// @file s/client_info.cpp

/**
 *    Copyright (C) 2008 10gen 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.
 */

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kSharding

#include "mongo/platform/basic.h"

#include "mongo/client/connpool.h"
#include "mongo/db/auth/authorization_manager_global.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/authz_session_external_state_s.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/server_status_metric.h"
#include "mongo/db/dbmessage.h"
#include "mongo/db/lasterror.h"
#include "mongo/db/stats/counters.h"
#include "mongo/db/stats/timer_stats.h"
#include "mongo/s/write_ops/batch_downconvert.h"
#include "mongo/s/client_info.h"
#include "mongo/s/config.h"
#include "mongo/s/chunk.h"
#include "mongo/s/cursors.h"
#include "mongo/s/grid.h"
#include "mongo/s/request.h"
#include "mongo/server.h"
#include "mongo/util/log.h"
#include "mongo/util/mongoutils/str.h"
#include "mongo/util/scopeguard.h"

namespace mongo {

using std::string;
using std::stringstream;

ClientInfo::ClientInfo(AbstractMessagingPort* messagingPort) : ClientBasic(messagingPort) {
    _cur = &_a;
    _prev = &_b;
    _autoSplitOk = true;
    if (messagingPort) {
        _remote = messagingPort->remote();
    }
}

ClientInfo::~ClientInfo() {}

void ClientInfo::addShardHost(const string& shardHost) {
    _cur->shardHostsWritten.insert(shardHost);
    _sinceLastGetError.insert(shardHost);
}

void ClientInfo::addHostOpTime(ConnectionString connStr, HostOpTime stat) {
    _cur->hostOpTimes[connStr] = stat;
}

void ClientInfo::addHostOpTimes(const HostOpTimeMap& hostOpTimes) {
    for (HostOpTimeMap::const_iterator it = hostOpTimes.begin(); it != hostOpTimes.end(); ++it) {
        addHostOpTime(it->first, it->second);
    }
}

void ClientInfo::newPeerRequest(const HostAndPort& peer) {
    if (!_remote.hasPort())
        _remote = peer;
    else if (_remote != peer) {
        stringstream ss;
        ss << "remotes don't match old [" << _remote.toString() << "] new [" << peer.toString()
           << "]";
        throw UserException(13134, ss.str());
    }

    newRequest();
}

void ClientInfo::newRequest() {
    _lastAccess = (int)time(0);

    RequestInfo* temp = _cur;
    _cur = _prev;
    _prev = temp;
    _cur->clear();
}

ClientInfo* ClientInfo::create(AbstractMessagingPort* messagingPort) {
    ClientInfo* info = _tlInfo.get();
    massert(16472, "A ClientInfo already exists for this thread", !info);
    info = new ClientInfo(messagingPort);
    info->setAuthorizationSession(new AuthorizationSession(
        new AuthzSessionExternalStateMongos(getGlobalAuthorizationManager())));
    _tlInfo.reset(info);
    info->newRequest();
    return info;
}

ClientInfo* ClientInfo::get(AbstractMessagingPort* messagingPort) {
    ClientInfo* info = _tlInfo.get();
    if (!info) {
        info = create(messagingPort);
    }
    massert(16483,
            mongoutils::str::stream()
                << "AbstractMessagingPort was provided to ClientInfo::get"
                << " but differs from the one stored in the current ClientInfo object. "
                << "Current ClientInfo messaging port " << (info->port() ? "is not" : "is")
                << " NULL",
            messagingPort == NULL || messagingPort == info->port());
    return info;
}

bool ClientInfo::exists() {
    return _tlInfo.get();
}

ClientBasic* ClientBasic::getCurrent() {
    return ClientInfo::get();
}


void ClientInfo::disconnect() {
    // should be handled by TL cleanup
    _lastAccess = 0;
}

void ClientInfo::disableForCommand() {
    RequestInfo* temp = _cur;
    _cur = _prev;
    _prev = temp;
}

static TimerStats gleWtimeStats;
static ServerStatusMetricField<TimerStats> displayGleLatency("getLastError.wtime", &gleWtimeStats);

boost::thread_specific_ptr<ClientInfo> ClientInfo::_tlInfo;


// Look for $gleStats in a command response, and fill in ClientInfo with the data,
// if found.
// This data will be used by subsequent GLE calls, to ensure we look for the correct
// write on the correct PRIMARY.
void saveGLEStats(const BSONObj& result, const std::string& hostString) {
    if (!ClientInfo::exists()) {
        return;
    }
    if (result[kGLEStatsFieldName].type() != Object) {
        return;
    }
    std::string errmsg;
    ConnectionString shardConn = ConnectionString::parse(hostString, errmsg);

    BSONElement subobj = result[kGLEStatsFieldName];
    OpTime lastOpTime = subobj[kGLEStatsLastOpTimeFieldName]._opTime();
    OID electionId = subobj[kGLEStatsElectionIdFieldName].OID();
    ClientInfo* clientInfo = ClientInfo::get(NULL);
    LOG(4) << "saveGLEStats lastOpTime:" << lastOpTime << " electionId:" << electionId;

    clientInfo->addHostOpTime(shardConn, HostOpTime(lastOpTime, electionId));
}


}  // namespace mongo