#!/usr/bin/env python3
"""Stop long running docker iamges."""

import argparse
import logging
import sys

import dateutil.parser
import docker
import docker.errors
import requests.exceptions
from docker.utils import kwargs_from_env
from docker_custodian.args import timedelta_type

log = logging.getLogger(__name__)


def stop_containers(client, max_run_time, matcher, dry_run):
    for container_summary in client.containers():
        container = client.inspect_container(container_summary["Id"])
        name = container["Name"].lstrip("/")
        if (
            matcher(name) and has_been_running_since(container, max_run_time)
        ):

            log.info("Stopping container %s %s: running since %s" % (
                container["Id"][:16],
                name,
                container["State"]["StartedAt"]))

            if not dry_run:
                stop_container(client, container["Id"])


def stop_container(client, cid):
    try:
        client.stop(cid)
    except requests.exceptions.Timeout as e:
        log.warn("Failed to stop container %s: %s" % (cid, e))
    except docker.errors.APIError as ae:
        log.warn("Error stopping %s: %s" % (cid, ae))


def build_container_matcher(prefixes):
    def matcher(name):
        return any(name.startswith(prefix) for prefix in prefixes)
    return matcher


def has_been_running_since(container, min_time):
    started_at = container.get("State", {}).get("StartedAt")
    if not started_at:
        return False

    return dateutil.parser.parse(started_at) <= min_time


def main():
    logging.basicConfig(
        level=logging.INFO,
        format="%(message)s",
        stream=sys.stdout)

    opts = get_opts()
    client = docker.APIClient(version="auto",
                              timeout=opts.timeout,
                              **kwargs_from_env())

    matcher = build_container_matcher(opts.prefix)
    stop_containers(client, opts.max_run_time, matcher, opts.dry_run)


def get_opts(args=None):
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--max-run-time",
        type=timedelta_type,
        help="Maximum time a container is allows to run. Time may "
        "be specified in any pytimeparse supported format."
    )
    parser.add_argument(
        "--prefix", action="append", default=[],
        help="Only stop containers which match one of the "
             "prefix."
    )
    parser.add_argument(
        "--dry-run", action="store_true",
        help="Only log actions, don't stop anything."
    )
    parser.add_argument(
        "-t", "--timeout", type=int, default=60,
        help="HTTP timeout in seconds for making docker API calls."
    )
    opts = parser.parse_args(args=args)

    if not opts.prefix:
        parser.error("Running with no --prefix will match nothing.")

    return opts


if __name__ == "__main__":
    main()