/*
 * 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.hudi.table.format.cow.vector.reader;

import org.apache.hudi.table.format.cow.vector.HeapRowColumnVector;

import org.apache.flink.formats.parquet.vector.reader.ColumnReader;
import org.apache.flink.table.data.columnar.vector.writable.WritableColumnVector;

import java.io.IOException;
import java.util.List;

/**
 * Row {@link ColumnReader}.
 */
public class RowColumnReader implements ColumnReader<WritableColumnVector> {

  private final List<ColumnReader> fieldReaders;

  public RowColumnReader(List<ColumnReader> fieldReaders) {
    this.fieldReaders = fieldReaders;
  }

  @Override
  public void readToVector(int readNumber, WritableColumnVector vector) throws IOException {
    HeapRowColumnVector rowColumnVector = (HeapRowColumnVector) vector;
    WritableColumnVector[] vectors = rowColumnVector.vectors;
    // row vector null array
    boolean[] isNulls = new boolean[readNumber];
    for (int i = 0; i < vectors.length; i++) {
      fieldReaders.get(i).readToVector(readNumber, vectors[i]);

      for (int j = 0; j < readNumber; j++) {
        if (i == 0) {
          isNulls[j] = vectors[i].isNullAt(j);
        } else {
          isNulls[j] = isNulls[j] && vectors[i].isNullAt(j);
        }
        if (i == vectors.length - 1 && isNulls[j]) {
          // rowColumnVector[j] is null only when all fields[j] of rowColumnVector[j] is
          // null
          rowColumnVector.setNullAt(j);
        }
      }
    }
  }
}
