/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *         http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.argeo.cms.ui.workbench.commands;
  
  import static org.argeo.cms.CmsMsg.changePassword;
  import static org.argeo.cms.CmsMsg.currentPassword;
  import static org.argeo.cms.CmsMsg.newPassword;
  import static org.argeo.cms.CmsMsg.passwordChanged;
  import static org.argeo.cms.CmsMsg.repeatNewPassword;
  import static org.eclipse.jface.dialogs.IMessageProvider.INFORMATION;
  
  import java.security.AccessController;
  import java.util.Arrays;
  
  import javax.naming.InvalidNameException;
  import javax.naming.ldap.LdapName;
  import javax.security.auth.Subject;
  import javax.security.auth.x500.X500Principal;
  import javax.transaction.UserTransaction;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.argeo.cms.CmsException;
  import org.argeo.eclipse.ui.dialogs.ErrorFeedback;
  import org.argeo.node.security.CryptoKeyring;
  import org.eclipse.core.commands.AbstractHandler;
  import org.eclipse.core.commands.ExecutionEvent;
  import org.eclipse.core.commands.ExecutionException;
  import org.eclipse.jface.dialogs.Dialog;
  import org.eclipse.jface.dialogs.MessageDialog;
  import org.eclipse.jface.dialogs.TitleAreaDialog;
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.graphics.Point;
  import org.eclipse.swt.layout.GridData;
  import org.eclipse.swt.layout.GridLayout;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Control;
  import org.eclipse.swt.widgets.Label;
  import org.eclipse.swt.widgets.Shell;
  import org.eclipse.swt.widgets.Text;
  import org.eclipse.ui.handlers.HandlerUtil;
  import org.osgi.service.useradmin.User;
  import org.osgi.service.useradmin.UserAdmin;
  
  /** Open the change password dialog */
  public class OpenChangePasswordDialog extends AbstractHandler {
  	private final static Log log = LogFactory.getLog(OpenChangePasswordDialog.class);
  	private UserAdmin userAdmin;
  	private UserTransaction userTransaction;
  	private CryptoKeyring keyring = null;
  
  	public Object execute(ExecutionEvent event) throws ExecutionException {
  		ChangePasswordDialog dialog = new ChangePasswordDialog(HandlerUtil.getActiveShell(event), userAdmin);
  		if (dialog.open() == Dialog.OK) {
  			MessageDialog.openInformation(HandlerUtil.getActiveShell(event), passwordChanged.lead(),
  					passwordChanged.lead());
  		}
  		return null;
  	}
  
  	@SuppressWarnings("unchecked")
  	protected void changePassword(char[] oldPassword, char[] newPassword) {
  		Subject subject = Subject.getSubject(AccessController.getContext());
  		String name = subject.getPrincipals(X500Principal.class).iterator().next().toString();
  		LdapName dn;
  		try {
  			dn = new LdapName(name);
  		} catch (InvalidNameException e) {
  			throw new CmsException("Invalid user dn " + name, e);
  		}
  		User user = (User) userAdmin.getRole(dn.toString());
  		if (!user.hasCredential(null, oldPassword))
  			throw new CmsException("Invalid password");
  		if (Arrays.equals(newPassword, new char[0]))
  			throw new CmsException("New password empty");
  		try {
  			userTransaction.begin();
  			user.getCredentials().put(null, newPassword);
  			if (keyring != null) {
  				keyring.changePassword(oldPassword, newPassword);
  				// TODO change secret keys in the CMS session
  			}
  			userTransaction.commit();
  		} catch (Exception e) {
  			try {
  				userTransaction.rollback();
 			} catch (Exception e1) {
 				log.error("Could not roll back", e1);
 			}
 			if (e instanceof RuntimeException)
 				throw (RuntimeException) e;
 			else
 				throw new CmsException("Cannot change password", e);
 		}
 	}
 
 	class ChangePasswordDialog extends TitleAreaDialog {
 		private static final long serialVersionUID = -6963970583882720962L;
 		private Text oldPassword, newPassword1, newPassword2;
 
 		public ChangePasswordDialog(Shell parentShell, UserAdmin securityService) {
 			super(parentShell);
 		}
 
 		protected Point getInitialSize() {
 			return new Point(400, 450);
 		}
 
 		protected Control createDialogArea(Composite parent) {
 			Composite dialogarea = (Composite) super.createDialogArea(parent);
 			dialogarea.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
 			Composite composite = new Composite(dialogarea, SWT.NONE);
 			composite.setLayout(new GridLayout(2, false));
 			composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false));
 			oldPassword = createLP(composite, currentPassword.lead());
 			newPassword1 = createLP(composite, newPassword.lead());
 			newPassword2 = createLP(composite, repeatNewPassword.lead());
 
 			setMessage(changePassword.lead(), INFORMATION);
 			parent.pack();
 			oldPassword.setFocus();
 			return composite;
 		}
 
 		@Override
 		protected void okPressed() {
 			try {
 				if (!newPassword1.getText().equals(newPassword2.getText()))
 					throw new CmsException("New passwords are different");
 				changePassword(oldPassword.getTextChars(), newPassword1.getTextChars());
 				close();
 			} catch (Exception e) {
 				ErrorFeedback.show("Cannot change password", e);
 			}
 		}
 
 		/** Creates label and password. */
 		protected Text createLP(Composite parent, String label) {
 			new Label(parent, SWT.NONE).setText(label);
 			Text text = new Text(parent, SWT.SINGLE | SWT.LEAD | SWT.PASSWORD | SWT.BORDER);
 			text.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false));
 			return text;
 		}
 
 		protected void configureShell(Shell shell) {
 			super.configureShell(shell);
 			shell.setText(changePassword.lead());
 		}
 	}
 
 	public void setUserAdmin(UserAdmin userAdmin) {
 		this.userAdmin = userAdmin;
 	}
 
 	public void setUserTransaction(UserTransaction userTransaction) {
 		this.userTransaction = userTransaction;
 	}
 
 	public void setKeyring(CryptoKeyring keyring) {
 		this.keyring = keyring;
 	}
 
 }