"""
Simple Workflow Utils
=====================

Utils for Amazon Simple Workflow operations.
"""

import json

import boto3

from ows_accounting import config
from ows_accounting.constants import header
from ows_accounting.constants import utils as constants


def _get_client():
    """Get aws swf client

    Returns:
        Boto3 SWF client
    """

    return boto3.client('swf')


def generate_workflow_id(prefix, **params):
    """Generate workflow id from params

    Args:
        prefix (str): prefix of workflow id.
        params (dict): user params for the workflow.

    Returns:
        str: workflow_id
    """
    template = (
        '{prefix}-{user_id}-{user_type}-{period_ids}-'
        '{transaction_types}-{locale}-{file_format}-'
        '{report_version}-{client_email}')
    workflow_id = template.format(
        prefix=prefix,
        **params
    )
    return workflow_id


def execute_workflow(workflow_id, correlation_id, **params):
    """Execute simple workflow.

    Example call:
        swf.execute_workflow(
           'custom_export_processing-accounting-18805-label-205-all-es_ES-txt',
           '868ae-83aa-8273-2874-1982',
           user_id='18805', user_type='label', period_ids='205',
           transaction_types='DT,DA', locale='es_ES', file_format='txt')

    Args:
        workflow_id (str): workflow id which uniquely identify each workflow.
        correlation_id (str): correlation_id in the header.
        params (dict): report specific params.
    """

    params[header.CORRELATION_ID] = '{}.1'.format(correlation_id)
    exe_start_to_close = constants.SWF_EXECUTION_START_TO_CLOSE_TIMEOUT
    task_start_to_close = constants.SWF_TASK_START_TO_CLOSE_TIMEOUT

    client = _get_client()
    client.start_workflow_execution(
        domain=config.SWF_DOMAIN,
        workflowId=workflow_id,
        workflowType={
            'name': config.CUSTOM_EXPORT_WORKFLOW_TYPE,
            'version': config.CUSTOM_EXPORT_WORKFLOW_TYPE_VERSION
        },
        taskList={
            'name': config.CUSTOM_EXPORT_TASKLIST
        },
        input=json.dumps(params, sort_keys=True),
        executionStartToCloseTimeout=str(exe_start_to_close),
        taskStartToCloseTimeout=str(task_start_to_close),
        childPolicy=constants.SWF_CHILD_POLICY)