import hashlib
from mock import Mock

from fixtures import (
    TempDir,
)

from twisted.application.service import (
    Service,
)

from twisted.trial import unittest
from twisted.internet.defer import succeed, inlineCallbacks
from twisted.python.filepath import (
    FilePath,
)

from foolscap.api import (
    Tub,
)

from .common import (
    SyncTestCase,
    UseTestPlugins,
    MemoryIntroducerClient,
)
from .storage_plugin import (
    DummyStorageClient,
)
from allmydata.util import base32, yamlutil
from allmydata.client import (
    config_from_string,
    create_client_from_config,
)
from allmydata.storage_client import (
    NativeStorageServer,
    StorageFarmBroker,
    _NullStorage,
)
from allmydata.interfaces import (
    IConnectionStatus,
)


class NativeStorageServerWithVersion(NativeStorageServer):
    def __init__(self, version):
        # note: these instances won't work for anything other than
        # get_available_space() because we don't upcall
        self.version = version
    def get_version(self):
        return self.version


class TestNativeStorageServer(unittest.TestCase):
    def test_get_available_space_new(self):
        nss = NativeStorageServerWithVersion(
            { "http://allmydata.org/tahoe/protocols/storage/v1":
                { "maximum-immutable-share-size": 111,
                  "available-space": 222,
                }
            })
        self.failUnlessEqual(nss.get_available_space(), 222)

    def test_get_available_space_old(self):
        nss = NativeStorageServerWithVersion(
            { "http://allmydata.org/tahoe/protocols/storage/v1":
                { "maximum-immutable-share-size": 111,
                }
            })
        self.failUnlessEqual(nss.get_available_space(), 111)

    def test_missing_nickname(self):
        ann = {"anonymous-storage-FURL": "pb://w2hqnbaa25yw4qgcvghl5psa3srpfgw3@tcp:127.0.0.1:51309/vucto2z4fxment3vfxbqecblbf6zyp6x",
               "permutation-seed-base32": "w2hqnbaa25yw4qgcvghl5psa3srpfgw3",
               }
        nss = NativeStorageServer("server_id", ann, None, {})
        self.assertEqual(nss.get_nickname(), "")


class GetConnectionStatus(unittest.TestCase):
    """
    Tests for ``NativeStorageServer.get_connection_status``.
    """
    def test_unrecognized_announcement(self):
        """
        When ``NativeStorageServer`` is constructed with a storage announcement it
        doesn't recognize, its ``get_connection_status`` nevertheless returns
        an object which provides ``IConnectionStatus``.
        """
        # Pretty hard to recognize anything from an empty announcement.
        ann = {}
        nss = NativeStorageServer("server_id", ann, Tub, {})
        nss.start_connecting(lambda: None)
        connection_status = nss.get_connection_status()
        self.assertTrue(IConnectionStatus.providedBy(connection_status))


class UnrecognizedAnnouncement(unittest.TestCase):
    """
    Tests for handling of announcements that aren't recognized and don't use
    *anonymous-storage-FURL*.

    Recognition failure is created by making up something completely novel for
    these tests.  In real use, recognition failure would most likely come from
    an announcement generated by a storage server plugin which is not loaded
    in the client.
    """
    ann = {
        u"name": u"tahoe-lafs-testing-v1",
        u"any-parameter": 12345,
    }
    server_id = b"abc"

    def _tub_maker(self, overrides):
        return Service()

    def native_storage_server(self):
        """
        Make a ``NativeStorageServer`` out of an unrecognizable announcement.
        """
        return NativeStorageServer(
            self.server_id,
            self.ann,
            self._tub_maker,
            {},
        )

    def test_no_exceptions(self):
        """
        ``NativeStorageServer`` can be instantiated with an unrecognized
        announcement.
        """
        self.native_storage_server()

    def test_start_connecting(self):
        """
        ``NativeStorageServer.start_connecting`` does not raise an exception.
        """
        server = self.native_storage_server()
        server.start_connecting(None)

    def test_stop_connecting(self):
        """
        ``NativeStorageServer.stop_connecting`` does not raise an exception.
        """
        server = self.native_storage_server()
        server.start_connecting(None)
        server.stop_connecting()

