# Copyright 2018 AT&T Intellectual Property.  All other 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 logging

LOG = logging.getLogger(__name__)


class XcomPuller(object):
    """XcomPuller provides a common source to get reused xcom values

    One XcomPuller should be created per task.
    Note: xcom values are found by using the current task instance
        and finding the <dag_name>.<task_name> that the xcom was added
        to the workflow.
        The point of this class is to keep all this very configurable
        naming in one place as much as possible so that changes to
        the dag names and step names have less places to update.
    """

    def __init__(self, main_dag_name, task_instance):
        self.mdn = main_dag_name
        self.ti = task_instance

    def _get_xcom(self, source_task, dag_id=None, key=None, log_result=True):
        """Find a particular xcom value"""
        if dag_id is None:
            source_dag = self.mdn
        else:
            source_dag = "{}.{}".format(self.mdn, dag_id)
        LOG.info("Retrieving xcom from %s.%s with key %s",
                 source_dag,
                 source_task,
                 key)
        xcom_val = self.ti.xcom_pull(task_ids=source_task,
                                     dag_id=source_dag,
                                     key=key)
        if log_result:
            # log the xcom value - don't put large values in xcom!
            LOG.info(xcom_val)

        return xcom_val

    def get_deployment_configuration(self):
        """Retrieve the deployment configuration dictionary"""
        source_task = 'get_deployment_configuration'
        source_dag = 'dag_deployment_configuration'
        key = None
        return self._get_xcom(source_task=source_task,
                              dag_id=source_dag,
                              key=key)

    def get_action_info(self):
        """Retrive the action and action parameter info dictionary

        Extract information related to current workflow. This is a dictionary
        that contains information about the workflow such as action_id, name
        and other related parameters
        """
        source_task = 'action_xcom'
        source_dag = None
        key = 'action'
        return self._get_xcom(source_task=source_task,
                              dag_id=source_dag,
                              key=key)

    def get_design_version(self):
        """Retrieve the design version being used for this workflow"""
        source_task = 'deckhand_get_design_version'
        source_dag = 'deckhand_get_design_version'
        key = None
        return self._get_xcom(source_task=source_task,
                              dag_id=source_dag,
                              key=key)