package org.argeo.cms.ui.util;
   
   import java.util.Locale;
   
   import javax.security.auth.Subject;
   import javax.security.auth.login.LoginContext;
   import javax.security.auth.login.LoginException;
   import javax.servlet.http.HttpServletRequest;
   
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.argeo.api.NodeConstants;
  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.ui.widgets.auth.CmsLogin;
  import org.argeo.cms.ui.widgets.auth.CmsLoginShell;
  import org.argeo.eclipse.ui.specific.UiContext;
  import org.eclipse.rap.rwt.RWT;
  import org.eclipse.rap.rwt.application.EntryPoint;
  import org.eclipse.swt.events.SelectionListener;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Display;
  
  public class LoginEntryPoint implements EntryPoint, CmsView {
  	protected final static String HEADER_WWW_AUTHENTICATE = "WWW-Authenticate";
  	protected final static String HEADER_AUTHORIZATION = "Authorization";
  	private final static Log log = LogFactory.getLog(LoginEntryPoint.class);
  	private LoginContext loginContext;
  	private UxContext uxContext = null;
  
  	@Override
  	public int createUI() {
  		final Display display = createDisplay();
  		UiContext.setData(CmsView.KEY, this);
  		CmsLoginShell loginShell = createCmsLoginShell();
  		try {
  			// try pre-auth
  			loginContext = new LoginContext(NodeConstants.LOGIN_CONTEXT_USER, loginShell);
  			loginContext.login();
  		} catch (LoginException e) {
  			loginShell.createUi();
  			loginShell.open();
  
  			// HttpServletRequest request = RWT.getRequest();
  			// String authorization = request.getHeader(HEADER_AUTHORIZATION);
  			// if (authorization == null ||
  			// !authorization.startsWith("Negotiate")) {
  			// HttpServletResponse response = RWT.getResponse();
  			// response.setStatus(401);
  			// response.setHeader(HEADER_WWW_AUTHENTICATE, "Negotiate");
  			// response.setDateHeader("Date", System.currentTimeMillis());
  			// response.setDateHeader("Expires", System.currentTimeMillis() +
  			// (24 * 60 * 60 * 1000));
  			// response.setHeader("Accept-Ranges", "bytes");
  			// response.setHeader("Connection", "Keep-Alive");
  			// response.setHeader("Keep-Alive", "timeout=5, max=97");
  			// // response.setContentType("text/html; charset=UTF-8");
  			// }
  
  			while (!loginShell.getShell().isDisposed()) {
  				if (!display.readAndDispatch())
  					display.sleep();
  			}
  		}
  
  		if (CurrentUser.getUsername(getSubject()) == null)
  			return -1;
  		uxContext = new SimpleUxContext();
  		return postLogin();
  	}
  
  	protected Display createDisplay() {
  		return new Display();
  	}
  
  	protected int postLogin() {
  		return 0;
  	}
  
  	protected HttpServletRequest getRequest() {
  		return RWT.getRequest();
  	}
  
  	protected CmsLoginShell createCmsLoginShell() {
  		return new CmsLoginShell(this) {
  
  			@Override
  			public void createContents(Composite parent) {
  				LoginEntryPoint.this.createLoginPage(parent, this);
  			}
  
  			@Override
  			protected void extendsCredentialsBlock(Composite credentialsBlock, Locale selectedLocale,
  					SelectionListener loginSelectionListener) {
  				LoginEntryPoint.this.extendsCredentialsBlock(credentialsBlock, selectedLocale, loginSelectionListener);
  			}
 
 		};
 	}
 
 	/**
 	 * To be overridden. CmsLogin#createCredentialsBlock() should be called at
 	 * some point in order to create the credentials composite. In order to use
 	 * the default layout, call CmsLogin#defaultCreateContents() but <b>not</b>
 	 * CmsLogin#createContent(), since it would lead to a stack overflow.
 	 */
 	protected void createLoginPage(Composite parent, CmsLogin login) {
 		login.defaultCreateContents(parent);
 	}
 
 	protected void extendsCredentialsBlock(Composite credentialsBlock, Locale selectedLocale,
 			SelectionListener loginSelectionListener) {
 
 	}
 
 	@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) {
 				log.warn("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 LoginContext getLoginContext() {
 	// return loginContext;
 	// }
 
 	protected Subject getSubject() {
 		return loginContext.getSubject();
 	}
 
 	@Override
 	public boolean isAnonymous() {
 		return CurrentUser.isAnonymous(getSubject());
 	}
 
 	@Override
 	public CmsImageManager getImageManager() {
 		// TODO Auto-generated method stub
 		return null;
 	}
 
 	@Override
 	public UxContext getUxContext() {
 		return uxContext;
 	}
 }