/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    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
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    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 Server Side 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/network_interface_mock.h"

#include <algorithm>
#include <functional>
#include <iterator>

#include "mongo/executor/connection_pool_stats.h"
#include "mongo/executor/network_connection_hook.h"
#include "mongo/logv2/log.h"
#include "mongo/util/str.h"
#include "mongo/util/time_support.h"

#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kNetwork


namespace mongo {
namespace executor {

using CallbackHandle = TaskExecutor::CallbackHandle;
using ResponseStatus = TaskExecutor::ResponseStatus;

NetworkInterfaceMock::NetworkInterfaceMock()
    : _clkSource(std::make_unique<ClockSourceMock>()),
      _waitingToRunMask(0),
      _currentlyRunning(kNoThread),
      _hasStarted(false),
      _inShutdown(false),
      _executorNextWakeupDate(Date_t::max()) {}

NetworkInterfaceMock::~NetworkInterfaceMock() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(!_hasStarted || inShutdown());
}

std::string NetworkInterfaceMock::getDiagnosticString() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    return str::stream() << "NetworkInterfaceMock -- waitingToRunMask:" << _waitingToRunMask
                         << ", now:" << _now_inlock().toString() << ", hasStarted:" << _hasStarted
                         << ", inShutdown: " << _inShutdown.load()
                         << ", operations: " << _operations.size()
                         << ", responses: " << _responses.size();
}

Date_t NetworkInterfaceMock::now() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    return _now_inlock();
}

std::string NetworkInterfaceMock::getHostName() {
    return "thisisourhostname";
}

/**
 * Starts a remote command with an implementation common to both the exhaust and non-exhaust
 * variants.
 */
template <typename CallbackFn>
Status NetworkInterfaceMock::_startCommand(const TaskExecutor::CallbackHandle& cbHandle,
                                           RemoteCommandRequestOnAny& request,
                                           CallbackFn&& onResponse,
                                           const BatonHandle& baton) {
    if (inShutdown()) {
        return {ErrorCodes::ShutdownInProgress, "NetworkInterfaceMock shutdown in progress"};
    }

    stdx::lock_guard<stdx::mutex> lk(_mutex);

    const Date_t now = _now_inlock();

    LOGV2(5440600, "Scheduling request", "when"_attr = now, "request"_attr = request);

    auto op = NetworkOperation(cbHandle, request, now, std::move(onResponse));

    // network interface mock only works with single target requests
    invariant(request.target.size() == 1);

    // If we don't have a hook, or we have already 'connected' to this host, enqueue the op.
    if (!_hook || _connections.count(request.target[0])) {
        _enqueueOperation_inlock(std::move(op));
    } else {
        _connectThenEnqueueOperation_inlock(request.target[0], std::move(op));
    }

    return Status::OK();
}

Status NetworkInterfaceMock::startCommand(const CallbackHandle& cbHandle,
                                          RemoteCommandRequestOnAny& request,
                                          RemoteCommandCompletionFn&& onFinish,
                                          const BatonHandle& baton) {
    return _startCommand(cbHandle, request, onFinish, baton);
}

Status NetworkInterfaceMock::startExhaustCommand(const CallbackHandle& cbHandle,
                                                 RemoteCommandRequestOnAny& request,
                                                 RemoteCommandOnReplyFn&& onReply,
                                                 const BatonHandle& baton) {
    return _startCommand(cbHandle, request, onReply, baton);
}

void NetworkInterfaceMock::setHandshakeReplyForHost(
    const mongo::HostAndPort& host, mongo::executor::RemoteCommandResponse&& reply) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    auto it = _handshakeReplies.find(host);
    if (it == std::end(_handshakeReplies)) {
        auto res = _handshakeReplies.emplace(host, std::move(reply));
        invariant(res.second);
    } else {
        it->second = std::move(reply);
    }
}

void NetworkInterfaceMock::cancelCommand(const CallbackHandle& cbHandle, const BatonHandle& baton) {
    invariant(!inShutdown());

    stdx::lock_guard<stdx::mutex> lk(_mutex);
    ResponseStatus rs(ErrorCodes::CallbackCanceled, "Network operation canceled", Milliseconds(0));

