/**
 *    Copyright (C) 2015 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/platform/basic.h"

#include "mongo/executor/connection_pool_asio.h"

#include "mongo/client/connection_string.h"
#include "mongo/executor/async_stream_factory.h"
#include "mongo/executor/async_timer_asio.h"
#include "mongo/executor/connection_pool_stats.h"
#include "mongo/executor/network_connection_hook.h"
#include "mongo/executor/network_interface_asio_test_utils.h"
#include "mongo/rpc/get_status_from_command_result.h"
#include "mongo/stdx/future.h"
#include "mongo/stdx/memory.h"
#include "mongo/unittest/integration_test.h"
#include "mongo/unittest/unittest.h"
#include "mongo/util/fail_point_service.h"
#include "mongo/util/scopeguard.h"
#include "mongo/util/time_support.h"

namespace mongo {
namespace executor {
namespace {

class MyNetworkConnectionHook : public NetworkConnectionHook {
public:
    Status validateHost(const HostAndPort& remoteHost,
                        const RemoteCommandResponse& isMasterReply) override {
        stdx::unique_lock<stdx::mutex> lk(_mutex);

        _count++;

        return Status::OK();
    }

    StatusWith<boost::optional<RemoteCommandRequest>> makeRequest(
        const HostAndPort& remoteHost) override {
        return StatusWith<boost::optional<RemoteCommandRequest>>(boost::none);
    }

    Status handleReply(const HostAndPort& remoteHost, RemoteCommandResponse&& response) override {
        MONGO_UNREACHABLE;
    }

    static int count() {
        stdx::unique_lock<stdx::mutex> lk(_mutex);

        return _count;
    }

private:
    static stdx::mutex _mutex;
    static int _count;
};

stdx::mutex MyNetworkConnectionHook::_mutex;
int MyNetworkConnectionHook::_count = 0;

TEST(ConnectionPoolASIO, TestPing) {
    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.networkConnectionHook = stdx::make_unique<MyNetworkConnectionHook>();
    options.connectionPoolOptions.maxConnections = 10;
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    const int N = 50;

    std::array<stdx::thread, N> threads;

    for (auto& thread : threads) {
        thread = stdx::thread([&net, &fixture]() {
            auto status = Status::OK();
            Deferred<RemoteCommandResponse> deferred;

            RemoteCommandRequest request{
                fixture.getServers()[0], "admin", BSON("ping" << 1), BSONObj(), nullptr};
            net.startCommand(
                   makeCallbackHandle(),
                   request,
                   [&deferred](RemoteCommandResponse resp) { deferred.emplace(std::move(resp)); })
                .transitional_ignore();

            ASSERT_OK(deferred.get().status);
        });
    }

    for (auto&& thread : threads) {
        thread.join();
    }

    ASSERT_LTE(MyNetworkConnectionHook::count(), 10);
}

/**
 * This test verifies a fix for SERVER-22391, where we raced if a new request
 * came in at the same time a host timeout was triggering.
 */
TEST(ConnectionPoolASIO, TestHostTimeoutRace) {
    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.connectionPoolOptions.hostTimeout = Milliseconds(1);
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    for (int i = 0; i < 1000; i++) {
        Deferred<RemoteCommandResponse> deferred;
        RemoteCommandRequest request{
            fixture.getServers()[0], "admin", BSON("ping" << 1), BSONObj(), nullptr};
        net.startCommand(makeCallbackHandle(),
                         request,
                         [&](RemoteCommandResponse resp) { deferred.emplace(std::move(resp)); })
            .transitional_ignore();

        ASSERT_OK(deferred.get().status);
        sleepmillis(1);
    }
}


/**
 * Verify that a connections that timeout immediately don't invariant.
 */
TEST(ConnectionPoolASIO, ConnSetupTimeout) {
    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    options.connectionPoolOptions.refreshTimeout = Milliseconds(-2);
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    Deferred<RemoteCommandResponse> deferred;
    RemoteCommandRequest request{
        fixture.getServers()[0], "admin", BSON("ping" << 1), BSONObj(), nullptr};
    net.startCommand(makeCallbackHandle(),
                     request,
                     [&](RemoteCommandResponse resp) { deferred.emplace(std::move(resp)); })
        .transitional_ignore();

    ASSERT_EQ(deferred.get().status.code(), ErrorCodes::NetworkInterfaceExceededTimeLimit);
}

