# Copyright 2017 Catalyst IT Limited
#
#    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 oslo_log import log as logging
from pecan import rest
import requests
import wsmeext.pecan as wsme_pecan

from qinling.api.controllers.v1 import resources
from qinling.api.controllers.v1 import types
from qinling.db import api as db_api
from qinling import exceptions as exc
from qinling import rpc
from qinling.utils import rest_utils

LOG = logging.getLogger(__name__)


class ExecutionsController(rest.RestController):
    def __init__(self, *args, **kwargs):
        self.engine_client = rpc.get_engine_client()

        super(ExecutionsController, self).__init__(*args, **kwargs)

    @rest_utils.wrap_wsme_controller_exception
    @wsme_pecan.wsexpose(
        resources.Execution,
        body=resources.Execution,
        status_code=201
    )
    def post(self, execution):
        params = execution.to_dict()

        LOG.info("Creating execution. [execution=%s]", params)

        function_id = params['function_id']
        is_sync = params.get('sync', True)

        # Check if the service url is existing.
        try:
            mapping = db_api.get_function_service_mapping(function_id)
            LOG.debug('Found Service url for function: %s', function_id)

            func_url = '%s/execute' % mapping.service_url
            LOG.info('Invoke function %s, url: %s', function_id, func_url)

            r = requests.post(func_url, data=params.get('input'))
            params.update(
                {'status': 'success', 'output': {'result': r.json()}}
            )
            db_model = db_api.create_execution(params)

            return resources.Execution.from_dict(db_model.to_dict())
        except exc.DBEntityNotFoundError:
            pass

        func = db_api.get_function(function_id)
        runtime_id = func.runtime_id
        params.update({'status': 'running'})

        db_model = db_api.create_execution(params)

        self.engine_client.create_execution(
            db_model.id, function_id, runtime_id, input=params.get('input'),
            is_sync=is_sync
        )

        if is_sync:
            db_model = db_api.get_execution(db_model.id)

        return resources.Execution.from_dict(db_model.to_dict())

    @rest_utils.wrap_wsme_controller_exception
    @wsme_pecan.wsexpose(resources.Executions)
    def get_all(self):
        LOG.info("Get all executions.")

        executions = [resources.Execution.from_dict(db_model.to_dict())
                      for db_model in db_api.get_executions()]

        return resources.Executions(executions=executions)

    @rest_utils.wrap_wsme_controller_exception
    @wsme_pecan.wsexpose(resources.Execution, types.uuid)
    def get(self, id):
        LOG.info("Fetch execution [id=%s]", id)

        execution_db = db_api.get_execution(id)

        return resources.Execution.from_dict(execution_db.to_dict())

    @rest_utils.wrap_wsme_controller_exception
    @wsme_pecan.wsexpose(None, types.uuid, status_code=204)
    def delete(self, id):
        """Delete the specified Execution."""
        LOG.info("Delete execution [id=%s]", id)

        return db_api.delete_execution(id)