import pytest

from multidict import MultiDict

from grpclib.const import Status
from grpclib.events import listen, SendRequest, SendMessage, RecvMessage
from grpclib.events import RecvInitialMetadata, RecvTrailingMetadata
from grpclib.testing import ChannelFor
from grpclib.exceptions import GRPCError

from dummy_pb2 import DummyRequest, DummyReply
from dummy_grpc import DummyServiceStub, DummyServiceBase


class DummyService(DummyServiceBase):

    async def UnaryUnary(self, stream):
        await stream.recv_message()
        await stream.send_initial_metadata(metadata={'initial': 'true'})
        await stream.send_message(DummyReply(value='pong'))
        await stream.send_trailing_metadata(metadata={'trailing': 'true'})

    async def UnaryStream(self, stream):
        raise GRPCError(Status.UNIMPLEMENTED)

    async def StreamUnary(self, stream):
        raise GRPCError(Status.UNIMPLEMENTED)

    async def StreamStream(self, stream):
        raise GRPCError(Status.UNIMPLEMENTED)


async def _test(event_type):
    service = DummyService()
    events = []

    async def callback(event_):
        events.append(event_)

    async with ChannelFor([service]) as channel:
        listen(channel, event_type, callback)
        stub = DummyServiceStub(channel)
        reply = await stub.UnaryUnary(DummyRequest(value='ping'),
                                      timeout=1,
                                      metadata={'request': 'true'})
        assert reply == DummyReply(value='pong')

    event, = events
    return event


@pytest.mark.asyncio
async def test_send_request():
    event = await _test(SendRequest)
    assert event.metadata == MultiDict({'request': 'true'})
    assert event.method_name == '/dummy.DummyService/UnaryUnary'
    assert event.deadline.time_remaining() > 0
    assert event.content_type == 'application/grpc+proto'


@pytest.mark.asyncio
async def test_send_message():
    event = await _test(SendMessage)
    assert event.message == DummyRequest(value='ping')


@pytest.mark.asyncio
async def test_recv_message():
    event = await _test(RecvMessage)
    assert event.message == DummyReply(value='pong')


@pytest.mark.asyncio
async def test_recv_initial_metadata():
    event = await _test(RecvInitialMetadata)
    assert event.metadata == MultiDict({'initial': 'true'})


@pytest.mark.asyncio
async def test_recv_trailing_metadata():
    event = await _test(RecvTrailingMetadata)
    assert event.metadata == MultiDict({'trailing': 'true'})