# Copyright 2010-2011 OpenStack Foundation
# All Rights Reserved.
#
#    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.

"""
Reference implementation registry server WSGI controller
"""

from oslo.config import cfg
from webob import exc

from glance.common import exception
from glance.common import utils
from glance.common import wsgi
import glance.db
import glance.openstack.common.log as logging
from glance.openstack.common import strutils
from glance.openstack.common import timeutils


LOG = logging.getLogger(__name__)

CONF = cfg.CONF

DISPLAY_FIELDS_IN_INDEX = ['id', 'name', 'size',
                           'disk_format', 'container_format',
                           'checksum']

SUPPORTED_FILTERS = ['name', 'status', 'container_format', 'disk_format',
                     'min_ram', 'min_disk', 'size_min', 'size_max',
                     'changes-since', 'protected']

SUPPORTED_SORT_KEYS = ('name', 'status', 'container_format', 'disk_format',
                       'size', 'id', 'created_at', 'updated_at')

SUPPORTED_SORT_DIRS = ('asc', 'desc')

SUPPORTED_PARAMS = ('limit', 'marker', 'sort_key', 'sort_dir')


def _normalize_image_location_for_db(image_data):
    """
    This function takes the legacy locations field and the newly added
    location_data field from the image_data values dictionary which flows
    over the wire between the registry and API servers and converts it
    into the location_data format only which is then consumable by the
    Image object.

    :param image_data: a dict of values representing information in the image
    :return: a new image data dict
    """
    if 'locations' not in image_data and 'location_data' not in image_data:
        image_data['locations'] = None
        return image_data

    locations = image_data.pop('locations', [])
    location_data = image_data.pop('location_data', [])

    location_data_dict = {}
    for l in locations:
        location_data_dict[l] = {}
    for l in location_data:
        location_data_dict[l['url']] = l['metadata']

    # NOTE(jbresnah) preserve original order.  tests assume original order,
    # should that be defined functionality
    ordered_keys = locations[:]
    for ld in location_data:
        if ld['url'] not in ordered_keys:
            ordered_keys.append(ld['url'])
    location_data = [{'url': l, 'metadata': location_data_dict[l]}
                     for l in ordered_keys]
    image_data['locations'] = location_data
    return image_data


class Controller(object):

    def __init__(self):
        self.db_api = glance.db.get_api()

    def _get_images(self, context, filters, **params):
        """Get images, wrapping in exception if necessary."""
        # NOTE(markwash): for backwards compatibility, is_public=True for
        # admins actually means "treat me as if I'm not an admin and show me
        # all my images"
        if context.is_admin and params.get('is_public') is True:
            params['admin_as_user'] = True
            del params['is_public']
        try:
            return self.db_api.image_get_all(context, filters=filters,
                                             **params)
        except exception.NotFound:
            LOG.info(_("Invalid marker. Image %(id)s could not be "
                       "found.") % {'id': params.get('marker')})
            msg = _("Invalid marker. Image could not be found.")
            raise exc.HTTPBadRequest(explanation=msg)
        except exception.Forbidden:
            LOG.info(_("Access denied to image %(id)s but returning "
                       "'not found'") % {'id': params.get('marker')})
            msg = _("Invalid marker. Image could not be found.")
            raise exc.HTTPBadRequest(explanation=msg)
        except Exception:
            LOG.exception(_("Unable to get images"))
            raise

    def index(self, req):
        """Return a basic filtered list of public, non-deleted images

        :param req: the Request object coming from the wsgi layer
        :retval a mapping of the following form::

            dict(images=[image_list])

        Where image_list is a sequence of mappings::

            {
            'id': <ID>,
            'name': <NAME>,
            'size': <SIZE>,
            'disk_format': <DISK_FORMAT>,
            'container_format': <CONTAINER_FORMAT>,
            'checksum': <CHECKSUM>
            }
        """
        params = self._get_query_params(req)
        images = self._get_images(req.context, **params)

        results = []
        for image in images:
            result = {}
            for field in DISPLAY_FIELDS_IN_INDEX:
                result[field] = image[field]
            results.append(result)

