# -*- coding: utf-8 -*-
'''
Cassandra NoSQL Database Module

:depends:   - pycassa Cassandra Python adapter
:configuration:
    The location of the 'nodetool' command, host, and thrift port needs to be
    specified via pillar::

        cassandra.nodetool: /usr/local/bin/nodetool
        cassandra.host: localhost
        cassandra.thrift_port: 9160
'''
from __future__ import absolute_import

# Import python libs
import logging
log = logging.getLogger(__name__)

# Import salt libs
import salt.utils

HAS_PYCASSA = False
try:
    from pycassa.system_manager import SystemManager
    HAS_PYCASSA = True
except ImportError:
    pass


def __virtual__():
    '''
    Only load if pycassa is available and the system is configured
    '''
    if not HAS_PYCASSA:
        return (False, 'The cassandra execution module cannot be loaded: pycassa not installed.')

    if HAS_PYCASSA and salt.utils.which('nodetool'):
        return 'cassandra'
    return (False, 'The cassandra execution module cannot be loaded: nodetool not found.')


def _nodetool(cmd):
    '''
    Internal cassandra nodetool wrapper. Some functions are not
    available via pycassa so we must rely on nodetool.
    '''
    nodetool = __salt__['config.option']('cassandra.nodetool')
    host = __salt__['config.option']('cassandra.host')
    return __salt__['cmd.run_stdout']('{0} -h {1} {2}'.format(nodetool, host, cmd))


def _sys_mgr():
    '''
    Return a pycassa system manager connection object
    '''
    thrift_port = str(__salt__['config.option']('cassandra.THRIFT_PORT'))
    host = __salt__['config.option']('cassandra.host')
    return SystemManager('{0}:{1}'.format(host, thrift_port))


def compactionstats():
    '''
    Return compactionstats info

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.compactionstats
    '''
    return _nodetool('compactionstats')


def version():
    '''
    Return the cassandra version

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.version
    '''
    return _nodetool('version')


def netstats():
    '''
    Return netstats info

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.netstats
    '''
    return _nodetool('netstats')


def tpstats():
    '''
    Return tpstats info

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.tpstats
    '''
    return _nodetool('tpstats')


def info():
    '''
    Return cassandra node info

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.info
    '''
    return _nodetool('info')


def ring():
    '''
    Return cassandra ring info

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.ring
    '''
    return _nodetool('ring')


def keyspaces():
    '''
    Return existing keyspaces

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.keyspaces
    '''
    sys = _sys_mgr()
    return sys.list_keyspaces()


def column_families(keyspace=None):
    '''
    Return existing column families for all keyspaces
    or just the provided one.

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.column_families
        salt '*' cassandra.column_families <keyspace>
    '''
    sys = _sys_mgr()
    ksps = sys.list_keyspaces()

    if keyspace:
        if keyspace in ksps:
            return list(sys.get_keyspace_column_families(keyspace).keys())
        else:
            return None
    else:
        ret = {}
        for kspace in ksps:
            ret[kspace] = list(sys.get_keyspace_column_families(kspace).keys())

        return ret


def column_family_definition(keyspace, column_family):
    '''
    Return a dictionary of column family definitions for the given
    keyspace/column_family

    CLI Example:

    .. code-block:: bash

        salt '*' cassandra.column_family_definition <keyspace> <column_family>

    '''
    sys = _sys_mgr()

    try:
        return vars(sys.get_keyspace_column_families(keyspace)[column_family])
    except Exception:
        log.debug('Invalid Keyspace/CF combination')
        return None
