/**
 *    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.
 */

#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kCommand

#include "mongo/platform/basic.h"

#include "mongo/db/commands.h"

#include "mongo/base/init.h"
#include "mongo/bson/util/bson_extract.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/resource_pattern.h"
#include "mongo/db/concurrency/d_concurrency.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/curop.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/op_observer.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/repl/replication_coordinator.h"
#include "mongo/db/service_context.h"
#include "mongo/logv2/log.h"

namespace mongo {

MONGO_FAIL_POINT_DEFINE(hangInAppendOplogNote);

namespace {
Status _performNoopWrite(OperationContext* opCtx, BSONObj msgObj, StringData note) {
    repl::ReplicationCoordinator* const replCoord = repl::ReplicationCoordinator::get(opCtx);
    // Use GlobalLock instead of DBLock to allow return when the lock is not available. It may
    // happen when the primary steps down and a shared global lock is acquired.
    Lock::GlobalLock lock(
        opCtx, MODE_IX, Date_t::now() + Milliseconds(1), Lock::InterruptBehavior::kLeaveUnlocked);

    if (!lock.isLocked()) {
        LOGV2_DEBUG(20495, 1, "Global lock is not available skipping noopWrite");
        return {ErrorCodes::LockFailed, "Global lock is not available"};
    }

    // Its a proxy for being a primary passing "local" will cause it to return true on secondary
    if (!replCoord->canAcceptWritesForDatabase(opCtx, "admin")) {
        return {ErrorCodes::NotWritablePrimary, "Not a primary"};
    }

    writeConflictRetry(opCtx, note, NamespaceString::kRsOplogNamespace.ns(), [&opCtx, &msgObj] {
        WriteUnitOfWork uow(opCtx);
        opCtx->getClient()->getServiceContext()->getOpObserver()->onOpMessage(opCtx, msgObj);
        uow.commit();
    });

    return Status::OK();
}
}  // namespace

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

class AppendOplogNoteCmd : public BasicCommand {
public:
    AppendOplogNoteCmd() : BasicCommand("appendOplogNote") {}

    AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
        return AllowedOnSecondary::kNever;
    }

    virtual bool adminOnly() const {
        return true;
    }

    virtual bool supportsWriteConcern(const BSONObj& cmd) const override {
        return true;
    }

    std::string help() const override {
        return "Adds a no-op entry to the oplog";
    }

    virtual Status checkAuthForCommand(Client* client,
                                       const std::string& dbname,
                                       const BSONObj& cmdObj) const {
        if (!AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
                ResourcePattern::forClusterResource(), ActionType::appendOplogNote)) {
            return Status(ErrorCodes::Unauthorized, "Unauthorized");
        }
        return Status::OK();
    }

    virtual bool run(OperationContext* opCtx,
                     const string& dbname,
                     const BSONObj& cmdObj,
                     BSONObjBuilder& result) {
        hangInAppendOplogNote.pauseWhileSet();

        auto replCoord = repl::ReplicationCoordinator::get(opCtx);
        if (!replCoord->isReplEnabled()) {
            uasserted(ErrorCodes::NoReplicationEnabled,
                      "Must have replication set up to run \"appendOplogNote\"");
        }

        BSONElement dataElement;
        auto dataStatus = bsonExtractTypedField(cmdObj, "data", Object, &dataElement);
        uassertStatusOK(dataStatus);

        Timestamp maxClusterTime;
        auto maxClusterTimeStatus =
            bsonExtractTimestampField(cmdObj, "maxClusterTime", &maxClusterTime);

        if (!maxClusterTimeStatus.isOK()) {
            if (maxClusterTimeStatus == ErrorCodes::NoSuchKey) {  // no need to use maxClusterTime
                uassertStatusOK(_performNoopWrite(opCtx, dataElement.Obj(), "appendOpLogNote"));
                return true;
            }
            uassertStatusOK(maxClusterTimeStatus);
        }

        auto lastAppliedOpTime = replCoord->getMyLastAppliedOpTime().getTimestamp();
        if (maxClusterTime > lastAppliedOpTime) {
            uassertStatusOK(_performNoopWrite(opCtx, dataElement.Obj(), "appendOpLogNote"));
        } else {
            std::stringstream ss;
            ss << "Requested maxClusterTime " << LogicalTime(maxClusterTime).toString()
               << " is less or equal to the last primary OpTime: "
               << LogicalTime(lastAppliedOpTime).toString();
            uasserted(ErrorCodes::StaleClusterTime, ss.str());
        }
        return true;
    }
};

MONGO_INITIALIZER(RegisterAppendOpLogNoteCmd)(InitializerContext* context) {
    new AppendOplogNoteCmd();
}

}  // namespace mongo