// progress_meter.h

/*    Copyright 2009 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.
 */

#pragma once

#include "mongo/util/thread_safe_string.h"

#include <string>

namespace mongo {

    class ProgressMeter {
        MONGO_DISALLOW_COPYING(ProgressMeter);
    public:
        ProgressMeter(unsigned long long total,
                      int secondsBetween = 3,
                      int checkInterval = 100,
                      std::string units = "",
                      std::string name = "Progress")
                : _showTotal(true),
                  _units(units) {
            _name = name.c_str();
            reset( total , secondsBetween , checkInterval );
        }

        ProgressMeter() : _active(0), _showTotal(true), _units("") {
            _name = "Progress";
        }

        // typically you do ProgressMeterHolder
        void reset( unsigned long long total , int secondsBetween = 3 , int checkInterval = 100 );

        void finished() { _active = 0; }
        bool isActive() const { return _active; }

        /**
         * @param n how far along we are relative to the total # we set in CurOp::setMessage
         * @return if row was printed
         */
        bool hit( int n = 1 );

        void setUnits( const std::string& units ) { _units = units; }
        std::string getUnit() const { return _units; }

        void setName(std::string name) { _name = name.c_str(); }
        std::string getName() const { return _name.toString(); }

        void setTotalWhileRunning( unsigned long long total ) {
            _total = total;
        }

        unsigned long long done() const { return _done; }

        unsigned long long hits() const { return _hits; }

        unsigned long long total() const { return _total; }

        void showTotal(bool doShow) {
            _showTotal = doShow;
        }

        std::string toString() const;

        bool operator==( const ProgressMeter& other ) const { return this == &other; }

    private:

        bool _active;

        unsigned long long _total;
        bool _showTotal;
        int _secondsBetween;
        int _checkInterval;

        unsigned long long _done;
        unsigned long long _hits;
        int _lastTime;

        std::string _units;
        ThreadSafeString _name;
    };

    // e.g.: 
    // CurOp * op = CurOp::get(txn);
    // ProgressMeterHolder pm(op->setMessage("index: (1/3) external sort", "Index: External Sort Progress", d->stats.nrecords, 10));
    // loop { pm.hit(); }
    class ProgressMeterHolder {
        MONGO_DISALLOW_COPYING(ProgressMeterHolder);
    public:
        ProgressMeterHolder( ProgressMeter& pm )
            : _pm( pm ) {
        }

        ~ProgressMeterHolder() {
            _pm.finished();
        }

        ProgressMeter* operator->() { return &_pm; }

        ProgressMeter* get() { return &_pm; }
        
        bool hit( int n = 1 ) { return _pm.hit( n ); }

        void finished() { _pm.finished(); }

        bool operator==( const ProgressMeter& other ) { return _pm == other; }

    private:
        ProgressMeter& _pm;
    };


}