// matcher_covered.cpp

/* Matcher is our boolean expression evaluator for "where" clauses */

/**
*    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/>.
*/

#include "pch.h"
#include "matcher.h"
#include "../util/goodies.h"
#include "../util/unittest.h"
#include "diskloc.h"
#include "../scripting/engine.h"
#include "db.h"
#include "client.h"

#include "pdfile.h"

namespace mongo {

    CoveredIndexMatcher::CoveredIndexMatcher( const BSONObj &jsobj, const BSONObj &indexKeyPattern, bool alwaysUseRecord) :
        _docMatcher( new Matcher( jsobj ) ),
        _keyMatcher( *_docMatcher, indexKeyPattern )
    {
        init( alwaysUseRecord );
    }
 
    CoveredIndexMatcher::CoveredIndexMatcher( const shared_ptr< Matcher > &docMatcher, const BSONObj &indexKeyPattern , bool alwaysUseRecord ) :
        _docMatcher( docMatcher ),
        _keyMatcher( *_docMatcher, indexKeyPattern )
    {
        init( alwaysUseRecord );
    }

    void CoveredIndexMatcher::init( bool alwaysUseRecord ) {
        _needRecord = 
        alwaysUseRecord || 
        ! ( _docMatcher->keyMatch() && 
           _keyMatcher.sameCriteriaCount( *_docMatcher ) &&
           ! _keyMatcher.hasType( BSONObj::opEXISTS ) );
        ;        
    }
    
    bool CoveredIndexMatcher::matchesCurrent( Cursor * cursor , MatchDetails * details ){
        return matches( cursor->currKey() , cursor->currLoc() , details );
    }
    
    bool CoveredIndexMatcher::matches(const BSONObj &key, const DiskLoc &recLoc , MatchDetails * details ) {
        if ( details )
            details->reset();
        
        if ( !_keyMatcher.matches(key, details ) ){
            return false;
        }
        
        if ( ! _needRecord ){
            return true;
        }

        if ( details )
            details->loadedObject = true;

        return _docMatcher->matches(recLoc.rec() , details );
    }
    

}