from contextlib import (
    contextmanager,
)
import inspect
from typing import (
    NamedTuple,
)

import pytest
import trio

from libp2p.exceptions import (
    ValidationError,
)
from libp2p.network.stream.exceptions import (
    StreamEOF,
)
from libp2p.peer.id import (
    ID,
)
from libp2p.pubsub.pb import (
    rpc_pb2,
)
from libp2p.pubsub.pubsub import (
    PUBSUB_SIGNING_PREFIX,
    SUBSCRIPTION_CHANNEL_SIZE,
)
from libp2p.tools.constants import (
    MAX_READ_LEN,
)
from libp2p.tools.utils import (
    connect,
)
from libp2p.utils import (
    encode_varint_prefixed,
)
from tests.utils.factories import (
    IDFactory,
    PubsubFactory,
    net_stream_pair_factory,
)
from tests.utils.pubsub.utils import (
    make_pubsub_msg,
)

TESTING_TOPIC = "TEST_SUBSCRIBE"
TESTING_DATA = b"data"


@pytest.mark.trio
async def test_subscribe_and_unsubscribe():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        assert TESTING_TOPIC in pubsubs_fsub[0].topic_ids

        await pubsubs_fsub[0].unsubscribe(TESTING_TOPIC)
        assert TESTING_TOPIC not in pubsubs_fsub[0].topic_ids


@pytest.mark.trio
async def test_re_subscribe():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        assert TESTING_TOPIC in pubsubs_fsub[0].topic_ids

        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        assert TESTING_TOPIC in pubsubs_fsub[0].topic_ids


@pytest.mark.trio
async def test_re_unsubscribe():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        # Unsubscribe from topic we didn't even subscribe to
        assert "NOT_MY_TOPIC" not in pubsubs_fsub[0].topic_ids
        await pubsubs_fsub[0].unsubscribe("NOT_MY_TOPIC")
        assert "NOT_MY_TOPIC" not in pubsubs_fsub[0].topic_ids

        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        assert TESTING_TOPIC in pubsubs_fsub[0].topic_ids

        await pubsubs_fsub[0].unsubscribe(TESTING_TOPIC)
        assert TESTING_TOPIC not in pubsubs_fsub[0].topic_ids

        await pubsubs_fsub[0].unsubscribe(TESTING_TOPIC)
        assert TESTING_TOPIC not in pubsubs_fsub[0].topic_ids


@pytest.mark.trio
async def test_peers_subscribe():
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        await connect(pubsubs_fsub[0].host, pubsubs_fsub[1].host)
        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        # Yield to let 0 notify 1
        await trio.sleep(1)
        assert pubsubs_fsub[0].my_id in pubsubs_fsub[1].peer_topics[TESTING_TOPIC]
        await pubsubs_fsub[0].unsubscribe(TESTING_TOPIC)
        # Yield to let 0 notify 1
        await trio.sleep(1)
        assert pubsubs_fsub[0].my_id not in pubsubs_fsub[1].peer_topics[TESTING_TOPIC]


@pytest.mark.trio
async def test_get_hello_packet():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:

        def _get_hello_packet_topic_ids():
            packet = pubsubs_fsub[0].get_hello_packet()
            return tuple(sub.topicid for sub in packet.subscriptions)

        # Test: No subscription, so there should not be any topic ids in the
        # hello packet.
        assert len(_get_hello_packet_topic_ids()) == 0

        # Test: After subscriptions, topic ids should be in the hello packet.
        topic_ids = ["t", "o", "p", "i", "c"]
        for topic in topic_ids:
            await pubsubs_fsub[0].subscribe(topic)
        topic_ids_in_hello = _get_hello_packet_topic_ids()
        for topic in topic_ids:
            assert topic in topic_ids_in_hello


@pytest.mark.trio
async def test_set_and_remove_topic_validator():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        is_sync_validator_called = False

        def sync_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            nonlocal is_sync_validator_called
            is_sync_validator_called = True
            return True

        is_async_validator_called = False

        async def async_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            nonlocal is_async_validator_called
            is_async_validator_called = True
            await trio.lowlevel.checkpoint()
            return True

        topic = "TEST_VALIDATOR"

        assert topic not in pubsubs_fsub[0].topic_validators

        # Register sync validator
        pubsubs_fsub[0].set_topic_validator(topic, sync_validator, False)

        assert topic in pubsubs_fsub[0].topic_validators
        topic_validator = pubsubs_fsub[0].topic_validators[topic]
        assert not topic_validator.is_async

