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to you under the Apache License, Version 2.0 (the
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  http://www.apache.org/licenses/LICENSE-2.0

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*/
package org.apache.edgent.test.analytics.math3;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.edgent.analytics.math3.Aggregations;
import org.apache.edgent.analytics.math3.MvResultMap;
import org.apache.edgent.analytics.math3.ResultMap;
import org.apache.edgent.analytics.math3.UnivariateAggregate;
import org.apache.edgent.analytics.math3.stat.Regression2;
import org.apache.edgent.analytics.math3.stat.Statistic2;
import org.apache.edgent.function.Functions;
import org.apache.edgent.test.providers.direct.DirectTopologyTestBase;
import org.apache.edgent.topology.TStream;
import org.apache.edgent.topology.TWindow;
import org.apache.edgent.topology.Topology;
import org.apache.edgent.topology.tester.Condition;
import org.junit.Test;

import com.google.gson.JsonObject;

/** test Aggregations, Statistics2 and Regression2 */
public class Statistics2Test  extends DirectTopologyTestBase {
  
  // Expected results for **continuous last-2** aggregations of (1, 4, 102, 0) for the various stats.
  protected static Map<UnivariateAggregate,Double[]> STAT_RESULTS = new HashMap<>();
  static {
    STAT_RESULTS.put(
        Statistic2.COUNT,
        new Double[] {
            1.0,  // 1
            2.0,  // 1,4  
            2.0,  // 4,102
            2.0   // 102,0
        });
    STAT_RESULTS.put(
        Statistic2.MIN,
        new Double[] {
            1.0,  // 1
            1.0,  // 1,4  
            4.0,  // 4,102
            0.0   // 102,0
        });
    STAT_RESULTS.put(
        Statistic2.MAX,
        new Double[] {
            1.0,   // 1
            4.0,   // 1,4  
            102.0, // 4,102
            102.0  // 102,0
        });
    STAT_RESULTS.put(
        Statistic2.SUM,
        new Double[] {
            1.0,   // 1
            5.0,   // 1,4  
            106.0, // 4,102
            102.0  // 102,0
        });
    STAT_RESULTS.put(
        Statistic2.MEAN,
        new Double[] {
            1.0,   // 1
            2.5,   // 1,4  
            53.0,  // 4,102
            51.0   // 102,0
        });
    STAT_RESULTS.put(
        Statistic2.STDDEV,
        new Double[] {
            0.0,   // 1
            2.12,  // 1,4  
            69.29, // 4,102
            72.12  // 102,0
        });
    STAT_RESULTS.put(
        Regression2.SLOPE,
        new Double[] {
            null,  // 1
            3.0,   // 1,4  
            98.0,  // 4,102
            -102.0 // 102,0
        });
  }
  
  /* test Aggregations.sum() */
  @Test
  public void testSum() throws Exception {
    Double act = Aggregations.sum(Arrays.asList(1, 2, 3.8));  // check with mixed Number
    Double exp = 1 + 2 + 3.8;
    assertEquals(exp, act, 0.01);

    act = Aggregations.sum(Arrays.asList());
    exp = 0.0;
    assertEquals(exp, act, 0.01);
  }
  
  /* test Aggregations.sumInts() */
  @Test
  public void testSumInts() throws Exception {
    long act = Aggregations.sumInts(Arrays.asList(1, 2, 3));
    long exp = 1 + 2 + 3;
    assertEquals(exp, act);
    
    act = Aggregations.sumInts(Arrays.asList());
    exp = 0;
    assertEquals(exp, act);
  }
  
  /* util to test Aggregations.aggregate(List<Number>, stat) */
  protected void aggregate(UnivariateAggregate stat, Double[] expResults) throws Exception {
    
