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.runners.spark.structuredstreaming.translation.helpers;
  
  import static org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop.emptyList;
  import static org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop.seqOf;
  
  import java.lang.reflect.Constructor;
  import org.apache.spark.sql.catalyst.encoders.ExpressionEncoder;
  import org.apache.spark.sql.catalyst.expressions.Expression;
  import org.apache.spark.sql.catalyst.expressions.objects.Invoke;
  import org.apache.spark.sql.catalyst.expressions.objects.NewInstance;
  import org.apache.spark.sql.catalyst.expressions.objects.StaticInvoke;
  import org.apache.spark.sql.types.DataType;
  import scala.Option;
  import scala.reflect.ClassTag;
  
  public class EncoderFactory {
    // default constructor to reflectively create static invoke expressions
    private static final Constructor<StaticInvoke> STATIC_INVOKE_CONSTRUCTOR =
        (Constructor<StaticInvoke>) StaticInvoke.class.getConstructors()[0];
  
    private static final Constructor<Invoke> INVOKE_CONSTRUCTOR =
        (Constructor<Invoke>) Invoke.class.getConstructors()[0];
  
    private static final Constructor<NewInstance> NEW_INSTANCE_CONSTRUCTOR =
        (Constructor<NewInstance>) NewInstance.class.getConstructors()[0];
  
    static <T> ExpressionEncoder<T> create(
        Expression serializer, Expression deserializer, Class<? super T> clazz) {
      return new ExpressionEncoder<>(serializer, deserializer, ClassTag.apply(clazz));
    }
  
    /**
     * Invoke method {@code fun} on Class {@code cls}, immediately propagating {@code null} if any
     * input arg is {@code null}.
     */
    static Expression invokeIfNotNull(Class<?> cls, String fun, DataType type, Expression... args) {
      return invoke(cls, fun, type, true, args);
    }
  
    /** Invoke method {@code fun} on Class {@code cls}. */
    static Expression invoke(Class<?> cls, String fun, DataType type, Expression... args) {
      return invoke(cls, fun, type, false, args);
    }
  
    private static Expression invoke(
        Class<?> cls, String fun, DataType type, boolean propagateNull, Expression... args) {
      try {
        // To address breaking interfaces between various version of Spark 3,  expressions are
        // created reflectively. This is fine as it's just needed once to create the query plan.
        switch (STATIC_INVOKE_CONSTRUCTOR.getParameterCount()) {
          case 6:
            // Spark 3.1.x
            return STATIC_INVOKE_CONSTRUCTOR.newInstance(
                cls, type, fun, seqOf(args), propagateNull, true);
          case 7:
            // Spark 3.2.0
            return STATIC_INVOKE_CONSTRUCTOR.newInstance(
                cls, type, fun, seqOf(args), emptyList(), propagateNull, true);
          case 8:
            // Spark 3.2.x, 3.3.x
            return STATIC_INVOKE_CONSTRUCTOR.newInstance(
                cls, type, fun, seqOf(args), emptyList(), propagateNull, true, true);
          default:
            throw new RuntimeException("Unsupported version of Spark");
        }
      } catch (IllegalArgumentException | ReflectiveOperationException ex) {
        throw new RuntimeException(ex);
      }
    }
  
    /** Invoke method {@code fun} on {@code obj} with provided {@code args}. */
    static Expression invoke(
        Expression obj, String fun, DataType type, boolean nullable, Expression... args) {
      try {
        // To address breaking interfaces between various version of Spark 3,  expressions are
        // created reflectively. This is fine as it's just needed once to create the query plan.
        switch (STATIC_INVOKE_CONSTRUCTOR.getParameterCount()) {
          case 6:
            // Spark 3.1.x
            return INVOKE_CONSTRUCTOR.newInstance(obj, fun, type, seqOf(args), false, nullable);
          case 7:
            // Spark 3.2.0
            return INVOKE_CONSTRUCTOR.newInstance(
                obj, fun, type, seqOf(args), emptyList(), false, nullable);
          case 8:
            // Spark 3.2.x, 3.3.x
            return INVOKE_CONSTRUCTOR.newInstance(
                obj, fun, type, seqOf(args), emptyList(), false, nullable, true);
          default:
            throw new RuntimeException("Unsupported version of Spark");
        }
      } catch (IllegalArgumentException | ReflectiveOperationException ex) {
        throw new RuntimeException(ex);
      }
    }
  
    static Expression newInstance(Class<?> cls, DataType type, Expression... args) {
      try {
        // To address breaking interfaces between various version of Spark 3,  expressions are
        // created reflectively. This is fine as it's just needed once to create the query plan.
        switch (NEW_INSTANCE_CONSTRUCTOR.getParameterCount()) {
          case 5:
            return NEW_INSTANCE_CONSTRUCTOR.newInstance(cls, seqOf(args), true, type, Option.empty());
          case 6:
            return NEW_INSTANCE_CONSTRUCTOR.newInstance(
                cls, seqOf(args), emptyList(), true, type, Option.empty());
          default:
            throw new RuntimeException("Unsupported version of Spark");
        }
      } catch (IllegalArgumentException | ReflectiveOperationException ex) {
        throw new RuntimeException(ex);
      }
    }
  }
  