/*
 * Copyright (C) 2011 Red Hat, Inc. and/or its affiliates.
 *
 * 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.jboss.errai.enterprise.client.cdi;

import org.jboss.errai.bus.client.api.messaging.Message;
import org.jboss.errai.bus.client.api.messaging.MessageCallback;

import javax.enterprise.inject.Any;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

/**
 * @author Christian Sadilek <csadilek@redhat.com>
 * @author Mike Brock
 */
public abstract class AbstractCDIEventCallback<T> implements MessageCallback {
  /**
   * The qualifiers a message must contain to be propagated.
   */
  protected final Set<String> qualifierSet = new HashSet<String>();

  public Set<String> getQualifiers() {
    return qualifierSet;
  }

  @SuppressWarnings("unchecked")
  @Override
  public final void callback(final Message message) {
    Set<String> msgQualifiers = message.get(Set.class, CDIProtocol.Qualifiers);

    if (msgQualifiers == null) {
      msgQualifiers = Collections.emptySet();
    }

    if (message.hasPart(CDIProtocol.FromClient)) {
      if (isDefault() || msgQualifiers.containsAll(qualifierSet)) {
        fireEvent((T) message.get(Object.class, CDIProtocol.BeanReference));
      }
    }
    else {
      // Our server-side CDI integration module knows of all client-side event
      // observers and sends a separate message specific to each matching
      // observer.
      if (msgQualifiers.equals(qualifierSet)) {
        fireEvent((T) message.get(Object.class, CDIProtocol.BeanReference));
      }
    }
  }

  protected boolean isDefault() {
    return qualifierSet.size() == 1 && qualifierSet.contains(Any.class.getName());
  }

  protected abstract void fireEvent(T event);
}