# -*- coding: utf-8 -*-
'''
powerpath support.

Assumes RedHat

'''
from __future__ import absolute_import, print_function, unicode_literals

# Import python libs
import os
import re

POLICY_MAP_DICT = {
    'Adaptive': 'ad',
    'CLAROpt': 'co',
    'LeastBlocks': 'lb',
    'LeastIos': 'li',
    'REquest': 're',
    'RoundRobin': 'rr',
    'StreamIo': 'si',
    'SymmOpt': 'so',
}

POLICY_RE = re.compile('.*policy=([^;]+)')


def has_powerpath():
    if os.path.exists('/sbin/emcpreg'):
        return True

    return False


def __virtual__():
    '''
    Provide this only on Linux systems until proven to
    work elsewhere.
    '''
    try:
        kernel_grain = __grains__['kernel']
    except Exception:
        return (False, 'The powerpath execution module cannot be loaded: unable to detect kernel grain.')

    if not has_powerpath():
        return (False, 'The powerpath execution module cannot be loaded: the emcpreg binary is not available.')

    if kernel_grain == 'Linux':
        return 'powerpath'

    return (False, 'The powerpath execution module cannot be loaded: only available on Linux.')


def list_licenses():
    '''
    returns a list of applied powerpath license keys
    '''
    KEY_PATTERN = re.compile('Key (.*)')

    keys = []
    out = __salt__['cmd.run']('/sbin/emcpreg -list')
    for line in out.splitlines():
        match = KEY_PATTERN.match(line)

        if not match:
            continue

        keys.append({'key': match.group(1)})

    return keys


def add_license(key):
    '''
    Add a license
    '''
    result = {
        'result': False,
        'retcode': -1,
        'output': ''
    }

    if not has_powerpath():
        result['output'] = 'PowerPath is not installed'
        return result

    cmd = '/sbin/emcpreg -add {0}'.format(key)
    ret = __salt__['cmd.run_all'](cmd, python_shell=True)

    result['retcode'] = ret['retcode']

    if ret['retcode'] != 0:
        result['output'] = ret['stderr']
    else:
        result['output'] = ret['stdout']
        result['result'] = True

    return result


def remove_license(key):
    '''
    Remove a license
    '''
    result = {
        'result': False,
        'retcode': -1,
        'output': ''
    }

    if not has_powerpath():
        result['output'] = 'PowerPath is not installed'
        return result

    cmd = '/sbin/emcpreg -remove {0}'.format(key)
    ret = __salt__['cmd.run_all'](cmd, python_shell=True)

    result['retcode'] = ret['retcode']

    if ret['retcode'] != 0:
        result['output'] = ret['stderr']
    else:
        result['output'] = ret['stdout']
        result['result'] = True

    return result
