# Copyright European Organization for Nuclear Research (CERN) since 2012
#
# 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 json import dumps

from requests import post

from rucio.client.baseclient import BaseClient, choice
from rucio.common.exception import RucioException, UnsupportedDIDType


class TouchClient(BaseClient):

    """
    Touch client class to send a trace that can be used to
    update accessed_at for file or dataset DIDs
    """

    DIDS_BASEURL = 'dids'
    TRACES_BASEURL = 'traces'

    def touch(self, scope, name, rse=None):
        """
        Sends a touch trace for a given file or dataset.

        :param scope: the scope of the file/dataset to update.
        :param name: the name of file/dataset to update.
        :param rse: optional parameter if a specific replica should be touched.
        :raises DataIdentifierNotFound: if given dids does not exist.
        :raises RSENotFound: if rse is not None and given rse does not exist.
        :raises UnsupportedDIDType: if type of the given DID is not FILE or DATASET.
        :raises RucioException: if trace could not be sent successfully.
        """

        trace = {}

        trace['eventType'] = 'touch'
        trace['clientState'] = 'DONE'
        trace['account'] = self.account
        if self.vo != 'def':
            trace['vo'] = self.vo

        if rse:
            self.get_rse(rse)  # pylint: disable=no-member

            trace['localSite'] = trace['remoteSite'] = rse

        info = self.get_did(scope, name)  # pylint: disable=no-member

        if info['type'] == 'CONTAINER':
            raise UnsupportedDIDType("%s:%s is a container." % (scope, name))

        if info['type'] == 'FILE':
            trace['scope'] = scope
            trace['filename'] = name
        elif info['type'] == 'DATASET':
            trace['datasetScope'] = scope
            trace['dataset'] = name

        url = '%s/%s/' % (choice(self.list_hosts), self.TRACES_BASEURL)

        try:
            post(url, verify=False, data=dumps(trace))
        except Exception as error:
            raise RucioException("Could not send trace. " + str(error))