"""
Nodegroups Pillar
=================

Introspection: to which nodegroups does my minion belong?
Provides a pillar with the default name of `nodegroups`
which contains a list of nodegroups which match for a given minion.

.. versionadded:: 2016.11.0

Command Line
------------

.. code-block:: bash

    salt-call pillar.get nodegroups
    local:
        - class_infra
        - colo_sj
        - state_active
        - country_US
        - type_saltmaster

Configuring Nodegroups Pillar
-----------------------------

.. code-block:: yaml

    extension_modules: /srv/salt/ext
    ext_pillar:
      - nodegroups:
          pillar_name: 'nodegroups'

"""

# Import futures

from salt.utils.minions import CkMinions

__version__ = "0.0.2"


def ext_pillar(minion_id, pillar, pillar_name=None):
    """
    A salt external pillar which provides the list of nodegroups of which the minion is a member.

    :param minion_id: used for compound matching nodegroups
    :param pillar: provided by salt, but not used by nodegroups ext_pillar
    :param pillar_name: optional name to use for the pillar, defaults to 'nodegroups'
    :return: a dictionary which is included by the salt master in the pillars returned to the minion
    """

    pillar_name = pillar_name or "nodegroups"
    all_nodegroups = __opts__["nodegroups"]
    nodegroups_minion_is_in = []
    ckminions = None
    for nodegroup_name in all_nodegroups.keys():
        ckminions = ckminions or CkMinions(__opts__)
        _res = ckminions.check_minions(all_nodegroups[nodegroup_name], "compound")
        match = _res["minions"]

        if minion_id in match:
            nodegroups_minion_is_in.append(nodegroup_name)

    return {pillar_name: nodegroups_minion_is_in}