# Copyright 2012 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.

import copy

from oslo.utils import encodeutils
from oslo.utils import strutils
import six
import six.moves.urllib.parse as urlparse

from escalatorclient.common import utils
from escalatorclient.openstack.common.apiclient import base
from escalatorclient.common.http import HTTPClient

CREATE_PARAMS = ('id', 'name', 'description', 'type', 'version', 'size',
                 'checksum', 'status', 'os_status', 'version_patch')

DEFAULT_PAGE_SIZE = 200
VERSION_PARAMS = ('type')
SORT_DIR_VALUES = ('asc', 'desc')
SORT_KEY_VALUES = (
    'name', 'id', 'cluster_id', 'created_at', 'updated_at', 'status')

OS_REQ_ID_HDR = 'x-openstack-request-id'


class Version(base.Resource):

    def __repr__(self):
        return "<Version %s>" % self._info

    def update(self, **fields):
        self.manager.update(self, **fields)

    def delete(self, **kwargs):
        return self.manager.delete(self)

    def data(self, **kwargs):
        return self.manager.data(self, **kwargs)


class VersionManager(base.ManagerWithFind):
    resource_class = Version

    def get_version_client(self):
        endpoint = "http://127.0.0.1:19292"
        client = HTTPClient(endpoint)
        return client

    def _list(self, url, response_key, obj_class=None, body=None):
        version_client = self.get_version_client()
        resp, body = version_client.get(url)

        if obj_class is None:
            obj_class = self.resource_class

        data = body[response_key]
        return ([obj_class(self, res, loaded=True) for res in data if res],
                resp)

    def _version_meta_from_headers(self, headers):
        meta = {'properties': {}}
        safe_decode = encodeutils.safe_decode
        for key, value in six.iteritems(headers):
            value = safe_decode(value, incoming='utf-8')
            if key.startswith('x-image-meta-property-'):
                _key = safe_decode(key[22:], incoming='utf-8')
                meta['properties'][_key] = value
            elif key.startswith('x-image-meta-'):
                _key = safe_decode(key[13:], incoming='utf-8')
                meta[_key] = value

        for key in ['is_public', 'protected', 'deleted']:
            if key in meta:
                meta[key] = strutils.bool_from_string(meta[key])

        return self._format_version_meta_for_user(meta)

    def _version_meta_to_headers(self, fields):
        headers = {}
        fields_copy = copy.deepcopy(fields)
        for key, value in six.iteritems(fields_copy):
            headers['%s' % key] = utils.to_str(value)
        return headers

    @staticmethod
    def _format_version_meta_for_user(meta):
        for key in ['size', 'min_ram', 'min_disk']:
            if key in meta:
                try:
                    meta[key] = int(meta[key]) if meta[key] else 0
                except ValueError:
                    pass
        return meta

    def _build_params(self, parameters):
        params = {'limit': parameters.get('page_size', DEFAULT_PAGE_SIZE)}

        if 'marker' in parameters:
            params['marker'] = parameters['marker']

        sort_key = parameters.get('sort_key')
        if sort_key is not None:
            if sort_key in SORT_KEY_VALUES:
                params['sort_key'] = sort_key
            else:
                raise ValueError('sort_key must be one of the following: %s.'
                                 % ', '.join(SORT_KEY_VALUES))

        sort_dir = parameters.get('sort_dir')
        if sort_dir is not None:
            if sort_dir in SORT_DIR_VALUES:
                params['sort_dir'] = sort_dir
            else:
                raise ValueError('sort_dir must be one of the following: %s.'
                                 % ', '.join(SORT_DIR_VALUES))

        filters = parameters.get('filters', {})
        params.update(filters)

        return params

    def list(self, **kwargs):
        """Get a list of versions.

        :param page_size: number of items to request in each paginated request
        :param limit: maximum number of versions to return
        :param marker:begin returning versions that appear later in version
                       list than that represented by this version id
        :param filters: dict of direct comparison filters that mimics the
                        structure of an version object
        :param return_request_id: If an empty list is provided, populate this
                              list with the request ID value from the header
                              x-openstack-request-id
        :rtype: list of :class:`version`
        """
        absolute_limit = kwargs.get('limit')
        page_size = kwargs.get('page_size', DEFAULT_PAGE_SIZE)

        def paginate(qp, return_request_id=None):
            for param, value in six.iteritems(qp):
                if isinstance(value, six.string_types):
                    # Note(flaper87) Url encoding should
                    # be moved inside http utils, at least
                    # shouldn't be here.
                    #
                    # Making sure all params are str before
                    # trying to encode them
                    qp[param] = encodeutils.safe_decode(value)

            url = '/v1/versions?%s' % urlparse.urlencode(qp)
            versions, resp = self._list(url, "versions")

            if return_request_id is not None:
                return_request_id.append(resp.headers.get(OS_REQ_ID_HDR, None))

            for version in versions:
                yield version

        return_request_id = kwargs.get('return_req_id', None)

        params = self._build_params(kwargs)

        seen = 0
        while True:
            seen_last_page = 0
            filtered = 0
            for version in paginate(params, return_request_id):
                last_version = version.id

                if (absolute_limit is not None and
                        seen + seen_last_page >= absolute_limit):
                    # Note(kragniz): we've seen enough images
                    return
                else:
                    seen_last_page += 1
                    yield version

            seen += seen_last_page

            if seen_last_page + filtered == 0:
                # Note(kragniz): we didn't get any versions in the last page
                return

            if absolute_limit is not None and seen >= absolute_limit:
                # Note(kragniz): reached the limit of versions to return
                return

            if page_size and seen_last_page + filtered < page_size:
                # Note(kragniz): we've reached the last page of the versions
                return

            # Note(kragniz): there are more versions to come
            params['marker'] = last_version
            seen_last_page = 0

    def version(self, **kwargs):
        """Get internal or external version of escalator.

        TODO(bcwaldon): document accepted params
        """
        fields = {}
        for field in kwargs:
            if field in VERSION_PARAMS:
                fields[field] = kwargs[field]
            else:
                msg = 'install() got an unexpected keyword argument \'%s\''
                raise TypeError(msg % field)

        url = '/v1/versions'
        hdrs = self._version_meta_to_headers(fields)
        resp, body = self.client.post(url, headers=None, data=hdrs)
        return Version(self, body)