    // for "continuous last-2" style inputs of (1, 4, 102, 0)
	  
	  int i = 0;
	  Double result;
	  
    result = Aggregations.aggregate(Arrays.asList(1), stat);
    assertResult(i, stat, expResults[i++], result);
    
    result = Aggregations.aggregate(Arrays.asList(1,4), stat);
    assertResult(i, stat, expResults[i++], result);
    
    result = Aggregations.aggregate(Arrays.asList(4,102), stat);
    assertResult(i, stat, expResults[i++], result);
    
    result = Aggregations.aggregate(Arrays.asList(102,0), stat);
    assertResult(i, stat, expResults[i++], result);
  }
  
  /* util to test Aggregations.aggregate(List<T>, getter, stat) */
  protected void aggregateT(UnivariateAggregate stat, Double[] expResults) throws Exception {
    
    // for "continuous last-2" style inputs of (1, 4, 102, 0)
    
    int i = 0;
    Double result;
    List<Object> values;
    
    values = Arrays.asList(1);
    result = Aggregations.aggregate(values, o -> Double.valueOf(o.toString()), stat);
    assertResult(i, stat, expResults[i++], result);
    
    values = Arrays.asList(1,4);
    result = Aggregations.aggregate(values, o -> Double.valueOf(o.toString()), stat);
    assertResult(i, stat, expResults[i++], result);
    
    values = Arrays.asList(4,102);
    result = Aggregations.aggregate(values, o -> Double.valueOf(o.toString()), stat);
    assertResult(i, stat, expResults[i++], result);
    
    values = Arrays.asList(102,0);
    result = Aggregations.aggregate(values, o -> Double.valueOf(o.toString()), stat);
    assertResult(i, stat, expResults[i++], result);
  }

  /* util to test Aggregations.aggregateN(List<Number>, stats) */
  protected void aggregateN(UnivariateAggregate[] stats) throws Exception {
    
    // for "continuous last-2" style inputs of (1, 4, 102, 0)
    
    int i = 0;
    ResultMap result;
    
    result = Aggregations.aggregateN(Arrays.asList(1), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    result = Aggregations.aggregateN(Arrays.asList(1,4), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    result = Aggregations.aggregateN(Arrays.asList(4,102), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    result = Aggregations.aggregateN(Arrays.asList(102,0), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
  }
  
  /* util to test Aggregations.aggregateN(List<T>, getter, stats) */
  protected void aggregateNT(UnivariateAggregate[] stats) throws Exception {
    
    // for "continuous last-2" style inputs of (1, 4, 102, 0)
    
    int i = 0;
    ResultMap result;
    List<Object> values;
    
    values = Arrays.asList(1);
    result = Aggregations.aggregateN(values, o -> Double.valueOf(o.toString()), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    values = Arrays.asList(1,4);
    result = Aggregations.aggregateN(values, o -> Double.valueOf(o.toString()), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    values = Arrays.asList(4,102);
    result = Aggregations.aggregateN(values, o -> Double.valueOf(o.toString()), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
    
    values = Arrays.asList(102,0);
    result = Aggregations.aggregateN(values, o -> Double.valueOf(o.toString()), stats);
    assertResult(i++, stats, STAT_RESULTS, result);
  }
	
  protected static void assertResult(int index, UnivariateAggregate stat, Double exp, Double act) {
	  if (exp == null && act == null)
	    return;  // match
	  assertFalse("index="+index+" "+stat.name()+" exp="+exp+" act="+act, exp == null || act == null);
    assertEquals("index="+index+" "+stat.name(), exp, act, 0.01);
	}
  
  protected static void assertResult(int i, UnivariateAggregate[] stats, Map<UnivariateAggregate,Double[]> expResults, ResultMap actResults) {
    for (UnivariateAggregate stat : stats) {
      Double act = actResults.get(stat);
      Double exp = expResults.get(stat)[i]; 
      
      assertResult(i, stat, exp, act);
    }
  }
	
  /* util to test Aggregations.aggregate(List<Number>, stat) */
  protected void testAggregate(UnivariateAggregate stat) throws Exception {
    aggregate(stat, STAT_RESULTS.get(stat));
  }
  
  @Test
  public void testCOUNT() throws Exception {
    testAggregate(Statistic2.COUNT);
  }
  
  @Test
  public void testMIN() throws Exception {
    testAggregate(Statistic2.MIN);
  }
  
