from sfa.util.faults import *
from sfa.util.namespace import *
from sfa.util.method import Method
from sfa.util.parameter import Parameter
from sfatables.runtime import SFATablesRules
import sys
from sfa.trust.credential import Credential
from sfa.util.sfalogging import logger

class CreateSliver(Method):
    """
    Allocate resources to a slice.  This operation is expected to
    start the allocated resources asynchornously after the operation
    has successfully completed.  Callers can check on the status of
    the resources using SliverStatus.

    @param slice_urn (string) URN of slice to allocate to
    @param credentials ([string]) of credentials
    @param rspec (string) rspec to allocate
    
    """
    interfaces = ['geni_am']
    accepts = [
        Parameter(str, "Slice URN"),
        Parameter(type([str]), "List of credentials"),
        Parameter(str, "RSpec"),
        Parameter(type([]), "List of user information")
        ]
    returns = Parameter(str, "Allocated RSpec")

    def __run_sfatables(self, manager, rules, hrn, origin_hrn, rspec):
        if rules.sorted_rule_list:
            contexts = rules.contexts
            request_context = manager.fetch_context(hrn, origin_hrn, contexts)
            rules.set_context(request_context)
            newrspec = rules.apply(rspec)
        else:    
            newrspec = rspec
        return newrspec


    def call(self, slice_xrn, creds, rspec, users):
        hrn, type = urn_to_hrn(slice_xrn)

        self.api.logger.info("interface: %s\ttarget-hrn: %s\tmethod-name: %s"%(self.api.interface, hrn, self.name))

        # Find the valid credentials
        ValidCreds = self.api.auth.checkCredentials(creds, 'createsliver', hrn)
        origin_hrn = Credential(string=ValidCreds[0]).get_gid_caller().get_hrn()

        manager_base = 'sfa.managers'

        if self.api.interface in ['geni_am']:
            mgr_type = self.api.config.SFA_GENI_AGGREGATE_TYPE
            manager_module = manager_base + ".geni_am_%s" % mgr_type
            manager = __import__(manager_module, fromlist=[manager_base])
            rspec = self.__run_sfatables(manager, SFATablesRules('INCOMING'),
                                         hrn, origin_hrn, rspec)

            return manager.CreateSliver(self.api, slice_xrn, ValidCreds, rspec, users)            
        return ''