/**
 *    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 <string>

#include "mongo/db/clientcursor.h"
#include "mongo/db/curop.h"
#include "mongo/db/dbmessage.h"
#include "mongo/db/query/canonical_query.h"
#include "mongo/util/net/message.h"

namespace mongo {

    class OperationContext;

    /**
     * Constructs a PlanExecutor for a query with the oplogReplay option set to true,
     * for the query 'cq' over the collection 'collection'. The PlanExecutor will
     * wrap a singleton OplogStart stage.
     *
     * The oplog start finding hack requires that 'cq' has a $gt or $gte predicate over
     * a field named 'ts'.
     *
     * On success, caller takes ownership of *execOut.
     */
    Status getOplogStartHack(OperationContext* txn,
                             Collection* collection,
                             CanonicalQuery* cq,
                             PlanExecutor** execOut);

    /**
     * Called from the getMore entry point in ops/query.cpp.
     */
    QueryResult::View getMore(OperationContext* txn,
                              const char* ns,
                              int ntoreturn,
                              long long cursorid,
                              CurOp& curop,
                              int pass,
                              bool& exhaust,
                              bool* isCursorAuthorized);

    /**
     * Run the query 'q' and place the result in 'result'.
     */
    std::string runQuery(OperationContext* txn,
                         Message& m,
                         QueryMessage& q,
                         const NamespaceString& ns,
                         CurOp& curop,
                         Message &result);

}  // namespace mongo