/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.myfaces.tobago.lifecycle;
  
  import org.apache.myfaces.tobago.config.TobagoConfig;
  import org.apache.myfaces.tobago.webapp.Secret;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.enterprise.inject.spi.CDI;
  import javax.faces.context.FacesContext;
  import javax.faces.event.PhaseEvent;
  import javax.faces.event.PhaseId;
  import javax.faces.event.PhaseListener;
  import java.lang.invoke.MethodHandles;
  import java.util.Map;
  
  public class SecretPhaseListener implements PhaseListener {
  
    private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  
    @Override
    public void afterPhase(final PhaseEvent event) {
      final FacesContext facesContext = event.getFacesContext();
      final TobagoConfig tobagoConfig = CDI.current().select(TobagoConfig.class).get();
  
      if (!facesContext.getResponseComplete()
          && facesContext.isPostback()
          && tobagoConfig.isCheckSessionSecret()
          && !check(facesContext)) {
        if (LOG.isDebugEnabled()) {
          LOG.debug("Secret is invalid!");
        }
        facesContext.renderResponse(); // this ends the normal lifecycle
      }
    }
  
    /**
     * Checks that the request contains a parameter {@link org.apache.myfaces.tobago.webapp.Secret#KEY} which is equals to
     * a secret value in the session.
     */
    private boolean check(final FacesContext facesContext) {
      final Map<String, String> requestParameterMap = facesContext.getExternalContext().getRequestParameterMap();
      final String fromRequest = requestParameterMap.get(Secret.KEY);
      final Secret secret = CDI.current().select(Secret.class).get();
      return secret.check(fromRequest);
    }
  
    @Override
    public void beforePhase(final PhaseEvent event) {
    }
  
    @Override
    public PhaseId getPhaseId() {
      return PhaseId.RESTORE_VIEW;
    }
  }