import yaml
import httplib
import urllib
import urllib2
import json
import time


class CASHandler(urllib2.HTTPHandler):
    # this is an auth handler, do it first
    handler_order = 1

    ticket_url = "/v1/tickets"

    def __init__(self, cas_endpoint, username, password, service):
        urllib2.HTTPHandler.__init__(self)
        self.cas_endpoint = cas_endpoint
        self.service = service
        self.http_handler = urllib2.HTTPHandler()
        
        params = urllib.urlencode({"username": username,
                                   "password": password})
        self.headers = {"Accept": "*/*", 
                "Content-type": "application/x-www-form-urlencoded",}

        conn = httplib.HTTPSConnection(cas_endpoint)
        conn.request("POST", CASHandler.ticket_url, params, self.headers)
        resp = conn.getresponse()
        if resp.status != 201:
            raise Exception("{0}: {1}".format(resp.status, resp.reason))
        self.location = resp.getheader('location')
        self.tgt = self.location.split("/")[-1]

    def http_open(self, req):
        # logging.error("{}".format(req.get_selector()))
        conn = httplib.HTTPSConnection(self.cas_endpoint)
        conn.request("POST", 
                     CASHandler.ticket_url + '/' + self.tgt,
                     "service=" + self.service,
                     self.headers)
        resp = conn.getresponse()
        st = resp.read()
        # logging.error("ST: {}".format(st))

        req.add_header("Service-Ticket", st)
        req.timeout = 5
        return self.do_open(httplib.HTTPConnection, req)


def copen(opener, site, path):
    retries = 3
    url = site + path
    for _ in range(0, retries):
        try:
            ret = opener.open(url)
            return json.load(ret)
        except Exception, e:
            print url, str(e)
            time.sleep(1)
    raise Exception("Number of retries({0}) exceed".format(retries))


def getconfigs():
    configfile = "/var/www/reseller-provisioning/config/cegonha.yml"
    config = yaml.load(open(configfile))
    cegonha = config["production"]["connection_url"]
    cas = config["production"]["cas_url"].replace("https://", '')
    service = config["production"]["service"]
    username = config["production"]["auth"]["user"]
    password = config["production"]["auth"]["pass"]

    confcegonha = "/var/www/reseller-provisioning/config/cegonha_openstack.yml"
    config_cegonha = yaml.load(open(confcegonha))
    vlan_id = config_cegonha["production"]["vlan_name"]
    range_cidr = config_cegonha["production"]["range_cidr"]
    return (cegonha, cas, username, password, service, vlan_id, range_cidr)
 

def getnumberofavaliableips(cegonha, cas, username, password, service, vlan_id, range_cidr):
    handler = CASHandler(cas, username, password, service)
    opener = urllib2.build_opener(handler)

    ranges = copen(opener, cegonha, "/vlans/{0}/ip_ranges.json".format(vlan_id))
    for i in ranges:
        if i["ip_range"]["name"] == range_cidr:
            range_id = i["ip_range"]["id"]
            break
    path = "/vlans/{0}/ip_ranges/{1}.json".format(vlan_id, range_id)
    _range = copen(opener, cegonha, path)
    return int(_range["ip_range"]["total_available_ips"])


if __name__ == "__main__":
    confs = getconfigs()
    ips = getnumberofavaliableips(*confs)
    print ips


def __run__(params):
    confs = getconfigs()
    try:
        ips = getnumberofavaliableips(*confs)
        if ips < int(params.get("error")):
            return [2, "CRITICAL: {0} ips disponiveis. Seguir procedimento {1}".format(ips, params.get("url"))]
        elif ips < int(params.get("warning")):
            return [1, "WARNING: {0} ips disponiveis. Seguir procedimento {1}".format(ips, params.get("url"))]
        else:
            return [0, "OK: {0} ips disponiveis".format(ips)]
    except Exception as e:
        return [2, "CRITICAL: {0}".format(str(e).replace('\n', ' '))]
    return [2, "CRITICAL: This alarm is broken, shouldn't reach here"]