#!/usr/bin/python
__author__ = 'chris'
from subprocess import CalledProcessError
import sys

sys.path.append('hooks')

from charmhelpers.contrib.storage.linux.ceph import Pool, pool_exists
from charmhelpers.core.hookenv import action_get, log, action_fail


def make_cache_tier():
    backer_pool = action_get("backer-pool")
    cache_pool = action_get("cache-pool")
    cache_mode = action_get("cache-mode")

    # Pre flight checks
    if not pool_exists('admin', backer_pool):
        log("Please create {} pool before calling create-cache-tier".format(
            backer_pool))
        action_fail("create-cache-tier failed. Backer pool {} must exist "
                    "before calling this".format(backer_pool))

    if not pool_exists('admin', cache_pool):
        log("Please create {} pool before calling create-cache-tier".format(
            cache_pool))
        action_fail("create-cache-tier failed. Cache pool {} must exist "
                    "before calling this".format(cache_pool))

    pool = Pool(service='admin', name=backer_pool)
    try:
        pool.add_cache_tier(cache_pool=cache_pool, mode=cache_mode)
    except CalledProcessError as err:
        log("Add cache tier failed with message: {}".format(
            err.message))
        action_fail("create-cache-tier failed.  Add cache tier failed with "
                    "message: {}".format(err.message))


if __name__ == '__main__':
    make_cache_tier()