#!/usr/bin/python

import sys
import time
import os
import utils
import ceilometer_utils

def install():
    utils.configure_source()
    packages = ['python-ceilometer', 'ceilometer-common', 'ceilometer-agent-central', 'ceilometer-collector', 'ceilometer-api']
    utils.install(*packages)

def amqp_joined():
    utils.relation_set(username=ceilometer_utils.RABBIT_USER, vhost=ceilometer_utils.RABBIT_VHOST)

def get_rabbit_conf():
    for relid in utils.relation_ids('amqp'):
        for unit in utils.relation_list(relid):
            conf = {
                "rabbit_host": utils.relation_get('private-address',
                                                  unit, relid),
                "rabbit_virtual_host": ceilometer_utils.RABBIT_VHOST,
                "rabbit_userid": ceilometer_utils.RABBIT_USER,
                "rabbit_password": utils.relation_get('password',
                                                      unit, relid)
                }
            if None not in conf.itervalues():
                return conf
    return None

def get_db_conf():
    for relid in utils.relation_ids('shared-db'):
        for unit in utils.relation_list(relid):
            conf = {
                "db_host": utils.relation_get('hostname', unit, relid),
                "db_port": utils.relation_get('port', unit, relid),
                "db_name": ceilometer_utils.CEILOMETER_DB
                }
            if None not in conf.itervalues():
                return conf
    return None

def get_keystone_conf():
    for relid in utils.relation_ids('identity-service'):
        for unit in utils.relation_list(relid):
            keystone_username = utils.relation_get('service_username', unit, relid)
            keystone_port = utils.relation_get('service_port', unit, relid)
            keystone_host = utils.relation_get('service_host', unit, relid)
            keystone_password = utils.relation_get('service_password', unit, relid)
            keystone_tenant = utils.relation_get('service_tenant', unit, relid)

            conf = {
                "keystone_os_username": keystone_username,
                "keystone_os_password": keystone_password,
                "keystone_os_tenant": keystone_tenant,
                "keystone_host": keystone_host,
                "keystone_port": keystone_port
            }
            if None not in conf.itervalues():
                return conf
    return None

def render_ceilometer_conf():
    context = get_rabbit_conf()
    contextdb = get_db_conf()
    contextkeystone = get_keystone_conf()

    if (context and contextdb and contextkeystone and os.path.exists(ceilometer_utils.CEILOMETER_CONF)):
        # merge contexts
        context.update(contextkeystone)
        context['metering_secret'] = ceilometer_utils.get_shared_secret()
        context['service_port'] = utils.config_get('service-port')
        context['db_connection'] = "mongodb://"+contextdb["db_host"]+":"+contextdb["db_port"]+"/"+contextdb["db_name"]

        with open(ceilometer_utils.CEILOMETER_CONF, "w") as conf:
            conf.write(utils.render_template(os.path.basename(ceilometer_utils.CEILOMETER_CONF), context))

        return True
    return False

def amqp_changed():
    if render_ceilometer_conf():
        utils.restart(*ceilometer_utils.CEILOMETER_SERVICES)

def db_joined():
    utils.relation_set(ceilometer_database=ceilometer_utils.CEILOMETER_DB)

def db_changed():
    if render_ceilometer_conf():
        utils.restart(*ceilometer_utils.CEILOMETER_SERVICES)

def config_changed():
    utils.update_ports()
    render_ceilometer_conf()

def keystone_joined():
    port = utils.config_get("service-port")
    url = "http://"+utils.get_host_ip()+":"+port
    region = utils.config_get("region")
    utils.relation_set(service=ceilometer_utils.CEILOMETER_SERVICE, public_url=url, admin_url=url, internal_url=url, region=region)

def keystone_changed():
    if render_ceilometer_conf():
        utils.restart(*ceilometer_utils.CEILOMETER_SERVICES)

def ceilometer_joined():
    pass

def ceilometer_changed():
    # check if we have rabbit and keystone already set
    context = get_rabbit_conf()
    contextkeystone = get_keystone_conf()

    if context and contextkeystone:
        context.update(contextkeystone)
        context['metering_secret'] = ceilometer_utils.get_shared_secret()

        utils.relation_set(metering_secret=context['metering_secret'])
        utils.relation_set(rabbit_host=context['rabbit_host'], rabbit_virtual_host=context['rabbit_virtual_host'], rabbit_userid=context['rabbit_userid'], rabbit_password=context['rabbit_password'])
        utils.relation_set(keystone_os_username=context['keystone_os_username'], keystone_os_password=context['keystone_os_password'], keystone_os_tenant=context['keystone_os_tenant'],
            keystone_host=context['keystone_host'], keystone_port=context['keystone_port'])
    else:
        # still waiting
        utils.juju_log("INFO", "ceilometer: rabbit and keystone credentials not yet received from peer.")

utils.do_hooks({
    "install": install,
    "amqp-relation-joined": amqp_joined,
    "amqp-relation-changed": amqp_changed,
    "shared-db-relation-joined": db_joined,
    "shared-db-relation-changed": db_changed,
    "config-changed": config_changed,
    "identity-service-relation-joined": keystone_joined,
    "identity-service-relation-changed": keystone_changed,
    "ceilometer-service-relation-joined": ceilometer_joined,
    "ceilometer-service-relation-changed": ceilometer_changed
})
sys.exit(0)