import asyncio

import pytest
import numpy as np

import ray
from ray import serve
import ray.serve.context as context
from ray.serve.backend_worker import create_backend_worker, wrap_to_ray_error
from ray.serve.controller import TrafficPolicy
from ray.serve.request_params import RequestMetadata
from ray.serve.router import Router
from ray.serve.config import BackendConfig
from ray.serve.exceptions import RayServeException

pytestmark = pytest.mark.asyncio


def setup_worker(name,
                 func_or_class,
                 init_args=None,
                 backend_config=BackendConfig({})):
    if init_args is None:
        init_args = ()

    @ray.remote
    class WorkerActor:
        def __init__(self):
            self.worker = create_backend_worker(func_or_class)(
                name, name + ":tag", init_args, backend_config)

        def ready(self):
            pass

        async def handle_request(self, *args, **kwargs):
            return await self.worker.handle_request(*args, **kwargs)

        def update_config(self, new_config):
            return self.worker.update_config(new_config)

    worker = WorkerActor.remote()
    ray.get(worker.ready.remote())
    return worker


async def test_runner_wraps_error():
    wrapped = wrap_to_ray_error(Exception())
    assert isinstance(wrapped, ray.exceptions.RayTaskError)


async def test_runner_actor(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    def echo(flask_request, i=None):
        return i

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "prod"

    worker = setup_worker(CONSUMER_NAME, echo)
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)

    q.set_traffic.remote(PRODUCER_NAME, TrafficPolicy({CONSUMER_NAME: 1.0}))

    for query in [333, 444, 555]:
        query_param = RequestMetadata(PRODUCER_NAME,
                                      context.TaskContext.Python)
        result = await q.enqueue_request.remote(query_param, i=query)
        assert result == query


async def test_ray_serve_mixin(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    CONSUMER_NAME = "runner-cls"
    PRODUCER_NAME = "prod-cls"

    class MyAdder:
        def __init__(self, inc):
            self.increment = inc

        def __call__(self, flask_request, i=None):
            return i + self.increment

    worker = setup_worker(CONSUMER_NAME, MyAdder, init_args=(3, ))
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)

    q.set_traffic.remote(PRODUCER_NAME, TrafficPolicy({CONSUMER_NAME: 1.0}))

    for query in [333, 444, 555]:
        query_param = RequestMetadata(PRODUCER_NAME,
                                      context.TaskContext.Python)
        result = await q.enqueue_request.remote(query_param, i=query)
        assert result == query + 3


async def test_task_runner_check_context(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    def echo(flask_request, i=None):
        # Accessing the flask_request without web context should throw.
        return flask_request.args["i"]

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "producer"

    worker = setup_worker(CONSUMER_NAME, echo)
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)

    q.set_traffic.remote(PRODUCER_NAME, TrafficPolicy({CONSUMER_NAME: 1.0}))
    query_param = RequestMetadata(PRODUCER_NAME, context.TaskContext.Python)
    result_oid = q.enqueue_request.remote(query_param, i=42)

    with pytest.raises(ray.exceptions.RayTaskError):
        await result_oid


async def test_task_runner_custom_method_single(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    class NonBatcher:
        def a(self, _):
            return "a"

        def b(self, _):
            return "b"

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "producer"

    worker = setup_worker(CONSUMER_NAME, NonBatcher)
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)

    q.set_traffic.remote(PRODUCER_NAME, TrafficPolicy({CONSUMER_NAME: 1.0}))

    query_param = RequestMetadata(
        PRODUCER_NAME, context.TaskContext.Python, call_method="a")
    a_result = await q.enqueue_request.remote(query_param)
    assert a_result == "a"

    query_param = RequestMetadata(
        PRODUCER_NAME, context.TaskContext.Python, call_method="b")
    b_result = await q.enqueue_request.remote(query_param)
    assert b_result == "b"

    query_param = RequestMetadata(
        PRODUCER_NAME, context.TaskContext.Python, call_method="non_exist")
    with pytest.raises(ray.exceptions.RayTaskError):
        await q.enqueue_request.remote(query_param)


async def test_task_runner_custom_method_batch(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    @serve.accept_batch
    class Batcher:
        def a(self, _):
            return ["a-{}".format(i) for i in range(serve.context.batch_size)]

        def b(self, _):
            return ["b-{}".format(i) for i in range(serve.context.batch_size)]

        def error_different_size(self, _):
            return [""] * (serve.context.batch_size * 2)

        def error_non_iterable(self, _):
            return 42

        def return_np_array(self, _):
            return np.array([1] * serve.context.batch_size).astype(np.int32)

