/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.onlab.onos.net.flow;


/**
 * Represents a generalized match &amp; action pair to be applied to
 * an infrastucture device.
 */
public interface FlowEntry extends FlowRule {


    public enum FlowEntryState {

        /**
         * Indicates that this rule has been submitted for addition.
         * Not necessarily in  the flow table.
         */
        PENDING_ADD,

        /**
         * Rule has been added which means it is in the flow table.
         */
        ADDED,

        /**
         * Flow has been marked for removal, might still be in flow table.
         */
        PENDING_REMOVE,

        /**
         * Flow has been removed from flow table and can be purged.
         */
        REMOVED,

        /**
         * Indicates that the installation of this flow has failed.
         */
        FAILED
    }

    /**
     * Returns the flow entry state.
     *
     * @return flow entry state
     */
    FlowEntryState state();

    /**
     * Returns the number of milliseconds this flow rule has been applied.
     *
     * @return number of millis
     */
    long life();

    /**
     * Returns the number of packets this flow rule has matched.
     *
     * @return number of packets
     */
    long packets();

    /**
     * Returns the number of bytes this flow rule has matched.
     *
     * @return number of bytes
     */
    long bytes();

    // TODO: consider removing this attribute
    /**
     * When this flow entry was last deemed active.
     * @return epoch time of last activity
     */
    long lastSeen();

    /**
     * Indicates the error type.
     * @return an integer value of the error
     */
    int errType();

    /**
     * Indicates the error code.
     * @return an integer value of the error
     */
    int errCode();

}