hazelcast-master/hazelcast-sql/src/main/java/com/hazelcast/jet/sql/impl/opt/logical/SelectByKeyMapLogicalRel.java
/*
 * Copyright 2023 Hazelcast Inc.
 *
 * Licensed under the Hazelcast Community License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://hazelcast.com/hazelcast-community-license
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hazelcast.jet.sql.impl.opt.logical;

import com.hazelcast.jet.sql.impl.schema.HazelcastTable;
import com.hazelcast.sql.impl.schema.map.PartitionedMapTable;
import org.apache.calcite.linq4j.Ord;
import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.RelOptCost;
import org.apache.calcite.plan.RelOptPlanner;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.plan.RelTraitSet;
import org.apache.calcite.rel.AbstractRelNode;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.RelWriter;
import org.apache.calcite.rel.metadata.RelMetadataQuery;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rex.RexNode;

import java.util.List;
import java.util.stream.Collectors;

public class SelectByKeyMapLogicalRel extends AbstractRelNode implements LogicalRel {

    private final RelOptTable table;
    private final RexNode keyCondition;
    private final List<? extends RexNode> projections;

    SelectByKeyMapLogicalRel(
            RelOptCluster cluster,
            RelTraitSet traitSet,
            RelDataType rowType,
            RelOptTable table,
            RexNode keyCondition,
            List<? extends RexNode> projections
    ) {
        super(cluster, traitSet);
        this.rowType = rowType;

        assert table.unwrap(HazelcastTable.class).getTarget() instanceof PartitionedMapTable;

        this.table = table;
        this.keyCondition = keyCondition;
        this.projections = projections;
    }

    public RelOptTable table() {
        return table;
    }

    public RexNode keyCondition() {
        return keyCondition;
    }

    public List<? extends RexNode> projections() {
        return projections;
    }

    @Override
    public RelOptCost computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq) {
        // zero as not starting any job
        return planner.getCostFactory().makeZeroCost();
    }

    @Override
    public RelWriter explainTerms(RelWriter pw) {
        return pw
                .item("table", table.getQualifiedName())
                .item("keyCondition", keyCondition)
                .item("projections", Ord.zip(rowType.getFieldList()).stream()
                        .map(field -> {
                            String fieldName = field.e.getName() == null ? "field#" + field.i : field.e.getName();
                            return fieldName + "=[" + projections.get(field.i) + "]";
                        }).collect(Collectors.joining(", "))
                );
    }

    @Override
    public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
        return new SelectByKeyMapLogicalRel(getCluster(), traitSet, rowType, table, keyCondition, projections);
    }
}
