/**
 * Copyright (C) 2003-2008 eXo Platform SAS.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see<http://www.gnu.org/licenses/>.
 */

package org.etk.core.security.jaas;

import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.login.LoginException;
import javax.security.auth.spi.LoginModule;

import org.etk.common.logging.Logger;
import org.etk.core.security.Authenticator;
import org.etk.core.security.Credential;
import org.etk.core.security.Identity;
import org.etk.core.security.PasswordCredential;
import org.etk.core.security.UsernameCredential;
import org.etk.kernel.container.KernelContainer;
import org.etk.kernel.container.KernelContainerContext;
import org.etk.kernel.container.RootContainer;

/**
 * @author <a href="mailto:andrew00x@gmail.com">Andrey Parfonov</a>
 * @version $Id: $
 */
public final class SharedStateLoginModule implements LoginModule {

  /**
   * The name of the option to use in order to specify the name of the portal
   * container
   */
  private static final String OPTION_PORTAL_CONTAINER_NAME = "portalContainerName";

  /**
   * The default name of the portal container
   */
  private static final String DEFAULT_PORTAL_CONTAINER_NAME = "portal";

  /**
   * Logger.
   */
  private static final Logger LOG = Logger.getLogger(SharedStateLoginModule.class);

  /**
   * The name of the portal container.
   */
  private String portalContainerName;

  /**
   * Shared state.
   */
  @SuppressWarnings("unchecked")
  private Map sharedState;

  /**
   * Subject.
   */
  private Subject subject;

  /**
   * {@inheritDoc}
   */
  @SuppressWarnings("unchecked")
  public boolean login() throws LoginException {
    if (LOG.isDebugEnabled()) {
      LOG.debug("in login");
    }
    try {
      String username = (String) sharedState.get("javax.security.auth.login.name");
      String password = (String) sharedState.get("javax.security.auth.login.password");
      if (username == null || password == null)
        return false;

      Authenticator authenticator = (Authenticator) getContainer().getComponentInstanceOfType(Authenticator.class);

      if (authenticator == null)
        throw new LoginException("No Authenticator component found, check your configuration");

      Credential[] credentials = new Credential[] { new UsernameCredential(username),
          new PasswordCredential(password) };

      String userId = authenticator.validateUser(credentials);
      Identity identity = authenticator.createIdentity(userId);

      sharedState.put("exo.security.identity", identity);
      sharedState.put("javax.security.auth.login.name", userId);
      // TODO use PasswordCredential wrapper
      subject.getPrivateCredentials().add(password);
      subject.getPublicCredentials().add(new UsernameCredential(username));
      return true;
    } catch (final Throwable e) {
      throw new LoginException(e.getMessage());
    }
  }

  /**
   * {@inheritDoc}
   */
  public boolean abort() throws LoginException {
    if (LOG.isDebugEnabled()) {
      LOG.debug("in abort");
    }
    return true;
  }

  /**
   * {@inheritDoc}
   */
  public boolean commit() throws LoginException {
    if (LOG.isDebugEnabled()) {
      LOG.debug("in commit");
    }
    return true;
  }

  /**
   * {@inheritDoc}
   */
  @SuppressWarnings("unchecked")
  public void initialize(Subject subject,
                         CallbackHandler callbackHandler,
                         Map sharedState,
                         Map options) {
    if (LOG.isDebugEnabled()) {
      LOG.debug("in initialize");
    }
    this.sharedState = sharedState;
    this.portalContainerName = getPortalContainerName(options);
    this.subject = subject;
  }

  /**
   * {@inheritDoc}
   */
  public boolean logout() throws LoginException {
    if (LOG.isDebugEnabled()) {
      LOG.debug("in logout");
    }
    return true;
  }

  /**
   * @return actual ExoContainer instance.
   */
  protected KernelContainer getContainer() throws Exception {
    KernelContainer container = KernelContainerContext.getCurrentContainer();
    if (container instanceof RootContainer) {
      container = RootContainer.getInstance().getPortalContainer(portalContainerName);
    }
    return container;
  }

  /**
   * Return portal container name if it provide with options,
   * DEFAULT_PORTAL_CONTAINER_NAME otherwise.
   * 
   * @param options
   * @return
   */
  @SuppressWarnings("unchecked")
  private String getPortalContainerName(Map options) {
    if (options != null) {
      String optionValue = (String) options.get(OPTION_PORTAL_CONTAINER_NAME);
      if (optionValue != null && optionValue.length() > 0) {
        if (LOG.isDebugEnabled())
          LOG.debug("The IdentitySetLoginModule will use the portal container " + optionValue);
        return optionValue;
      }
    }
    return DEFAULT_PORTAL_CONTAINER_NAME;
  }
}