        LOG.info(_("Returning image list"))
        return dict(images=results)

    def detail(self, req):
        """Return a filtered list of public, non-deleted images in detail

        :param req: the Request object coming from the wsgi layer
        :retval a mapping of the following form::

            dict(images=[image_list])

        Where image_list is a sequence of mappings containing
        all image model fields.
        """
        params = self._get_query_params(req)

        images = self._get_images(req.context, **params)
        image_dicts = [make_image_dict(i) for i in images]
        LOG.info(_("Returning detailed image list"))
        return dict(images=image_dicts)

    def _get_query_params(self, req):
        """Extract necessary query parameters from http request.

        :param req: the Request object coming from the wsgi layer
        :retval dictionary of filters to apply to list of images
        """
        params = {
            'filters': self._get_filters(req),
            'limit': self._get_limit(req),
            'sort_key': self._get_sort_key(req),
            'sort_dir': self._get_sort_dir(req),
            'marker': self._get_marker(req),
        }

        if req.context.is_admin:
            # Only admin gets to look for non-public images
            params['is_public'] = self._get_is_public(req)

        for key, value in params.items():
            if value is None:
                del params[key]

        # Fix for LP Bug #1132294
        # Ensure all shared images are returned in v1
        params['member_status'] = 'all'
        return params

    def _get_filters(self, req):
        """Return a dictionary of query param filters from the request

        :param req: the Request object coming from the wsgi layer
        :retval a dict of key/value filters
        """
        filters = {}
        properties = {}

        for param in req.params:
            if param in SUPPORTED_FILTERS:
                filters[param] = req.params.get(param)
            if param.startswith('property-'):
                _param = param[9:]
                properties[_param] = req.params.get(param)

        if 'changes-since' in filters:
            isotime = filters['changes-since']
            try:
                filters['changes-since'] = timeutils.parse_isotime(isotime)
            except ValueError:
                raise exc.HTTPBadRequest(_("Unrecognized changes-since value"))

        if 'protected' in filters:
            value = self._get_bool(filters['protected'])
            if value is None:
                raise exc.HTTPBadRequest(_("protected must be True, or "
                                           "False"))

            filters['protected'] = value

        # only allow admins to filter on 'deleted'
        if req.context.is_admin:
            deleted_filter = self._parse_deleted_filter(req)
            if deleted_filter is not None:
                filters['deleted'] = deleted_filter
            elif 'changes-since' not in filters:
                filters['deleted'] = False
        elif 'changes-since' not in filters:
            filters['deleted'] = False

        if properties:
            filters['properties'] = properties

        return filters

    def _get_limit(self, req):
        """Parse a limit query param into something usable."""
        try:
            limit = int(req.params.get('limit', CONF.limit_param_default))
        except ValueError:
            raise exc.HTTPBadRequest(_("limit param must be an integer"))

        if limit < 0:
            raise exc.HTTPBadRequest(_("limit param must be positive"))

        return min(CONF.api_limit_max, limit)

    def _get_marker(self, req):
        """Parse a marker query param into something usable."""
        marker = req.params.get('marker', None)

        if marker and not utils.is_uuid_like(marker):
            msg = _('Invalid marker format')
            raise exc.HTTPBadRequest(explanation=msg)

        return marker

    def _get_sort_key(self, req):
        """Parse a sort key query param from the request object."""
        sort_key = req.params.get('sort_key', None)
        if sort_key is not None and sort_key not in SUPPORTED_SORT_KEYS:
            _keys = ', '.join(SUPPORTED_SORT_KEYS)
            msg = _("Unsupported sort_key. Acceptable values: %s") % (_keys,)
            raise exc.HTTPBadRequest(explanation=msg)
        return sort_key

    def _get_sort_dir(self, req):
        """Parse a sort direction query param from the request object."""
        sort_dir = req.params.get('sort_dir', None)
        if sort_dir is not None and sort_dir not in SUPPORTED_SORT_DIRS:
            _keys = ', '.join(SUPPORTED_SORT_DIRS)
            msg = _("Unsupported sort_dir. Acceptable values: %s") % (_keys,)
            raise exc.HTTPBadRequest(explanation=msg)
        return sort_dir