    def test_try_to_connect(self):
        """
        ``NativeStorageServer.try_to_connect`` does not raise an exception.
        """
        server = self.native_storage_server()
        server.start_connecting(None)
        server.try_to_connect()

    def test_various_data_methods(self):
        """
        The data accessors of ``NativeStorageServer`` that depend on the
        announcement do not raise an exception.
        """
        server = self.native_storage_server()
        server.get_permutation_seed()
        server.get_name()
        server.get_longname()
        server.get_tubid()
        server.get_lease_seed()
        server.get_foolscap_write_enabler_seed()
        server.get_nickname()


class PluginMatchedAnnouncement(SyncTestCase):
    """
    Tests for handling by ``NativeStorageServer`` of storage server
    announcements that are handled by an ``IFoolscapStoragePlugin``.
    """
    @inlineCallbacks
    def setUp(self):
        super(PluginMatchedAnnouncement, self).setUp()
        tempdir = TempDir()
        self.useFixture(tempdir)
        self.basedir = FilePath(tempdir.path)
        self.basedir.child(u"private").makedirs()
        self.useFixture(UseTestPlugins())

        self.config = config_from_string(
            self.basedir.asTextMode().path,
            u"tub.port",
"""
[client]
introducer.furl = pb://tubid@example.invalid/swissnum
storage.plugins = tahoe-lafs-dummy-v1
""",
        )
        self.node = yield create_client_from_config(
            self.config,
            _introducer_factory=MemoryIntroducerClient,
        )
        [self.introducer_client] = self.node.introducer_clients

    def publish(self, server_id, announcement):
        for subscription in self.introducer_client.subscribed_to:
            if subscription.service_name == u"storage":
                subscription.cb(
                    server_id,
                    announcement,
                    *subscription.args,
                    **subscription.kwargs
                )

    def get_storage(self, server_id, node):
        storage_broker = node.get_storage_broker()
        native_storage_server = storage_broker.servers[server_id]
        return native_storage_server._storage

    def test_ignored_non_enabled_plugin(self):
        """
        An announcement that could be matched by a plugin that is not enabled is
        not matched.
        """
        server_id = b"v0-abcdef"
        ann = {
            u"service-name": u"storage",
            # notice how the announcement is for a different storage plugin
            # than the one that is enabled.
            u"name": u"tahoe-lafs-dummy-v2",
        }
        self.publish(server_id, ann)
        storage = self.get_storage(server_id, self.node)
        self.assertIsInstance(storage, _NullStorage)

    def test_enabled_plugin(self):
        """
        An announcement that could be matched by a plugin that is enabled is
        matched and the plugin's storage client is used.
        """
        server_id = b"v0-abcdef"
        ann = {
            u"service-name": u"storage",
            u"name": u"tahoe-lafs-dummy-v1",
        }
        self.publish(server_id, ann)
        storage = self.get_storage(server_id, self.node)
        self.assertIsInstance(storage, DummyStorageClient)


class TestStorageFarmBroker(unittest.TestCase):

    def test_static_servers(self):
        broker = StorageFarmBroker(True, lambda h: Mock())

        key_s = 'v0-1234-1'
        servers_yaml = """\
storage:
  v0-1234-1:
    ann:
      anonymous-storage-FURL: pb://ge@nowhere/fake
      permutation-seed-base32: aaaaaaaaaaaaaaaaaaaaaaaa
"""
        servers = yamlutil.safe_load(servers_yaml)
        permseed = base32.a2b("aaaaaaaaaaaaaaaaaaaaaaaa")
        broker.set_static_servers(servers["storage"])
        self.failUnlessEqual(len(broker._static_server_ids), 1)
        s = broker.servers[key_s]
        self.failUnlessEqual(s.announcement,
                             servers["storage"]["v0-1234-1"]["ann"])
        self.failUnlessEqual(s.get_serverid(), key_s)
        self.assertEqual(s.get_permutation_seed(), permseed)