  @Test
  public void testMAX() throws Exception {
    testAggregate(Statistic2.MAX);
  }
  
  @Test
  public void testSUM() throws Exception {
    testAggregate(Statistic2.SUM);
  }
  
  @Test
  public void testMEAN() throws Exception {
    testAggregate(Statistic2.MEAN);
  }
  
  @Test
  public void testSTDDEV() throws Exception {
    testAggregate(Statistic2.STDDEV);
  }
  
  @Test
  public void testSLOPE() throws Exception {
    testAggregate(Regression2.SLOPE);
  }
  
  @Test
  public void testEmptyAggregate() throws Exception {
    Double result;
    
    result = Aggregations.aggregate(Collections.emptyList(), Statistic2.COUNT);
    assertResult(0, Statistic2.COUNT, null, result);

    result = Aggregations.aggregate(Collections.emptyList(), Statistic2.MIN);
    assertResult(0, Statistic2.MIN, null, result);

    // ...
    
    ResultMap resultMap =  Aggregations.aggregateN(Collections.emptyList(), Statistic2.MIN);
    assertTrue(resultMap.isEmpty());
    
    resultMap =  Aggregations.aggregateN(Arrays.asList(1));
    assertTrue(resultMap.isEmpty());
    
    resultMap =  Aggregations.aggregateN(Arrays.asList(1), new UnivariateAggregate[0]);
    assertTrue(resultMap.isEmpty());
  }
  
  @Test
  public void testAggregateT() throws Exception {
    aggregateT(Statistic2.MIN, STAT_RESULTS.get(Statistic2.MIN));
  }
  
  /* test Aggregations.aggregateN(List<Number>, stats) */
  @Test
  public void testAggregateN() throws Exception {
    aggregateN(STAT_RESULTS.keySet().toArray(new UnivariateAggregate[0]));
  }
  
  /* test Aggregations.aggregateN(List<T>, getter, stats) */
  @Test
  public void testAggregateNT() throws Exception {
    aggregateNT(STAT_RESULTS.keySet().toArray(new UnivariateAggregate[0]));
  }
  
  /* test Aggregations.newResultToJson() */
  @Test
  public void testNewResultsToJson() throws Exception {
    ResultMap result = new ResultMap();
    result.put(Statistic2.MIN, 2.5);
    result.put(Statistic2.MAX, 4.5);
    
    JsonObject jo = ResultMap.toJsonObject().apply(result);
    
    assertTrue(jo.get(Statistic2.MIN.name()) != null);
    assertEquals(jo.get(Statistic2.MIN.name()).getAsDouble(), 2.5, 0.01);
    assertTrue(jo.get(Statistic2.MAX.name()) != null);
    assertEquals(jo.get(Statistic2.MAX.name()).getAsDouble(), 4.5, 0.01);
  }
  
  /* test Aggregations.newMvResultToJson() */
  @Test
  public void testNewMvResultsToJson() throws Exception {
    ResultMap var1result = new ResultMap();
    var1result.put(Statistic2.MIN, 2.5);
    var1result.put(Statistic2.MAX, 4.5);
    
    ResultMap var2result = new ResultMap();
    var2result.put(Statistic2.SUM, 27.1);

    MvResultMap result = new MvResultMap();
    result.put("var1", var1result);
    result.put("var2", var2result);

    JsonObject jo = MvResultMap.toJsonObject().apply(result);

    assertTrue(jo.get("var1") != null);
    JsonObject joVar1 = jo.get("var1").getAsJsonObject();
    assertTrue(joVar1.get(Statistic2.MIN.name()) != null);
    assertEquals(joVar1.get(Statistic2.MIN.name()).getAsDouble(), 2.5, 0.01);
    assertTrue(joVar1.get(Statistic2.MAX.name()) != null);
    assertEquals(joVar1.get(Statistic2.MAX.name()).getAsDouble(), 4.5, 0.01);
    
    assertTrue(jo.get("var2") != null);
    JsonObject joVar2 = jo.get("var2").getAsJsonObject();
    assertTrue(joVar2.get(Statistic2.SUM.name()) != null);
    assertEquals(joVar2.get(Statistic2.SUM.name()).getAsDouble(), 27.1, 0.01);
  }

