# (c) Copyright 2014-2016 Hewlett-Packard Development Company, L.P.
#
# 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 requests

from oslo_serialization import jsonutils as json

from freezerclient import exceptions
from freezerclient import utils


class SessionManager(object):

    def __init__(self, client, verify=True):
        self.client = client
        self.endpoint = '{0}/v2/{1}/sessions/'.format(
            self.client.endpoint, self.client.project_id)
        self.verify = verify

    @property
    def headers(self):
        return utils.create_headers_for_request(self.client.auth_token)

    def create(self, doc, session_id=''):
        session_id = session_id or doc.get('session_id', '')
        endpoint = self.endpoint + session_id
        r = requests.post(endpoint,
                          data=json.dumps(doc),
                          headers=self.headers,
                          verify=self.verify)
        if r.status_code != 201:
            raise exceptions.ApiClientException(r)
        session_id = r.json()['session_id']
        return session_id

    def delete(self, session_id):
        endpoint = self.endpoint + session_id
        r = requests.delete(endpoint, headers=self.headers, verify=self.verify)
        if r.status_code != 204:
            raise exceptions.ApiClientException(r)

    def list_all(self, limit=10, offset=0, search=None):
        data = json.dumps(search) if search else None
        query = {'limit': int(limit), 'offset': int(offset)}
        r = requests.get(self.endpoint, headers=self.headers,
                         params=query, data=data, verify=self.verify)
        if r.status_code != 200:
            raise exceptions.ApiClientException(r)
        return r.json()['sessions']

    def list(self, limit=10, offset=0, search={}):
        new_search = search.copy()
        new_search['match'] = search.get('match', [])
        return self.list_all(limit, offset, new_search)

    def get(self, session_id):
        endpoint = self.endpoint + session_id
        r = requests.get(endpoint, headers=self.headers, verify=self.verify)
        if r.status_code == 200:
            return r.json()
        if r.status_code == 404:
            return None
        raise exceptions.ApiClientException(r)

    def update(self, session_id, update_doc):
        endpoint = self.endpoint + session_id
        r = requests.patch(endpoint,
                           headers=self.headers,
                           data=json.dumps(update_doc),
                           verify=self.verify)
        if r.status_code != 200:
            raise exceptions.ApiClientException(r)
        return r.json()['version']

    def add_job(self, session_id, job_id):
        # endpoint /v2/sessions/{sessions_id}/jobs/{job_id}
        endpoint = '{0}{1}/jobs/{2}'.format(self.endpoint, session_id, job_id)
        r = requests.put(endpoint,
                         headers=self.headers, verify=self.verify)
        if r.status_code != 204:
            raise exceptions.ApiClientException(r)
        return

    def remove_job(self, session_id, job_id):
        # endpoint /v2/sessions/{sessions_id}/jobs/{job_id}
        endpoint = '{0}{1}/jobs/{2}'.format(self.endpoint, session_id, job_id)
        retry = 5
        r = ''
        while retry:
            r = requests.delete(endpoint,
                                headers=self.headers, verify=self.verify)
            if r.status_code == 204:
                return
            retry -= 1
        raise exceptions.ApiClientException(r)

    def start_session(self, session_id, job_id, session_tag):
        """
        Informs the api that the client is starting the session
        identified by the session_id and request the session_tag
        to be incremented up to the requested value.
        The returned session_id could be:
         * current_tag + 1 if the session has started
         * > current_tag + 1 if the action had already been started
           by some other node and this node was out of sync

        :param session_id:
        :param job_id:
        :param session_tag: the new session_id
        :return: the response obj:
                 { result: string 'running' or 'error',
                  'session_tag': the new session_tag )
        """
        # endpoint /v2/sessions/{sessions_id}/action
        endpoint = '{0}{1}/action'.format(self.endpoint, session_id)
        doc = {"start": {
            "job_id": job_id,
            "current_tag": session_tag
        }}
        r = requests.post(endpoint,
                          headers=self.headers,
                          data=json.dumps(doc),
                          verify=self.verify)
        if r.status_code != 202:
            raise exceptions.ApiClientException(r)
        return r.json()

    def end_session(self, session_id, job_id, session_tag, result):
        """
        Informs the freezer service that the job has ended.
        Provides information about the job's result and the session tag

        :param session_id:
        :param job_id:
        :param session_tag:
        :param result:
        :return:
        """
        # endpoint /v2/sessions/{sessions_id}/action
        endpoint = '{0}{1}/action'.format(self.endpoint, session_id)
        doc = {"end": {
            "job_id": job_id,
            "current_tag": session_tag,
            "result": result
        }}
        r = requests.post(endpoint,
                          headers=self.headers,
                          data=json.dumps(doc),
                          verify=self.verify)
        if r.status_code != 202:
            raise exceptions.ApiClientException(r)
        return r.json()
