import asyncio
import os
import random
from time import sleep

import pytest
from tlz import partition_all, first

from dask import delayed
from distributed import Client, Nanny, wait
from distributed.comm import CommClosedError
from distributed.client import wait
from distributed.metrics import time
from distributed.utils import sync, ignoring, CancelledError
from distributed.utils_test import (
    gen_cluster,
    cluster,
    inc,
    div,
    slowinc,
    slowadd,
    captured_logger,
)
from distributed.utils_test import loop  # noqa: F401


def test_submit_after_failed_worker_sync(loop):
    with cluster(active_rpc_timeout=10, disconnect_timeout=10) as (s, [a, b]):
        with Client(s["address"], loop=loop) as c:
            L = c.map(inc, range(10))
            wait(L)
            a["proc"]().terminate()
            total = c.submit(sum, L)
            assert total.result() == sum(map(inc, range(10)))


@gen_cluster(client=True, timeout=60, active_rpc_timeout=10)
async def test_submit_after_failed_worker_async(c, s, a, b):
    n = await Nanny(s.address, nthreads=2, loop=s.loop)
    while len(s.workers) < 3:
        await asyncio.sleep(0.1)

    L = c.map(inc, range(10))
    await wait(L)

    s.loop.add_callback(n.kill)
    total = c.submit(sum, L)
    result = await total
    assert result == sum(map(inc, range(10)))

    await n.close()


@gen_cluster(client=True, timeout=60)
async def test_submit_after_failed_worker(c, s, a, b):
    L = c.map(inc, range(10))
    await wait(L)
    await a.close()

    total = c.submit(sum, L)
    result = await total
    assert result == sum(map(inc, range(10)))


def test_gather_after_failed_worker(loop):
    with cluster(active_rpc_timeout=10, disconnect_timeout=10) as (s, [a, b]):
        with Client(s["address"], loop=loop) as c:
            L = c.map(inc, range(10))
            wait(L)
            a["proc"]().terminate()
            result = c.gather(L)
            assert result == list(map(inc, range(10)))


@gen_cluster(
    client=True,
    Worker=Nanny,
    nthreads=[("127.0.0.1", 1)] * 4,
    config={"distributed.comm.timeouts.connect": "1s"},
)
async def test_gather_then_submit_after_failed_workers(c, s, w, x, y, z):
    L = c.map(inc, range(20))
    await wait(L)

    w.process.process._process.terminate()
    total = c.submit(sum, L)

    for i in range(3):
        await wait(total)
        addr = first(s.tasks[total.key].who_has).address
        for worker in [x, y, z]:
            if worker.worker_address == addr:
                worker.process.process._process.terminate()
                break

        result = await c.gather([total])
        assert result == [sum(map(inc, range(20)))]


@gen_cluster(Worker=Nanny, timeout=60, client=True)
async def test_failed_worker_without_warning(c, s, a, b):
    L = c.map(inc, range(10))
    await wait(L)

    original_pid = a.pid
    with ignoring(CommClosedError):
        await c._run(os._exit, 1, workers=[a.worker_address])
    start = time()
    while a.pid == original_pid:
        await asyncio.sleep(0.01)
        assert time() - start < 10

    await asyncio.sleep(0.5)

    start = time()
    while len(s.nthreads) < 2:
        await asyncio.sleep(0.01)
        assert time() - start < 10

    await wait(L)

    L2 = c.map(inc, range(10, 20))
    await wait(L2)
    assert all(len(keys) > 0 for keys in s.has_what.values())
    nthreads2 = dict(s.nthreads)

    await c.restart()

    L = c.map(inc, range(10))
    await wait(L)
    assert all(len(keys) > 0 for keys in s.has_what.values())

    assert not (set(nthreads2) & set(s.nthreads))  # no overlap


@gen_cluster(Worker=Nanny, client=True, timeout=60)
async def test_restart(c, s, a, b):
    assert s.nthreads == {a.worker_address: 1, b.worker_address: 2}

    x = c.submit(inc, 1)
    y = c.submit(inc, x)
    z = c.submit(div, 1, 0)
    await y

    assert set(s.who_has) == {x.key, y.key}

    f = await c.restart()
    assert f is c

    assert len(s.workers) == 2
    assert not any(ws.occupancy for ws in s.workers.values())

    assert not s.who_has

    assert x.cancelled()
    assert y.cancelled()
    assert z.cancelled()
    assert z.key not in s.exceptions

    assert not s.who_wants
    assert not any(cs.wants_what for cs in s.clients.values())


