#! /usr/bin/env python

# A script to lunch python binaries
# usage: ./launch.py heartbeat

import os, sys

import json



import requests
import boto3
import traceback

# We expect this to run in the docker image.  cron runs out of /root
# and doesn't want to change, we might create a 'tracker' user and set this
# as there home.  but for now....
os.chdir('/tracker')

sys.path.insert(0, '.')

hostname = requests.get('http://169.254.169.254/latest/meta-data/hostname').text
instance_id = requests.get('http://169.254.169.254/latest/meta-data/instance-id').text

def launch_script(script, this_logger):

    import importlib
    import importlib.util as iutil
    found = iutil.find_spec(script)
    if not found:
        this_logger.error(
            "No script module called {0} is found ({0}.py should exist in this folder)".format(script))
        return False

    from tracker import db
    db.setup_session(application_name=script[0:30].lower())

    this_logger.info("Launching {}, db {}".format(script, db.Session.get_bind()))
    cronitor_id = os.environ.get('WL_CRONITOR_ID')
    send_cloudwatch_fail_event = (
            # default true:
            (os.environ.get("WL_SEND_CW_FAIL_EVENT") or 'true').lower()
            in ['t', 'true', '1', 'on']
    )

    if not cronitor_id:
        this_logger.warning("No cronitor setup for {}".format(script))
    else:
        requests.get("https://cronitor.link/{}/run".format(cronitor_id))
    try:
        importlib.import_module(script)
    except Exception as e:
        this_logger.exception("Unhandled error in script. {}".format(e), exc=e)
        if send_cloudwatch_fail_event:
            cw = boto3.client('events')
            event_detail = {
                'script': script,
                'error': str(e),
                'traceback': traceback.format_exc(),
                'hostname': hostname,
                'instance-id': instance_id,
            }
            put_attempt = cw.put_events(Entries=[{
                'Source': 'tracker-script',
                'DetailType': 'tracker-job-failure',
                'Detail': json.dumps(event_detail),
            }])

            this_logger.info("Sent cw event", extra=put_attempt)
        if cronitor_id:
            from urllib.parse import quote
            failmsg = quote(str(e)[:100])
            requests.get("https://cronitor.link/{}/fail&msg={}".format(cronitor_id, failmsg))
        return False

    else:
        if cronitor_id:
            requests.get("https://cronitor.link/{}/complete".format(cronitor_id))
    try:
        db.Session.remove()
    except Exception as e:
        logger.exception("Error removing database session, this could be fatal. {}".format(e))

    return True


if __name__ == '__main__':

    try:
        script = sys.argv[1]
    except IndexError:
        print("Script name argument is required.", file=sys.stderr)
        sys.exit(2)
    from tracker import logger
    logger.setup_logging()
    this_logger = logger.get_logger('launch')

    print(json.dumps(dict(
        log_signal="script_starting",
        script=script
    )))

    success = launch_script(script, this_logger)

    final_log = json.dumps(dict(
        log_signal="script_complete",
        script=script,
        status="SUCCESSFULLY" if success else "BADLY",
        human="Task {} completed {}".format(script, "SUCCESSFULLY" if success else "BADLY"),
    ))
    print(final_log)

    sys.exit(0 if success else 5)