    def _get_bool(self, value):
        value = value.lower()
        if value == 'true' or value == '1':
            return True
        elif value == 'false' or value == '0':
            return False

        return None

    def _get_is_public(self, req):
        """Parse is_public into something usable."""
        is_public = req.params.get('is_public', None)

        if is_public is None:
            # NOTE(vish): This preserves the default value of showing only
            #             public images.
            return True
        elif is_public.lower() == 'none':
            return None

        value = self._get_bool(is_public)
        if value is None:
            raise exc.HTTPBadRequest(_("is_public must be None, True, or "
                                       "False"))

        return value

    def _parse_deleted_filter(self, req):
        """Parse deleted into something usable."""
        deleted = req.params.get('deleted')
        if deleted is None:
            return None
        return strutils.bool_from_string(deleted)

    def show(self, req, id):
        """Return data about the given image id."""
        try:
            image = self.db_api.image_get(req.context, id)
            msg = _("Successfully retrieved image %(id)s")
            LOG.info(msg % {'id': id})
        except exception.NotFound:
            msg = _("Image %(id)s not found")
            LOG.info(msg % {'id': id})
            raise exc.HTTPNotFound()
        except exception.Forbidden:
            # If it's private and doesn't belong to them, don't let on
            # that it exists
            msg = _("Access denied to image %(id)s but returning 'not found'")
            LOG.info(msg % {'id': id})
            raise exc.HTTPNotFound()
        except Exception:
            LOG.exception(_("Unable to show image %s"), id)
            raise

        return dict(image=make_image_dict(image))

    @utils.mutating
    def delete(self, req, id):
        """Deletes an existing image with the registry.

        :param req: wsgi Request object
        :param id:  The opaque internal identifier for the image

        :retval Returns 200 if delete was successful, a fault if not. On
        success, the body contains the deleted image information as a mapping.
        """
        try:
            deleted_image = self.db_api.image_destroy(req.context, id)
            msg = _("Successfully deleted image %(id)s")
            LOG.info(msg % {'id': id})
            return dict(image=make_image_dict(deleted_image))
        except exception.ForbiddenPublicImage:
            msg = _("Delete denied for public image %(id)s")
            LOG.info(msg % {'id': id})
            raise exc.HTTPForbidden()
        except exception.Forbidden:
            # If it's private and doesn't belong to them, don't let on
            # that it exists
            msg = _("Access denied to image %(id)s but returning 'not found'")
            LOG.info(msg % {'id': id})
            return exc.HTTPNotFound()
        except exception.NotFound:
            msg = _("Image %(id)s not found")
            LOG.info(msg % {'id': id})
            return exc.HTTPNotFound()
        except Exception:
            LOG.exception(_("Unable to delete image %s"), id)
            raise

    @utils.mutating
    def create(self, req, body):
        """Registers a new image with the registry.

        :param req: wsgi Request object
        :param body: Dictionary of information about the image

        :retval Returns the newly-created image information as a mapping,
                which will include the newly-created image's internal id
                in the 'id' field
        """
        image_data = body['image']

        # Ensure the image has a status set
        image_data.setdefault('status', 'active')

        # Set up the image owner
        if not req.context.is_admin or 'owner' not in image_data:
            image_data['owner'] = req.context.owner

        image_id = image_data.get('id')
        if image_id and not utils.is_uuid_like(image_id):
            msg = _("Rejecting image creation request for invalid image "
                    "id '%(bad_id)s'")
            LOG.info(msg % {'bad_id': image_id})
            msg = _("Invalid image id format")
            return exc.HTTPBadRequest(explanation=msg)

        if 'location' in image_data:
            image_data['locations'] = [image_data.pop('location')]

        try:
            image_data = _normalize_image_location_for_db(image_data)
            image_data = self.db_api.image_create(req.context, image_data)
            image_data = dict(image=make_image_dict(image_data))
            msg = _("Successfully created image %(id)s") % image_data['image']
            LOG.info(msg)
            return image_data
        except exception.Duplicate:
            msg = _("Image with identifier %s already exists!") % image_id
            LOG.error(msg)
            return exc.HTTPConflict(msg)
        except exception.Invalid as e:
            msg = (_("Failed to add image metadata. "
                     "Got error: %(e)s") % {'e': e})
            LOG.error(msg)
            return exc.HTTPBadRequest(msg)
        except Exception:
            LOG.exception(_("Unable to create image %s"), image_id)
            raise

