package org.argeo.ssh;
   
   import java.io.IOException;
   import java.nio.file.Path;
   import java.nio.file.Paths;
   
   import org.apache.sshd.server.SshServer;
   import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
   import org.apache.sshd.server.scp.ScpCommandFactory;
  import org.apache.sshd.server.shell.ProcessShellFactory;
  import org.argeo.util.OS;
  
  /** A simple SSH server with some defaults. Supports SCP. */
  @SuppressWarnings("restriction")
  public class BasicSshServer {
  	private Integer port;
  	private Path hostKeyPath;
  
  	private SshServer sshd = null;
  
  	public BasicSshServer(Integer port, Path hostKeyPath) {
  		this.port = port;
  		this.hostKeyPath = hostKeyPath;
  	}
  
  	public void init() {
  		try {
  			sshd = SshServer.setUpDefaultServer();
  			sshd.setPort(port);
  			if (hostKeyPath == null)
  				throw new IllegalStateException("An SSH server key must be set");
  			sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(hostKeyPath));
  			// sshd.setShellFactory(new ProcessShellFactory(new String[] { "/bin/sh", "-i",
  			// "-l" }));
  			String[] shellCommand = OS.LOCAL.getDefaultShellCommand();
  			sshd.setShellFactory(new ProcessShellFactory(shellCommand));
  			sshd.setCommandFactory(new ScpCommandFactory());
  			sshd.start();
  		} catch (Exception e) {
  			throw new RuntimeException("Cannot start SSH server on port " + port, e);
  		}
  	}
  
  	public void destroy() {
  		try {
  			sshd.stop();
  		} catch (IOException e) {
  			throw new RuntimeException("Cannot stop SSH server on port " + port, e);
  		}
  	}
  
  	public Integer getPort() {
  		return port;
  	}
  
  	public void setPort(Integer port) {
  		this.port = port;
  	}
  
  	public Path getHostKeyPath() {
  		return hostKeyPath;
  	}
  
  	public void setHostKeyPath(Path hostKeyPath) {
  		this.hostKeyPath = hostKeyPath;
  	}
  
  	public static void main(String[] args) {
  		int port = 2222;
  		Path hostKeyPath = Paths.get("hostkey.ser");
  		try {
  			if (args.length > 0)
  				port = Integer.parseInt(args[0]);
  			if (args.length > 1)
  				hostKeyPath = Paths.get(args[1]);
  		} catch (Exception e1) {
  			printUsage();
  		}
  
  		BasicSshServer sshServer = new BasicSshServer(port, hostKeyPath);
  		sshServer.init();
  		Runtime.getRuntime().addShutdownHook(new Thread("Shutdown SSH server") {
  
  			@Override
  			public void run() {
  				sshServer.destroy();
  			}
  		});
  		try {
  			synchronized (sshServer) {
  				sshServer.wait();
  			}
  		} catch (InterruptedException e) {
  			sshServer.destroy();
  		}
  
  	}
  
  	public static void printUsage() {
 		System.out.println("java " + BasicSshServer.class.getName() + " [port] [server key path]");
 	}
 
 }