import argparse
import json
import logging
import sys
import time

import requests
from urllib3.exceptions import InsecureRequestWarning

requests.packages.urllib3.disable_warnings(category=InsecureRequestWarning)


def main(args):
    # Icinga2 API URL
    url = f"{args.api}/v1"

    logging.basicConfig(level=logging.INFO)

    while True:
        current_time = time.time()

        # Get all checks
        objects = ["hosts", "services"]
        for obj in objects:
            response = None
            for i in range(3):
                try:
                    response = requests.get(url + "/objects/" + obj, auth=(args.username, args.password), verify=not args.insecure)
                    response.raise_for_status()
                    break
                except requests.exceptions.ConnectionError as e:
                    logging.error(f'Failed to reach Icinga2: {e}')
                    logging.error('Sleeping 60 seconds')
                    time.sleep(60)
            if not response:
                logging.error('Gave up, no response.')
                sys.exit(1)  # systemd should restart us

            checks = response.json()["results"]

            # Loop through all checks
            for check in checks:
                if not check['attrs']['active']:
                    continue

                last_check_time = check["attrs"]["last_check"]
                check_interval = check["attrs"]["check_interval"]
                check_timeout = check["attrs"]["check_timeout"] or args.default_timeout

                # If the check is overdue.
                if current_time - last_check_time > check_interval + check_timeout + 60:
                    headers = {'Accept': 'application/json', 'Content-Type': 'application/json'}
                    next_check_time = last_check_time + check_interval + check_timeout

                    if obj == 'services':
                        check_filter = f'host.name=="{check["attrs"]["host_name"]}" && service.name=="{check["attrs"]["name"]}"'
                    elif obj == 'hosts':
                        check_filter = f'host.name=="{check["name"]}"'
                    else:
                        raise Exception

                    # Set the check to unknown
                    data = {
                        "type": check['type'],
                        "filter": check_filter,
                        "exit_status": 3 if check['type'] == 'Service' else 1,
                        "plugin_output": f"<Check is overdue for {int(current_time - next_check_time)} seconds.>",
                    }

                    # Trigger a full failure.
                    for _ in range(4):
                        response = requests.post(url + "/actions/process-check-result", data=json.dumps(data), headers=headers, auth=(args.username, args.password), verify=not args.insecure)
                        response.raise_for_status()
                        time.sleep(3)

                    # Rerun the check
                    data = {
                        "type": check['type'],
                        "filter": check_filter,
                        'force': True
                    }
                    response = requests.post(url + "/actions/reschedule-check", data=json.dumps(data), headers=headers, auth=(args.username, args.password), verify=not args.insecure)
                    response.raise_for_status()
                    logging.info(f'Failed {check["type"].lower()} {check["name"]} - {int(current_time - next_check_time)} seconds overdue.')
        time.sleep(args.interval)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument('--api', default='https://localhost:5665', help='Base Icinga2 API.')
    parser.add_argument('--insecure', action='store_true', help='Disable SSL verification.')
    parser.add_argument('--username', default='icingaweb2', help='API username.')
    parser.add_argument('--password', required=True, help='API password.')
    parser.add_argument('--default-timeout', default=600, type=int, help='If a check does not have a timeout set, use this many seconds as the default. Default: 600 (10 minutes).')
    parser.add_argument('--interval', default=900, type=int, help='Interval between service scans. Default: 900 (15 minutes).')
    args = parser.parse_args()
    main(args)