/** *    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_test_fixture.h"

#include "mongo/stdx/memory.h"

namespace mongo {
namespace executor {
namespace connection_pool_test_details {

TimerImpl::TimerImpl(PoolImpl* global) : _global(global) {}

TimerImpl::~TimerImpl() {
    cancelTimeout();
}

void TimerImpl::setTimeout(Milliseconds timeout, TimeoutCallback cb) {
    _cb = std::move(cb);
    _expiration = _global->now() + timeout;

    _timers.emplace(this);
}

void TimerImpl::cancelTimeout() {
    _timers.erase(this);
}

void TimerImpl::clear() {
    _timers.clear();
}

void TimerImpl::fireIfNecessary() {
    auto now = PoolImpl().now();

    auto timers = _timers;

    for (auto&& x : timers) {
        if (_timers.count(x) && (x->_expiration <= now)) {
            x->_cb();
        }
    }
}

std::set<TimerImpl*> TimerImpl::_timers;

ConnectionImpl::ConnectionImpl(const HostAndPort& hostAndPort, size_t generation, PoolImpl* global)
    : _hostAndPort(hostAndPort),
      _timer(global),
      _global(global),
      _id(_idCounter++),
      _generation(generation) {}

void ConnectionImpl::indicateUsed() {
    _lastUsed = _global->now();
}

void ConnectionImpl::indicateSuccess() {
    _status = Status::OK();
}

void ConnectionImpl::indicateFailure(Status status) {
    _status = std::move(status);
}

void ConnectionImpl::resetToUnknown() {
    _status = ConnectionPool::kConnectionStateUnknown;
}

size_t ConnectionImpl::id() const {
    return _id;
}

const HostAndPort& ConnectionImpl::getHostAndPort() const {
    return _hostAndPort;
}

bool ConnectionImpl::isHealthy() {
    return true;
}

void ConnectionImpl::clear() {
    _setupQueue.clear();
    _refreshQueue.clear();
    _pushSetupQueue.clear();
    _pushRefreshQueue.clear();
}

void ConnectionImpl::pushSetup(PushSetupCallback status) {
    _pushSetupQueue.push_back(status);

    if (_setupQueue.size()) {
        auto connPtr = _setupQueue.front();
        auto callback = _pushSetupQueue.front();
        _setupQueue.pop_front();
        _pushSetupQueue.pop_front();

        auto cb = connPtr->_setupCallback;
        cb(connPtr, callback());
    }
}

void ConnectionImpl::pushSetup(Status status) {
    pushSetup([status]() { return status; });
}

size_t ConnectionImpl::setupQueueDepth() {
    return _setupQueue.size();
}

void ConnectionImpl::pushRefresh(PushRefreshCallback status) {
    _pushRefreshQueue.push_back(status);

    if (_refreshQueue.size()) {
        auto connPtr = _refreshQueue.front();
        auto callback = _pushRefreshQueue.front();

        _refreshQueue.pop_front();
        _pushRefreshQueue.pop_front();

        auto cb = connPtr->_refreshCallback;
        cb(connPtr, callback());
    }
}

void ConnectionImpl::pushRefresh(Status status) {
    pushRefresh([status]() { return status; });
}

size_t ConnectionImpl::refreshQueueDepth() {
    return _refreshQueue.size();
}

Date_t ConnectionImpl::getLastUsed() const {
    return _lastUsed;
}

const Status& ConnectionImpl::getStatus() const {
    return _status;
}

void ConnectionImpl::setTimeout(Milliseconds timeout, TimeoutCallback cb) {
    _timer.setTimeout(timeout, cb);
}

void ConnectionImpl::cancelTimeout() {
    _timer.cancelTimeout();
}

void ConnectionImpl::setup(Milliseconds timeout, SetupCallback cb) {
    _setupCallback = std::move(cb);

    _timer.setTimeout(
        timeout,
        [this] { _setupCallback(this, Status(ErrorCodes::ExceededTimeLimit, "timeout")); });

    _setupQueue.push_back(this);

    if (_pushSetupQueue.size()) {
        auto connPtr = _setupQueue.front();
        auto callback = _pushSetupQueue.front();
        _setupQueue.pop_front();
        _pushSetupQueue.pop_front();

        auto cb = connPtr->_setupCallback;
        cb(connPtr, callback());
    }
}

void ConnectionImpl::refresh(Milliseconds timeout, RefreshCallback cb) {
    _refreshCallback = std::move(cb);

    _timer.setTimeout(
        timeout,
        [this] { _refreshCallback(this, Status(ErrorCodes::ExceededTimeLimit, "timeout")); });

    _refreshQueue.push_back(this);

    if (_pushRefreshQueue.size()) {
        auto connPtr = _refreshQueue.front();
        auto callback = _pushRefreshQueue.front();

        _refreshQueue.pop_front();
        _pushRefreshQueue.pop_front();

        auto cb = connPtr->_refreshCallback;
        cb(connPtr, callback());
    }
}

size_t ConnectionImpl::getGeneration() const {
    return _generation;
}

std::deque<ConnectionImpl::PushSetupCallback> ConnectionImpl::_pushSetupQueue;
std::deque<ConnectionImpl::PushRefreshCallback> ConnectionImpl::_pushRefreshQueue;
std::deque<ConnectionImpl*> ConnectionImpl::_setupQueue;
std::deque<ConnectionImpl*> ConnectionImpl::_refreshQueue;
size_t ConnectionImpl::_idCounter = 1;

std::unique_ptr<ConnectionPool::ConnectionInterface> PoolImpl::makeConnection(
    const HostAndPort& hostAndPort, size_t generation) {
    return stdx::make_unique<ConnectionImpl>(hostAndPort, generation, this);
}

std::unique_ptr<ConnectionPool::TimerInterface> PoolImpl::makeTimer() {
    return stdx::make_unique<TimerImpl>(this);
}

Date_t PoolImpl::now() {
    return _now.get_value_or(Date_t::now());
}

void PoolImpl::setNow(Date_t now) {
    _now = now;
    TimerImpl::fireIfNecessary();
}

boost::optional<Date_t> PoolImpl::_now;

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