/*
 * Copyright (c) 2008-2021, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed 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 com.hazelcast.jet.sql.impl.opt.physical;

import com.hazelcast.jet.sql.impl.opt.OptUtils;
import com.hazelcast.jet.sql.impl.opt.logical.FilterLogicalRel;
import org.apache.calcite.plan.RelOptRule;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.rel.RelNode;

import java.util.Collection;

import static com.hazelcast.jet.sql.impl.opt.JetConventions.LOGICAL;

final class FilterPhysicalRule extends RelOptRule {

    static final RelOptRule INSTANCE = new FilterPhysicalRule();

    private FilterPhysicalRule() {
        super(
                operand(FilterLogicalRel.class, LOGICAL, some(operand(RelNode.class, any()))),
                FilterPhysicalRule.class.getSimpleName()
        );
    }

    @Override
    public void onMatch(RelOptRuleCall call) {
        FilterLogicalRel logicalFilter = call.rel(0);
        RelNode input = logicalFilter.getInput();

        RelNode convertedInput = OptUtils.toPhysicalInput(input);
        Collection<RelNode> transformedInputs = OptUtils.extractPhysicalRelsFromSubset(convertedInput);
        for (RelNode transformedInput : transformedInputs) {
            FilterPhysicalRel rel = new FilterPhysicalRel(
                    logicalFilter.getCluster(),
                    transformedInput.getTraitSet(),
                    transformedInput,
                    logicalFilter.getCondition()
            );
            call.transformTo(rel);
        }
    }
}
