/**
 * Copyright (C) 2017 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 <string>

#include "mongo/base/status.h"
#include "mongo/util/uuid.h"

namespace mongo {
class BSONElement;
class BSONObj;
class OperationContext;

// OplogApplicationValidity represents special conditions relevant to authorization for
// oplog application.
//
// kNeedsSuperuser means the oplog application command is empty or contains an empty nested
// applyOps command oplog entry, or a createCollection or renameCollection mixed in a batch.
//
// kNeedsUseUUID means any oplog entry in the command contains a UUID, so the useUUID action
// must be authorized.
//
// kNeedsForceAndUseUUID means the command contains one oplog entry which is a collection create
// with a specified UUID, so both the forceUUID and useUUID actions must be authorized.
//
// kOk means no special conditions apply.
//
// Only kOk and kNeedsUseUUID are valid for 'doTxn'.  All are valid for 'applyOps'.
enum class OplogApplicationValidity { kOk, kNeedsUseUUID, kNeedsForceAndUseUUID, kNeedsSuperuser };

// OplogApplicationChecks contains helper functions for checking the applyOps and doTxn commands.
class OplogApplicationChecks {
public:
    /**
     * Checks the authorization for an entire oplog application command.
     */
    static Status checkAuthForCommand(OperationContext* opCtx,
                                      const std::string& dbname,
                                      const BSONObj& cmdObj,
                                      OplogApplicationValidity validity);

    /**
     * Checks that 'opsElement' is an array and all elements of the array are valid operations.
     */
    static Status checkOperationArray(const BSONElement& opsElement);

private:
    static UUID getUUIDFromOplogEntry(const BSONObj& oplogEntry);

    /**
     * Checks the authorization for a single operation contained within an oplog application
     * command.
     */
    static Status checkOperationAuthorization(OperationContext* opCtx,
                                              const std::string& dbname,
                                              const BSONObj& oplogEntry,
                                              AuthorizationSession* authSession,
                                              bool alwaysUpsert);
    /**
     * Returns OK if 'e' contains a valid operation.
     */
    static Status checkOperation(const BSONElement& e);
};

}  // namespace mongo