/**
 * 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.kafka.streams.kstream.internals;

import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.streams.kstream.KStreamBuilder;
import org.apache.kafka.streams.kstream.KTable;
import org.apache.kafka.streams.KeyValue;
import org.apache.kafka.test.KStreamTestDriver;
import org.apache.kafka.test.MockProcessorSupplier;
import org.apache.kafka.test.MockValueJoiner;
import org.apache.kafka.test.TestUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

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

public class KTableKTableOuterJoinTest {

    final private String topic1 = "topic1";
    final private String topic2 = "topic2";

    final private Serde<Integer> intSerde = Serdes.Integer();
    final private Serde<String> stringSerde = Serdes.String();

    private KStreamTestDriver driver = null;
    private File stateDir = null;

    @After
    public void tearDown() {
        if (driver != null) {
            driver.close();
        }
        driver = null;
    }

    @Before
    public void setUp() throws IOException {
        stateDir = TestUtils.tempDirectory("kafka-test");
    }

    @Test
    public void testJoin() throws Exception {
        KStreamBuilder builder = new KStreamBuilder();

        final int[] expectedKeys = new int[]{0, 1, 2, 3};

        KTable<Integer, String> table1;
        KTable<Integer, String> table2;
        KTable<Integer, String> joined;
        MockProcessorSupplier<Integer, String> processor;

        processor = new MockProcessorSupplier<>();
        table1 = builder.table(intSerde, stringSerde, topic1);
        table2 = builder.table(intSerde, stringSerde, topic2);
        joined = table1.outerJoin(table2, MockValueJoiner.STRING_JOINER);
        joined.toStream().process(processor);

        Collection<Set<String>> copartitionGroups = builder.copartitionGroups();

        assertEquals(1, copartitionGroups.size());
        assertEquals(new HashSet<>(Arrays.asList(topic1, topic2)), copartitionGroups.iterator().next());

        KTableValueGetterSupplier<Integer, String> getterSupplier = ((KTableImpl<Integer, String, String>) joined).valueGetterSupplier();

        driver = new KStreamTestDriver(builder, stateDir);
        driver.setTime(0L);

        KTableValueGetter<Integer, String> getter = getterSupplier.get();
        getter.init(driver.context());

        // push two items to the primary stream. the other table is empty

        for (int i = 0; i < 2; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:X0+null", "1:X1+null");
        checkJoinedValues(getter, kv(0, "X0+null"), kv(1, "X1+null"), kv(2, null), kv(3, null));

        // push two items to the other stream. this should produce two items.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], "Y" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:X0+Y0", "1:X1+Y1");
        checkJoinedValues(getter, kv(0, "X0+Y0"), kv(1, "X1+Y1"), kv(2, null), kv(3, null));

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:X0+Y0", "1:X1+Y1", "2:X2+null", "3:X3+null");
        checkJoinedValues(getter, kv(0, "X0+Y0"), kv(1, "X1+Y1"), kv(2, "X2+null"), kv(3, "X3+null"));

        // push all items to the other stream. this should produce four items.
        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic2, expectedKeys[i], "YY" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:X0+YY0", "1:X1+YY1", "2:X2+YY2", "3:X3+YY3");
        checkJoinedValues(getter, kv(0, "X0+YY0"), kv(1, "X1+YY1"), kv(2, "X2+YY2"), kv(3, "X3+YY3"));

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:X0+YY0", "1:X1+YY1", "2:X2+YY2", "3:X3+YY3");
        checkJoinedValues(getter, kv(0, "X0+YY0"), kv(1, "X1+YY1"), kv(2, "X2+YY2"), kv(3, "X3+YY3"));

        // push two items with null to the other stream as deletes. this should produce two item.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], null);
        }

        processor.checkAndClearProcessResult("0:X0+null", "1:X1+null");
        checkJoinedValues(getter, kv(0, "X0+null"), kv(1, "X1+null"), kv(2, "X2+YY2"), kv(3, "X3+YY3"));

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "XX" + expectedKeys[i]);
        }

        processor.checkAndClearProcessResult("0:XX0+null", "1:XX1+null", "2:XX2+YY2", "3:XX3+YY3");
        checkJoinedValues(getter, kv(0, "XX0+null"), kv(1, "XX1+null"), kv(2, "XX2+YY2"), kv(3, "XX3+YY3"));

        // push middle two items to the primary stream with null. this should produce two items.

        for (int i = 1; i < 3; i++) {
            driver.process(topic1, expectedKeys[i], null);
        }

        processor.checkAndClearProcessResult("1:null", "2:null+YY2");
        checkJoinedValues(getter, kv(0, "XX0+null"), kv(1, null), kv(2, "null+YY2"), kv(3, "XX3+YY3"));
    }

    @Test
    public void testNotSendingOldValue() throws Exception {
        final KStreamBuilder builder = new KStreamBuilder();

        final int[] expectedKeys = new int[]{0, 1, 2, 3};

        KTable<Integer, String> table1;
        KTable<Integer, String> table2;
        KTable<Integer, String> joined;
        MockProcessorSupplier<Integer, String> proc;

        table1 = builder.table(intSerde, stringSerde, topic1);
        table2 = builder.table(intSerde, stringSerde, topic2);
        joined = table1.outerJoin(table2, MockValueJoiner.STRING_JOINER);

        proc = new MockProcessorSupplier<>();
        builder.addProcessor("proc", proc, ((KTableImpl<?, ?, ?>) joined).name);

        driver = new KStreamTestDriver(builder, stateDir);
        driver.setTime(0L);

        assertFalse(((KTableImpl<?, ?, ?>) table1).sendingOldValueEnabled());
        assertFalse(((KTableImpl<?, ?, ?>) table2).sendingOldValueEnabled());
        assertFalse(((KTableImpl<?, ?, ?>) joined).sendingOldValueEnabled());