        # if the Introducer announces the same thing, we're supposed to
        # ignore it

        ann2 = {
            "service-name": "storage",
            "anonymous-storage-FURL": "pb://{}@nowhere/fake2".format(base32.b2a(str(1))),
            "permutation-seed-base32": "bbbbbbbbbbbbbbbbbbbbbbbb",
        }
        broker._got_announcement(key_s, ann2)
        s2 = broker.servers[key_s]
        self.assertIdentical(s2, s)
        self.assertEqual(s2.get_permutation_seed(), permseed)

    def test_static_permutation_seed_pubkey(self):
        broker = StorageFarmBroker(True, lambda h: Mock())
        server_id = "v0-4uazse3xb6uu5qpkb7tel2bm6bpea4jhuigdhqcuvvse7hugtsia"
        k = "4uazse3xb6uu5qpkb7tel2bm6bpea4jhuigdhqcuvvse7hugtsia"
        ann = {
            "anonymous-storage-FURL": "pb://abcde@nowhere/fake",
        }
        broker.set_static_servers({server_id.decode("ascii"): {"ann": ann}})
        s = broker.servers[server_id]
        self.assertEqual(s.get_permutation_seed(), base32.a2b(k))

    def test_static_permutation_seed_explicit(self):
        broker = StorageFarmBroker(True, lambda h: Mock())
        server_id = "v0-4uazse3xb6uu5qpkb7tel2bm6bpea4jhuigdhqcuvvse7hugtsia"
        k = "w5gl5igiexhwmftwzhai5jy2jixn7yx7"
        ann = {
            "anonymous-storage-FURL": "pb://abcde@nowhere/fake",
            "permutation-seed-base32": k,
        }
        broker.set_static_servers({server_id.decode("ascii"): {"ann": ann}})
        s = broker.servers[server_id]
        self.assertEqual(s.get_permutation_seed(), base32.a2b(k))

    def test_static_permutation_seed_hashed(self):
        broker = StorageFarmBroker(True, lambda h: Mock())
        server_id = "unparseable"
        ann = {
            "anonymous-storage-FURL": "pb://abcde@nowhere/fake",
        }
        broker.set_static_servers({server_id.decode("ascii"): {"ann": ann}})
        s = broker.servers[server_id]
        self.assertEqual(s.get_permutation_seed(),
                         hashlib.sha256(server_id).digest())

    @inlineCallbacks
    def test_threshold_reached(self):
        introducer = Mock()
        new_tubs = []
        def make_tub(*args, **kwargs):
            return new_tubs.pop()
        broker = StorageFarmBroker(True, make_tub)
        done = broker.when_connected_enough(5)
        broker.use_introducer(introducer)
        # subscribes to "storage" to learn of new storage nodes
        subscribe = introducer.mock_calls[0]
        self.assertEqual(subscribe[0], 'subscribe_to')
        self.assertEqual(subscribe[1][0], 'storage')
        got_announcement = subscribe[1][1]

        data = {
            "service-name": "storage",
            "anonymous-storage-FURL": None,
            "permutation-seed-base32": "aaaaaaaaaaaaaaaaaaaaaaaa",
        }

        def add_one_server(x):
            data["anonymous-storage-FURL"] = "pb://{}@nowhere/fake".format(base32.b2a(str(x)))
            tub = Mock()
            new_tubs.append(tub)
            got_announcement('v0-1234-{}'.format(x), data)
            self.assertEqual(tub.mock_calls[-1][0], 'connectTo')
            got_connection = tub.mock_calls[-1][1][1]
            rref = Mock()
            rref.callRemote = Mock(return_value=succeed(1234))
            got_connection(rref)

        # first 4 shouldn't trigger connected_threashold
        for x in range(4):
            add_one_server(x)
            self.assertFalse(done.called)

        # ...but the 5th *should* trigger the threshold
        add_one_server(42)

        # so: the OneShotObserverList only notifies via
        # foolscap.eventually() -- which forces the Deferred call
        # through the reactor -- so it's no longer synchronous,
        # meaning that we have to do "real reactor stuff" for the
        # Deferred from when_connected_enough() to actually fire. (or
        # @patch() out the reactor in foolscap.eventually to be a
        # Clock() so we can advance time ourselves, but ... luckily
        # eventually() uses 0 as the timeout currently)

        yield done
        self.assertTrue(done.called)