"""
Base Processing Accounting Work Flow
=====================================
Base Work Flow class that processing accounting flows should extend.
Standardizes how flow domain, name, and workflow_id are generated and adds
default on_exception method.

Flows should override the decider method.
"""

import datetime
import logging
import os

import boto3
from botocore.config import Config
from garcon import activity
import raven
import sentry_sdk

logger = logging.getLogger('garcon')


class FlowBase(object):
    """Base Garcon Workflow that other Flows can extend
    """

    def __init__(self, flow_name, version, domain=None):
        """Initializes Flow

        Initializes the Flow's:
            domain - 'prod_swf_processing_accounting' or 'dev
            name - '<feed_name>_processing_accounting'

        Args:
            flow_name (str): name of the work flow.
            version (str): Version of the workflow type to filter on. should
                be a 'x.x' float (ex. 1.0, 1.1, etc.)
        """

        self.domain = get_domain(domain)
        self.name = generate_workflow_name(flow_name, domain)
        self.version = version
        self.client = boto3.client('swf', config=Config(
            connect_timeout=60,
            region_name='us-east-1',
            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)

    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.
        """
        # client grabs sentry dns from SENTRY_DSN environment variable
        if os.environ.get('SENTRY_DSN'):
            client = raven.Client()
            client.captureException()

        # client grabs new sentry dsn from SENTRY_DSN_NEW environment variable
        sentry_dsn_new = os.environ.get('SENTRY_DSN_NEW')
        if sentry_dsn_new:
            sentry_sdk.init(
                sentry_dsn_new,
            )
            sentry_sdk.capture_exception(exception)

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

    def workflow_id(self, initial_context=None):
        """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 decider(self, schedule):
        raise NotImplementedError()


def generate_workflow_name(workflow_name, domain=None):
    """Generate workflow name

    To play nice with non-class based Flows

    Args:
        workflow_name (str): name of the work flow.
        domain (str): SWF domain name
    Returns:
        str: SWF name in the format of '<workflow_name>_processing_accounting'
    """

    assert workflow_name.islower() and ' ' not in workflow_name, (
        'feed name must be lower case with no spaces')

    if domain:
        return workflow_name
    return '{workflow_name}_processing-accounting'.format(
        workflow_name=workflow_name)


def get_domain(domain=None):
    """Get workflow domain

    To play nice with non-class based Flows

    Args:
        domain (str): SWF domain name
    Returns:
        str: SWF domain the workflow should use
    """
    if domain:
        return domain
    return '{}_swf_processing_accounting'.format(os.getenv('Environment'))