/**
*    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.
*/

#include "mongo/platform/basic.h"

#include "mongo/db/dbwebserver.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/stats/snapshots.h"
#include "mongo/util/mongoutils/html.h"

namespace mongo {
namespace {

    using namespace html;

    using std::fixed;
    using std::setprecision;
    using std::string;
    using std::stringstream;

    class DBTopStatus : public WebStatusPlugin {
    public:
        DBTopStatus() : WebStatusPlugin( "dbtop" , 50 , "(occurrences|percent of elapsed)" ) {}

        void display( stringstream& ss , double elapsed , const Top::UsageData& usage ) {
            ss << "<td>";
            ss << usage.count;
            ss << "</td><td>";
            double per = 100 * ((double)usage.time)/elapsed;
            if( per == (int) per )
                ss << (int) per;
            else
                ss << setprecision(1) << fixed << per;
            ss << '%';
            ss << "</td>";
        }

        void display( stringstream& ss , double elapsed , const string& ns , const Top::CollectionData& data ) {
            if ( ns != "TOTAL" && data.total.count == 0 )
                return;
            ss << "<tr><th>" << html::escape( ns ) << "</th>";

            display( ss , elapsed , data.total );

            display( ss , elapsed , data.readLock );
            display( ss , elapsed , data.writeLock );

            display( ss , elapsed , data.queries );
            display( ss , elapsed , data.getmore );
            display( ss , elapsed , data.insert );
            display( ss , elapsed , data.update );
            display( ss , elapsed , data.remove );

            ss << "</tr>\n";
        }

        void run(OperationContext* txn, stringstream& ss) {
            StatusWith<SnapshotDiff> diff = statsSnapshots.computeDelta();

            if ( ! diff.isOK() )
                return;

            ss << "<table border=1 cellpadding=2 cellspacing=0>";
            ss << "<tr align='left'><th>";
            ss << a("http://dochub.mongodb.org/core/whatisanamespace", "namespace") <<
               "NS</a></th>"
               "<th colspan=2>total</th>"
               "<th colspan=2>Reads</th>"
               "<th colspan=2>Writes</th>"
               "<th colspan=2>Queries</th>"
               "<th colspan=2>GetMores</th>"
               "<th colspan=2>Inserts</th>"
               "<th colspan=2>Updates</th>"
               "<th colspan=2>Removes</th>";
            ss << "</tr>\n";

            const Top::UsageMap& usage = diff.getValue().usageDiff;
            unsigned long long elapsed = diff.getValue().timeElapsed;
            for ( Top::UsageMap::const_iterator i=usage.begin(); i != usage.end(); ++i ) {
                display( ss , (double) elapsed , i->first , i->second );
            }

            ss << "</table>";

        }

        virtual void init() {}
    } dbtopStatus;

}  // namespace
}  // namespace mongo