        # Validate with sync validator
        test_msg = make_pubsub_msg(
            origin_id=IDFactory(),
            topic_ids=[topic],
            data=b"test",
            seqno=b"\x00" * 8,
        )
        topic_validator.validator(IDFactory(), test_msg)

        assert is_sync_validator_called
        assert not is_async_validator_called

        # Register with async validator
        pubsubs_fsub[0].set_topic_validator(topic, async_validator, True)

        is_sync_validator_called = False
        assert topic in pubsubs_fsub[0].topic_validators
        topic_validator = pubsubs_fsub[0].topic_validators[topic]
        assert topic_validator.is_async

        # Validate with async validator
        test_msg = make_pubsub_msg(
            origin_id=IDFactory(),
            topic_ids=[topic],
            data=b"test",
            seqno=b"\x00" * 8,
        )
        validator = topic_validator.validator
        if topic_validator.is_async:
            import inspect

            if inspect.iscoroutinefunction(validator):
                await validator(IDFactory(), test_msg)
        else:
            validator(IDFactory(), test_msg)

        assert is_async_validator_called
        assert not is_sync_validator_called

        # Remove validator
        pubsubs_fsub[0].remove_topic_validator(topic)
        assert topic not in pubsubs_fsub[0].topic_validators


@pytest.mark.trio
async def test_get_msg_validators():
    calls = [0, 0]  # [sync, async]

    def sync_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
        calls[0] += 1
        return True

    async def async_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
        calls[1] += 1
        await trio.lowlevel.checkpoint()
        return True

    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        topic_1 = "TEST_VALIDATOR_1"
        topic_2 = "TEST_VALIDATOR_2"
        topic_3 = "TEST_VALIDATOR_3"

        # Register sync validator for topic 1 and 2
        pubsubs_fsub[0].set_topic_validator(topic_1, sync_validator, False)
        pubsubs_fsub[0].set_topic_validator(topic_2, sync_validator, False)

        # Register async validator for topic 3
        pubsubs_fsub[0].set_topic_validator(topic_3, async_validator, True)

        msg = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=[topic_1, topic_2, topic_3],
            data=b"1234",
            seqno=b"\x00" * 8,
        )

        topic_validators = pubsubs_fsub[0].get_msg_validators(msg)
        for topic_validator in topic_validators:
            validator = topic_validator.validator
            if topic_validator.is_async:
                if inspect.iscoroutinefunction(validator):
                    await validator(IDFactory(), msg)
            else:
                validator(IDFactory(), msg)

        assert calls[0] == 2
        assert calls[1] == 1


@pytest.mark.parametrize(
    "is_topic_1_val_passed, is_topic_2_val_passed",
    ((False, True), (True, False), (True, True)),
)
@pytest.mark.trio
async def test_validate_msg(is_topic_1_val_passed, is_topic_2_val_passed):
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:

        def passed_sync_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            return True

        def failed_sync_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            return False

        async def passed_async_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            await trio.lowlevel.checkpoint()
            return True

        async def failed_async_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
            await trio.lowlevel.checkpoint()
            return False

        topic_1 = "TEST_SYNC_VALIDATOR"
        topic_2 = "TEST_ASYNC_VALIDATOR"

        if is_topic_1_val_passed:
            pubsubs_fsub[0].set_topic_validator(topic_1, passed_sync_validator, False)
        else:
            pubsubs_fsub[0].set_topic_validator(topic_1, failed_sync_validator, False)

        if is_topic_2_val_passed:
            pubsubs_fsub[0].set_topic_validator(topic_2, passed_async_validator, True)
        else:
            pubsubs_fsub[0].set_topic_validator(topic_2, failed_async_validator, True)

        msg = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=[topic_1, topic_2],
            data=b"1234",
            seqno=b"\x00" * 8,
        )

        if is_topic_1_val_passed and is_topic_2_val_passed:
            await pubsubs_fsub[0].validate_msg(pubsubs_fsub[0].my_id, msg)
        else:
            with pytest.raises(ValidationError):
                await pubsubs_fsub[0].validate_msg(pubsubs_fsub[0].my_id, msg)


@pytest.mark.trio
async def test_continuously_read_stream(monkeypatch, nursery, security_protocol):
    async def wait_for_event_occurring(event):
        await trio.lowlevel.checkpoint()
        with trio.fail_after(0.1):
            await event.wait()

    class Events(NamedTuple):
        push_msg: trio.Event
        handle_subscription: trio.Event
        handle_rpc: trio.Event

