/**
 * Copyright 2010 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 org.waveprotocol.box.server.rpc.render.view;

import org.waveprotocol.wave.model.conversation.Conversation;
import org.waveprotocol.wave.model.conversation.ConversationBlip;
import org.waveprotocol.wave.model.conversation.ConversationThread;
import org.waveprotocol.wave.model.util.Pair;
import org.waveprotocol.wave.model.wave.ParticipantId;


/**
 * Maps between model objects and model ids.
 *
 * A model id uniquely identifies a model object within other model objects of
 * the same type, and within the current model session. The model ids for two
 * distinct blips will be different. However, the model id for a blip may be the
 * same as the model id for some thread.
 *
 */
public interface ModelIdMapper {
  /** @return the model id of a group of conversations {@code c}. */
  String conversationsId(ConversationView c);

  /** @return the model id of a conversation {@code c}. */
  String convId(Conversation c);

  /** @return the model id of a thread {@code c}. */
  String threadId(ConversationThread t);

  /** @return the model id of a blip {@code c}. */
  String blipId(ConversationBlip b);

  /** @return the model id of a participant {@code p}. */
  String participantId(Conversation c, ParticipantId p);

  //
  // Reverse mappings.
  //

  /** @return the blip identified by {@code modelId}, if there is one. */
  ConversationBlip locateBlip(String modelId);

  /** @return the thread identified by {@code modelId}, if there is one. */
  ConversationThread locateThread(String modelId);

  /** @return the conversation identified by {@code modelId}, if there is one. */
  Conversation locateConversation(String modelId);

  /** @return the participant identified by {@code modelId}, if there is one. */
  Pair<Conversation, ParticipantId> locateParticipant(String modelId);
}