package org.argeo.cms.e4.maintenance;
   
   import java.text.DateFormat;
   import java.text.SimpleDateFormat;
   import java.util.Enumeration;
   import java.util.GregorianCalendar;
   import java.util.TimeZone;
   
   import org.argeo.cms.ui.util.CmsUiUtils;
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.layout.GridData;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Display;
  import org.eclipse.swt.widgets.Text;
  import org.osgi.service.log.LogEntry;
  import org.osgi.service.log.LogListener;
  import org.osgi.service.log.LogReaderService;
  
  class LogDeploymentUi extends AbstractOsgiComposite implements LogListener {
  	private static final long serialVersionUID = 590221539553514693L;
  
  	private DateFormat dateFormat = new SimpleDateFormat("MMdd HH:mm");
  
  	private Display display;
  	private Text logDisplay;
  
  	public LogDeploymentUi(Composite parent, int style) {
  		super(parent, style);
  	}
  
  	@Override
  	protected void initUi(int style) {
  		LogReaderService logReader = getService(LogReaderService.class);
  		// FIXME use server push
  		// logReader.addLogListener(this);
  		this.display = getDisplay();
  		this.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
  		logDisplay = new Text(this, SWT.WRAP | SWT.MULTI | SWT.READ_ONLY);
  		logDisplay.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
  		CmsUiUtils.markup(logDisplay);
  		Enumeration<LogEntry> logEntries = (Enumeration<LogEntry>) logReader.getLog();
  		while (logEntries.hasMoreElements())
  			logDisplay.append(printEntry(logEntries.nextElement()));
  	}
  
  	private String printEntry(LogEntry entry) {
  		StringBuilder sb = new StringBuilder();
  		GregorianCalendar calendar = new GregorianCalendar(TimeZone.getDefault());
  		calendar.setTimeInMillis(entry.getTime());
  		sb.append(dateFormat.format(calendar.getTime())).append(' ');
  		sb.append(entry.getMessage());
  		sb.append('\n');
  		return sb.toString();
  	}
  
  	@Override
  	public void logged(LogEntry entry) {
  		if (display.isDisposed())
  			return;
  		display.asyncExec(() -> {
  			if (logDisplay.isDisposed())
  				return;
  			logDisplay.append(printEntry(entry));
  		});
  		display.wake();
  	}
  
  	// @Override
  	// public void dispose() {
  	// super.dispose();
  	// getService(LogReaderService.class).removeLogListener(this);
  	// }
  }