// expression_parser_tree.cpp

/**
 *    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.
 */

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

#include "mongo/bson/bsonobj.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/matcher/expression_array.h"
#include "mongo/db/matcher/expression_leaf.h"
#include "mongo/db/matcher/expression_tree.h"
#include "mongo/stdx/memory.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

// static
const int MatchExpressionParser::kMaximumTreeDepth = 100;

Status MatchExpressionParser::_parseTreeList(const BSONObj& arr,
                                             ListOfMatchExpression* out,
                                             const CollatorInterface* collator,
                                             int level) {
    if (arr.isEmpty())
        return Status(ErrorCodes::BadValue, "$and/$or/$nor must be a nonempty array");

    BSONObjIterator i(arr);
    while (i.more()) {
        BSONElement e = i.next();

        if (e.type() != Object)
            return Status(ErrorCodes::BadValue, "$or/$and/$nor entries need to be full objects");

        StatusWithMatchExpression sub = _parse(e.Obj(), collator, level);
        if (!sub.isOK())
            return sub.getStatus();

        out->add(sub.getValue().release());
    }
    return Status::OK();
}

StatusWithMatchExpression MatchExpressionParser::_parseNot(const char* name,
                                                           const BSONElement& e,
                                                           const CollatorInterface* collator,
                                                           int level) {
    if (e.type() == RegEx) {
        StatusWithMatchExpression s = _parseRegexElement(name, e);
        if (!s.isOK())
            return s;
        std::unique_ptr<NotMatchExpression> n = stdx::make_unique<NotMatchExpression>();
        Status s2 = n->init(s.getValue().release());
        if (!s2.isOK())
            return StatusWithMatchExpression(s2);
        return {std::move(n)};
    }

    if (e.type() != Object)
        return StatusWithMatchExpression(ErrorCodes::BadValue, "$not needs a regex or a document");

    BSONObj notObject = e.Obj();
    if (notObject.isEmpty())
        return StatusWithMatchExpression(ErrorCodes::BadValue, "$not cannot be empty");

    std::unique_ptr<AndMatchExpression> theAnd = stdx::make_unique<AndMatchExpression>();
    Status s = _parseSub(name, notObject, theAnd.get(), collator, level);
    if (!s.isOK())
        return StatusWithMatchExpression(s);

    // TODO: this seems arbitrary?
    // tested in jstests/not2.js
    for (unsigned i = 0; i < theAnd->numChildren(); i++)
        if (theAnd->getChild(i)->matchType() == MatchExpression::REGEX)
            return StatusWithMatchExpression(ErrorCodes::BadValue, "$not cannot have a regex");

    std::unique_ptr<NotMatchExpression> theNot = stdx::make_unique<NotMatchExpression>();
    s = theNot->init(theAnd.release());
    if (!s.isOK())
        return StatusWithMatchExpression(s);

    return {std::move(theNot)};
}
}