// tokenizer.h


/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    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
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    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 Server Side 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 <string>

#include "mongo/base/string_data.h"
#include "mongo/db/fts/fts_language.h"

namespace mongo {

namespace fts {

struct Token {
    enum Type { WHITESPACE, DELIMITER, TEXT, INVALID };
    Token(Type type, StringData data, unsigned offset) : type(type), data(data), offset(offset) {}

    bool ok() const {
        return type != INVALID;
    }

    Type type;
    StringData data;
    unsigned offset;
};

class Tokenizer {
    MONGO_DISALLOW_COPYING(Tokenizer);

public:
    Tokenizer(const FTSLanguage* language, StringData str);

    bool more() const;
    Token next();

private:
    Token::Type _type(char c) const;
    bool _skipWhitespace();

    unsigned _pos;
    const StringData _raw;
    bool _english;
};
}
}