        // push two items to the primary stream. the other table is empty

        for (int i = 0; i < 2; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+null<-null)", "1:(X1+null<-null)");

        // push two items to the other stream. this should produce two items.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], "Y" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+Y0<-null)", "1:(X1+Y1<-null)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+Y0<-null)", "1:(X1+Y1<-null)", "2:(X2+null<-null)", "3:(X3+null<-null)");

        // push all items to the other stream. this should produce four items.
        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic2, expectedKeys[i], "YY" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+YY0<-null)", "1:(X1+YY1<-null)", "2:(X2+YY2<-null)", "3:(X3+YY3<-null)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+YY0<-null)", "1:(X1+YY1<-null)", "2:(X2+YY2<-null)", "3:(X3+YY3<-null)");

        // push two items with null to the other stream as deletes. this should produce two item.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], null);
        }

        proc.checkAndClearProcessResult("0:(X0+null<-null)", "1:(X1+null<-null)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "XX" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(XX0+null<-null)", "1:(XX1+null<-null)", "2:(XX2+YY2<-null)", "3:(XX3+YY3<-null)");

        // push middle two items to the primary stream with null. this should produce two items.

        for (int i = 1; i < 3; i++) {
            driver.process(topic1, expectedKeys[i], null);
        }

        proc.checkAndClearProcessResult("1:(null<-null)", "2:(null+YY2<-null)");
    }

    @Test
    public void testSendingOldValue() throws Exception {
        final KStreamBuilder builder = new KStreamBuilder();

        final int[] expectedKeys = new int[]{0, 1, 2, 3};

        KTable<Integer, String> table1;
        KTable<Integer, String> table2;
        KTable<Integer, String> joined;
        MockProcessorSupplier<Integer, String> proc;

        table1 = builder.table(intSerde, stringSerde, topic1);
        table2 = builder.table(intSerde, stringSerde, topic2);
        joined = table1.outerJoin(table2, MockValueJoiner.STRING_JOINER);

        ((KTableImpl<?, ?, ?>) joined).enableSendingOldValues();

        proc = new MockProcessorSupplier<>();
        builder.addProcessor("proc", proc, ((KTableImpl<?, ?, ?>) joined).name);

        driver = new KStreamTestDriver(builder, stateDir);
        driver.setTime(0L);

        assertTrue(((KTableImpl<?, ?, ?>) table1).sendingOldValueEnabled());
        assertTrue(((KTableImpl<?, ?, ?>) table2).sendingOldValueEnabled());
        assertTrue(((KTableImpl<?, ?, ?>) joined).sendingOldValueEnabled());

        // push two items to the primary stream. the other table is empty

        for (int i = 0; i < 2; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+null<-null)", "1:(X1+null<-null)");

        // push two items to the other stream. this should produce two items.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], "Y" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+Y0<-X0+null)", "1:(X1+Y1<-X1+null)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+Y0<-X0+Y0)", "1:(X1+Y1<-X1+Y1)", "2:(X2+null<-null)", "3:(X3+null<-null)");

        // push all items to the other stream. this should produce four items.
        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic2, expectedKeys[i], "YY" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+YY0<-X0+Y0)", "1:(X1+YY1<-X1+Y1)", "2:(X2+YY2<-X2+null)", "3:(X3+YY3<-X3+null)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "X" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(X0+YY0<-X0+YY0)", "1:(X1+YY1<-X1+YY1)", "2:(X2+YY2<-X2+YY2)", "3:(X3+YY3<-X3+YY3)");

        // push two items with null to the other stream as deletes. this should produce two item.

        for (int i = 0; i < 2; i++) {
            driver.process(topic2, expectedKeys[i], null);
        }

        proc.checkAndClearProcessResult("0:(X0+null<-X0+YY0)", "1:(X1+null<-X1+YY1)");

        // push all four items to the primary stream. this should produce four items.

        for (int i = 0; i < expectedKeys.length; i++) {
            driver.process(topic1, expectedKeys[i], "XX" + expectedKeys[i]);
        }

        proc.checkAndClearProcessResult("0:(XX0+null<-X0+null)", "1:(XX1+null<-X1+null)", "2:(XX2+YY2<-X2+YY2)", "3:(XX3+YY3<-X3+YY3)");

        // push middle two items to the primary stream with null. this should produce two items.

        for (int i = 1; i < 3; i++) {
            driver.process(topic1, expectedKeys[i], null);
        }

        proc.checkAndClearProcessResult("1:(null<-XX1+null)", "2:(null+YY2<-XX2+YY2)");
    }

    private KeyValue<Integer, String> kv(Integer key, String value) {
        return new KeyValue<>(key, value);
    }

    private void checkJoinedValues(KTableValueGetter<Integer, String> getter, KeyValue<Integer, String>... expected) {
        for (KeyValue<Integer, String> kv : expected) {
            String value = getter.get(kv.key);
            if (kv.value == null) {
                assertNull(value);
            } else {
                assertEquals(kv.value, value);
            }
        }
    }
}