"""
Views for verifying the health (heartbeat) of the app.
"""


import logging

from common.djangoapps.util.json_request import JsonResponse

from .runchecks import runchecks


log = logging.getLogger(__name__)


def heartbeat(request):
    """
    Simple view that a loadbalancer can check to verify that the app is up. Returns a json doc
    of service id: status or message. If the status for any service is anything other than True,
    it returns HTTP code 503 (Service Unavailable); otherwise, it returns 200.
    """
    check_results = {}
    try:
        check_results = runchecks('extended' in request.GET)

        status_code = 200  # Default to OK
        for check in check_results:
            if not check_results[check]['status']:
                status_code = 503  # 503 on any failure
    except Exception as e:  # lint-amnesty, pylint: disable=broad-except
        status_code = 503
        check_results = {'error': str(e)}

    if status_code == 503:
        log.error('Heartbeat check failed (%s): %s', status_code, check_results)

    return JsonResponse(check_results, status=status_code)