package org.apache.samoa.topology.impl;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2013 Yahoo! 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.
 * #L%
 */

import org.apache.samoa.topology.AbstractTopology;
import org.apache.samoa.topology.IProcessingItem;

/**
 * Topology for multithreaded engine.
 * 
 * @author Anh Thu Vu
 * 
 */
public class ThreadsTopology extends AbstractTopology {
  ThreadsTopology(String name) {
    super(name);
  }

  public void run() {
    if (this.getEntranceProcessingItems() == null)
      throw new IllegalStateException("You need to set entrance PI before running the topology.");
    if (this.getEntranceProcessingItems().size() != 1)
      throw new IllegalStateException("ThreadsTopology supports 1 entrance PI only. Number of entrance PIs is "
          + this.getEntranceProcessingItems().size());

    this.setupProcessingItemInstances();
    ThreadsEntranceProcessingItem entrancePi = (ThreadsEntranceProcessingItem) this.getEntranceProcessingItems()
        .toArray()[0];
    if (entrancePi == null)
      throw new IllegalStateException("You need to set entrance PI before running the topology.");
    entrancePi.getProcessor().onCreate(0); // id=0 as it is not used in simple mode
    entrancePi.startSendingEvents();
  }

  /*
   * Tell all the ThreadsProcessingItems to create & init their replicas
   * (ThreadsProcessingItemInstance)
   */
  private void setupProcessingItemInstances() {
    for (IProcessingItem pi : this.getProcessingItems()) {
      if (pi instanceof ThreadsProcessingItem) {
        ThreadsProcessingItem tpi = (ThreadsProcessingItem) pi;
        tpi.setupInstances();
      }
    }
  }
}