content: /*
   * 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.beam.sdk.extensions.sql.impl;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.hasSize;
  import static org.hamcrest.Matchers.instanceOf;
  import static org.junit.Assert.assertEquals;
  
  import java.util.List;
  import org.apache.beam.sdk.coders.CannotProvideCoderException;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.CoderRegistry;
  import org.apache.beam.sdk.coders.VarLongCoder;
  import org.apache.beam.sdk.extensions.sql.udf.AggregateFn;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.jdbc.JavaTypeFactoryImpl;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.type.RelDataType;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.type.RelDataTypeFactory;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.type.RelDataTypeSystem;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.schema.AggregateFunction;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.schema.FunctionParameter;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  import org.junit.runners.Parameterized;
  
  /** Tests for {@link LazyAggregateCombineFn}. */
  @RunWith(JUnit4.class)
  public class LazyAggregateCombineFnTest {
    @Rule public ExpectedException exceptions = ExpectedException.none();
  
    @Test
    public void getAccumulatorCoderInfersCoderForWildcardTypeParameter()
        throws CannotProvideCoderException {
      LazyAggregateCombineFn<Long, ?, ?> combiner = new LazyAggregateCombineFn<>(new Sum());
      Coder<?> coder = combiner.getAccumulatorCoder(CoderRegistry.createDefault(), VarLongCoder.of());
      assertThat(coder, instanceOf(VarLongCoder.class));
    }
  
    @Test
    public void mergeAccumulators() {
      LazyAggregateCombineFn<Long, Long, Long> combiner = new LazyAggregateCombineFn<>(new Sum());
      long merged = combiner.mergeAccumulators(ImmutableList.of(1L, 1L));
      assertEquals(2L, merged);
    }
  
    @RunWith(Parameterized.class)
    public static class UdafImplTest {
      @Parameterized.Parameters(name = "aggregateFn: {0}")
      public static Object[] data() {
        return new Object[] {new Sum(), new SumChild()};
      }
  
      @Parameterized.Parameter public AggregateFn aggregateFn;
  
      @Test
      public void subclassGetUdafImpl() {
        LazyAggregateCombineFn<?, ?, ?> combiner = new LazyAggregateCombineFn<>(aggregateFn);
        AggregateFunction aggregateFunction = combiner.getUdafImpl();
        RelDataTypeFactory typeFactory = new JavaTypeFactoryImpl(RelDataTypeSystem.DEFAULT);
        RelDataType expectedType = typeFactory.createJavaType(Long.class);
  
        List<FunctionParameter> params = aggregateFunction.getParameters();
        assertThat(params, hasSize(1));
        RelDataType paramType = params.get(0).getType(typeFactory);
        assertEquals(expectedType, paramType);
  
        RelDataType returnType = aggregateFunction.getReturnType(typeFactory);
        assertEquals(expectedType, returnType);
      }
    }
  
    @Test
    public void nonparameterizedGetUdafImpl_throwsIllegalStateException() {
      LazyAggregateCombineFn<?, ?, ?> combiner =
          new LazyAggregateCombineFn<>(new NonParameterizedAggregateFn());
      AggregateFunction aggregateFunction = combiner.getUdafImpl();
      RelDataTypeFactory typeFactory = new JavaTypeFactoryImpl(RelDataTypeSystem.DEFAULT);
  
      exceptions.expect(IllegalStateException.class);
  
      List<FunctionParameter> params = aggregateFunction.getParameters();
      params.get(0).getType(typeFactory);
    }
  
    public static class Sum implements AggregateFn<Long, Long, Long> {
  
      @Override
      public Long createAccumulator() {
        return 0L;
      }
  
      @Override
      public Long addInput(Long mutableAccumulator, Long input) {
        return mutableAccumulator + input;
      }
  
      @Override
      public Long mergeAccumulators(Long mutableAccumulator, Iterable<Long> immutableAccumulators) {
        for (Long x : immutableAccumulators) {
          mutableAccumulator += x;
        }
        return mutableAccumulator;
      }
  
      @Override
      public Long extractOutput(Long mutableAccumulator) {
        return mutableAccumulator;
      }
    }
  
    public static class SumChild extends Sum {}
  
    public static class NonParameterizedAggregateFn implements AggregateFn {
  
      @Override
      public @Nullable Object createAccumulator() {
        return null;
      }
  
      @Override
      public @Nullable Object addInput(Object mutableAccumulator, Object input) {
        return null;
      }
  
      @Override
      public @Nullable Object mergeAccumulators(
          Object mutableAccumulator, Iterable immutableAccumulators) {
        return null;
      }
  
      @Override
      public @Nullable Object extractOutput(Object mutableAccumulator) {
        return null;
      }
    }
  }
  