    _interruptWithResponse_inlock(cbHandle, rs);
}

void NetworkInterfaceMock::_interruptWithResponse_inlock(const CallbackHandle& cbHandle,
                                                         const ResponseStatus& response) {

    auto matchFn = [&cbHandle](const auto& ops) { return ops.isForCallback(cbHandle); };
    auto noi = std::find_if(_operations.begin(), _operations.end(), matchFn);

    // We've effectively observed the NetworkOperation.
    noi->markAsProcessing();
    _scheduleResponse_inlock(noi, _now_inlock(), response);
}

Status NetworkInterfaceMock::setAlarm(const TaskExecutor::CallbackHandle& cbHandle,
                                      const Date_t when,
                                      unique_function<void(Status)> action) {
    if (inShutdown()) {
        return {ErrorCodes::ShutdownInProgress, "NetworkInterfaceMock shutdown in progress"};
    }

    stdx::unique_lock<stdx::mutex> lk(_mutex);

    if (when <= _now_inlock()) {
        lk.unlock();
        action(Status::OK());
        return Status::OK();
    }
    _alarms.emplace(cbHandle, when, std::move(action));

    return Status::OK();
}

void NetworkInterfaceMock::cancelAlarm(const TaskExecutor::CallbackHandle& cbHandle) {
    // Alarms live in a priority queue, so removing them isn't worth it
    // Thus we add the handle to a map and check at fire time
    _canceledAlarms.insert(cbHandle);
}

Status NetworkInterfaceMock::schedule(unique_function<void(Status)> action) {
    // Call the task immediately, we have no out-of-line executor
    action(Status::OK());

    // Say we scheduled the task fine, because we ran it inline
    return Status::OK();
}

bool NetworkInterfaceMock::onNetworkThread() {
    return _currentlyRunning == kNetworkThread;
}

void NetworkInterfaceMock::startup() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    _startup_inlock();
}

void NetworkInterfaceMock::_startup_inlock() {
    invariant(!_hasStarted);
    _hasStarted = true;
    _inShutdown.store(false);
    invariant(_currentlyRunning == kNoThread);
    _currentlyRunning = kExecutorThread;
}

void NetworkInterfaceMock::shutdown() {
    invariant(!inShutdown());

    stdx::unique_lock<stdx::mutex> lk(_mutex);
    if (!_hasStarted) {
        _startup_inlock();
    }
    _inShutdown.store(true);
    auto todo = std::exchange(_operations, {});

    const Date_t now = _now_inlock();
    _waitingToRunMask |= kExecutorThread;  // Prevents network thread from scheduling.
    lk.unlock();
    for (auto& op : todo) {
        auto response = NetworkResponse{{},
                                        now,
                                        ResponseStatus{ErrorCodes::ShutdownInProgress,
                                                       "Shutting down mock network",
                                                       Milliseconds(0)}};
        if (op.processResponse(std::move(response))) {
            LOGV2_WARNING(
                22590,
                "Mock network interface shutting down with outstanding request: {request}",
                "Mock network interface shutting down with outstanding request",
                "request"_attr = op.getRequest());
        }
    }
    lk.lock();
    invariant(_currentlyRunning == kExecutorThread);
    _currentlyRunning = kNoThread;
    _waitingToRunMask = kNetworkThread;
    _shouldWakeNetworkCondition.notify_one();
}

bool NetworkInterfaceMock::inShutdown() const {
    return _inShutdown.load();
}

void NetworkInterfaceMock::enterNetwork() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    while (!_isNetworkThreadRunnable_inlock()) {
        _shouldWakeNetworkCondition.wait(lk);
    }
    _currentlyRunning = kNetworkThread;
    _waitingToRunMask &= ~kNetworkThread;
}

