package org.argeo.cms.e4.rcp;
   
   import java.security.PrivilegedExceptionAction;
   
   import javax.security.auth.Subject;
   import javax.security.auth.login.LoginContext;
   import javax.security.auth.login.LoginException;
   
   import org.argeo.cms.CmsException;
  import org.argeo.cms.auth.CurrentUser;
  import org.argeo.cms.ui.CmsImageManager;
  import org.argeo.cms.ui.CmsView;
  import org.argeo.cms.ui.UxContext;
  import org.argeo.cms.util.SimpleUxContext;
  import org.argeo.cms.widgets.auth.CmsLoginShell;
  import org.argeo.node.NodeConstants;
  import org.eclipse.core.runtime.IConfigurationElement;
  import org.eclipse.core.runtime.IExtension;
  import org.eclipse.core.runtime.Platform;
  import org.eclipse.equinox.app.IApplication;
  import org.eclipse.equinox.app.IApplicationContext;
  import org.eclipse.swt.widgets.Display;
  
  public class CmsE4Application implements IApplication, CmsView {
  	private LoginContext loginContext;
  	private IApplication e4Application;
  	private UxContext uxContext;
  
  	@Override
  	public Object start(IApplicationContext context) throws Exception {
  		Subject subject = new Subject();
  		Display display = createDisplay();
  		CmsLoginShell loginShell = new CmsLoginShell(this);
  		// TODO customize CmsLoginShell to be smaller and centered
  		loginShell.setSubject(subject);
  		try {
  			// try pre-auth
  			loginContext = new LoginContext(NodeConstants.LOGIN_CONTEXT_USER, subject, loginShell);
  			loginContext.login();
  		} catch (LoginException e) {
  			e.printStackTrace();
  			loginShell.createUi();
  			loginShell.open();
  
  			while (!loginShell.getShell().isDisposed()) {
  				if (!display.readAndDispatch())
  					display.sleep();
  			}
  		}
  		if (CurrentUser.getUsername(getSubject()) == null)
  			throw new CmsException("Cannot log in");
  
  		// try {
  		// CallbackHandler callbackHandler = new DefaultLoginDialog(
  		// display.getActiveShell());
  		// loginContext = new LoginContext(
  		// NodeConstants.LOGIN_CONTEXT_SINGLE_USER, subject,
  		// callbackHandler);
  		// } catch (LoginException e1) {
  		// throw new CmsException("Cannot initialize login context", e1);
  		// }
  		//
  		// // login
  		// try {
  		// loginContext.login();
  		// subject = loginContext.getSubject();
  		// } catch (LoginException e) {
  		// e.printStackTrace();
  		// display.dispose();
  		// try {
  		// Thread.sleep(2000);
  		// } catch (InterruptedException e1) {
  		// // silent
  		// }
  		// return null;
  		// }
  
  		uxContext = new SimpleUxContext();
  
  		e4Application = getApplication(null);
  		Object res = Subject.doAs(subject, new PrivilegedExceptionAction<Object>() {
  
  			@Override
  			public Object run() throws Exception {
  				return e4Application.start(context);
  			}
  
  		});
  		return res;
  	}
  
  	@Override
  	public void stop() {
  		if (e4Application != null)
  			e4Application.stop();
  	}
  
  	static IApplication getApplication(String[] args) {
  		IExtension extension = Platform.getExtensionRegistry().getExtension(Platform.PI_RUNTIME,
 				Platform.PT_APPLICATIONS, "org.eclipse.e4.ui.workbench.swt.E4Application");
 		try {
 			IConfigurationElement[] elements = extension.getConfigurationElements();
 			if (elements.length > 0) {
 				IConfigurationElement[] runs = elements[0].getChildren("run");
 				if (runs.length > 0) {
 					Object runnable;
 					runnable = runs[0].createExecutableExtension("class");
 					if (runnable instanceof IApplication)
 						return (IApplication) runnable;
 				}
 			}
 		} catch (Exception e) {
 			throw new IllegalStateException("Cannot find e4 application", e);
 		}
 		throw new IllegalStateException("Cannot find e4 application");
 	}
 
 	public static Display createDisplay() {
 		Display.setAppName("Argeo CMS RCP");
 
 		// create the display
 		Display newDisplay = Display.getCurrent();
 		if (newDisplay == null) {
 			newDisplay = new Display();
 		}
 		// Set the priority higher than normal so as to be higher
 		// than the JobManager.
 		Thread.currentThread().setPriority(Math.min(Thread.MAX_PRIORITY, Thread.NORM_PRIORITY + 1));
 		return newDisplay;
 	}
 
 	//
 	// CMS VIEW
 	//
 
 	@Override
 	public UxContext getUxContext() {
 		return uxContext;
 	}
 
 	@Override
 	public void navigateTo(String state) {
 		// TODO Auto-generated method stub
 
 	}
 
 	@Override
 	public void authChange(LoginContext loginContext) {
 		if (loginContext == null)
 			throw new CmsException("Login context cannot be null");
 		// logout previous login context
 		// if (this.loginContext != null)
 		// try {
 		// this.loginContext.logout();
 		// } catch (LoginException e1) {
 		// System.err.println("Could not log out: " + e1);
 		// }
 		this.loginContext = loginContext;
 	}
 
 	@Override
 	public void logout() {
 		if (loginContext == null)
 			throw new CmsException("Login context should not bet null");
 		try {
 			CurrentUser.logoutCmsSession(loginContext.getSubject());
 			loginContext.logout();
 		} catch (LoginException e) {
 			throw new CmsException("Cannot log out", e);
 		}
 	}
 
 	@Override
 	public void exception(Throwable e) {
 		// TODO Auto-generated method stub
 
 	}
 
 	@Override
 	public CmsImageManager getImageManager() {
 		// TODO Auto-generated method stub
 		return null;
 	}
 
 	protected Subject getSubject() {
 		return loginContext.getSubject();
 	}
 
 	@Override
 	public boolean isAnonymous() {
 		return CurrentUser.isAnonymous(getSubject());
 	}
 
 }