@gen_cluster(Worker=Nanny, client=True, timeout=60)
async def test_restart_cleared(c, s, a, b):
    x = 2 * delayed(1) + 1
    f = c.compute(x)
    await wait([f])

    await c.restart()

    for coll in [s.tasks, s.unrunnable]:
        assert not coll


def test_restart_sync_no_center(loop):
    with cluster(nanny=True) as (s, [a, b]):
        with Client(s["address"], loop=loop) as c:
            x = c.submit(inc, 1)
            c.restart()
            assert x.cancelled()
            y = c.submit(inc, 2)
            assert y.result() == 3
            assert len(c.nthreads()) == 2


def test_restart_sync(loop):
    with cluster(nanny=True) as (s, [a, b]):
        with Client(s["address"], loop=loop) as c:
            x = c.submit(div, 1, 2)
            x.result()

            assert sync(loop, c.scheduler.who_has)
            c.restart()
            assert not sync(loop, c.scheduler.who_has)
            assert x.cancelled()
            assert len(c.nthreads()) == 2

            with pytest.raises(CancelledError):
                x.result()

            y = c.submit(div, 1, 3)
            assert y.result() == 1 / 3


@gen_cluster(Worker=Nanny, client=True, timeout=60)
async def test_restart_fast(c, s, a, b):
    L = c.map(sleep, range(10))

    start = time()
    await c.restart()
    assert time() - start < 10
    assert len(s.nthreads) == 2

    assert all(x.status == "cancelled" for x in L)

    x = c.submit(inc, 1)
    result = await x
    assert result == 2


def test_worker_doesnt_await_task_completion(loop):
    with cluster(nanny=True, nworkers=1) as (s, [w]):
        with Client(s["address"], loop=loop) as c:
            future = c.submit(sleep, 100)
            sleep(0.1)
            start = time()
            c.restart()
            stop = time()
            assert stop - start < 5


def test_restart_fast_sync(loop):
    with cluster(nanny=True) as (s, [a, b]):
        with Client(s["address"], loop=loop) as c:
            L = c.map(sleep, range(10))

            start = time()
            c.restart()
            assert time() - start < 10
            assert len(c.nthreads()) == 2

            assert all(x.status == "cancelled" for x in L)

            x = c.submit(inc, 1)
            assert x.result() == 2


@gen_cluster(Worker=Nanny, client=True, timeout=60)
async def test_fast_kill(c, s, a, b):
    L = c.map(sleep, range(10))

    start = time()
    await c.restart()
    assert time() - start < 10

    assert all(x.status == "cancelled" for x in L)

    x = c.submit(inc, 1)
    result = await x
    assert result == 2


@gen_cluster(Worker=Nanny, timeout=60)
async def test_multiple_clients_restart(s, a, b):
    c1 = await Client(s.address, asynchronous=True)
    c2 = await Client(s.address, asynchronous=True)

    x = c1.submit(inc, 1)
    y = c2.submit(inc, 2)
    xx = await x
    yy = await y
    assert xx == 2
    assert yy == 3

    await c1.restart()

    assert x.cancelled()
    start = time()
    while not y.cancelled():
        await asyncio.sleep(0.01)
        assert time() < start + 5

    await c1.close()
    await c2.close()


@gen_cluster(Worker=Nanny, timeout=60)
async def test_restart_scheduler(s, a, b):
    import gc

    gc.collect()
    addrs = (a.worker_address, b.worker_address)
    await s.restart()
    assert len(s.nthreads) == 2
    addrs2 = (a.worker_address, b.worker_address)

    assert addrs != addrs2


@gen_cluster(Worker=Nanny, client=True, timeout=60)
async def test_forgotten_futures_dont_clean_up_new_futures(c, s, a, b):
    x = c.submit(inc, 1)
    await c.restart()
    y = c.submit(inc, 1)
    del x
    import gc

    gc.collect()
    await asyncio.sleep(0.1)
    await y


@gen_cluster(client=True, timeout=60, active_rpc_timeout=10)
async def test_broken_worker_during_computation(c, s, a, b):
    s.allowed_failures = 100
    n = await Nanny(s.address, nthreads=2, loop=s.loop)

    start = time()
    while len(s.nthreads) < 3:
        await asyncio.sleep(0.01)
        assert time() < start + 5