void NetworkInterfaceMock::exitNetwork() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    if (_currentlyRunning != kNetworkThread) {
        return;
    }
    _currentlyRunning = kNoThread;
    if (_isExecutorThreadRunnable_inlock()) {
        _shouldWakeExecutorCondition.notify_one();
    }
    _waitingToRunMask |= kNetworkThread;
}

bool NetworkInterfaceMock::hasReadyRequests() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    return _hasReadyRequests_inlock();
}

bool NetworkInterfaceMock::_hasReadyRequests_inlock() {
    auto noi = std::find_if(
        _operations.begin(), _operations.end(), [](auto& op) { return op.hasReadyRequest(); });
    return noi != _operations.end();
}

NetworkInterfaceMock::NetworkOperationIterator NetworkInterfaceMock::getNextReadyRequest() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);

    auto findNextReadyRequest = [&] {
        return std::find_if(
            _operations.begin(), _operations.end(), [](auto& op) { return op.hasReadyRequest(); });
    };

    auto noi = findNextReadyRequest();
    while (noi == _operations.end()) {
        _waitingToRunMask |= kExecutorThread;
        _runReadyNetworkOperations_inlock(&lk);

        noi = findNextReadyRequest();
    }
    noi->markAsProcessing();

    return noi;
}

NetworkInterfaceMock::NetworkOperationIterator NetworkInterfaceMock::getFrontOfUnscheduledQueue() {
    return getNthUnscheduledRequest(0);
}

NetworkInterfaceMock::NetworkOperationIterator NetworkInterfaceMock::getNthUnscheduledRequest(
    size_t n) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    invariant(_hasReadyRequests_inlock());

    // Linear time, but it's just for testing so no big deal.
    auto noi = _operations.begin();
    for (; noi != _operations.end(); ++noi) {
        if (noi->hasReadyRequest()) {
            if (n == 0) {
                return noi;
            } else {
                --n;
            }
        }
    }

    return _operations.end();
}

void NetworkInterfaceMock::_scheduleResponse_inlock(NetworkOperationIterator noi,
                                                    Date_t when,
                                                    const TaskExecutor::ResponseStatus& response) {
    auto insertBefore = std::find_if(_responses.begin(),
                                     _responses.end(),
                                     [when](const auto& response) { return response.when > when; });

    _responses.insert(insertBefore, NetworkResponse{noi, when, response});
    LOGV2(5440601,
          "Scheduling response",
          "when"_attr = when,
          "request"_attr = noi->getRequest(),
          "response"_attr = response);
}

void NetworkInterfaceMock::scheduleResponse(NetworkOperationIterator noi,
                                            Date_t when,
                                            const TaskExecutor::ResponseStatus& response) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    noi->assertNotBlackholed();
    _scheduleResponse_inlock(noi, when, response);
}

RemoteCommandRequest NetworkInterfaceMock::scheduleSuccessfulResponse(const BSONObj& response) {
    return scheduleSuccessfulResponse(RemoteCommandResponse(response, Milliseconds(0)));
}

RemoteCommandRequest NetworkInterfaceMock::scheduleSuccessfulResponse(
    const RemoteCommandResponse& response) {
    return scheduleSuccessfulResponse(getNextReadyRequest(), response);
}

RemoteCommandRequest NetworkInterfaceMock::scheduleSuccessfulResponse(
    NetworkOperationIterator noi, const RemoteCommandResponse& response) {
    return scheduleSuccessfulResponse(noi, now(), response);
}

RemoteCommandRequest NetworkInterfaceMock::scheduleSuccessfulResponse(
    NetworkOperationIterator noi, Date_t when, const RemoteCommandResponse& response) {
    scheduleResponse(noi, when, response);
    return noi->getRequest();
}

RemoteCommandRequest NetworkInterfaceMock::scheduleErrorResponse(const Status& response) {
    return scheduleErrorResponse(getNextReadyRequest(), response);
}

RemoteCommandRequest NetworkInterfaceMock::scheduleErrorResponse(const ResponseStatus response) {
    auto noi = getNextReadyRequest();
    scheduleResponse(noi, now(), response);
    return noi->getRequest();
}

