Source code for boto3_helpers.medialive

from collections import defaultdict

from boto3 import client as boto3_client
from jmespath import search as json_search

from boto3_helpers.pagination import yield_all_items

PARENT_ACTION_PATH = (
    'ScheduleActionStartSettings'
    '.FollowModeScheduleActionStartSettings'
    '.ReferenceActionName'
)


def _parse_action_chains(eml_actions):
    parent_map = {}
    for schedule_action in eml_actions:
        action_name = schedule_action['ActionName']
        parent_name = json_search(PARENT_ACTION_PATH, schedule_action) or action_name
        parent_map[action_name] = parent_name

    children_map = defaultdict(set)
    for action_name, parent_name in parent_map.items():
        children_map[action_name].add(action_name)

        while True:
            children_map[parent_name].add(action_name)
            if parent_name == parent_map[parent_name]:
                break
            parent_name = parent_map[parent_name]

    return parent_map, children_map


def delete_schedule_action_chain(
    channel_id, delete_action_name, dry_run=False, eml_client=None
):
    """Delete a MediaLive scheduled action, plus any actions that depend on it.
    Return the names of the actions that were deleted.

    * *channel_id* is the MediaLive channel ID.
    * *delete_action_name* is the name of the scheduled action to delete.
    * *dry_run* determines whether the delete actions are actually executed. Set to
      ``False`` to return the names of the actions that _would_ have been deleted.
    * *eml_client* (optional) is a ``boto3.client('medialive')`` instance.

    Usage:

    .. code-block:: python

        from boto3_helpers.medialive import delete_schedule_action_chain

        deleted_actions = delete_schedule_action_chain(
            '24601', 'switch-immediate'
        )

    MediaLive's deletion rules still apply: you can't delete an action chain associated
    with the most recent input switch.

    """
    eml_client = eml_client or boto3_client('medialive')
    eml_actions = yield_all_items(
        eml_client, 'describe_schedule', 'ScheduleActions', ChannelId=channel_id
    )
    parent_map, children_map = _parse_action_chains(eml_actions)

    if delete_action_name not in parent_map:
        raise ValueError(
            f'Action name {delete_action_name} was not present in the schedule'
        )

    all_deletes = sorted(children_map[delete_action_name])

    if not dry_run:
        eml_client.batch_update_schedule(
            ChannelId=channel_id, Deletes={'ActionNames': all_deletes}
        )

    return all_deletes