"""
Send events from Docker events
:Depends:   Docker API >= 1.22
"""
import logging
import traceback

import salt.utils.event
import salt.utils.json

try:
    import docker  # pylint: disable=import-error
    import docker.utils  # pylint: disable=import-error

    HAS_DOCKER_PY = True
except ImportError:
    HAS_DOCKER_PY = False

log = logging.getLogger(__name__)  # pylint: disable=invalid-name

# Default timeout as of docker-py 1.0.0
CLIENT_TIMEOUT = 60

# Define the module's virtual name
__virtualname__ = "docker_events"


def __virtual__():
    """
    Only load if docker libs are present
    """
    if not HAS_DOCKER_PY:
        return (False, "Docker_events engine could not be imported")
    return True


def start(
    docker_url="unix://var/run/docker.sock",
    timeout=CLIENT_TIMEOUT,
    tag="salt/engines/docker_events",
    filters=None,
):
    """
    Scan for Docker events and fire events

    Example Config

    .. code-block:: yaml

        engines:
          - docker_events:
              docker_url: unix://var/run/docker.sock
              filters:
                event:
                - start
                - stop
                - die
                - oom

    The config above sets up engines to listen
    for events from the Docker daemon and publish
    them to the Salt event bus.

    For filter reference, see https://docs.docker.com/engine/reference/commandline/events/
    """

    if __opts__.get("__role") == "master":
        fire_master = salt.utils.event.get_master_event(
            __opts__, __opts__["sock_dir"]
        ).fire_event
    else:
        fire_master = None

    def fire(tag, msg):
        """
        How to fire the event
        """
        if fire_master:
            fire_master(msg, tag)
        else:
            __salt__["event.send"](tag, msg)

    try:
        # docker-py 2.0 renamed this client attribute
        client = docker.APIClient(base_url=docker_url, timeout=timeout)
    except AttributeError:
        # pylint: disable=not-callable
        client = docker.Client(base_url=docker_url, timeout=timeout)
        # pylint: enable=not-callable

    try:
        events = client.events(filters=filters)
        for event in events:
            data = salt.utils.json.loads(
                event.decode(__salt_system_encoding__, errors="replace")
            )
            # https://github.com/docker/cli/blob/master/cli/command/system/events.go#L109
            # https://github.com/docker/engine-api/blob/master/types/events/events.go
            # Each output includes the event type, actor id, name and action.
            # status field can be ommited
            if data["Action"]:
                fire("{}/{}".format(tag, data["Action"]), data)
            else:
                fire("{}/{}".format(tag, data["status"]), data)
    except Exception:  # pylint: disable=broad-except
        traceback.print_exc()
