                   {'image_id': self.image.image_id,
                    'error': utils.exception_to_str(e)})
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPBadRequest(
                explanation=utils.exception_to_str(e))
        except exception.Duplicate as e:
            msg = (_("Unable to upload duplicate image data for image"
                     "%(image_id)s: %(error)s") %
                   {'image_id': self.image.image_id,
                    'error': utils.exception_to_str(e)})
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPConflict(explanation=msg)
        except exception.Forbidden as e:
            msg = (_("Not allowed to upload image data for image %(image_id)s:"
                     " %(error)s") % {'image_id': self.image.image_id,
                                      'error': utils.exception_to_str(e)})
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPForbidden(explanation=msg)
        except exception.NotFound as e:
            msg = (_("Image %(image_id)s could not be found after upload."
                     " The image may have been deleted during the upload:"
                     " %(error)s") % {'image_id': self.image.image_id,
                                      'error': utils.exception_to_str(e)})
            self.notifier.error('image.upload', msg)
            raise webob.exc.HTTPNotFound(explanation=utils.exception_to_str(e))
        except webob.exc.HTTPError as e:
            with excutils.save_and_reraise_exception():
                msg = (_("Failed to upload image data for image %(image_id)s"
                         " due to HTTP error: %(error)s") %
                       {'image_id': self.image.image_id,
                        'error': utils.exception_to_str(e)})
                self.notifier.error('image.upload', msg)
        except Exception as e:
            with excutils.save_and_reraise_exception():
                msg = (_("Failed to upload image data for image %(image_id)s "
                         "due to internal error: %(error)s") %
                       {'image_id': self.image.image_id,
                        'error': utils.exception_to_str(e)})
                self.notifier.error('image.upload', msg)
        else:
            payload = format_image_notification(self.image)
            self.notifier.info('image.upload', payload)
            self.notifier.info('image.activate', payload)


class TaskRepoProxy(glance.domain.proxy.TaskRepo):

    def __init__(self, task_repo, context, notifier):
        self.task_repo = task_repo
        self.context = context
        self.notifier = notifier
        proxy_kwargs = {'context': self.context, 'notifier': self.notifier}
        super(TaskRepoProxy, self).__init__(task_repo,
                                            task_proxy_class=TaskProxy,
                                            task_proxy_kwargs=proxy_kwargs)

    def add(self, task):
        self.notifier.info('task.create',
                           format_task_notification(task))
        super(TaskRepoProxy, self).add(task)

    def remove(self, task):
        payload = format_task_notification(task)
        payload['deleted'] = True
        payload['deleted_at'] = timeutils.isotime()
        self.notifier.info('task.delete', payload)
        super(TaskRepoProxy, self).remove(task)


class TaskStubRepoProxy(glance.domain.proxy.TaskStubRepo):

    def __init__(self, task_stub_repo, context, notifier):
        self.task_stub_repo = task_stub_repo
        self.context = context
        self.notifier = notifier
        proxy_kwargs = {'context': self.context, 'notifier': self.notifier}
        super(TaskStubRepoProxy, self).__init__(
            task_stub_repo,
            task_stub_proxy_class=TaskStubProxy,
            task_stub_proxy_kwargs=proxy_kwargs)


class TaskFactoryProxy(glance.domain.proxy.TaskFactory):
    def __init__(self, task_factory, context, notifier):
        kwargs = {'context': context, 'notifier': notifier}
        super(TaskFactoryProxy, self).__init__(
            task_factory,
            task_proxy_class=TaskProxy,
            task_proxy_kwargs=kwargs)


class TaskProxy(glance.domain.proxy.Task):

    def __init__(self, task, context, notifier):
        self.task = task
        self.context = context
        self.notifier = notifier
        super(TaskProxy, self).__init__(task)

    def begin_processing(self):
        self.notifier.info(
            'task.processing',
            format_task_notification(self.task)
        )
        return super(TaskProxy, self).begin_processing()

    def succeed(self, result):
        self.notifier.info('task.success',
                           format_task_notification(self.task))
        return super(TaskProxy, self).succeed(result)

    def fail(self, message):
        self.notifier.info('task.failure',
                           format_task_notification(self.task))
        return super(TaskProxy, self).fail(message)

    def run(self, executor):
        self.notifier.info('task.run',
                           format_task_notification(self.task))
        return super(TaskProxy, self).run(executor)


class TaskStubProxy(glance.domain.proxy.TaskStub):

    def __init__(self, task, context, notifier):
        self.task = task
        self.context = context
        self.notifier = notifier
        super(TaskStubProxy, self).__init__(task)