RemoteCommandRequest NetworkInterfaceMock::scheduleErrorResponse(NetworkOperationIterator noi,
                                                                 const Status& response) {
    return scheduleErrorResponse(noi, now(), response);
}

RemoteCommandRequest NetworkInterfaceMock::scheduleErrorResponse(NetworkOperationIterator noi,
                                                                 Date_t when,
                                                                 const Status& response) {
    scheduleResponse(noi, when, response);
    return noi->getRequest();
}

void NetworkInterfaceMock::blackHole(NetworkOperationIterator noi) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    noi->markAsBlackholed();
}

Date_t NetworkInterfaceMock::runUntil(Date_t until) {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    invariant(until > _now_inlock());
    while (until > _now_inlock()) {
        _runReadyNetworkOperations_inlock(&lk);
        if (_hasReadyRequests_inlock()) {
            break;
        }
        Date_t newNow = _executorNextWakeupDate;
        if (!_alarms.empty() && _alarms.top().when < newNow) {
            newNow = _alarms.top().when;
        }
        if (!_responses.empty() && _responses.front().when < newNow) {
            newNow = _responses.front().when;
        }
        if (until < newNow) {
            newNow = until;
        }

        auto duration = newNow - _now_inlock();
        invariant(duration >= Milliseconds{0});
        _clkSource->advance(duration);

        _waitingToRunMask |= kExecutorThread;
    }
    _runReadyNetworkOperations_inlock(&lk);
    return _now_inlock();
}

void NetworkInterfaceMock::advanceTime(Date_t newTime) {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);

    auto duration = newTime - _now_inlock();
    invariant(duration > Milliseconds{0});
    _clkSource->advance(duration);

    _waitingToRunMask |= kExecutorThread;
    _runReadyNetworkOperations_inlock(&lk);
}

void NetworkInterfaceMock::runReadyNetworkOperations() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    _runReadyNetworkOperations_inlock(&lk);
}

void NetworkInterfaceMock::waitForWork() {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kExecutorThread);
    _waitForWork_inlock(&lk);
}

void NetworkInterfaceMock::waitForWorkUntil(Date_t when) {
    stdx::unique_lock<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kExecutorThread);
    _executorNextWakeupDate = when;
    if (_executorNextWakeupDate <= _now_inlock()) {
        return;
    }
    _waitForWork_inlock(&lk);
}

void NetworkInterfaceMock::_enqueueOperation_inlock(NetworkOperation&& op) {
    const auto timeout = op.getRequest().timeout;
    auto cbh = op.getCallbackHandle();
    _operations.emplace_back(std::forward<NetworkOperation>(op));

    if (timeout != RemoteCommandRequest::kNoTimeout) {
        invariant(timeout >= Milliseconds(0));
        _alarms.emplace(cbh, _now_inlock() + timeout, [this, cbh](Status) {
            auto response = ResponseStatus(
                ErrorCodes::NetworkInterfaceExceededTimeLimit, "Network timeout", Milliseconds(0));
            _interruptWithResponse_inlock(cbh, std::move(response));
        });
    }
}

void NetworkInterfaceMock::_connectThenEnqueueOperation_inlock(const HostAndPort& target,
                                                               NetworkOperation&& op) {
    invariant(_hook);  // if there is no hook, we shouldn't even hit this codepath
    invariant(!_connections.count(target));

    auto handshakeReplyIter = _handshakeReplies.find(target);

    auto handshakeReply = (handshakeReplyIter != std::end(_handshakeReplies))
        ? handshakeReplyIter->second
        : RemoteCommandResponse(BSONObj(), Milliseconds(0));

    auto valid = _hook->validateHost(target, op.getRequest().cmdObj, handshakeReply);
    if (!valid.isOK()) {
        auto response = NetworkResponse{{}, _now_inlock(), valid};
        op.processResponse(std::move(response));
        return;
    }

