/**
    * 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 storm.starter.tools;
  
  import org.testng.annotations.DataProvider;
  import org.testng.annotations.Test;
  
  import java.util.Map;
  
  import static org.fest.assertions.api.Assertions.assertThat;
  
  public class SlidingWindowCounterTest {
  
    private static final int ANY_WINDOW_LENGTH_IN_SLOTS = 2;
    private static final Object ANY_OBJECT = "ANY_OBJECT";
  
    @DataProvider
    public Object[][] illegalWindowLengths() {
      return new Object[][]{ { -10 }, { -3 }, { -2 }, { -1 }, { 0 }, { 1 } };
    }
  
    @Test(expectedExceptions = IllegalArgumentException.class, dataProvider = "illegalWindowLengths")
    public void lessThanTwoSlotsShouldThrowIAE(int windowLengthInSlots) {
      new SlidingWindowCounter<Object>(windowLengthInSlots);
    }
  
    @DataProvider
    public Object[][] legalWindowLengths() {
      return new Object[][]{ { 2 }, { 3 }, { 20 } };
    }
  
    @Test(dataProvider = "legalWindowLengths")
    public void twoOrMoreSlotsShouldBeValid(int windowLengthInSlots) {
      new SlidingWindowCounter<Object>(windowLengthInSlots);
    }
  
    @Test
    public void newInstanceShouldHaveEmptyCounts() {
      // given
      SlidingWindowCounter<Object> counter = new SlidingWindowCounter<Object>(ANY_WINDOW_LENGTH_IN_SLOTS);
  
      // when
      Map<Object, Long> counts = counter.getCountsThenAdvanceWindow();
  
      // then
      assertThat(counts).isEmpty();
    }
  
    @DataProvider
    public Object[][] simulatedCounterIterations() {
      return new Object[][]{ { 2, new int[]{ 3, 2, 0, 0, 1, 0, 0, 0 }, new long[]{ 3, 5, 2, 0, 1, 1, 0, 0 } },
          { 3, new int[]{ 3, 2, 0, 0, 1, 0, 0, 0 }, new long[]{ 3, 5, 5, 2, 1, 1, 1, 0 } },
          { 4, new int[]{ 3, 2, 0, 0, 1, 0, 0, 0 }, new long[]{ 3, 5, 5, 5, 3, 1, 1, 1 } },
          { 5, new int[]{ 3, 2, 0, 0, 1, 0, 0, 0 }, new long[]{ 3, 5, 5, 5, 6, 3, 1, 1 } },
          { 5, new int[]{ 3, 11, 5, 13, 7, 17, 0, 3, 50, 600, 7000 },
              new long[]{ 3, 14, 19, 32, 39, 53, 42, 40, 77, 670, 7653 } }, };
    }
  
    @Test(dataProvider = "simulatedCounterIterations")
    public void testCounterWithSimulatedRuns(int windowLengthInSlots, int[] incrementsPerIteration,
        long[] expCountsPerIteration) {
      // given
      SlidingWindowCounter<Object> counter = new SlidingWindowCounter<Object>(windowLengthInSlots);
      int numIterations = incrementsPerIteration.length;
  
      for (int i = 0; i < numIterations; i++) {
        int numIncrements = incrementsPerIteration[i];
        long expCounts = expCountsPerIteration[i];
        // Objects are absent if they were zero both this iteration
        // and the last -- if only this one, we need to report zero.
        boolean expAbsent = ((expCounts == 0) && ((i == 0) || (expCountsPerIteration[i - 1] == 0)));
  
        // given (for this iteration)
        for (int j = 0; j < numIncrements; j++) {
          counter.incrementCount(ANY_OBJECT);
        }
  
        // when (for this iteration)
        Map<Object, Long> counts = counter.getCountsThenAdvanceWindow();
  
        // then (for this iteration)
        if (expAbsent) {
          assertThat(counts).doesNotContainKey(ANY_OBJECT);
        }
       else {
         assertThat(counts.get(ANY_OBJECT)).isEqualTo(expCounts);
       }
     }
   }
 
 }