  /* test Aggregations.aggregateN(list, stats) in a Stream/Window context */
  @Test
  public void testAggregateNStream() throws Exception {
    // Aggregations.aggregate are ignorant of Stream/Window but
    // to be safe verify a full Stream/Window based use case works
    
    UnivariateAggregate[] stats = STAT_RESULTS.keySet().toArray(new UnivariateAggregate[0]);
    
    Topology topology = newTopology("testAggregateNStream");
    
    // (1, 4, 102, 0)
    TStream<Integer> sourceData = sourceData(topology);
    
    TWindow<Integer, Integer> window = sourceData.last(2, Functions.unpartitioned());
    
    TStream<ResultMap> aggregate = window.aggregate( (list,partition) -> {
        return Aggregations.aggregateN(list, stats);
    });
    
    Condition<Long> count = topology.getTester().atLeastTupleCount(aggregate, 4);
    Condition<List<ResultMap>> contents = topology.getTester().streamContents(aggregate);
    complete(topology, count);
    assertTrue(count.valid());
      
    List<ResultMap> tuples = contents.getResult();
    assertEquals(4, tuples.size());
    
    for (int i = 0; i < tuples.size(); i++) {
      assertResult(i, stats, STAT_RESULTS, tuples.get(i));
    }
  }

  /* test Aggregations.aggregateN(list, stats) in a multivariable Stream/Window context */
  @Test
  public void testMvAggregateNStream() throws Exception {
    // Aggregations.aggregate are ignorant of Stream/Window but
    // to be safe verify a full Stream/Window based use case works (TStream<MvResultMap>)
    
    UnivariateAggregate[] stats = { Statistic2.MIN, Statistic2.MAX };
    
    Map<UnivariateAggregate,Double[]> var2_STAT_RESULTS = new HashMap<>();
    var2_STAT_RESULTS.put(Statistic2.MIN, new Double[] {1001.0, 1001.0, 1004.0, 1000.0});
    var2_STAT_RESULTS.put(Statistic2.MAX, new Double[] {1001.0, 1004.0, 1102.0, 1102.0});
    
    
    Topology topology = newTopology("testAggregateNStream");
    
    // (1, 4, 102, 0)
    TStream<SensorReadings> sourceData = sourceData(topology)
        .map(i -> new SensorReadings(i, i+1000));
    
    TWindow<SensorReadings, Integer> window = sourceData.last(2, Functions.unpartitioned());
    
    TStream<MvResultMap> aggregate = window.aggregate( (list,partition) -> {
        ResultMap var1result = Aggregations.aggregateN(list, sr -> sr.var1, stats);
        ResultMap var2result = Aggregations.aggregateN(list, sr -> sr.var2, stats);
        MvResultMap result = new MvResultMap();
        result.put("var1", var1result);
        result.put("var2", var2result);
        return result;
    });
    
    Condition<Long> count = topology.getTester().atLeastTupleCount(aggregate, 4);
    Condition<List<MvResultMap>> contents = topology.getTester().streamContents(aggregate);
    complete(topology, count);
    assertTrue(count.valid());
      
    List<MvResultMap> tuples = contents.getResult();
    assertEquals(4, tuples.size());
    
    for (int i = 0; i < tuples.size(); i++) {
      MvResultMap results = tuples.get(i);
      assertResult(i, stats, STAT_RESULTS, results.get("var1"));
      assertResult(i, stats, var2_STAT_RESULTS, results.get("var2"));
    }
  }
  
  protected static class SensorReadings {
    int var1;
    int var2;
    SensorReadings(int var1, int var2) {
      this.var1 = var1;
      this.var2 = var2;
    }
  }
  
  protected static TStream<Integer> sourceData(Topology topology)
  {
      return topology.of(1, 4, 102, 0);
  }
  
}