"""
Base Work Flow.

Base Work Flow class that new activity_detector flows should extend.
Standardizes generated workflow_id and adds default on_exception method.

Flows must override the decider method.
"""

import datetime
import logging
import os

import boto3
from botocore.config import Config
from ddtrace import tracer as ddtracer
from garcon import activity
import sentry_sdk

logger = logging.getLogger('garcon')


class BaseFlow:
    """Base Garcon Workflow that other Flows can extend."""

    @ddtracer.wrap(resource='flow.init', name='flow_init')
    def __init__(self, *, flow_name, version, swf_domain=None):
        """Initialize Flow.

        Args:
            flow_name (str):
            version (str):
            swf_domain (str):
        """
        if swf_domain:
            self.domain = swf_domain
        else:
            self.domain = get_domain()

        self.name = flow_name
        self.version = version

        self.client = boto3.client('swf', config=Config(
            connect_timeout=60,
            region_name=os.getenv('AWS_REGION'),
            read_timeout=180,
            retries={'max_attempts': 2}))

        self.create = activity.create(
            self.client, self.domain, self.name, version=self.version,
            on_exception=self.on_exception)

        # Sentry logging
        sentry_dsn = os.getenv('SENTRY_DSN')
        if sentry_dsn:
            sentry_sdk.init(sentry_dsn)
            self.sentry_client = sentry_sdk
        else:
            self.sentry_client = None

        if ddtracer.enabled:
            with ddtracer.trace('flow_init') as dd_span:
                dd_span.set_tag('flow_name', flow_name)
                dd_span.set_tag('swf_domain', self.domain)

    def on_exception(self, actor, exception):
        """Capture an exception that has occurred in the application.

        Args:
            actor (ActivityWorker, DeciderWorker): The actor that has received
                the exception.
            exception (Exception): The exception to capture.
        """
        if self.sentry_client:
            self.sentry_client.capture_exception()

        if isinstance(actor, activity.Activity):
            actor.logger.error(exception, exc_info=True)
        else:
            logger.error(exception, exc_info=True)

    def workflow_id(self, initial_context):
        """Generate workflow id.

        Assumes a unique workflow is defined by it's context date and
        defaults to today's date. If that is not the case this method
        should be overridden.

        Args:
            initial_context (dict): The initial context for the flow.
        Returns:
            str: A unique identifier for a workflow being executed
                In the forms of '<self.flow_name>-YYYY-MM-DD', where
                YYYY-MM-DD is the context date or, if none passed the
                current date.
        """
        if 'context_date' not in initial_context:
            date = datetime.datetime.today().strftime('%Y-%m-%d')
        else:
            date = initial_context['context_date']

        return '{flow_name}-{date}'.format(flow_name=self.name, date=date)


def get_domain():
    """Get workflow domain.

    Returns:
        str: SWF domain the workflow should use.
    """
    env = os.getenv('Environment')
    if not env or env == 'dev':
        domain = os.getenv('DEV_SWF_DOMAIN', 'dev')
    else:
        domain = '{}_{}'.format(env, 'activity_detector')
    return domain