#!/usr/bin/python
# 
# vsys_vnet_admin.py - basic command-line client to show assigned network
# segments to the vsys_vnet tag in PlanetLab, and to assign new vsys_vnet tags
# using available segments
# 
# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
#

import ipaddr
from optparse import OptionParser
import os
import pprint
import sys
import xmlrpclib

def plapi(url):
    """ Returns a XMLRPC proxy to the PLAPI service on the given url """
    return xmlrpclib.ServerProxy(url, allow_none = True)

def get_assigned(plapi, auth):
    """ Returns a dictionary with the assigned network segments as key
    and the slice name as value"""
    info = plapi.GetSliceTags(auth, {'tagname': 'vsys_vnet'}, ('name', 'value'))
    return dict((d['value'], d['name']) for d in info)

def get_next_available(assigned, base, prefix):
    """ Returns the next available network segment to be assigned to a 
    new vsys_vnet tag """
    net = ipaddr.IPNetwork(base)
    iter_sub = net.iter_subnets(new_prefix=prefix)

    try:
        while True:
            sub = iter_sub.next()
            if not [ s for s in map(ipaddr.IPNetwork, assigned.keys()) \
                    if sub == s or s in sub or sub in s]:
               return sub.exploded 
    except StopIteration:
        pass

    return None

def assign_vsys_vent(plapi, auth, vsys_vnet, pl_slice):
    return plapi.AddSliceTag(auth, pl_slice, 'vsys_vnet', vsys_vnet)

if __name__ == "__main__":
    pl_user = os.environ.get('PL_USER')
    pl_pwd = os.environ.get('PL_PASS')
    pl_url = "https://www.planet-lab.eu:443/PLCAPI/"
    pl_slice = os.environ.get('PL_SLICE')

    usage = """Usage: 
   %prog : displays and check current assignments
or %prog -a -S <slicename> : assigns a range to slice <slicename>"""
    parser = OptionParser(usage=usage)
    parser.add_option("-u", "--user", dest="pl_user", help="PlanetLab account user name", default=pl_user)
    parser.add_option("-p", "--password", dest="pl_pwd", help="PlanetLab account password", default=pl_pwd)
    parser.add_option("-l", "--url", dest="pl_url", help="PlanetLab XMLRPC url", default=pl_url)
    parser.add_option("-b", "--base", dest="basenet",
                      help="Base network address to perform assignment (defaults to 10.0.0.0/8)", default="10.0.0.0/8")
    parser.add_option("-n", "--prefix", dest="prefix", help="Network prefix for segments (defaults to 21)", default = "21")
    parser.add_option("-a", "--assign", action="store_true", dest="assign", default=False,
                      help="If specified, assign next available network segment as a vsys_vnet tag to the target slice")
    parser.add_option("-S", "--slice", dest="pl_slice", default=pl_slice,
                      help="target PlanetLab slice name, for --assign", )

    (options, args) = parser.parse_args()
   
    if not options.pl_user or not options.pl_pwd:
        print "Error: PlanetLab user and password are required to proceed."
        sys.exit(1)

    api = plapi(options.pl_url)
    
    auth = dict(AuthMethod='password', Username=options.pl_user, AuthString=options.pl_pwd)
    assigned = get_assigned(api, auth)
   
    if options.assign:
        vsys_vnet = get_next_available(assigned, options.basenet, int(options.prefix))
        if not vsys_vnet:
            print "Error: There are no available network segments at the moment to assign"
            sys.exit(1)

        print "The next available network segment is %s." % vsys_vnet
        proceed = raw_input ("Do you wish to proceed with the assignment of the vsys_vnet tag? [y/N] ")
        if proceed.lower() in ['yes', 'y']:
            pl_slice = options.pl_slice
            if not pl_slice:
                pl_slice = raw_input ("Please, enter your slice name \n")

            if pl_slice in assigned.values():
                print "Error: This slice already has a tag vsys_vnet assigned!!!"
                sys.exit(1)

            slice_tag_id = assign_vsys_vent(api, auth, vsys_vnet, pl_slice)

            if slice_tag_id and slice_tag_id > 0:
                print "Success: the new slice tag id is %d" % slice_tag_id
            else:
                print "Error: Something wrong happened!"

    else:
        pp = pprint.PrettyPrinter(indent=4)
        pp.pprint(assigned)