from __future__ import absolute_import

import time
from twisted.internet.defer import inlineCallbacks

from ...peerdiscovery.churn import RandomChurn, PingChurn
from ...community import _DEFAULT_ADDRESSES
from ...dht.community import DHTCommunity
from ..base import TestBase
from ..mocking.community import MockCommunity
from ..mocking.endpoint import MockEndpointListener
from ..mocking.ipv8 import MockIPv8


class TestChurn(TestBase):

    def setUp(self):
        super(TestChurn, self).setUp()
        while _DEFAULT_ADDRESSES:
            _DEFAULT_ADDRESSES.pop()

        node_count = 2
        self.overlays = [MockCommunity() for _ in range(node_count)]
        self.strategies = [RandomChurn(self.overlays[i], ping_interval=0.0) for i in range(node_count)]

    def tearDown(self):
        for overlay in self.overlays:
            overlay.unload()
        return super(TestChurn, self).tearDown()

    @inlineCallbacks
    def test_keep_reachable(self):
        """
        Check if we don't remove reachable nodes.
        """
        peer = self.overlays[1].my_peer
        fake_last_response = time.time() - 30
        peer.last_response = fake_last_response
        self.overlays[0].network.add_verified_peer(peer)

        # Node inactive! We should ping it!
        self.strategies[0].take_step()

        yield self.deliver_messages()

        # Node should have responded by now and not be removed.
        self.assertNotEqual(peer.last_response, fake_last_response)
        self.strategies[0].take_step()

        self.assertEqual(len(self.overlays[0].network.verified_peers), 1)

    @inlineCallbacks
    def test_remove_unreachable(self):
        """
        Check if we remove unreachable nodes.
        """
        peer = self.overlays[1].my_peer
        fake_last_response = time.time() - 30
        peer.last_response = fake_last_response
        self.overlays[0].network.add_verified_peer(peer)
        self.overlays[1].endpoint.close()

        # Node inactive! We should ping it!
        self.strategies[0].take_step()

        yield self.deliver_messages()

        # Node should not have responded.
        self.assertEqual(peer.last_response, fake_last_response)
        # Nothing will happen the next 30 seconds, so we forward the clock a bit.
        peer.last_response = 1
        # Now the node should be removed.
        self.strategies[0].take_step()

        self.assertEqual(len(self.overlays[0].network.verified_peers), 0)

    @inlineCallbacks
    def test_no_nodes(self):
        """
        Nothing should happen if we have no nodes to check.
        """
        self.strategies[0].sample_size = 0 # Don't check anything
        peer = self.overlays[1].my_peer
        peer.last_response = 1 # 50 years ago
        self.overlays[0].network.add_verified_peer(peer)

        self.strategies[0].take_step()

        yield self.deliver_messages()

        self.assertEqual(len(self.overlays[0].network.verified_peers), 1)

    @inlineCallbacks
    def test_ping_timeout(self):
        """
        Don't overload inactive nodes with pings, send it once within some timeout.
        """
        peer = self.overlays[1].my_peer
        peer.last_response = time.time() - 30
        self.overlays[0].network.add_verified_peer(peer)
        self.strategies[0].ping_interval = 10000.0
        # Hook up listener
        sniffer = MockEndpointListener(self.overlays[1].endpoint)

        # Node inactive! We should ping it!
        self.strategies[0].take_step()
        # Only once though
        self.strategies[0].take_step()

        yield self.deliver_messages()

        self.assertEqual(len(sniffer.received_packets), 1)

    @inlineCallbacks
    def test_ping_timeout_resend(self):
        """
        Don't overload inactive nodes with pings, send it again after some timeout.
        """
        peer = self.overlays[1].my_peer
        peer.last_response = time.time() - 30
        self.overlays[0].network.add_verified_peer(peer)
        self.strategies[0].ping_interval = -1.0
        # Hook up listener
        sniffer = MockEndpointListener(self.overlays[1].endpoint)

        # Node inactive! We should ping it!
        self.strategies[0].take_step()
        # Timeout has passed, send it again.
        self.strategies[0].take_step()

        yield self.deliver_messages()

        self.assertEqual(len(sniffer.received_packets), 2)


class TestPingChurn(TestBase):

    def setUp(self):
        super(TestPingChurn, self).setUp()

        self.overlays = []
        self.strategies = []

        self.initialize(DHTCommunity, 2)

    def create_node(self, *args, **kwargs):
        peer = MockIPv8(u"low", DHTCommunity)

        self.overlays.append(peer.overlay)
        self.strategies.append(PingChurn(peer.overlay, ping_interval=0.0))

        return peer

    @inlineCallbacks
    def test_ping_all(self):
        yield self.introduce_nodes()
        bucket = self.overlays[0].routing_table.trie[u'']

        node1 = bucket.get(self.overlays[1].my_node_id)
        node1.failed = 1
        node1.last_response = 0

        self.strategies[0].take_step()
        yield self.deliver_messages()

        self.assertTrue(node1.failed == 0)
        self.assertNotEqual(node1.last_response, 0)

    @inlineCallbacks
    def test_ping_all_skip(self):
        yield self.introduce_nodes()
        bucket = self.overlays[0].routing_table.trie[u'']
        node1 = bucket.get(self.overlays[1].my_node_id)
        node1.failed = 1
        node1.last_response = time.time()

        self.strategies[0].take_step()
        self.assertTrue(node1.failed == 1)
