import re

from PLC.Faults import *
from PLC.Parameter import Parameter
from PLC.Filter import Filter
from PLC.Debug import profile
from PLC.Table import Row, Table
from PLC.KeyTypes import KeyType, KeyTypes
from PLC.Storage.AlchemyObject import AlchemyObj

class Key(AlchemyObj):
    """
    Representation of a row in the keys table. To use, instantiate with a
    dict of values. Update as you would a dict. Commit to the database
    with sync().
    """

    tablename = 'keys'
    fields = {
        'key_id': Parameter(str, "Key identifier", primary_key=True),
        'key_type': Parameter(str, "Key type"),
        'key': Parameter(str, "Key string", max = 4096), # backwards compatibility
        'name': Parameter(str, "Key name"),
        'uuid': Parameter(str, "Key name", ro=True)
        }

    def sync(self, commit = True, validate = True):
        # sync the nova record and the plc record
        assert 'key' in self
        assert 'name' in self
        AlchemyObj.sync(self, commit=commit, validate=validate)
        nova_key = {
            'public_key': self['key'],
            'name': self['name'] 
        }
        self.object = self.api.client_shell.nova.keypairs.create(**nova_key)
        self['uuid'] = self.object.uuid
        AlchemyObj.insert(self, dict(self))

    def delete(self):
        assert 'key_id' in self
        assert 'name' in self
        self.api.client_shell.nova.keypairs.delete(self.id)

    def validate_public_key(self, key):
        # Key must not be blacklisted
        pass
        return key

    def validate_name(self, name):
        keys = Keys(self.api, name)
        if keys:
            raise PLCInvalidArgument, "Key name alredy in use"

    def validate(self):
        # Basic validation
        NovaObject.validate(self)

        assert 'public_key' in self
        key = self['public_key']

        if self['key_type'] == 'ssh':
            # Accept only SSH version 2 keys without options. From
            # sshd(8):
            #
            # Each protocol version 2 public key consists of: options,
            # keytype, base64 encoded key, comment.  The options field
            # is optional...The comment field is not used for anything
            # (but may be convenient for the user to identify the
            # key). For protocol version 2 the keytype is ``ssh-dss''
            # or ``ssh-rsa''.

            good_ssh_key = r'^.*(?:ssh-dss|ssh-rsa)[ ]+[A-Za-z0-9+/=]+(?: .*)?$'
            if not re.match(good_ssh_key, key, re.IGNORECASE):
                raise PLCInvalidArgument, "Invalid SSH version 2 public key"

    def blacklist(self, commit = True):
        """
        Permanently blacklist key (and all other identical keys),
        preventing it from ever being added again. Because this could
        affect multiple keys associated with multiple accounts, it
        should be admin only.
        """

        assert 'key_id' in self
        assert 'key' in self

        pass

class Keys(list):
    """
    Representation of row(s) from the keys table in the
    database.
    """

    def __init__(self, api, key_filter = None, columns = None):
        self.api = api
        keysManager = self.api.client_shell.nova.keypairs
        keyPairs = []

        if key_filter is not None:
            if isinstance(key_filter, (list, tuple, set, int, long)):
                keyPairs = filter(lambda kp: kp.uuid in key_filter,
                                  keysManager.findall())
            elif isinstance(key_filter, dict):
                keyPairs = keysManager.findall(**key_filter)
            elif isinstnace(key_filter, StringTypes):
                keyPairs = keyManagers.findall(uuid = key_filter)
            else:
                raise PLCInvalidArgument, "Wrong key filter %r"%key_filter

        self.extend(keyPairs)