// expression_tree.h

/**
 *    Copyright (C) 2013 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.
 */

#pragma once

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


/**
 * this contains all Expessions that define the structure of the tree
 * they do not look at the structure of the documents themselves, just combine other things
 */
namespace mongo {

class ListOfMatchExpression : public MatchExpression {
public:
    ListOfMatchExpression(MatchType type) : MatchExpression(type) {}
    virtual ~ListOfMatchExpression();

    /**
     * @param e - I take ownership
     */
    void add(MatchExpression* e);

    /**
     * clears all the thingsd we own, and does NOT delete
     * someone else has taken ownership
     */
    void clearAndRelease() {
        _expressions.clear();
    }

    virtual size_t numChildren() const {
        return _expressions.size();
    }

    virtual MatchExpression* getChild(size_t i) const {
        return _expressions[i];
    }

    virtual std::vector<MatchExpression*>* getChildVector() {
        return &_expressions;
    }

    bool equivalent(const MatchExpression* other) const;

protected:
    void _debugList(StringBuilder& debug, int level) const;

    void _listToBSON(BSONArrayBuilder* out) const;

private:
    std::vector<MatchExpression*> _expressions;
};

class AndMatchExpression : public ListOfMatchExpression {
public:
    AndMatchExpression() : ListOfMatchExpression(AND) {}
    virtual ~AndMatchExpression() {}

    virtual bool matches(const MatchableDocument* doc, MatchDetails* details = 0) const;
    virtual bool matchesSingleElement(const BSONElement& e) const;

    virtual MatchExpression* shallowClone() const {
        AndMatchExpression* self = new AndMatchExpression();
        for (size_t i = 0; i < numChildren(); ++i) {
            self->add(getChild(i)->shallowClone());
        }
        if (getTag()) {
            self->setTag(getTag()->clone());
        }
        return self;
    }

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

    virtual void toBSON(BSONObjBuilder* out) const;
};

class OrMatchExpression : public ListOfMatchExpression {
public:
    OrMatchExpression() : ListOfMatchExpression(OR) {}
    virtual ~OrMatchExpression() {}

    virtual bool matches(const MatchableDocument* doc, MatchDetails* details = 0) const;
    virtual bool matchesSingleElement(const BSONElement& e) const;

    virtual MatchExpression* shallowClone() const {
        OrMatchExpression* self = new OrMatchExpression();
        for (size_t i = 0; i < numChildren(); ++i) {
            self->add(getChild(i)->shallowClone());
        }
        if (getTag()) {
            self->setTag(getTag()->clone());
        }
        return self;
    }

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

    virtual void toBSON(BSONObjBuilder* out) const;
};

class NorMatchExpression : public ListOfMatchExpression {
public:
    NorMatchExpression() : ListOfMatchExpression(NOR) {}
    virtual ~NorMatchExpression() {}

    virtual bool matches(const MatchableDocument* doc, MatchDetails* details = 0) const;
    virtual bool matchesSingleElement(const BSONElement& e) const;

    virtual MatchExpression* shallowClone() const {
        NorMatchExpression* self = new NorMatchExpression();
        for (size_t i = 0; i < numChildren(); ++i) {
            self->add(getChild(i)->shallowClone());
        }
        if (getTag()) {
            self->setTag(getTag()->clone());
        }
        return self;
    }

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

    virtual void toBSON(BSONObjBuilder* out) const;
};

class NotMatchExpression : public MatchExpression {
public:
    NotMatchExpression() : MatchExpression(NOT) {}
    NotMatchExpression(MatchExpression* e) : MatchExpression(NOT), _exp(e) {}
    /**
     * @param exp - I own it, and will delete
     */
    virtual Status init(MatchExpression* exp) {
        _exp.reset(exp);
        return Status::OK();
    }

    virtual MatchExpression* shallowClone() const {
        NotMatchExpression* self = new NotMatchExpression();
        MatchExpression* child = _exp->shallowClone();
        self->init(child);
        if (getTag()) {
            self->setTag(getTag()->clone());
        }
        return self;
    }

    virtual bool matches(const MatchableDocument* doc, MatchDetails* details = 0) const {
        return !_exp->matches(doc, NULL);
    }

    virtual bool matchesSingleElement(const BSONElement& e) const {
        return !_exp->matchesSingleElement(e);
    }

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

    virtual void toBSON(BSONObjBuilder* out) const;

    bool equivalent(const MatchExpression* other) const;

    virtual size_t numChildren() const {
        return 1;
    }

    virtual MatchExpression* getChild(size_t i) const {
        return _exp.get();
    }

    MatchExpression* releaseChild(void) {
        return _exp.release();
    }

    void resetChild(MatchExpression* newChild) {
        _exp.reset(newChild);
    }

private:
    std::unique_ptr<MatchExpression> _exp;
};
}