from PLC.Method import Method
from PLC.Parameter import Parameter, Mixed
from PLC.Filter import Filter
from PLC.Auth import Auth
from PLC.Nodes import Node, Nodes
from PLC.SliceTags import SliceTag, SliceTags

class GetSliceSshKeys(Method):
    """
    This method exposes the public ssh keys for a slice's slivers.
    It expects a slice name or id, and returns a dictionary on hostnames.
    This method is designed to help third-party software authenticate
    slivers (e.g. the OMF Experiment Controller). 
    For this reason it is accessible with anonymous authentication.
    """

    roles = ['admin', 'pi', 'user', 'tech', 'anonymous' ]

    applicable_fields = {
        'slice_id' : Slice.fields['slice_id'],
        'name' : Slice.fields['name'],
        }

    accepts = [
        Auth(),
        Mixed(Slice.fields['slice_id'],
              Slice.fields['name'])
        ]

    returns = Parameter (dict, " ssh keys hashed on hostnames")

    def call(self, auth, slice_id_or_name):
        filter={}
        if isinstance(int,slice_id_or_name):
            filter['slice_id']=slice_id_or_name
        elif isinstance(str,slice_id_or_name):
            filter['name']=slice_id_or_name
        filter['tagname']='ssh_key'
        # retrieve only sliver tags
        filter['~node_id']=None
        
        # slice_tags don't expose hostname, sigh..
        slice_tags=SliceTags(api,filter)
        node_ids = [st['node_id'] for st in slice_tags]
        # fetch nodes
        nodes=Nodes(api,node_ids)
        # hash on node_id
        nodes_hash=dict([n['node_id'],n['hostname'] for n in nodes])
        # return values hashed on hostname
        return dict([ (nodes_hash[nodes_hash[st['node_id']]],st['value']) for st in slice_tags])