    @contextmanager
    def mock_methods():
        event_push_msg = trio.Event()
        event_handle_subscription = trio.Event()
        event_handle_rpc = trio.Event()

        async def mock_push_msg(msg_forwarder, msg):
            event_push_msg.set()
            await trio.lowlevel.checkpoint()

        def mock_handle_subscription(origin_id, sub_message):
            event_handle_subscription.set()

        async def mock_handle_rpc(rpc, sender_peer_id):
            event_handle_rpc.set()
            await trio.lowlevel.checkpoint()

        with monkeypatch.context() as m:
            m.setattr(pubsubs_fsub[0], "push_msg", mock_push_msg)
            m.setattr(pubsubs_fsub[0], "handle_subscription", mock_handle_subscription)
            m.setattr(pubsubs_fsub[0].router, "handle_rpc", mock_handle_rpc)
            yield Events(event_push_msg, event_handle_subscription, event_handle_rpc)

    async with (
        PubsubFactory.create_batch_with_floodsub(
            1, security_protocol=security_protocol
        ) as pubsubs_fsub,
        net_stream_pair_factory(security_protocol=security_protocol) as stream_pair,
    ):
        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        # Kick off the task `continuously_read_stream`
        nursery.start_soon(pubsubs_fsub[0].continuously_read_stream, stream_pair[0])

        # Test: `push_msg` is called when publishing to a subscribed topic.
        publish_subscribed_topic = rpc_pb2.RPC(
            publish=[rpc_pb2.Message(topicIDs=[TESTING_TOPIC])]
        )
        with mock_methods() as events:
            await stream_pair[1].write(
                encode_varint_prefixed(publish_subscribed_topic.SerializeToString())
            )
            await wait_for_event_occurring(events.push_msg)
            # Make sure the other events are not emitted.
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.handle_subscription)
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.handle_rpc)

        # Test: `push_msg` is not called when publishing to a topic-not-subscribed.
        publish_not_subscribed_topic = rpc_pb2.RPC(
            publish=[rpc_pb2.Message(topicIDs=["NOT_SUBSCRIBED"])]
        )
        with mock_methods() as events:
            await stream_pair[1].write(
                encode_varint_prefixed(publish_not_subscribed_topic.SerializeToString())
            )
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.push_msg)

        # Test: `handle_subscription` is called when a subscription message is received.
        subscription_msg = rpc_pb2.RPC(subscriptions=[rpc_pb2.RPC.SubOpts()])
        with mock_methods() as events:
            await stream_pair[1].write(
                encode_varint_prefixed(subscription_msg.SerializeToString())
            )
            await wait_for_event_occurring(events.handle_subscription)
            # Make sure the other events are not emitted.
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.push_msg)
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.handle_rpc)

        # Test: `handle_rpc` is called when a control message is received.
        control_msg = rpc_pb2.RPC(control=rpc_pb2.ControlMessage())
        with mock_methods() as events:
            await stream_pair[1].write(
                encode_varint_prefixed(control_msg.SerializeToString())
            )
            await wait_for_event_occurring(events.handle_rpc)
            # Make sure the other events are not emitted.
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.push_msg)
            with pytest.raises(trio.TooSlowError):
                await wait_for_event_occurring(events.handle_subscription)
        # After all messages, close the write end to signal EOF
        await stream_pair[1].close()
        # Now reading should raise StreamEOF
        with pytest.raises(StreamEOF):
            await stream_pair[0].read(1)


# TODO: Add the following tests after they are aligned with Go.
#   (Issue #191: https://github.com/libp2p/py-libp2p/issues/191)
#         - `test_stream_handler`
#         - `test_handle_peer_queue`


@pytest.mark.trio
async def test_handle_subscription():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        assert len(pubsubs_fsub[0].peer_topics) == 0
        sub_msg_0 = rpc_pb2.RPC.SubOpts(subscribe=True, topicid=TESTING_TOPIC)
        peer_ids = [IDFactory() for _ in range(2)]
        # Test: One peer is subscribed
        pubsubs_fsub[0].handle_subscription(peer_ids[0], sub_msg_0)
        assert (
            len(pubsubs_fsub[0].peer_topics) == 1
            and TESTING_TOPIC in pubsubs_fsub[0].peer_topics
        )
        assert len(pubsubs_fsub[0].peer_topics[TESTING_TOPIC]) == 1
        assert peer_ids[0] in pubsubs_fsub[0].peer_topics[TESTING_TOPIC]
        # Test: Another peer is subscribed
        pubsubs_fsub[0].handle_subscription(peer_ids[1], sub_msg_0)
        assert len(pubsubs_fsub[0].peer_topics) == 1
        assert len(pubsubs_fsub[0].peer_topics[TESTING_TOPIC]) == 2
        assert peer_ids[1] in pubsubs_fsub[0].peer_topics[TESTING_TOPIC]
        # Test: Subscribe to another topic
        another_topic = "ANOTHER_TOPIC"
        sub_msg_1 = rpc_pb2.RPC.SubOpts(subscribe=True, topicid=another_topic)
        pubsubs_fsub[0].handle_subscription(peer_ids[0], sub_msg_1)
        assert len(pubsubs_fsub[0].peer_topics) == 2
        assert another_topic in pubsubs_fsub[0].peer_topics
        assert peer_ids[0] in pubsubs_fsub[0].peer_topics[another_topic]
        # Test: unsubscribe
        unsub_msg = rpc_pb2.RPC.SubOpts(subscribe=False, topicid=TESTING_TOPIC)
        pubsubs_fsub[0].handle_subscription(peer_ids[0], unsub_msg)
        assert peer_ids[0] not in pubsubs_fsub[0].peer_topics[TESTING_TOPIC]