    @utils.mutating
    def update(self, req, id, body):
        """Updates an existing image with the registry.

        :param req: wsgi Request object
        :param body: Dictionary of information about the image
        :param id:  The opaque internal identifier for the image

        :retval Returns the updated image information as a mapping,
        """
        image_data = body['image']
        from_state = body.get('from_state', None)

        # Prohibit modification of 'owner'
        if not req.context.is_admin and 'owner' in image_data:
            del image_data['owner']

        if 'location' in image_data:
            image_data['locations'] = [image_data.pop('location')]

        purge_props = req.headers.get("X-Glance-Registry-Purge-Props", "false")
        try:
            LOG.debug(_("Updating image %(id)s with metadata: "
                        "%(image_data)r"), {'id': id,
                                            'image_data': image_data})
            image_data = _normalize_image_location_for_db(image_data)
            if purge_props == "true":
                purge_props = True
            else:
                purge_props = False

            updated_image = self.db_api.image_update(req.context, id,
                                                     image_data,
                                                     purge_props=purge_props,
                                                     from_state=from_state)

            msg = _("Updating metadata for image %(id)s")
            LOG.info(msg % {'id': id})
            return dict(image=make_image_dict(updated_image))
        except exception.Invalid as e:
            msg = (_("Failed to update image metadata. "
                     "Got error: %(e)s") % {'e': e})
            LOG.error(msg)
            return exc.HTTPBadRequest(msg)
        except exception.NotFound:
            msg = _("Image %(id)s not found")
            LOG.info(msg % {'id': id})
            raise exc.HTTPNotFound(body='Image not found',
                                   request=req,
                                   content_type='text/plain')
        except exception.ForbiddenPublicImage:
            msg = _("Update denied for public image %(id)s")
            LOG.info(msg % {'id': id})
            raise exc.HTTPForbidden()
        except exception.Forbidden:
            # If it's private and doesn't belong to them, don't let on
            # that it exists
            msg = _("Access denied to image %(id)s but returning 'not found'")
            LOG.info(msg % {'id': id})
            raise exc.HTTPNotFound(body='Image not found',
                                   request=req,
                                   content_type='text/plain')
        except exception.Conflict as e:
            LOG.info(unicode(e))
            raise exc.HTTPConflict(body='Image operation conflicts',
                                   request=req,
                                   content_type='text/plain')
        except Exception:
            LOG.exception(_("Unable to update image %s"), id)
            raise


def _limit_locations(image):
    locations = image.pop('locations', [])
    try:
        image['location'] = locations[0]['url']
    except IndexError:
        image['location'] = None
    image['location_data'] = locations


def make_image_dict(image):
    """Create a dict representation of an image which we can use to
    serialize the image.
    """

    def _fetch_attrs(d, attrs):
        return dict([(a, d[a]) for a in attrs
                    if a in d.keys()])

    # TODO(sirp): should this be a dict, or a list of dicts?
    # A plain dict is more convenient, but list of dicts would provide
    # access to created_at, etc
    properties = dict((p['name'], p['value'])
                      for p in image['properties'] if not p['deleted'])

    image_dict = _fetch_attrs(image, glance.db.IMAGE_ATTRS)
    image_dict['properties'] = properties
    _limit_locations(image_dict)

    return image_dict


def create_resource():
    """Images resource factory method."""
    deserializer = wsgi.JSONRequestDeserializer()
    serializer = wsgi.JSONResponseSerializer()
    return wsgi.Resource(Controller(), deserializer, serializer)
