/**
 *    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.
 */

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kCommand

#include "mongo/platform/basic.h"

#include <string>

#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/fsync.h"
#include "mongo/db/curop.h"
#include "mongo/db/dbmessage.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/matcher/matcher.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/stats/fill_locker_info.h"
#include "mongo/util/log.h"

namespace mongo {

    class CurrentOpCommand : public Command {
    public:

        CurrentOpCommand() : Command("currentOp") {}

        bool isWriteCommandForConfigServer() const final { return false; }

        bool slaveOk() const final { return true; }

        bool adminOnly() const final { return true; }

        Status checkAuthForCommand(ClientBasic* client,
                                   const std::string& dbname,
                                   const BSONObj& cmdObj) final {

            bool isAuthorized = AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
                                    ResourcePattern::forClusterResource(),
                                    ActionType::inprog);
            return isAuthorized ? Status::OK() : Status(ErrorCodes::Unauthorized, "Unauthorized");
        }

        bool run(OperationContext* txn,
                 const std::string& db,
                 BSONObj& cmdObj,
                 int options,
                 std::string& errmsg,
                 BSONObjBuilder& result) final {

            const bool includeAll = cmdObj["$all"].trueValue();

            // Filter the output
            BSONObj filter;
            {
                BSONObjBuilder b;
                BSONObjIterator i(cmdObj);
                invariant(i.more());
                i.next(); // skip {currentOp: 1} which is required to be the first element
                while (i.more()) {
                    BSONElement e = i.next();
                    if (str::equals("$all", e.fieldName())) {
                        continue;
                    }

                    b.append(e);
                }
                filter = b.obj();
            }

            const WhereCallbackReal whereCallback(txn, db);
            const Matcher matcher(filter, whereCallback);

            BSONArrayBuilder inprogBuilder(result.subarrayStart("inprog"));

            for (ServiceContext::LockedClientsCursor cursor(txn->getClient()->getServiceContext());
                 Client* client = cursor.next();) {

                invariant(client);

                stdx::lock_guard<Client> lk(*client);
                const OperationContext* opCtx = client->getOperationContext();

                if (!includeAll) {
                    // Skip over inactive connections.
                    if (!opCtx)
                        continue;
                }

                BSONObjBuilder infoBuilder;

                // The client information
                client->reportState(infoBuilder);

                // Operation context specific information
                infoBuilder.appendBool("active", static_cast<bool>(opCtx));
                if (opCtx) {
                    infoBuilder.append("opid", opCtx->getOpID());
                    // CurOp
                    if (CurOp::get(opCtx)) {
                        CurOp::get(opCtx)->reportState(&infoBuilder);
                    }

                    // LockState
                    Locker::LockerInfo lockerInfo;
                    opCtx->lockState()->getLockerInfo(&lockerInfo);
                    fillLockerInfo(lockerInfo, infoBuilder);
                }

                infoBuilder.done();

                const BSONObj info = infoBuilder.obj();

                if (includeAll || matcher.matches(info)) {
                    inprogBuilder.append(info);
                }
            }

            inprogBuilder.done();

            if (lockedForWriting()) {
                result.append("fsyncLock", true);
                result.append("info",
                              "use db.fsyncUnlock() to terminate the fsync write/snapshot lock");
            }

            return true;
        }

    } currentOpCommand;

}  // namespace mongo