/*    Copyright (C) 2014 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.
 */

#pragma once

#include <string>

#include "mongo/base/status.h"
#include "mongo/db/jsobj.h"

namespace mongo {

    struct WriteConcernOptions {
    public:

        enum SyncMode { NONE, FSYNC, JOURNAL };

        static const int kNoTimeout = 0;
        static const int kNoWaiting = -1;

        static const BSONObj Default;
        static const BSONObj Acknowledged;
        static const BSONObj Unacknowledged;

        static const char kMajority[]; // = "majority"

        WriteConcernOptions() { reset(); }

        WriteConcernOptions(int numNodes,
                            SyncMode sync,
                            int timeout);

        WriteConcernOptions(const std::string& mode,
                            SyncMode sync,
                            int timeout);

        Status parse( const BSONObj& obj );

        /**
         * Extracts the write concern settings from the BSONObj. The BSON object should have
         * the format:
         *
         * {
         *     ...
         *     secondaryThrottle: <bool>, // optional
         *     _secondaryThrottle: <bool>, // optional
         *     writeConcern: <BSONObj> // optional
         * }
         *
         * Note: secondaryThrottle takes precedence over _secondaryThrottle.
         *
         * Also sets output parameter rawWriteConcernObj if the writeCocnern field exists.
         *
         * Returns OK if the parse was successful. Also returns ErrorCodes::WriteConcernNotDefined
         * when secondary throttle is true but write concern was not specified.
         */
        Status parseSecondaryThrottle(const BSONObj& doc,
                                      BSONObj* rawWriteConcernObj);

        /**
         * Return true if the server needs to wait for other secondary nodes to satisfy this
         * write concern setting. Errs on the false positive for non-empty wMode.
         */
        bool shouldWaitForOtherNodes() const;

        void reset() {
            syncMode = NONE;
            wNumNodes = 0;
            wMode = "";
            wTimeout = 0;
        }

        // Returns the BSON representation of this object.
        // Warning: does not return the same object passed on the last parse() call.
        BSONObj toBSON() const;

        SyncMode syncMode;

        // The w parameter for this write concern. The wMode represents the string format and
        // takes precedence over the numeric format wNumNodes.
        int wNumNodes;
        std::string wMode;

        // Timeout in milliseconds.
        int wTimeout;
    };

}