    auto swHookPostconnectCommand = _hook->makeRequest(target);

    if (!swHookPostconnectCommand.isOK()) {
        auto response = NetworkResponse{{}, _now_inlock(), swHookPostconnectCommand.getStatus()};
        op.processResponse(std::move(response));
        return;
    }

    boost::optional<RemoteCommandRequest> hookPostconnectCommand =
        std::move(swHookPostconnectCommand.getValue());

    if (!hookPostconnectCommand) {
        // If we don't have a post connect command, enqueue the actual command.
        _connections.emplace(op.getRequest().target);
        _enqueueOperation_inlock(std::move(op));
        return;
    }

    auto cbh = op.getCallbackHandle();
    // The completion handler for the postconnect command schedules the original command.
    auto postconnectCompletionHandler =
        [this, op = std::move(op)](TaskExecutor::ResponseOnAnyStatus rs) mutable {
            stdx::lock_guard<stdx::mutex> lk(_mutex);
            if (!rs.isOK()) {
                auto response = NetworkResponse{{}, _now_inlock(), rs};
                op.processResponse(std::move(response));
                return;
            }

            auto handleStatus = _hook->handleReply(op.getRequest().target, std::move(rs));

            if (!handleStatus.isOK()) {
                auto response = NetworkResponse{{}, _now_inlock(), handleStatus};
                op.processResponse(std::move(response));
                return;
            }

            _connections.emplace(op.getRequest().target);
            _enqueueOperation_inlock(std::move(op));
        };

    auto postconnectOp = NetworkOperation(cbh,
                                          std::move(*hookPostconnectCommand),
                                          _now_inlock(),
                                          std::move(postconnectCompletionHandler));

    _enqueueOperation_inlock(std::move(postconnectOp));
}

void NetworkInterfaceMock::setConnectionHook(std::unique_ptr<NetworkConnectionHook> hook) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(!_hasStarted);
    invariant(!_hook);
    _hook = std::move(hook);
}

void NetworkInterfaceMock::setEgressMetadataHook(
    std::unique_ptr<rpc::EgressMetadataHook> metadataHook) {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(!_hasStarted);
    invariant(!_metadataHook);
    _metadataHook = std::move(metadataHook);
}

void NetworkInterfaceMock::signalWorkAvailable() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    _waitingToRunMask |= kExecutorThread;
    if (_currentlyRunning == kNoThread) {
        _shouldWakeExecutorCondition.notify_one();
    }
}

void NetworkInterfaceMock::_runReadyNetworkOperations_inlock(stdx::unique_lock<stdx::mutex>* lk) {
    while (!_alarms.empty() && _now_inlock() >= _alarms.top().when) {
        // It's safe to remove the const qualifier here as we immediately remove the top.
        AlarmInfo alarm = std::move(const_cast<AlarmInfo&>(_alarms.top()));
        _alarms.pop();

        // If the handle isn't cancelled, then run it
        auto iter = _canceledAlarms.find(alarm.handle);
        if (iter == _canceledAlarms.end()) {
            lk->unlock();
            alarm.action(Status::OK());
            lk->lock();
        } else {
            _canceledAlarms.erase(iter);
        }
    }
    while (!_responses.empty() && _now_inlock() >= _responses.front().when) {
        invariant(_currentlyRunning == kNetworkThread);
        auto response = std::exchange(_responses.front(), {});
        _responses.pop_front();
        _waitingToRunMask |= kExecutorThread;
        lk->unlock();

        auto noi = response.noi;