/**
 * Verify that connection refreshes actually occur, and that they drop down the totalAvailable
 * correctly.  Verifies SERVER-25006
 */
TEST(ConnectionPoolASIO, ConnRefreshHappens) {
    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    options.connectionPoolOptions.refreshRequirement = Milliseconds(10);
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    std::array<Deferred<RemoteCommandResponse>, 10> deferreds;

    RemoteCommandRequest request{fixture.getServers()[0],
                                 "admin",
                                 BSON("sleep" << 1 << "lock"
                                              << "none"
                                              << "secs"
                                              << 2),
                                 BSONObj(),
                                 nullptr};

    for (auto& deferred : deferreds) {
        net.startCommand(makeCallbackHandle(),
                         request,
                         [&](RemoteCommandResponse resp) { deferred.emplace(std::move(resp)); })
            .transitional_ignore();
    }

    for (auto& deferred : deferreds) {
        ASSERT_EQ(deferred.get().isOK(), true);
    }

    sleepmillis(1000);

    ConnectionPoolStats cps;
    net.appendConnectionStats(&cps);

    ASSERT_LTE(cps.totalAvailable + cps.totalInUse, 1u);
    ASSERT_EQ(cps.totalCreated, 10u);
}

/**
 * Verify that when a refresh fails, it doesn't trigger an invariant
 */
TEST(ConnectionPoolASIO, ConnRefreshSurvivesFailure) {
    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    options.connectionPoolOptions.refreshRequirement = Milliseconds(0);
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    Deferred<RemoteCommandResponse> deferred;

    RemoteCommandRequest request{
        fixture.getServers()[0], "admin", BSON("ping" << 1), BSONObj(), nullptr};
    net.startCommand(makeCallbackHandle(),
                     request,
                     [&](RemoteCommandResponse resp) { deferred.emplace(std::move(resp)); })
        .transitional_ignore();

    deferred.get();

    getGlobalFailPointRegistry()
        ->getFailPoint("NetworkInterfaceASIOasyncRunCommandFail")
        ->setMode(FailPoint::nTimes, 1);

    sleepmillis(1000);

    ConnectionPoolStats cps;
    net.appendConnectionStats(&cps);

    ASSERT_EQ(cps.totalAvailable, 0u);
    ASSERT_EQ(cps.totalCreated, 1u);
}

/**
 * Tests that thrashing the timer while calls to setup are occurring doesn't crash.  This could
 * occur if a setup connection goes through, but the timer thread is too over-worked to cancel the
 * timers before they're invoked
 */
TEST(ConnectionPoolASIO, ConnSetupSurvivesFailure) {
    const int kNumThreads = 8;
    const int kNumOps = 1000;

    auto fixture = unittest::getFixtureConnectionString();

    NetworkInterfaceASIO::Options options;
    options.streamFactory = stdx::make_unique<AsyncStreamFactory>();
    options.timerFactory = stdx::make_unique<AsyncTimerFactoryASIO>();
    options.connectionPoolOptions.refreshTimeout = Seconds(1);
    options.connectionPoolOptions.maxConnections = kNumThreads;
    NetworkInterfaceASIO net{std::move(options)};

    net.startup();
    auto guard = MakeGuard([&] { net.shutdown(); });

    AtomicWord<size_t> unfinished(kNumThreads * kNumOps);
    AtomicWord<size_t> unstarted(kNumThreads * kNumOps);

    std::array<stdx::thread, kNumThreads> threads;
    stdx::mutex mutex;
    stdx::condition_variable condvar;

    for (auto& thread : threads) {
        thread = stdx::thread([&] {
            for (int i = 0; i < kNumOps; i++) {
                RemoteCommandRequest request{fixture.getServers()[0],
                                             "admin",
                                             BSON("sleep" << 1 << "lock"
                                                          << "none"
                                                          << "secs"
                                                          << 3),
                                             BSONObj(),
                                             nullptr};
                net.startCommand(makeCallbackHandle(),
                                 request,
                                 [&](RemoteCommandResponse resp) {
                                     if (!unfinished.subtractAndFetch(1)) {
                                         condvar.notify_one();
                                     }
                                 })
                    .transitional_ignore();
                unstarted.subtractAndFetch(1);
            }
        });
    }

    stdx::thread timerThrasher([&] {
        while (unstarted.load()) {
            net.setAlarm(Date_t::now() + Seconds(1), [] {}).transitional_ignore();
        }
    });


    for (auto& thread : threads) {
        thread.join();
    }

    stdx::unique_lock<stdx::mutex> lk(mutex);
    condvar.wait(lk, [&] { return !unfinished.load(); });

    timerThrasher.join();
}

}  // namespace
}  // namespace executor
}  // namespace mongo