/*
Licensed to the Apache Software Foundation (ASF) under one
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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
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*/
package org.apache.edgent.topology;

import static org.apache.edgent.function.Functions.identity;
import static org.apache.edgent.function.Functions.unpartitioned;
import static org.apache.edgent.function.Functions.zero;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;
import static org.junit.Assume.assumeTrue;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.TimeUnit;

import org.apache.edgent.topology.tester.Condition;
import org.junit.Ignore;
import org.junit.Test;

@Ignore
public abstract class TWindowTest extends TopologyAbstractTest{
    @Test
    public void testCountBasedBatch() throws Exception{
        Topology top = newTopology();
        List<Integer> intList = new ArrayList<>();
        for(int i = 0; i < 1000;i++)
            intList.add(i);
        TStream<Integer> ints = top.source(() -> intList);
        
        TWindow<Integer, Integer> window = ints.last(100, tuple -> 0);
        TStream<Integer> sizes = window.batch((tuples, key) -> {
            return tuples.size();
        });
        Condition<List<Integer> > contents = top.getTester().streamContents(sizes,
                100,100,100,100,100,100,100,100,100,100);
        complete(top, contents);
        assertTrue(contents.valid());
    }
    
    @Test
    public void testTimeBasedBatch() throws Exception{
      // Timing variances on shared machines can cause this test to fail
      assumeTrue(!Boolean.getBoolean("edgent.build.ci"));
      
        Topology top = newTopology();
        TStream<Integer> ints = top.poll(() -> {
            return 1;
        }, 10, TimeUnit.MILLISECONDS);
        
        TWindow<Integer, Integer> window = ints.last(1000, TimeUnit.MILLISECONDS, tuple -> 0);
        TStream<Integer> sizes = window.batch((tuples, key) -> {
            return tuples.size();
        });

        Condition<List<Integer> > contents = top.getTester().streamContents(sizes,
           100, 100, 100, 100, 100, 100, 100, 100, 100, 100);
        complete(top, contents);
        System.out.println(contents.getResult());
        for(Integer size : contents.getResult()){
            assertTrue("size="+size, size >= 90 && size <= 110);
        }
    }
    
    @Test
    public void testKeyedWindowSum() throws Exception {
        Topology t = newTopology();
        
        TStream<Integer> integers = t.collection(Arrays.asList(1,2,3,4,4,3,4,4,3));
        TWindow<Integer, Integer> window = integers.last(9, identity());
        assertSame(identity(), window.getKeyFunction());
        assertSame(t, window.topology());
        assertSame(integers, window.feeder());

        TStream<Integer> sums = window.aggregate((tuples, key) -> {
            // All tuples in a partition are equal due to identity
            assertEquals(1, new HashSet<>(tuples).size());
            int sum = 0;
            for(Integer tuple : tuples)
                sum+=tuple;
            return sum;
        });
        
        Condition<Long> tc = t.getTester().tupleCount(sums, 9);
        Condition<List<Integer>> contents = t.getTester().streamContents(sums, 
                1, 2, 3, 4, 8, 6, 12, 16, 9);
        complete(t, tc);

        assertTrue(contents.valid());
    }
    
    @Test
    public void testWindowSum() throws Exception {
        Topology t = newTopology();
        
        TStream<Integer> integers = t.collection(Arrays.asList(1,2,3,4));
        TWindow<Integer, Integer> window = integers.last(4, unpartitioned());
        assertSame(unpartitioned(), window.getKeyFunction());
        TStream<Integer> sums = window.aggregate((tuples, key) -> {
            assertEquals(Integer.valueOf(0), key);
            int sum = 0;
            for(Integer tuple : tuples)
                sum+=tuple;
            return sum;
        });

        Condition<Long> tc = t.getTester().tupleCount(sums, 4);
        Condition<List<Integer>> contents = t.getTester().streamContents(sums, 1, 3, 6, 10);
        complete(t, tc);

        assertTrue(contents.valid());
    }
    
    @Test
    public void testTimeWindowTimeDiff() throws Exception {
		// Timing variances on shared machines can cause this test to fail
    	assumeTrue(!Boolean.getBoolean("edgent.build.ci"));
    	
        Topology t = newTopology();
        
        // Define data
        ConcurrentLinkedQueue<Long> diffs = new ConcurrentLinkedQueue<>();
        
        // Poll data
        TStream<Long> times = t.poll(() -> {   
            return System.currentTimeMillis();
        }, 1, TimeUnit.MILLISECONDS);

        TWindow<Long, Integer> window = times.last(1, TimeUnit.SECONDS, unpartitioned());
        assertSame(zero(), window.getKeyFunction());
        TStream<Long> diffStream = window.aggregate((tuples, key) -> {
            assertEquals(Integer.valueOf(0), key);
            if(tuples.size() < 2){
                return null;
            }
            return tuples.get(tuples.size() -1) - tuples.get(0);
        });
        
        diffStream.sink((tuple) -> diffs.add(tuple));
        
        Condition<Long> tc = t.getTester().tupleCount(diffStream, 5000);
        complete(t, tc);
        
        for(Long diff : diffs){
            assertTrue("Diff is: " + diff, diff >=0 && diff < 1060);
        }
        
    }
    
    public static boolean withinTolerance(double expected, Double actual, double tolerance) {
        double lowBound = (1.0 - tolerance) * expected;
        double highBound = (1.0 + tolerance) * expected;
        return (actual < highBound && actual > lowBound);
    }
}