    N = 256
    expected_result = N * (N + 1) // 2
    i = 0
    L = c.map(inc, range(N), key=["inc-%d-%d" % (i, j) for j in range(N)])
    while len(L) > 1:
        i += 1
        L = c.map(
            slowadd,
            *zip(*partition_all(2, L)),
            key=["add-%d-%d" % (i, j) for j in range(len(L) // 2)]
        )

    await asyncio.sleep(random.random() / 20)
    with ignoring(CommClosedError):  # comm will be closed abrupty
        await c._run(os._exit, 1, workers=[n.worker_address])

    await asyncio.sleep(random.random() / 20)
    while len(s.workers) < 3:
        await asyncio.sleep(0.01)

    with ignoring(
        CommClosedError, EnvironmentError
    ):  # perhaps new worker can't be contacted yet
        await c._run(os._exit, 1, workers=[n.worker_address])

    [result] = await c.gather(L)
    assert isinstance(result, int)
    assert result == expected_result

    await n.close()


@gen_cluster(client=True, Worker=Nanny, timeout=60)
async def test_restart_during_computation(c, s, a, b):
    xs = [delayed(slowinc)(i, delay=0.01) for i in range(50)]
    ys = [delayed(slowinc)(i, delay=0.01) for i in xs]
    zs = [delayed(slowadd)(x, y, delay=0.01) for x, y in zip(xs, ys)]
    total = delayed(sum)(zs)
    result = c.compute(total)

    await asyncio.sleep(0.5)
    assert s.rprocessing
    await c.restart()
    assert not s.rprocessing

    assert len(s.nthreads) == 2
    assert not s.tasks


@gen_cluster(client=True, timeout=60)
async def test_worker_who_has_clears_after_failed_connection(c, s, a, b):
    n = await Nanny(s.address, nthreads=2, loop=s.loop)

    start = time()
    while len(s.nthreads) < 3:
        await asyncio.sleep(0.01)
        assert time() < start + 5

    futures = c.map(slowinc, range(20), delay=0.01, key=["f%d" % i for i in range(20)])
    await wait(futures)

    result = await c.submit(sum, futures, workers=a.address)
    for dep in set(a.dep_state) - set(a.task_state):
        a.release_dep(dep, report=True)

    n_worker_address = n.worker_address
    with ignoring(CommClosedError):
        await c._run(os._exit, 1, workers=[n_worker_address])

    while len(s.workers) > 2:
        await asyncio.sleep(0.01)

    total = c.submit(sum, futures, workers=a.address)
    await total

    assert not a.has_what.get(n_worker_address)
    assert not any(n_worker_address in s for s in a.who_has.values())

    await n.close()


@pytest.mark.slow
@gen_cluster(client=True, timeout=60, Worker=Nanny, nthreads=[("127.0.0.1", 1)])
async def test_restart_timeout_on_long_running_task(c, s, a):
    with captured_logger("distributed.scheduler") as sio:
        future = c.submit(sleep, 3600)
        await asyncio.sleep(0.1)
        await c.restart(timeout=20)

    text = sio.getvalue()
    assert "timeout" not in text.lower()


@gen_cluster(client=True, scheduler_kwargs={"worker_ttl": "500ms"})
async def test_worker_time_to_live(c, s, a, b):
    assert set(s.workers) == {a.address, b.address}
    a.periodic_callbacks["heartbeat"].stop()
    await asyncio.sleep(0.010)
    assert set(s.workers) == {a.address, b.address}

    start = time()
    while set(s.workers) == {a.address, b.address}:
        await asyncio.sleep(0.050)
        assert time() < start + 2

    set(s.workers) == {b.address}
