/*
 * 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.pig.test;

import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Random;

import junit.framework.TestCase;

import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.POStatus;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.Result;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.PODistinct;
import org.apache.pig.test.PORead;
import org.junit.Before;
import org.junit.Test;

public class TestPODistinct extends TestCase {
	DataBag input = BagFactory.getInstance().newDefaultBag();
    Random r = new Random();
    final int MAX_VALUE = 10;
    final int MAX_SAMPLES = 100;

    @Before
    public void setUp() {
         // System.out.println();
    }

 
    @Test
    public void testPODistictWithInt() throws ExecException {
    	
       	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            t.append(r.nextInt(MAX_VALUE));
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }

    public void testPODistictWithNullValues() throws ExecException {
    	
    	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            t.append(null);
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }
  
    public void testPODistictWithIntAndNullValues() throws ExecException {
    	
      	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            t.append(r.nextInt(MAX_VALUE));
            input.add(t);
            t = tf.newTuple();
            t.append(null);
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }
 
    public void testPODistictWithIntNullValues() throws ExecException {
    	
    	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            t.append(r.nextInt(MAX_VALUE));
            t.append(null);
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }
    public void testPODistictWithNullIntValues() throws ExecException {
    	
    	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            t.append(null);
            t.append(r.nextInt(MAX_VALUE));
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }
    
    public void testPODistictArityWithNullValues() throws ExecException {
    	
    	input = BagFactory.getInstance().newDefaultBag();
        TupleFactory tf = TupleFactory.getInstance();
        for (int i = 0; i < MAX_SAMPLES; i++) {
            Tuple t = tf.newTuple();
            if ( r.nextInt(MAX_VALUE) % 3 == 0 ){
            	t.append(null);
            }
            t.append(r.nextInt(MAX_VALUE));
            t.append(r.nextInt(MAX_VALUE));
            input.add(t);
            // System.out.println(t);
        }

    	confirmDistinct();
     }

    public void confirmDistinct() throws ExecException {
	   	
	    PORead read = new PORead(new OperatorKey("", r.nextLong()), input);
	    List<PhysicalOperator> inputs = new LinkedList<PhysicalOperator>();
	    inputs.add(read);
	    PODistinct distinct = new PODistinct(new OperatorKey("", r.nextLong()),
	            -1, inputs);
	    Map<Tuple, Integer> output = new HashMap<Tuple, Integer>();
	    Tuple t = null;
	    Result res = distinct.getNext(t);
	    t = (Tuple) res.result;
	    while (res.returnStatus != POStatus.STATUS_EOP) {
	        if (output.containsKey(t)) {
	            int i = output.get(t);
	            output.put(t, ++i);
	        } else {
	            output.put(t, 1);
	        }
	        res = distinct.getNext(t);
	        t = (Tuple) res.result;
	    }
	    for (Map.Entry<Tuple, Integer> e : output.entrySet()) {
	        int i = e.getValue();
	        // System.out.println(e.getKey());
	        assertEquals(1, i);
	    }
    }

}