001/*
002 * VM-Operator
003 * Copyright (C) 2025 Michael N. Lipp
004 * 
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
017 */
018
019package org.jdrupes.vmoperator.runner.qemu;
020
021import java.io.IOException;
022import java.nio.file.Path;
023import org.jdrupes.vmoperator.runner.qemu.events.VserportChangeEvent;
024import org.jgrapes.core.Channel;
025import org.jgrapes.core.annotation.Handler;
026import org.jgrapes.util.events.ConfigurationUpdate;
027
028/**
029 * A component that handles the communication with an agent
030 * running in the VM.
031 * 
032 * If the log level for this class is set to fine, the messages 
033 * exchanged on the socket are logged.
034 */
035public abstract class AgentConnector extends QemuConnector {
036
037    protected String channelId;
038
039    /**
040     * Instantiates a new agent connector.
041     *
042     * @param componentChannel the component channel
043     * @throws IOException Signals that an I/O exception has occurred.
044     */
045    public AgentConnector(Channel componentChannel) throws IOException {
046        super(componentChannel);
047    }
048
049    /**
050     * As the initial configuration of this component depends on the 
051     * configuration of the {@link Runner}, it doesn't have a handler 
052     * for the {@link ConfigurationUpdate} event. The values are 
053     * forwarded from the {@link Runner} instead.
054     *
055     * @param channelId the channel id
056     * @param socketPath the socket path
057     */
058    /* default */ void configure(String channelId, Path socketPath) {
059        super.configure(socketPath);
060        this.channelId = channelId;
061        logger.fine(() -> getClass().getSimpleName() + " configured with"
062            + " channelId=" + channelId);
063    }
064
065    /**
066     * When the virtual serial port with the configured channel id has
067     * been opened call {@link #agentConnected()}.
068     *
069     * @param event the event
070     */
071    @Handler
072    public void onVserportChanged(VserportChangeEvent event) {
073        if (event.id().equals(channelId) && event.isOpen()) {
074            agentConnected();
075        }
076    }
077
078    /**
079     * Called when the agent in the VM opens the connection. The
080     * default implementation does nothing.
081     */
082    @SuppressWarnings("PMD.EmptyMethodInAbstractClassShouldBeAbstract")
083    protected void agentConnected() {
084        // Default is to do nothing.
085    }
086}