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

import argparse
from datetime import datetime
from datetime import timedelta
import importlib
import json
import logging
import time

import boto.swf.layer1 as swf_layer1
import boto.swf.layer2 as swf
from garcon import activity
from garcon import decider

from analytics_aggregation import flows


def execute_flow(flow, context, output_file=None, **kwargs):
    """Launch the workflow execution.

    Args:
        flow (module): Garcon flow module.
        context (str): Initial context parsed from JSON.
        output_file: Optional path to file to store all args as well
            as workflow_id and run_id.
        kwargs: Extensible call API.
    """
    active_executions = swf_layer1.Layer1().list_open_workflow_executions(
        flow.domain, (datetime.now() - timedelta(days=1)).timestamp(),
        workflow_id=flow.name)
    if len(active_executions.get('executionInfos')):
        print(
            'Workflow {flow_name} already started, exit'.format(
                flow_name=flow.name))
        return

    start_kwargs = dict(
        workflow_id=flow.workflow_id(json.loads(context)),
        input=context)

    if hasattr(flow, 'timeout'):
        start_kwargs.update(execution_start_to_close_timeout=str(flow.timeout))

    execution = swf.WorkflowType(
        name=flow.name,
        domain=flow.domain,
        version=flow.version,
        task_list=flow.name).start(**start_kwargs)

    if output_file:
        with open(output_file, 'w') as out_file:
            start_kwargs.update(run_id=execution.runId)
            json.dump(start_kwargs, out_file)

    return execution


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

    Args:
        flow (module): Garcon flow module.
        kwargs (dict): 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 (module): Garcon flow module.
        kwargs (dict): Extensible call API.
    """
    worker = activity.ActivityWorker(flow)
    worker.run()


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


def garcon(*args):
    """Main entry point for the Garcon command line integration.

    Args:
        args (tuple): Args for the flow.
    """
    parser = argparse.ArgumentParser(description='Garcon command line util')
    parser.add_argument('cmd', choices=_COMMANDS.keys(),
                        help='garcon command')
    parser.add_argument('flow', choices=flows.__all__,
                        help='name of the flow')
    parser.add_argument('-c', '--context',
                        help='initial context [json]')
    parser.add_argument('-l', '--log_level',
                        help='logging level', default='error',
                        choices=['critical', 'error', 'warning', 'info',
                                 'debug'])
    parser.add_argument('-o', '--output_file',
                        help='full path to output file, if applicable')

    # parse cl args (allows easy unit testing)
    args = parser.parse_args(args) if args else parser.parse_args()

    # import the flow module
    flow = importlib.import_module(
        '.{}.flow'.format(args.flow), flows.__name__)

    # look for the flow class, if it exists, otherwise fall back
    # on the flow module itself.
    flow_class = getattr(flow, 'Flow', None)
    if flow_class:
        flow = flow_class()

    # execute command
    args.context = args.context or '{}'
    logging.basicConfig(level=getattr(logging, args.log_level.upper()))
    _COMMANDS[args.cmd](flow=flow,
                        context=args.context,
                        output_file=args.output_file)