/*
 * Copyright 2014-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.onosproject.net.flow.instructions;

/**
 * Abstraction of a single traffic treatment step.
 */
public interface Instruction {

    /**
     * Represents the type of traffic treatment.
     */
    enum Type {
        /**
         * Signifies that the traffic requires no action.
         *
         * In OF10, the behavior of NOACTION is DROP.
         * In OF13, the behavior depends on current Action Set.
         */
        NOACTION,

        /**
         * Signifies that the traffic should be output to a port.
         */
        OUTPUT,

        /**
         * Signifies that traffic should be sent out of a group.
         */
        GROUP,

        /**
         * Signifies that the traffic should be enqueued to an already-configured
         queue on a port.
         */
        QUEUE,

        /**
         * Signifies that traffic should be metered according to a meter.
         */
        METER,

        /**
         * Signifies that the traffic should be modified in L0 way.
         */
        L0MODIFICATION,

        /**
         * Signifies that the traffic should be modified in L1 way.
         */
        L1MODIFICATION,

        /**
         * Signifies that the traffic should be modified in L2 way.
         */
        L2MODIFICATION,

        /**
         * Signifies that the traffic should be passed to another table.
         */
        TABLE,

        /**
         * Signifies that the traffic should be modified in L3 way.
         */
        L3MODIFICATION,

        /**
         * Signifies that metadata be attached to traffic.
         */
        METADATA,

        /**
         * Signifies that the traffic should be modified in L4 way.
         */
        L4MODIFICATION,

        /**
         * Signifies that a protocol-independent instruction will be used.
         */
        PROTOCOL_INDEPENDENT,

        /**
         * Signifies that an extension instruction will be used.
         */
        EXTENSION,

        /**
         * Signifies that statistics will be triggered.
         */
        STAT_TRIGGER,

        /**
         * Signifies that the packet should be truncated.
         */
        TRUNCATE
    }

    /**
     * Returns the type of instruction.
     *
     * @return type of instruction
     */
    Type type();

}