@pytest.mark.trio
async def test_handle_talk():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        sub = await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        msg_0 = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=[TESTING_TOPIC],
            data=b"1234",
            seqno=b"\x00" * 8,
        )
        pubsubs_fsub[0].notify_subscriptions(msg_0)
        msg_1 = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=["NOT_SUBSCRIBED"],
            data=b"1234",
            seqno=b"\x11" * 8,
        )
        pubsubs_fsub[0].notify_subscriptions(msg_1)
        assert (
            len(pubsubs_fsub[0].topic_ids) == 1
            and sub == pubsubs_fsub[0].subscribed_topics_receive[TESTING_TOPIC]
        )
        assert (await sub.get()) == msg_0


@pytest.mark.trio
async def test_message_all_peers(monkeypatch, security_protocol):
    async with (
        PubsubFactory.create_batch_with_floodsub(
            1, security_protocol=security_protocol
        ) as pubsubs_fsub,
        net_stream_pair_factory(security_protocol=security_protocol) as stream_pair,
    ):
        peer_id = IDFactory()
        mock_peers = {peer_id: stream_pair[0]}
        with monkeypatch.context() as m:
            m.setattr(pubsubs_fsub[0], "peers", mock_peers)

            empty_rpc = rpc_pb2.RPC()
            empty_rpc_bytes = empty_rpc.SerializeToString()
            empty_rpc_bytes_len_prefixed = encode_varint_prefixed(empty_rpc_bytes)
            await pubsubs_fsub[0].message_all_peers(empty_rpc_bytes)
            assert (
                await stream_pair[1].read(MAX_READ_LEN)
            ) == empty_rpc_bytes_len_prefixed


@pytest.mark.trio
async def test_subscribe_and_publish():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]

        list_data = [b"d0", b"d1"]
        event_receive_data_started = trio.Event()

        async def publish_data(topic):
            await event_receive_data_started.wait()
            for data in list_data:
                await pubsub.publish(topic, data)

        async def receive_data(topic):
            i = 0
            event_receive_data_started.set()
            assert topic not in pubsub.topic_ids
            subscription = await pubsub.subscribe(topic)
            async with subscription:
                assert topic in pubsub.topic_ids
                async for msg in subscription:
                    assert msg.data == list_data[i]
                    i += 1
                    if i == len(list_data):
                        break
            assert topic not in pubsub.topic_ids

        async with trio.open_nursery() as nursery:
            nursery.start_soon(receive_data, TESTING_TOPIC)
            nursery.start_soon(publish_data, TESTING_TOPIC)


@pytest.mark.trio
async def test_subscribe_and_publish_full_channel():
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]

        extra_data_0 = b"extra_data_0"
        extra_data_1 = b"extra_data_1"

        # Test: Subscription channel is of size `SUBSCRIPTION_CHANNEL_SIZE`.
        #   When the channel is full, new received messages are dropped.
        #   After the channel has empty slot, the channel can receive new messages.

        # Assume `SUBSCRIPTION_CHANNEL_SIZE` is smaller than `2**(4*8)`.
        list_data = [i.to_bytes(4, "big") for i in range(SUBSCRIPTION_CHANNEL_SIZE)]
        # Expect `extra_data_0` is dropped and `extra_data_1` is appended.
        expected_list_data = list_data + [extra_data_1]

        subscription = await pubsub.subscribe(TESTING_TOPIC)
        for data in list_data:
            await pubsub.publish(TESTING_TOPIC, data)

        # Publish `extra_data_0` which should be dropped since the channel is
        # already full.
        await pubsub.publish(TESTING_TOPIC, extra_data_0)
        # Consume a message and there is an empty slot in the channel.
        assert (await subscription.get()).data == expected_list_data.pop(0)
        # Publish `extra_data_1` which should be appended to the channel.
        await pubsub.publish(TESTING_TOPIC, extra_data_1)

        for expected_data in expected_list_data:
            assert (await subscription.get()).data == expected_data


@pytest.mark.trio
async def test_publish_push_msg_is_called(monkeypatch):
    msg_forwarders = []
    msgs = []

    async def push_msg(msg_forwarder, msg):
        msg_forwarders.append(msg_forwarder)
        msgs.append(msg)
        await trio.lowlevel.checkpoint()

