/* Copyright (c) 2009 Google Inc.
 *
 * 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 com.google.wave.api.event;

import java.util.HashMap;
import java.util.Map;

/**
 * The types of events.
 */
public enum EventType {
  WAVELET_BLIP_CREATED(WaveletBlipCreatedEvent.class),
  WAVELET_BLIP_REMOVED(WaveletBlipRemovedEvent.class),
  WAVELET_PARTICIPANTS_CHANGED(WaveletParticipantsChangedEvent.class),
  WAVELET_SELF_ADDED(WaveletSelfAddedEvent.class),
  WAVELET_SELF_REMOVED(WaveletSelfRemovedEvent.class),
  WAVELET_TITLE_CHANGED(WaveletTitleChangedEvent.class),
  WAVELET_CREATED(WaveletCreatedEvent.class),
  WAVELET_FETCHED(WaveletFetchedEvent.class),
  WAVELET_TAGS_CHANGED(WaveletTagsChangedEvent.class),

  BLIP_CONTRIBUTORS_CHANGED(BlipContributorsChangedEvent.class),
  BLIP_SUBMITTED(BlipSubmittedEvent.class),
  DOCUMENT_CHANGED(DocumentChangedEvent.class),
  FORM_BUTTON_CLICKED(FormButtonClickedEvent.class),
  GADGET_STATE_CHANGED(GadgetStateChangedEvent.class),
  ANNOTATED_TEXT_CHANGED(AnnotatedTextChangedEvent.class),

  OPERATION_ERROR(OperationErrorEvent.class),
  UNKNOWN(null);

  private static final Map<Class<?>, EventType> REVERSE_LOOKUP_MAP =
      new HashMap<Class<?>, EventType>();

  static {
    for (EventType eventType : EventType.values()) {
      REVERSE_LOOKUP_MAP.put(eventType.getClazz(), eventType);
    }
  }

  /** The class that represents this event. */
  private final Class<? extends Event> clazz;

  /**
   * Constructor.
   *
   * @param clazz the class that represents this event.
   */
  private EventType(Class<? extends Event> clazz) {
    this.clazz = clazz;
  }

  /**
   * Returns the class that represents this event type.
   *
   * @return the class that represents this event type.
   */
  public Class<? extends Event> getClazz() {
    return clazz;
  }

  /**
   * Converts a string into an {@link EventType} ignoring case in the process.
   *
   * @param name the name of the event type.
   * @return the converted event type.
   */
  public static EventType valueOfIgnoreCase(String name) {
    try {
      return valueOf(name.toUpperCase());
    } catch (IllegalArgumentException e) {
      return UNKNOWN;
    }
  }

  /**
   * Returns an {@link EventType} enumeration that has the given class. If no
   * match is found, UNKNOWN is returned.
   *
   * @param clazz The class that represents an event type.
   * @return An {@link EventType} that has the given class.
   */
  public static EventType fromClass(Class<?> clazz) {
    if (!REVERSE_LOOKUP_MAP.containsKey(clazz)) {
      return UNKNOWN;
    }
    return REVERSE_LOOKUP_MAP.get(clazz);
  }
}