/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.apex.malhar.lib.window.impl;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.joda.time.Duration;

import org.apache.apex.malhar.lib.io.ConsoleOutputOperator;
import org.apache.apex.malhar.lib.util.KeyValPair;
import org.apache.apex.malhar.lib.window.ControlTuple;
import org.apache.apex.malhar.lib.window.TriggerOption;
import org.apache.apex.malhar.lib.window.Tuple;
import org.apache.apex.malhar.lib.window.Window;
import org.apache.apex.malhar.lib.window.WindowOption;
import org.apache.apex.malhar.lib.window.WindowState;
import org.apache.apex.malhar.lib.window.WindowedStorage;
import org.apache.apex.malhar.lib.window.accumulation.InnerJoin;

import org.apache.hadoop.conf.Configuration;

import com.datatorrent.api.Context;
import com.datatorrent.api.DAG;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.InputOperator;
import com.datatorrent.api.LocalMode;
import com.datatorrent.api.StreamingApplication;
import com.datatorrent.common.util.BaseOperator;

/**
 * Example application using {@link KeyedWindowedMergeOperatorImpl}. Generators send streams of key-value pairs of
 * <{@link String}, {@link Integer}>, Merge operator combines the two streams base on the key of the tuple.
 */
public class KeyedWindowedMergeOperatorTestApplication implements StreamingApplication
{
  private static WindowedStorage.WindowedPlainStorage<WindowState> windowStateMap = new InMemoryWindowedStorage<>();
  private static final long windowDuration = 1000;
  private static final String[] keys = new String[]{"A", "B", "C", "D", "E"};


  public static Window.TimeWindow assignTestWindow(long timestamp)
  {
    long beginTimestamp = timestamp - timestamp % windowDuration;
    Window.TimeWindow window = new Window.TimeWindow(beginTimestamp, windowDuration);
    if (!windowStateMap.containsWindow(window)) {
      windowStateMap.put(window, new WindowState());
    }
    return window;
  }

  public static class NumGen1 extends BaseOperator implements InputOperator
  {
    private int i;
    private long watermarkTime;
    private long startingTime;

    public final transient DefaultOutputPort<Tuple.WindowedTuple<KeyValPair<String, Integer>>> output = new DefaultOutputPort<>();
    public final transient DefaultOutputPort<ControlTuple> watermarkDefaultOutputPort = new DefaultOutputPort<>();

    @Override
    public void setup(Context.OperatorContext context)
    {
      super.setup(context);
      startingTime = System.currentTimeMillis();
      watermarkTime = System.currentTimeMillis() + 10000;
      i = 1;
    }

    @Override
    public void emitTuples()
    {
      while (i <= 20) {
        if (System.currentTimeMillis() - startingTime >= (i + 1) * 400) {
          output.emit(new Tuple.WindowedTuple<KeyValPair<String, Integer>>(assignTestWindow(System.currentTimeMillis()), new KeyValPair<String, Integer>(keys[i % 5], i)));
          i++;
        }
      }
    }

    @Override
    public void endWindow()
    {
      if (i <= 20) {
        watermarkDefaultOutputPort.emit(new WatermarkImpl(watermarkTime));
      }
    }
  }

  public static class NumGen2 extends BaseOperator implements InputOperator
  {
    private int i;
    private long watermarkTime;
    private long startingTime;

    public final transient DefaultOutputPort<Tuple.WindowedTuple<KeyValPair<String, Integer>>> output = new DefaultOutputPort<>();
    public final transient DefaultOutputPort<ControlTuple> watermarkDefaultOutputPort = new DefaultOutputPort<>();


    @Override
    public void setup(Context.OperatorContext context)
    {
      super.setup(context);
      startingTime = System.currentTimeMillis();
      watermarkTime = System.currentTimeMillis() + 10000;
      i = 1;
    }

    @Override
    public void emitTuples()
    {
      while (i <= 20) {
        if (System.currentTimeMillis() - startingTime >= (i + 1) * 400) {
          output.emit(new Tuple.WindowedTuple<KeyValPair<String, Integer>>(assignTestWindow(System.currentTimeMillis()), new KeyValPair<String, Integer>(keys[i % 5], 10 * i)));
          i++;
        }
      }
    }

    @Override
    public void endWindow()
    {
      if (i <= 20) {
        watermarkDefaultOutputPort.emit(new WatermarkImpl(watermarkTime));
      }
    }
  }

  public static class Collector extends BaseOperator
  {
    public static Map<String, List<List<Integer>>> result = new HashMap<>();

    public final transient DefaultOutputPort<Tuple.WindowedTuple<KeyValPair<String, List<List<Integer>>>>> output = new DefaultOutputPort<>();

    public final transient DefaultInputPort<Tuple.WindowedTuple<KeyValPair<String, List<List<Integer>>>>> input = new DefaultInputPort<Tuple.WindowedTuple<KeyValPair<String, List<List<Integer>>>>>()
    {
      @Override
      public void process(Tuple.WindowedTuple<KeyValPair<String, List<List<Integer>>>> tuple)
      {
        result.put(tuple.getValue().getKey(), tuple.getValue().getValue());
        output.emit(tuple);
      }
    };
  }

  @Override
  public void populateDAG(DAG dag, Configuration conf)
  {
    KeyedWindowedMergeOperatorImpl<String, Integer, Integer, List<Set<Integer>>, List<List<Integer>>> op
        = dag.addOperator("Merge", new KeyedWindowedMergeOperatorImpl<String, Integer, Integer, List<Set<Integer>>, List<List<Integer>>>());

    //op.setAccumulation(new CoGroup<Integer>());
    op.setAccumulation(new InnerJoin<Integer>());

    op.setDataStorage(new InMemoryWindowedKeyedStorage<String, List<Set<Integer>>>());
    op.setRetractionStorage(new InMemoryWindowedKeyedStorage<String, List<List<Integer>>>());
    op.setWindowStateStorage(windowStateMap);

    // Can select one of the following window options, or don't select any of them.
    op.setWindowOption(new WindowOption.GlobalWindow());
    //op.setWindowOption(new WindowOption.TimeWindows(Duration.millis(4000)));

    op.setTriggerOption(new TriggerOption().withEarlyFiringsAtEvery(1).accumulatingFiredPanes());
    op.setAllowedLateness(Duration.millis(500));

    NumGen1 numGen1 = dag.addOperator("numGen1", new NumGen1());
    NumGen2 numGen2 = dag.addOperator("numGen2", new NumGen2());

    Collector collector = dag.addOperator("collector", new Collector());
    ConsoleOutputOperator con = dag.addOperator("console", new ConsoleOutputOperator());

    dag.addStream("num1", numGen1.output, op.input);
    dag.addStream("num2", numGen2.output, op.input2);
    dag.addStream("wm1", numGen1.watermarkDefaultOutputPort, op.controlInput);
    dag.addStream("wm2", numGen2.watermarkDefaultOutputPort, op.controlInput2);

    dag.addStream("MergedResult", op.output, collector.input);
    dag.addStream("output", collector.output, con.input);
  }

  public static void main(String[] args) throws Exception
  {
    LocalMode lma = LocalMode.newInstance();
    Configuration conf = new Configuration(false);
    lma.prepareDAG(new KeyedWindowedMergeOperatorTestApplication(), conf);
    LocalMode.Controller lc = lma.getController();
    lc.run(20000);
  }
}