    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        with monkeypatch.context() as m:
            m.setattr(pubsubs_fsub[0], "push_msg", push_msg)

            await pubsubs_fsub[0].publish(TESTING_TOPIC, TESTING_DATA)
            await pubsubs_fsub[0].publish(TESTING_TOPIC, TESTING_DATA)

            assert len(msgs) == 2, (
                "`push_msg` should be called every time `publish` is called"
            )
            assert (msg_forwarders[0] == msg_forwarders[1]) and (
                msg_forwarders[1] == pubsubs_fsub[0].my_id
            )
            assert msgs[0].seqno != msgs[1].seqno, (
                "`seqno` should be different every time"
            )


@pytest.mark.trio
async def test_push_msg(monkeypatch):
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        msg_0 = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=[TESTING_TOPIC],
            data=TESTING_DATA,
            seqno=b"\x00" * 8,
        )

        @contextmanager
        def mock_router_publish():
            event = trio.Event()

            async def router_publish(*args, **kwargs):
                event.set()
                await trio.lowlevel.checkpoint()

            with monkeypatch.context() as m:
                m.setattr(pubsubs_fsub[0].router, "publish", router_publish)
                yield event

        with mock_router_publish() as event:
            # Test: `msg` is not seen before `push_msg`, and is seen after `push_msg`.
            assert not pubsubs_fsub[0]._is_msg_seen(msg_0)
            await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg_0)
            assert pubsubs_fsub[0]._is_msg_seen(msg_0)
            # Test: Ensure `router.publish` is called in `push_msg`
            with trio.fail_after(0.1):
                await event.wait()

        with mock_router_publish() as event:
            # Test: `push_msg` the message again and it will be reject.
            #   `router_publish` is not called then.
            await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg_0)
            await trio.sleep(0.01)
            assert not event.is_set()

            # Test: `push_msg` a new msg but forwarder as not self, it will be reject.
            #   `router_publish` is not called then.
            msg_0A = make_pubsub_msg(
                origin_id=pubsubs_fsub[0].my_id,
                topic_ids=[TESTING_TOPIC],
                data=TESTING_DATA,
                seqno=b"\x33" * 8,
            )
            await pubsubs_fsub[0].push_msg(pubsubs_fsub[1].my_id, msg_0A)
            await trio.sleep(0.01)
            assert not event.is_set()

            sub = await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
            # Test: `push_msg` succeeds with another unseen msg.
            msg_1 = make_pubsub_msg(
                origin_id=pubsubs_fsub[0].my_id,
                topic_ids=[TESTING_TOPIC],
                data=TESTING_DATA,
                seqno=b"\x11" * 8,
            )
            assert not pubsubs_fsub[0]._is_msg_seen(msg_1)
            await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg_1)
            assert pubsubs_fsub[0]._is_msg_seen(msg_1)
            with trio.fail_after(0.1):
                await event.wait()
            # Test: Subscribers are notified when `push_msg` new messages.
            assert (await sub.get()) == msg_1

        with mock_router_publish() as event:
            # Test: add a topic validator and `push_msg` the message that
            # does not pass the validation.
            # `router_publish` is not called then.
            def failed_sync_validator(peer_id: ID, msg: rpc_pb2.Message) -> bool:
                return False

            pubsubs_fsub[0].set_topic_validator(
                TESTING_TOPIC, failed_sync_validator, False
            )

            msg_2 = make_pubsub_msg(
                origin_id=pubsubs_fsub[0].my_id,
                topic_ids=[TESTING_TOPIC],
                data=TESTING_DATA,
                seqno=b"\x22" * 8,
            )

            await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg_2)
            await trio.sleep(0.01)
            assert not event.is_set()


@pytest.mark.trio
async def test_strict_signing():
    async with PubsubFactory.create_batch_with_floodsub(
        2, strict_signing=True
    ) as pubsubs_fsub:
        await connect(pubsubs_fsub[0].host, pubsubs_fsub[1].host)
        await pubsubs_fsub[0].subscribe(TESTING_TOPIC)
        await pubsubs_fsub[1].subscribe(TESTING_TOPIC)
        await trio.sleep(1)

        await pubsubs_fsub[0].publish(TESTING_TOPIC, TESTING_DATA)
        await trio.sleep(1)

        assert pubsubs_fsub[0].seen_messages.length() == 1
        assert pubsubs_fsub[1].seen_messages.length() == 1


