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.calcite.rel.rules;
  
  import org.apache.calcite.plan.RelOptRuleCall;
  import org.apache.calcite.plan.RelRule;
  import org.apache.calcite.rel.core.Filter;
  import org.apache.calcite.rex.RexBuilder;
  import org.apache.calcite.rex.RexNode;
  import org.apache.calcite.rex.RexUtil;
  import org.apache.calcite.tools.RelBuilderFactory;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.immutables.value.Value;
  
  import java.util.Arrays;
  import java.util.List;
  
  /**
   * Planner rule that merges a
   * {@link Filter} into a {@link MultiJoin},
   * creating a richer {@code MultiJoin}.
   *
   * @see org.apache.calcite.rel.rules.ProjectMultiJoinMergeRule
   * @see CoreRules#FILTER_MULTI_JOIN_MERGE
   */
  @Value.Enclosing
  public class FilterMultiJoinMergeRule
      extends RelRule<FilterMultiJoinMergeRule.Config>
      implements TransformationRule {
  
    /** Creates a FilterMultiJoinMergeRule. */
    protected FilterMultiJoinMergeRule(Config config) {
      super(config);
    }
  
    @Deprecated // to be removed before 2.0
    public FilterMultiJoinMergeRule(RelBuilderFactory relBuilderFactory) {
      this(Config.DEFAULT.withRelBuilderFactory(relBuilderFactory)
          .as(Config.class));
    }
  
    @Deprecated // to be removed before 2.0
    public FilterMultiJoinMergeRule(Class<? extends Filter> filterClass,
        RelBuilderFactory relBuilderFactory) {
      this(Config.DEFAULT.withRelBuilderFactory(relBuilderFactory)
          .as(Config.class)
          .withOperandFor(filterClass, MultiJoin.class));
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public void onMatch(RelOptRuleCall call) {
      Filter filter = call.rel(0);
      MultiJoin multiJoin = call.rel(1);
  
      // Create a new post-join filter condition
      // Conditions are nullable, so ImmutableList can't be used here
      List<@Nullable RexNode> filters =
          Arrays.asList(filter.getCondition(), multiJoin.getPostJoinFilter());
  
      final RexBuilder rexBuilder = multiJoin.getCluster().getRexBuilder();
      MultiJoin newMultiJoin =
          new MultiJoin(
              multiJoin.getCluster(),
              multiJoin.getInputs(),
              multiJoin.getJoinFilter(),
              multiJoin.getRowType(),
              multiJoin.isFullOuterJoin(),
              multiJoin.getOuterJoinConditions(),
              multiJoin.getJoinTypes(),
              multiJoin.getProjFields(),
              multiJoin.getJoinFieldRefCountsMap(),
              RexUtil.composeConjunction(rexBuilder, filters, true));
  
      call.transformTo(newMultiJoin);
    }
  
    /** Rule configuration. */
    @Value.Immutable
    public interface Config extends RelRule.Config {
      Config DEFAULT = ImmutableFilterMultiJoinMergeRule.Config.of()
          .withOperandFor(Filter.class, MultiJoin.class);
  
      @Override default FilterMultiJoinMergeRule toRule() {
        return new FilterMultiJoinMergeRule(this);
      }
  
      /** Defines an operand tree for the given classes. */
      default Config withOperandFor(Class<? extends Filter> filterClass,
          Class<? extends MultiJoin> multiJoinClass) {
        return withOperandSupplier(b0 ->
            b0.operand(filterClass).oneInput(b1 ->
                b1.operand(multiJoinClass).anyInputs()))
            .as(Config.class);
      }
    }
  }
  