// stemmer.cpp

/**
*    Copyright (C) 2012 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 <cstdlib>

#include "mongo/db/fts/stemmer.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

namespace fts {

Stemmer::Stemmer(const FTSLanguage* language) {
    _stemmer = NULL;
    if (language->str() != "none")
        _stemmer = sb_stemmer_new(language->str().c_str(), "UTF_8");
}

Stemmer::~Stemmer() {
    if (_stemmer) {
        sb_stemmer_delete(_stemmer);
        _stemmer = NULL;
    }
}

StringData Stemmer::stem(StringData word) const {
    if (!_stemmer)
        return word;

    const sb_symbol* sb_sym =
        sb_stemmer_stem(_stemmer, (const sb_symbol*)word.rawData(), word.size());

    if (sb_sym == NULL) {
        // out of memory
        invariant(false);
    }

    return StringData((const char*)(sb_sym), sb_stemmer_length(_stemmer));
}
}
}