/*
 * 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.paimon.crosspartition;

import org.apache.paimon.data.BinaryRow;
import org.apache.paimon.data.InternalRow;
import org.apache.paimon.types.RowKind;
import org.apache.paimon.utils.ProjectToRowFunction;
import org.apache.paimon.utils.RowIterator;

import java.util.function.BiConsumer;
import java.util.function.Function;

/** A {@link ExistingProcessor} to delete old record. */
public class DeleteExistingProcessor implements ExistingProcessor {

    private final ProjectToRowFunction setPartition;
    private final BucketAssigner bucketAssigner;
    private final BiConsumer<InternalRow, Integer> collector;

    public DeleteExistingProcessor(
            ProjectToRowFunction setPartition,
            BucketAssigner bucketAssigner,
            BiConsumer<InternalRow, Integer> collector) {
        this.setPartition = setPartition;
        this.bucketAssigner = bucketAssigner;
        this.collector = collector;
    }

    @Override
    public boolean processExists(InternalRow newRow, BinaryRow previousPart, int previousBucket) {
        // retract old record
        InternalRow retract = setPartition.apply(newRow, previousPart);
        retract.setRowKind(RowKind.DELETE);
        collector.accept(retract, previousBucket);
        bucketAssigner.decrement(previousPart, previousBucket);

        // new record
        return true;
    }

    @Override
    public void bulkLoadNewRecords(
            Function<SortOrder, RowIterator> iteratorFunction,
            Function<InternalRow, BinaryRow> extractPrimary,
            Function<InternalRow, BinaryRow> extractPartition,
            Function<BinaryRow, Integer> assignBucket) {
        ExistingProcessor.bulkLoadCollectFirst(
                collector,
                iteratorFunction.apply(SortOrder.DESCENDING),
                extractPrimary,
                extractPartition,
                assignBucket);
    }
}
