/*
 * Copyright 2016-present Open Networking Laboratory
 *
 * 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.bmv2.api.runtime;

import com.google.common.annotations.Beta;
import org.apache.commons.lang3.tuple.Pair;
import org.onlab.util.ImmutableByteSequence;
import org.onosproject.net.DeviceId;

import java.util.Collection;
import java.util.List;

/**
 * An agent to control a BMv2 device.
 */
@Beta
public interface Bmv2DeviceAgent {

    /**
     * Returns the device ID of this agent.
     *
     * @return a device id
     */
    DeviceId deviceId();

    /**
     * Pings the device, returns true if the device is reachable, false otherwise.
     *
     * @return true if reachable, false otherwise
     */
    boolean ping();

    /**
     * Adds a new table entry. If successful returns a table-specific identifier of the installed entry.
     *
     * @param entry a table entry
     * @return a long value
     * @throws Bmv2RuntimeException if any error occurs
     */
    long addTableEntry(Bmv2TableEntry entry) throws Bmv2RuntimeException;

    /**
     * Modifies an existing entry at by updating its action.
     *
     * @param tableName a string value
     * @param entryId   a long value
     * @param action    an action
     * @throws Bmv2RuntimeException if any error occurs
     */
    void modifyTableEntry(String tableName, long entryId, Bmv2Action action) throws Bmv2RuntimeException;

    /**
     * Deletes currently installed entry.
     *
     * @param tableName a string value
     * @param entryId   a long value
     * @throws Bmv2RuntimeException if any error occurs
     */
    void deleteTableEntry(String tableName, long entryId) throws Bmv2RuntimeException;

    /**
     * Sets a default action for the given table.
     *
     * @param tableName a string value
     * @param action    an action value
     * @throws Bmv2RuntimeException if any error occurs
     */
    void setTableDefaultAction(String tableName, Bmv2Action action) throws Bmv2RuntimeException;

    /**
     * Returns information on the ports currently configured in the switch.
     *
     * @return collection of port information
     * @throws Bmv2RuntimeException if any error occurs
     */
    Collection<Bmv2PortInfo> getPortsInfo() throws Bmv2RuntimeException;

    /**
     * Returns a list of table entries installed in the given table.
     *
     * @param tableName a string value
     * @return a list of parsed table entries
     * @throws Bmv2RuntimeException if any error occurs
     */
    List<Bmv2ParsedTableEntry> getTableEntries(String tableName) throws Bmv2RuntimeException;

    /**
     * Requests the device to transmit a given packet over the given port.
     *
     * @param portNumber a port number
     * @param packet a byte sequence
     * @throws Bmv2RuntimeException
     */
    void transmitPacket(int portNumber, ImmutableByteSequence packet) throws Bmv2RuntimeException;

    /**
     * Resets the state of the switch.
     *
     * @throws Bmv2RuntimeException if any error occurs
     */
    void resetState() throws Bmv2RuntimeException;

    /**
     * Returns the JSON configuration currently used to process packets.
     *
     * @return a JSON-formatted string value
     * @throws Bmv2RuntimeException if any error occurs
     */
    String dumpJsonConfig() throws Bmv2RuntimeException;

    /**
     * Returns the MD5 sum of the JSON-formatted configuration currently used to process packets.
     *
     * @return a string value
     * @throws Bmv2RuntimeException if any error occurs
     */
    String getJsonConfigMd5() throws Bmv2RuntimeException;

    /**
     * Returns the counter values for a given table and entry.
     *
     * @param tableName a table name
     * @param entryId an entry id
     * @return a pair of long values, where the left value is the number of bytes and the right the number of packets
     * @throws Bmv2RuntimeException if any error occurs
     */
    Pair<Long, Long> readTableEntryCounter(String tableName, long entryId) throws Bmv2RuntimeException;

    /**
     * Returns the values of a given counter instance.
     *
     * @param counterName a counter name
     * @param index       an integer value
     * @return a pair of long values, where the left value is the number of bytes and the right value is the number of
     * packets
     * @throws Bmv2RuntimeException if any error occurs
     */
    Pair<Long, Long> readCounter(String counterName, int index) throws Bmv2RuntimeException;

    /**
     * Returns the ID of the current BMv2 process instance (used to distinguish between different executions of the
     * same BMv2 device).
     *
     * @return an integer value
     * @throws Bmv2RuntimeException if any error occurs
     */
    int getProcessInstanceId() throws Bmv2RuntimeException;

    /**
     * Uploads a new JSON configuration on the device.
     *
     * @param jsonString a string value
     * @throws Bmv2RuntimeException if any error occurs
     */
    void uploadNewJsonConfig(String jsonString) throws Bmv2RuntimeException;

    /**
     * Triggers a configuration swap on the device.
     *
     * @throws Bmv2RuntimeException
     */
    void swapJsonConfig() throws Bmv2RuntimeException;
}