from functools import wraps

import requests
from flask import current_app


def cronitor(task_name):
    def decorator(func):
        def ping_cronitor(command):
            if not current_app.config['CRONITOR_ENABLED']:
                return

            # it's useful to have a log that a periodic task has started in case it
            # get stuck without generating any other logs - we know it got this far
            current_app.logger.info(f'Pinging Cronitor for Celery task {task_name}')

            task_slug = current_app.config['CRONITOR_KEYS'].get(task_name)
            if not task_slug:
                current_app.logger.error(
                    'Cronitor enabled but task_name {} not found in environment'.format(task_name)
                )
                return

            if command not in {'run', 'complete', 'fail'}:
                raise ValueError('command {} not a valid cronitor command'.format(command))

            try:
                resp = requests.get(
                    'https://cronitor.link/{}/{}'.format(task_slug, command),
                    # cronitor limits msg to 1000 characters
                    params={
                        'host': current_app.config['API_HOST_NAME'],
                    }
                )
                resp.raise_for_status()
            except requests.RequestException as e:
                current_app.logger.warning('Cronitor API failed for task {} due to {}'.format(
                    task_name,
                    repr(e)
                ))

        @wraps(func)
        def inner_decorator(*args, **kwargs):
            ping_cronitor('run')
            status = 'fail'
            try:
                ret = func(*args, **kwargs)
                status = 'complete'
                return ret
            finally:
                ping_cronitor(status)

        return inner_decorator
    return decorator