        LOGV2(5440602,
              "Processing response",
              "when"_attr = response.when,
              "request"_attr = noi->getRequest(),
              "response"_attr = response.response);

        if (_metadataHook) {
            _metadataHook
                ->readReplyMetadata(noi->getRequest().opCtx,
                                    noi->getRequest().target.toString(),
                                    response.response.data)
                .transitional_ignore();
        }

        noi->processResponse(std::move(response));

        lk->lock();
    }
    invariant(_currentlyRunning == kNetworkThread);
    if (!(_waitingToRunMask & kExecutorThread)) {
        return;
    }
    _shouldWakeExecutorCondition.notify_one();
    _currentlyRunning = kNoThread;
    while (!_isNetworkThreadRunnable_inlock()) {
        _shouldWakeNetworkCondition.wait(*lk);
    }
    _currentlyRunning = kNetworkThread;
    _waitingToRunMask &= ~kNetworkThread;
}

bool NetworkInterfaceMock::hasReadyNetworkOperations() {
    stdx::lock_guard<stdx::mutex> lk(_mutex);
    invariant(_currentlyRunning == kNetworkThread);
    if (!_alarms.empty() && _now_inlock() >= _alarms.top().when) {
        return true;
    }

    if (!_responses.empty() && _responses.front().when <= _now_inlock()) {
        return true;
    }
    return false;
}

void NetworkInterfaceMock::_waitForWork_inlock(stdx::unique_lock<stdx::mutex>* lk) {
    if (_waitingToRunMask & kExecutorThread) {
        _waitingToRunMask &= ~kExecutorThread;
        return;
    }
    _currentlyRunning = kNoThread;
    while (!_isExecutorThreadRunnable_inlock()) {
        _waitingToRunMask |= kNetworkThread;
        _shouldWakeNetworkCondition.notify_one();
        _shouldWakeExecutorCondition.wait(*lk);
    }
    _currentlyRunning = kExecutorThread;
    _waitingToRunMask &= ~kExecutorThread;
}

bool NetworkInterfaceMock::_isNetworkThreadRunnable_inlock() {
    if (_currentlyRunning != kNoThread) {
        return false;
    }
    if (_waitingToRunMask != kNetworkThread) {
        return false;
    }
    return true;
}

bool NetworkInterfaceMock::_isExecutorThreadRunnable_inlock() {
    if (_currentlyRunning != kNoThread) {
        return false;
    }
    return _waitingToRunMask & kExecutorThread;
}

NetworkInterfaceMock::NetworkOperation::NetworkOperation()
    : _requestDate(), _request(), _onResponse() {}

NetworkInterfaceMock::NetworkOperation::NetworkOperation(
    const CallbackHandle& cbHandle,
    const RemoteCommandRequestOnAny& theRequest,
    Date_t theRequestDate,
    RemoteCommandCompletionFn onResponse)
    : _requestDate(theRequestDate),
      _cbHandle(cbHandle),
      _requestOnAny(theRequest),
      _request(theRequest, 0),
      _onResponse(std::move(onResponse)) {
    invariant(theRequest.target.size() == 1);
}

std::string NetworkInterfaceMock::NetworkOperation::getDiagnosticString() const {
    return str::stream() << "NetworkOperation -- request:'" << _request.toString()
                         << ", reqDate: " << _requestDate.toString();
}

bool NetworkInterfaceMock::NetworkOperation::processResponse(NetworkResponse response) {
    if (_isFinished) {
        // Nothing to do.
        return false;
    }

    // If there's no more to come, then we're done after this response.
    _isFinished = !response.response.moreToCome;
    ON_BLOCK_EXIT([&] {
        if (_isFinished) {
            _onResponse = {};
        }
    });

    auto responseOnAny =
        TaskExecutor::ResponseOnAnyStatus(_request.target, std::move(response.response));
    _onResponse(responseOnAny);

    return true;
}

NetworkInterfaceMock::InNetworkGuard::InNetworkGuard(NetworkInterfaceMock* net) : _net(net) {
    _net->enterNetwork();
}

void NetworkInterfaceMock::InNetworkGuard::dismiss() {
    _callExitNetwork = false;
    _net->exitNetwork();
}

NetworkInterfaceMock::InNetworkGuard::~InNetworkGuard() {
    if (_callExitNetwork)
        _net->exitNetwork();
}

NetworkInterfaceMock* NetworkInterfaceMock::InNetworkGuard::operator->() const {
    return _net;
}

}  // namespace executor
}  // namespace mongo
