/**
 *    Copyright (C) 2015 MongoDB 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.
 */

#pragma once

#include "mongo/db/matcher/expression.h"

namespace mongo {

/**
 * Common base class for $where match expression implementations.
 */
class WhereMatchExpressionBase : public MatchExpression {
public:
    struct WhereParams {
        std::string code;
        BSONObj scope;  // Owned.
    };

    explicit WhereMatchExpressionBase(WhereParams params);

    size_t numChildren() const final {
        return 0;
    }

    MatchExpression* getChild(size_t i) const final {
        MONGO_UNREACHABLE;
    }

    std::vector<MatchExpression*>* getChildVector() final {
        return nullptr;
    }

    bool matchesSingleElement(const BSONElement& e, MatchDetails* details = nullptr) const final {
        return false;
    }

    void debugString(StringBuilder& debug, int level = 0) const final;

    void serialize(BSONObjBuilder* out) const final;

    bool equivalent(const MatchExpression* other) const final;

    MatchCategory getCategory() const final {
        return MatchCategory::kOther;
    }

protected:
    const std::string& getCode() const {
        return _code;
    }

    const BSONObj& getScope() const {
        return _scope;
    }

private:
    ExpressionOptimizerFunc getOptimizer() const final {
        return [](std::unique_ptr<MatchExpression> expression) { return expression; };
    }

    const std::string _code;
    const BSONObj _scope;  // Owned.
};

}  // namespace mongo