import unittest

from twisted.internet import defer

from mock import Mock, patch

from synapse.util.distributor import Distributor


class DistributorTestCase(unittest.TestCase):

    def setUp(self):
        self.dist = Distributor()

    def test_signal_dispatch(self):
        self.dist.declare("alert")

        observer = Mock()
        self.dist.observe("alert", observer)

        d = self.dist.fire("alert", 1, 2, 3)

        self.assertTrue(d.called)
        observer.assert_called_with(1, 2, 3)

    def test_signal_dispatch_deferred(self):
        self.dist.declare("whine")

        d_inner = defer.Deferred()
        def observer():
            return d_inner
        self.dist.observe("whine", observer)

        d_outer = self.dist.fire("whine")

        self.assertFalse(d_outer.called)

        d_inner.callback(None)
        self.assertTrue(d_outer.called)

    def test_signal_catch(self):
        self.dist.declare("alarm")

        observers = [Mock() for i in 1, 2]
        for o in observers:
            self.dist.observe("alarm", o)

        observers[0].side_effect = Exception("Awoogah!")

        with patch("synapse.util.distributor.logger",
                spec=["warning"]
        ) as mock_logger:
            d = self.dist.fire("alarm", "Go")
            self.assertTrue(d.called)

            observers[0].assert_called_once("Go")
            observers[1].assert_called_once("Go")

            self.assertEquals(mock_logger.warning.call_count, 1)
            self.assertIsInstance(mock_logger.warning.call_args[0][0],
                    str)

    def test_signal_prereg(self):
        observer = Mock()
        self.dist.observe("flare", observer)

        self.dist.declare("flare")
        self.dist.fire("flare", 4, 5)

        observer.assert_called_with(4, 5)

    def test_signal_undeclared(self):
        with self.assertRaises(KeyError):
            self.dist.fire("notification")