@pytest.mark.trio
async def test_strict_signing_failed_validation(monkeypatch):
    async with PubsubFactory.create_batch_with_floodsub(
        2, strict_signing=True
    ) as pubsubs_fsub:
        msg = make_pubsub_msg(
            origin_id=pubsubs_fsub[0].my_id,
            topic_ids=[TESTING_TOPIC],
            data=TESTING_DATA,
            seqno=b"\x00" * 8,
        )
        priv_key = pubsubs_fsub[0].sign_key
        assert priv_key is not None, (
            "Private key should not be None when strict_signing=True"
        )
        signature = priv_key.sign(
            PUBSUB_SIGNING_PREFIX.encode() + msg.SerializeToString()
        )

        event = trio.Event()

        def _is_msg_seen(msg):
            return False

        # Use router publish to check if `push_msg` succeed.
        async def router_publish(*args, **kwargs):
            await trio.lowlevel.checkpoint()
            # The event will only be set if `push_msg` succeed.
            event.set()

        monkeypatch.setattr(pubsubs_fsub[0], "_is_msg_seen", _is_msg_seen)
        monkeypatch.setattr(pubsubs_fsub[0].router, "publish", router_publish)

        # Test: no signature attached in `msg`
        await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
        await trio.sleep(0.01)
        assert not event.is_set()

        # Test: `msg.key` does not match `msg.from_id`
        msg.key = pubsubs_fsub[1].host.get_public_key().serialize()
        msg.signature = signature
        await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
        await trio.sleep(0.01)
        assert not event.is_set()

        # Test: invalid signature
        msg.key = pubsubs_fsub[0].host.get_public_key().serialize()
        msg.signature = b"\x12" * 100
        await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
        await trio.sleep(0.01)
        assert not event.is_set()

        # Finally, assert the signature indeed will pass validation
        msg.key = pubsubs_fsub[0].host.get_public_key().serialize()
        msg.signature = signature
        await pubsubs_fsub[0].push_msg(pubsubs_fsub[0].my_id, msg)
        await trio.sleep(0.01)
        assert event.is_set()


@pytest.mark.trio
async def test_blacklist_basic_operations():
    """Test basic blacklist operations: add, remove, check, clear."""
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]

        # Create test peer IDs
        peer1 = IDFactory()
        peer2 = IDFactory()
        peer3 = IDFactory()

        # Initially no peers should be blacklisted
        assert len(pubsub.get_blacklisted_peers()) == 0
        assert not pubsub.is_peer_blacklisted(peer1)
        assert not pubsub.is_peer_blacklisted(peer2)
        assert not pubsub.is_peer_blacklisted(peer3)

        # Add peers to blacklist
        pubsub.add_to_blacklist(peer1)
        pubsub.add_to_blacklist(peer2)

        # Check blacklist state
        assert len(pubsub.get_blacklisted_peers()) == 2
        assert pubsub.is_peer_blacklisted(peer1)
        assert pubsub.is_peer_blacklisted(peer2)
        assert not pubsub.is_peer_blacklisted(peer3)

        # Remove one peer from blacklist
        pubsub.remove_from_blacklist(peer1)

        # Check state after removal
        assert len(pubsub.get_blacklisted_peers()) == 1
        assert not pubsub.is_peer_blacklisted(peer1)
        assert pubsub.is_peer_blacklisted(peer2)
        assert not pubsub.is_peer_blacklisted(peer3)

        # Add peer3 and then clear all
        pubsub.add_to_blacklist(peer3)
        assert len(pubsub.get_blacklisted_peers()) == 2

        pubsub.clear_blacklist()
        assert len(pubsub.get_blacklisted_peers()) == 0
        assert not pubsub.is_peer_blacklisted(peer1)
        assert not pubsub.is_peer_blacklisted(peer2)
        assert not pubsub.is_peer_blacklisted(peer3)

        # Test duplicate additions (should not increase size)
        pubsub.add_to_blacklist(peer1)
        pubsub.add_to_blacklist(peer1)
        assert len(pubsub.get_blacklisted_peers()) == 1

        # Test removing non-blacklisted peer (should not cause errors)
        pubsub.remove_from_blacklist(peer2)
        assert len(pubsub.get_blacklisted_peers()) == 1


@pytest.mark.trio
async def test_blacklist_blocks_new_peer_connections(monkeypatch):
    """Test that blacklisted peers are rejected when trying to connect."""
    async with PubsubFactory.create_batch_with_floodsub(1) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]

        # Create a blacklisted peer ID
        blacklisted_peer = IDFactory()

        # Add peer to blacklist
        pubsub.add_to_blacklist(blacklisted_peer)

        new_stream_called = False

        async def mock_new_stream(*args, **kwargs):
            nonlocal new_stream_called
            new_stream_called = True
            # Create a mock stream
            from unittest.mock import (
                AsyncMock,
                Mock,
            )

            mock_stream = Mock()
            mock_stream.write = AsyncMock()
            mock_stream.reset = AsyncMock()
            mock_stream.get_protocol = Mock(return_value="test_protocol")
            return mock_stream

        router_add_peer_called = False

        def mock_add_peer(*args, **kwargs):
            nonlocal router_add_peer_called
            router_add_peer_called = True

        with monkeypatch.context() as m:
            m.setattr(pubsub.host, "new_stream", mock_new_stream)
            m.setattr(pubsub.router, "add_peer", mock_add_peer)

