"""CLI functions to run decider, worker and exec processes."""

from argparse import ArgumentParser
from datetime import date
import sys
import time

import boto.swf.layer2 as swf

from garcon import activity
from garcon import decider

from flows import config
from flows.flow import MrSnowflake


def start(flow, context):
    """Start a flow.

    Args:
        flow (object): garcon flow
        context (str): the context to pass to the flow.

    Returns:
        WorkflowExecution: executing the workflow returns information about the
            execution.

    """
    workflow_id = flow.workflow_id()
    return swf.WorkflowType(
        name=flow.name, domain=flow.domain,
        version=config.SWF_VERSION, task_list=flow.name).start(
            workflow_id=workflow_id,
            execution_start_to_close_timeout=str(flow.timeout),
            input=context)


def run_decider(flow, **kwargs):
    """Launch the SWF decider process.

    Args:
        flow (object): garcon flow
        kwargs: extensible call api
    """
    worker = decider.DeciderWorker(flow)
    while True:
        worker.run()
        time.sleep(1)


def run_activity_worker(flow, **kwargs):
    """Launch the activity worker process.

    Args:
        flow (object): garcon flow
        kwargs: extensible call api
    """
    worker = activity.ActivityWorker(flow)
    worker.run()


_COMMANDS = {
    'exec': start,
    'decider': run_decider,
    'worker': run_activity_worker
}


parser = ArgumentParser(
    description='MR-Snowflake flow command line.',
    epilog='© {year} The Orchard'.format(year=str(date.today().year)))

parser.add_argument(
    'cmd', help='garcon command (exec, decider, worker)',
    choices=list(_COMMANDS.keys()))

parser.add_argument(
    '-c', '--context', dest='context', help='initial context [json]',
    default='{}')


if __name__ == '__main__':
    args = parser.parse_args()

    if len(sys.argv) <= 1:
        parser.print_help()
        exit()

    flow = MrSnowflake()
    _COMMANDS[args.cmd](flow, context=args.context)