package org.openslx.taskmanager.tasks;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
import org.apache.commons.io.FileUtils;
import org.openslx.satserver.util.Archive;
import org.openslx.satserver.util.Util;
import org.openslx.taskmanager.api.AbstractTask;

import com.google.gson.annotations.Expose;

public class SshdConfigGenerator extends AbstractTask
{
	@Expose
	private int listenPort = 0;
	@Expose
	private String allowPasswordLogin = "no";
	@Expose
	private String publicKey = "";
	@Expose
	private String filename = null;

	private Output status = new Output();

	@Override
	protected boolean initTask()
	{
		this.setStatusObject( status );
		if ( !Util.isAllowedDir( this.filename ) )
			status.error = "Invalid directory for " + this.filename;
		if ( allowPasswordLogin == null || ( !allowPasswordLogin.equals( "yes" ) && !allowPasswordLogin.equals( "no" ) ) )
			status.error = "Invalid value for allowPasswordLogin: " + allowPasswordLogin;
		if ( listenPort > 65535 || listenPort < 1 )
			status.error = "Invalid value for listenPort: " + listenPort;
		if ( publicKey != null && !publicKey.isEmpty() && !publicKey.matches( "^[a-z0-9\\-]+ [A-Za-z0-9=/\\+]+ .*" ) )
			status.error = "Invalid public key: '" + publicKey + "'";
		return status.error == null;
	}

	@Override
	protected boolean execute()
	{
		TarArchiveOutputStream outArchive = null;
		try {
			// Prepare sshd config
			String template;
			try {
				template = FileUtils.readFileToString( new File( "./data/sshd_config.template" ), StandardCharsets.UTF_8 );
			} catch ( IOException e ) {
				status.error = e.toString();
				return false;
			}
			template = template.replace( "%PORT%", Integer.toString( this.listenPort ) );
			template = template.replace( "%PASSWORDLOGIN%", allowPasswordLogin );
			try {
				outArchive = Archive.createTarArchive( this.filename );
			} catch ( IOException e ) {
				status.error = "Could not create archive at " + this.filename;
				return false;
			}
			boolean ok = Archive.tarCreateFileFromString( outArchive, "/etc/ssh/sshd_config", template, 0644 );
			if ( publicKey != null && !publicKey.isEmpty() ) {
				String name = "sshd_conf_mod-" + publicKey.hashCode() + "-" + System.currentTimeMillis() + ".pub";
				ok |= Archive.tarCreateFileFromString( outArchive, "/root/.ssh/authorized_keys.d/" + name, publicKey, 0600 );
			}
			ok |= Archive.tarCreateSymlink( outArchive, "../sshd.service", "/etc/systemd/system/network.target.wants/sshd.service" );
			if ( !ok ) {
				status.error = "Could not create module archive contents";
				return false;
			}
		} finally {
			Util.multiClose( outArchive );
		}
		return true;
	}

	/**
	 * Output - contains additional status data of this task
	 */
	private static class Output
	{
		protected String error = null;
	}

}