            # Attempt to handle the blacklisted peer
            await pubsub._handle_new_peer(blacklisted_peer)

            # Verify that both new_stream and router.add_peer was not called
            assert not new_stream_called, (
                "new_stream should be not be called to get hello packet"
            )
            assert not router_add_peer_called, (
                "Router.add_peer should not be called for blacklisted peer"
            )
            assert blacklisted_peer not in pubsub.peers, (
                "Blacklisted peer should not be in peers dict"
            )


@pytest.mark.trio
async def test_blacklist_blocks_messages_from_blacklisted_originator():
    """Test that messages from blacklisted originator (from field) are rejected."""
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]
        blacklisted_originator = pubsubs_fsub[1].my_id  # Use existing peer ID

        # Add the originator to blacklist
        pubsub.add_to_blacklist(blacklisted_originator)

        # Create a message with blacklisted originator
        msg = make_pubsub_msg(
            origin_id=blacklisted_originator,
            topic_ids=[TESTING_TOPIC],
            data=TESTING_DATA,
            seqno=b"\x00" * 8,
        )

        # Subscribe to the topic
        await pubsub.subscribe(TESTING_TOPIC)

        # Track if router.publish is called
        router_publish_called = False

        async def mock_router_publish(msg_forwarder: ID, pubsub_msg: rpc_pb2.Message):
            nonlocal router_publish_called
            router_publish_called = True
            await trio.lowlevel.checkpoint()

        original_router_publish = pubsub.router.publish
        pubsub.router.publish = mock_router_publish

        try:
            # Attempt to push message from blacklisted originator
            await pubsub.push_msg(blacklisted_originator, msg)

            # Verify message was rejected
            assert not router_publish_called, (
                "Router.publish should not be called for blacklisted originator"
            )
            assert not pubsub._is_msg_seen(msg), (
                "Message from blacklisted originator should not be marked as seen"
            )

        finally:
            pubsub.router.publish = original_router_publish


@pytest.mark.trio
async def test_blacklist_allows_non_blacklisted_peers():
    """Test that non-blacklisted peers can send messages normally."""
    async with PubsubFactory.create_batch_with_floodsub(3) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]
        allowed_peer = pubsubs_fsub[1].my_id
        blacklisted_peer = pubsubs_fsub[2].my_id

        # Blacklist one peer but not the other
        pubsub.add_to_blacklist(blacklisted_peer)

        # Create messages from both peers
        msg_from_allowed = make_pubsub_msg(
            origin_id=allowed_peer,
            topic_ids=[TESTING_TOPIC],
            data=b"allowed_data",
            seqno=b"\x00" * 8,
        )

        msg_from_blacklisted = make_pubsub_msg(
            origin_id=blacklisted_peer,
            topic_ids=[TESTING_TOPIC],
            data=b"blacklisted_data",
            seqno=b"\x11" * 8,
        )

        # Subscribe to the topic
        sub = await pubsub.subscribe(TESTING_TOPIC)

        # Track router.publish calls
        router_publish_calls = []

        async def mock_router_publish(msg_forwarder: ID, pubsub_msg: rpc_pb2.Message):
            router_publish_calls.append((msg_forwarder, pubsub_msg))
            await trio.lowlevel.checkpoint()

        original_router_publish = pubsub.router.publish
        pubsub.router.publish = mock_router_publish

        try:
            # Send message from allowed peer (should succeed)
            await pubsub.push_msg(allowed_peer, msg_from_allowed)

            # Send message from blacklisted peer (should be rejected)
            await pubsub.push_msg(allowed_peer, msg_from_blacklisted)

            # Verify only allowed message was processed
            assert len(router_publish_calls) == 1, (
                "Only one message should be processed"
            )
            assert pubsub._is_msg_seen(msg_from_allowed), (
                "Allowed message should be marked as seen"
            )
            assert not pubsub._is_msg_seen(msg_from_blacklisted), (
                "Blacklisted message should not be marked as seen"
            )

            # Verify subscription received the allowed message
            received_msg = await sub.get()
            assert received_msg.data == b"allowed_data"

        finally:
            pubsub.router.publish = original_router_publish


@pytest.mark.trio
async def test_blacklist_integration_with_existing_functionality():
    """Test that blacklisting works correctly with existing pubsub functionality."""
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]
        other_peer = pubsubs_fsub[1].my_id

        # Test that seen messages cache still works with blacklisting
        pubsub.add_to_blacklist(other_peer)

        msg = make_pubsub_msg(
            origin_id=other_peer,
            topic_ids=[TESTING_TOPIC],
            data=TESTING_DATA,
            seqno=b"\x00" * 8,
        )

