import os

from foolscap import Referenceable
from twisted.application import service
from twisted.python.failure import Failure

from amdlib.util.assertutil import precondition

from allmydata.bucketstore import BucketStore
from zope.interface import implements
from allmydata.interfaces import RIStorageServer

class BucketAlreadyExistsError(Exception):
    pass

class StorageServer(service.MultiService, Referenceable):
    implements(RIStorageServer)
    name = 'storageserver'

    def __init__(self, store_dir):
        if not os.path.isdir(store_dir):
            os.mkdir(store_dir)
        service.MultiService.__init__(self)
        self._bucketstore = BucketStore(store_dir)
        self._bucketstore.setServiceParent(self)

    def remote_allocate_bucket(self, verifierid, bucket_num, size, leaser):
        if self._bucketstore.has_bucket(verifierid):
            raise BucketAlreadyExistsError()
        lease = self._bucketstore.allocate_bucket(verifierid, bucket_num, size, leaser)
        return lease

    def remote_get_bucket(self, verifierid):
        return self._bucketstore.get_bucket(verifierid)