package com.yahoo.labs.samoa.topology.impl;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2014 - 2015 Apache Software Foundation
 * %%
 * 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 java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.s4.base.KeyFinder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.yahoo.labs.samoa.core.ContentEvent;
import com.yahoo.labs.samoa.topology.AbstractStream;

/**
 * S4 Platform specific stream.
 * 
 * @author severien
 * 
 */
public class S4Stream extends AbstractStream {

  public static final int SHUFFLE = 0;
  public static final int GROUP_BY_KEY = 1;
  public static final int BROADCAST = 2;

  private static final Logger logger = LoggerFactory.getLogger(S4Stream.class);

  private S4DoTask app;
  private int processingItemParalellism;
  private int shuffleCounter;

  private static final String NAME = "STREAM-";
  private static int OBJ_COUNTER = 0;

  /* The stream list */
  public List<StreamType> streams;

  public S4Stream(S4DoTask app) {
    super();
    this.app = app;
    this.processingItemParalellism = 1;
    this.shuffleCounter = 0;
    this.streams = new ArrayList<StreamType>();
    this.setStreamId(NAME + OBJ_COUNTER);
    OBJ_COUNTER++;
  }

  public S4Stream(S4DoTask app, S4ProcessingItem pi) {
    super();
    this.app = app;
    this.processingItemParalellism = 1;
    this.shuffleCounter = 0;
    this.streams = new ArrayList<StreamType>();
    this.setStreamId(NAME + OBJ_COUNTER);
    OBJ_COUNTER++;

  }

  /**
   * 
   * @return
   */
  public int getParallelism() {
    return processingItemParalellism;
  }

  public void setParallelism(int parallelism) {
    this.processingItemParalellism = parallelism;
  }

  public void addStream(String streamID, KeyFinder<S4Event> finder,
      S4ProcessingItem pi, int type) {
    String streamName = streamID + "_" + pi.getName();
    org.apache.s4.core.Stream<S4Event> stream = this.app.createStream(
        streamName, pi);
    stream.setName(streamName);
    logger.debug("Stream name S4Stream {}", streamName);
    if (finder != null)
      stream.setKey(finder);
    this.streams.add(new StreamType(stream, type));

  }

  @Override
  public void put(ContentEvent event) {

    for (int i = 0; i < streams.size(); i++) {

      switch (streams.get(i).getType()) {
      case SHUFFLE:
        S4Event s4event = new S4Event(event);
        s4event.setStreamId(streams.get(i).getStream().getName());
        if (getParallelism() == 1) {
          s4event.setKey("0");
        } else {
          s4event.setKey(Integer.toString(shuffleCounter));
        }
        streams.get(i).getStream().put(s4event);
        shuffleCounter++;
        if (shuffleCounter >= (getParallelism())) {
          shuffleCounter = 0;
        }

        break;

      case GROUP_BY_KEY:
        S4Event s4event1 = new S4Event(event);
        s4event1.setStreamId(streams.get(i).getStream().getName());
        HashCodeBuilder hb = new HashCodeBuilder();
        hb.append(event.getKey());
        String key = Integer.toString(hb.build() % getParallelism());
        s4event1.setKey(key);
        streams.get(i).getStream().put(s4event1);
        break;

      case BROADCAST:
        for (int p = 0; p < this.getParallelism(); p++) {
          S4Event s4event2 = new S4Event(event);
          s4event2.setStreamId(streams.get(i).getStream().getName());
          s4event2.setKey(Integer.toString(p));
          streams.get(i).getStream().put(s4event2);
        }
        break;

      default:
        break;
      }

    }

  }

  /**
   * Subclass for definig stream connection type
   * 
   * @author severien
   * 
   */
  class StreamType {
    org.apache.s4.core.Stream<S4Event> stream;
    int type;

    public StreamType(org.apache.s4.core.Stream<S4Event> s, int t) {
      this.stream = s;
      this.type = t;
    }

    public org.apache.s4.core.Stream<S4Event> getStream() {
      return stream;
    }

    public void setStream(org.apache.s4.core.Stream<S4Event> stream) {
      this.stream = stream;
    }

    public int getType() {
      return type;
    }

    public void setType(int type) {
      this.type = type;
    }

  }
}