        # First attempt - should be rejected due to blacklist
        await pubsub.push_msg(other_peer, msg)
        assert not pubsub._is_msg_seen(msg)

        # Remove from blacklist
        pubsub.remove_from_blacklist(other_peer)

        # Now the message should be processed
        await pubsub.subscribe(TESTING_TOPIC)
        await pubsub.push_msg(other_peer, msg)
        assert pubsub._is_msg_seen(msg)

        # If we try to send the same message again, it should be rejected
        # due to seen cache (not blacklist)
        router_publish_called = False

        async def mock_router_publish(msg_forwarder: ID, pubsub_msg: rpc_pb2.Message):
            nonlocal router_publish_called
            router_publish_called = True
            await trio.lowlevel.checkpoint()

        original_router_publish = pubsub.router.publish
        pubsub.router.publish = mock_router_publish

        try:
            await pubsub.push_msg(other_peer, msg)
            assert not router_publish_called, (
                "Duplicate message should be rejected by seen cache"
            )
        finally:
            pubsub.router.publish = original_router_publish


@pytest.mark.trio
async def test_blacklist_blocks_messages_from_blacklisted_source():
    """Test that messages from blacklisted source (forwarder) are rejected."""
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        pubsub = pubsubs_fsub[0]
        blacklisted_forwarder = pubsubs_fsub[1].my_id

        # Add the forwarder to blacklist
        pubsub.add_to_blacklist(blacklisted_forwarder)

        # Create a message
        msg = make_pubsub_msg(
            origin_id=pubsubs_fsub[1].my_id,
            topic_ids=[TESTING_TOPIC],
            data=TESTING_DATA,
            seqno=b"\x00" * 8,
        )

        # Subscribe to the topic so we can check if message is processed
        await pubsub.subscribe(TESTING_TOPIC)

        # Track if router.publish is called (it shouldn't be for blacklisted forwarder)
        router_publish_called = False

        async def mock_router_publish(msg_forwarder: ID, pubsub_msg: rpc_pb2.Message):
            nonlocal router_publish_called
            router_publish_called = True
            await trio.lowlevel.checkpoint()

        original_router_publish = pubsub.router.publish
        pubsub.router.publish = mock_router_publish

        try:
            # Attempt to push message from blacklisted forwarder
            await pubsub.push_msg(blacklisted_forwarder, msg)

            # Verify message was rejected
            assert not router_publish_called, (
                "Router.publish should not be called for blacklisted forwarder"
            )
            assert not pubsub._is_msg_seen(msg), (
                "Message from blacklisted forwarder should not be marked as seen"
            )

        finally:
            pubsub.router.publish = original_router_publish


@pytest.mark.trio
async def test_blacklist_tears_down_existing_connection():
    """
    Verify that if a peer is already in pubsub.peers and pubsub.peer_topics,
    calling add_to_blacklist(peer_id) immediately resets its stream and
    removes it from both places.
    """
    # Create two pubsub instances (floodsub), so they can connect to each other
    async with PubsubFactory.create_batch_with_floodsub(2) as pubsubs_fsub:
        pubsub0, pubsub1 = pubsubs_fsub

        # 1) Connect peer1 to peer0
        await connect(pubsub0.host, pubsub1.host)
        # Give handle_peer_queue some time to run
        await trio.sleep(0.1)

        # After connect, pubsub0.peers should contain pubsub1.my_id
        assert pubsub1.my_id in pubsub0.peers

        # 2) Manually record a subscription from peer1 under TESTING_TOPIC,
        #    so that peer1 shows up in pubsub0.peer_topics[TESTING_TOPIC].
        sub_msg = rpc_pb2.RPC.SubOpts(subscribe=True, topicid=TESTING_TOPIC)
        pubsub0.handle_subscription(pubsub1.my_id, sub_msg)

        assert TESTING_TOPIC in pubsub0.peer_topics
        assert pubsub1.my_id in pubsub0.peer_topics[TESTING_TOPIC]

        # 3) Now blacklist peer1
        pubsub0.add_to_blacklist(pubsub1.my_id)

        # Allow the asynchronous teardown task (_teardown_if_connected) to run
        await trio.sleep(0.1)

        # 4a) pubsub0.peers should no longer contain peer1
        assert pubsub1.my_id not in pubsub0.peers

        # 4b) pubsub0.peer_topics[TESTING_TOPIC] should no longer contain peer1
        #     (or TESTING_TOPIC may have been removed entirely if no other peers remain)
        if TESTING_TOPIC in pubsub0.peer_topics:
            assert pubsub1.my_id not in pubsub0.peer_topics[TESTING_TOPIC]
        else:
            # It’s also fine if the entire topic entry was pruned
            assert TESTING_TOPIC not in pubsub0.peer_topics