/*
 * 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.iceberg.io;

import java.util.List;
import java.util.function.Function;
import org.apache.iceberg.DeleteFile;
import org.apache.iceberg.PartitionSpec;
import org.apache.iceberg.StructLike;
import org.apache.iceberg.deletes.DeleteGranularity;
import org.apache.iceberg.deletes.PositionDelete;
import org.apache.iceberg.deletes.PositionDeleteIndex;
import org.apache.iceberg.deletes.SortingPositionOnlyDeleteWriter;
import org.apache.iceberg.relocated.com.google.common.collect.Lists;
import org.apache.iceberg.util.CharSequenceSet;

/**
 * A position delete writer capable of writing to multiple specs and partitions if the incoming
 * stream of deletes is not ordered. If the incoming records are ordered by an external process, use
 * {@link ClusteredPositionDeleteWriter} instead.
 *
 * <p>Note this writer stores only positions. It does not store deleted records.
 */
public class FanoutPositionOnlyDeleteWriter<T>
    extends FanoutWriter<PositionDelete<T>, DeleteWriteResult> {

  private final FileWriterFactory<T> writerFactory;
  private final OutputFileFactory fileFactory;
  private final FileIO io;
  private final long targetFileSizeInBytes;
  private final DeleteGranularity granularity;
  private final List<DeleteFile> deleteFiles;
  private final CharSequenceSet referencedDataFiles;
  private final List<DeleteFile> rewrittenDeleteFiles;
  private final Function<CharSequence, PositionDeleteIndex> loadPreviousDeletes;

  public FanoutPositionOnlyDeleteWriter(
      FileWriterFactory<T> writerFactory,
      OutputFileFactory fileFactory,
      FileIO io,
      long targetFileSizeInBytes) {
    this(writerFactory, fileFactory, io, targetFileSizeInBytes, DeleteGranularity.PARTITION);
  }

  public FanoutPositionOnlyDeleteWriter(
      FileWriterFactory<T> writerFactory,
      OutputFileFactory fileFactory,
      FileIO io,
      long targetFileSizeInBytes,
      DeleteGranularity granularity) {
    this(
        writerFactory,
        fileFactory,
        io,
        targetFileSizeInBytes,
        granularity,
        path -> null /* no access to previous deletes */);
  }

  public FanoutPositionOnlyDeleteWriter(
      FileWriterFactory<T> writerFactory,
      OutputFileFactory fileFactory,
      FileIO io,
      long targetFileSizeInBytes,
      DeleteGranularity granularity,
      Function<CharSequence, PositionDeleteIndex> loadPreviousDeletes) {
    this.writerFactory = writerFactory;
    this.fileFactory = fileFactory;
    this.io = io;
    this.targetFileSizeInBytes = targetFileSizeInBytes;
    this.granularity = granularity;
    this.deleteFiles = Lists.newArrayList();
    this.referencedDataFiles = CharSequenceSet.empty();
    this.rewrittenDeleteFiles = Lists.newArrayList();
    this.loadPreviousDeletes = loadPreviousDeletes;
  }

  @Override
  protected FileWriter<PositionDelete<T>, DeleteWriteResult> newWriter(
      PartitionSpec spec, StructLike partition) {
    return new SortingPositionOnlyDeleteWriter<>(
        () ->
            new RollingPositionDeleteWriter<>(
                writerFactory, fileFactory, io, targetFileSizeInBytes, spec, partition),
        granularity,
        loadPreviousDeletes);
  }

  @Override
  protected void addResult(DeleteWriteResult result) {
    deleteFiles.addAll(result.deleteFiles());
    referencedDataFiles.addAll(result.referencedDataFiles());
    rewrittenDeleteFiles.addAll(result.rewrittenDeleteFiles());
  }

  @Override
  protected DeleteWriteResult aggregatedResult() {
    return new DeleteWriteResult(deleteFiles, referencedDataFiles, rewrittenDeleteFiles);
  }
}
