// index_descriptor.cpp

/**
*    Copyright (C) 2014 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/db/index/index_descriptor.h"

namespace mongo {

    namespace {
        void populateOptionsMap( std::map<StringData, BSONElement>& theMap,
                                 const BSONObj& spec ) {

            BSONObjIterator it( spec );
            while ( it.more() ) {
                const BSONElement e = it.next();

                StringData fieldName = e.fieldNameStringData();
                if ( fieldName == "key" ||
                     fieldName == "ns" ||
                     fieldName == "name" ||
                     fieldName == "v" ||
                     fieldName == "background" || // this is a creation time option only
                     fieldName == "dropDups" || // this is a creation time option only
                     fieldName == "sparse" || // checked specially
                     fieldName == "unique" // check specially
                     ) {
                    continue;
                }
                theMap[ fieldName ] = e;
            }
        }
    }

    bool IndexDescriptor::areIndexOptionsEquivalent( const IndexDescriptor* other ) const {

        if ( isSparse() != other->isSparse() ) {
            return false;
        }

        if ( !isIdIndex() &&
             unique() != other->unique() ) {
            // Note: { _id: 1 } or { _id: -1 } implies unique: true.
            return false;
        }

        // Then compare the rest of the options.

        std::map<StringData, BSONElement> existingOptionsMap;
        populateOptionsMap( existingOptionsMap, infoObj() );

        std::map<StringData, BSONElement> newOptionsMap;
        populateOptionsMap( newOptionsMap, other->infoObj() );

        return existingOptionsMap == newOptionsMap;
    }

}
