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 java.util.List;
024import org.jdrupes.vmoperator.runner.qemu.events.VserportChangeEvent;
025import org.jgrapes.core.Channel;
026import org.jgrapes.core.annotation.Handler;
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     * Extracts the channel id and the socket path from the QEMU
051     * command line.
052     *
053     * @param command the command
054     * @param chardev the chardev
055     */
056    @SuppressWarnings("PMD.CognitiveComplexity")
057    protected void configureConnection(List<String> command, String chardev) {
058        Path socketPath = null;
059        for (var arg : command) {
060            if (arg.startsWith("virtserialport,")
061                && arg.contains("chardev=" + chardev)) {
062                for (var prop : arg.split(",")) {
063                    if (prop.startsWith("id=")) {
064                        channelId = prop.substring(3);
065                    }
066                }
067            }
068            if (arg.startsWith("socket,")
069                && arg.contains("id=" + chardev)) {
070                for (var prop : arg.split(",")) {
071                    if (prop.startsWith("path=")) {
072                        socketPath = Path.of(prop.substring(5));
073                    }
074                }
075            }
076        }
077        if (channelId == null || socketPath == null) {
078            logger.warning(() -> "Definition of chardev " + chardev
079                + " missing in runner template.");
080            return;
081        }
082        logger.fine(() -> getClass().getSimpleName() + " configured with"
083            + " channelId=" + channelId);
084        super.configure(socketPath);
085    }
086
087    /**
088     * When the virtual serial port with the configured channel id has
089     * been opened call {@link #agentConnected()}.
090     *
091     * @param event the event
092     */
093    @Handler
094    public void onVserportChanged(VserportChangeEvent event) {
095        if (event.id().equals(channelId)) {
096            if (event.isOpen()) {
097                agentConnected();
098            } else {
099                agentDisconnected();
100            }
101        }
102    }
103
104    /**
105     * Called when the agent in the VM opens the connection. The
106     * default implementation does nothing.
107     */
108    @SuppressWarnings("PMD.EmptyMethodInAbstractClassShouldBeAbstract")
109    protected void agentConnected() {
110        // Default is to do nothing.
111    }
112
113    /**
114     * Called when the agent in the VM closes the connection. The
115     * default implementation does nothing.
116     */
117    @SuppressWarnings("PMD.EmptyMethodInAbstractClassShouldBeAbstract")
118    protected void agentDisconnected() {
119        // Default is to do nothing.
120    }
121
122}