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "producer"

    backend_config = BackendConfig(
        {
            "max_batch_size": 4,
            "batch_wait_timeout": 2
        }, accepts_batches=True)
    worker = setup_worker(
        CONSUMER_NAME, Batcher, backend_config=backend_config)

    await q.set_traffic.remote(PRODUCER_NAME,
                               TrafficPolicy({
                                   CONSUMER_NAME: 1.0
                               }))
    await q.set_backend_config.remote(CONSUMER_NAME, backend_config)

    def make_request_param(call_method):
        return RequestMetadata(
            PRODUCER_NAME, context.TaskContext.Python, call_method=call_method)

    a_query_param = make_request_param("a")
    b_query_param = make_request_param("b")

    futures = [q.enqueue_request.remote(a_query_param) for _ in range(2)]
    futures += [q.enqueue_request.remote(b_query_param) for _ in range(2)]

    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)

    gathered = await asyncio.gather(*futures)
    assert set(gathered) == {"a-0", "a-1", "b-0", "b-1"}

    with pytest.raises(RayServeException, match="doesn't preserve batch size"):
        different_size = make_request_param("error_different_size")
        await q.enqueue_request.remote(different_size)

    with pytest.raises(RayServeException, match="iterable"):
        non_iterable = make_request_param("error_non_iterable")
        await q.enqueue_request.remote(non_iterable)

    np_array = make_request_param("return_np_array")
    result_np_value = await q.enqueue_request.remote(np_array)
    assert isinstance(result_np_value, np.int32)


async def test_task_runner_perform_batch(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    def batcher(*args, **kwargs):
        return [serve.context.batch_size] * serve.context.batch_size

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "producer"

    config = BackendConfig(
        {
            "max_batch_size": 2,
            "batch_wait_timeout": 10
        }, accepts_batches=True)

    worker = setup_worker(CONSUMER_NAME, batcher, backend_config=config)
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)
    await q.set_backend_config.remote(CONSUMER_NAME, config)
    await q.set_traffic.remote(PRODUCER_NAME,
                               TrafficPolicy({
                                   CONSUMER_NAME: 1.0
                               }))

    query_param = RequestMetadata(PRODUCER_NAME, context.TaskContext.Python)

    my_batch_sizes = await asyncio.gather(
        *[q.enqueue_request.remote(query_param) for _ in range(3)])
    assert my_batch_sizes == [2, 2, 1]


async def test_task_runner_perform_async(serve_instance):
    q = ray.remote(Router).remote()
    await q.setup.remote("")

    @ray.remote
    class Barrier:
        def __init__(self, release_on):
            self.release_on = release_on
            self.current_waiters = 0
            self.event = asyncio.Event()

        async def wait(self):
            self.current_waiters += 1
            if self.current_waiters == self.release_on:
                self.event.set()
            else:
                await self.event.wait()

    barrier = Barrier.remote(release_on=10)

    async def wait_and_go(*args, **kwargs):
        await barrier.wait.remote()
        return "done!"

    CONSUMER_NAME = "runner"
    PRODUCER_NAME = "producer"

    config = BackendConfig({"max_concurrent_queries": 10}, is_blocking=False)

    worker = setup_worker(CONSUMER_NAME, wait_and_go, backend_config=config)
    await q.add_new_worker.remote(CONSUMER_NAME, "replica1", worker)
    await q.set_backend_config.remote(CONSUMER_NAME, config)
    q.set_traffic.remote(PRODUCER_NAME, TrafficPolicy({CONSUMER_NAME: 1.0}))

    query_param = RequestMetadata(PRODUCER_NAME, context.TaskContext.Python)

    done, not_done = await asyncio.wait(
        [q.enqueue_request.remote(query_param) for _ in range(10)], timeout=10)
    assert len(done) == 10
    for item in done:
        await item == "done!"


if __name__ == "__main__":
    import sys
    sys.exit(pytest.main(["-v", "-s", __file__]))