/*
 * 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.tsfile.external.commons.io.function;

import org.apache.tsfile.external.commons.io.IOExceptionList;
import org.apache.tsfile.external.commons.io.IOIndexedException;

import java.io.IOException;
import java.util.function.BiFunction;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

/** Keep this code package-private for now. */
final class IOStreams {

  static final Object NONE = new Object();

  static <T> void forAll(final Stream<T> stream, final IOConsumer<T> action)
      throws IOExceptionList {
    forAll(stream, action, (i, e) -> e);
  }

  @SuppressWarnings("resource") // adapt()
  static <T> void forAll(
      final Stream<T> stream,
      final IOConsumer<T> action,
      final BiFunction<Integer, IOException, IOException> exSupplier)
      throws IOExceptionList {
    IOStream.adapt(stream).forAll(action, IOIndexedException::new);
  }

  @SuppressWarnings("unused") // IOStreams.rethrow() throws
  static <T> void forEach(final Stream<T> stream, final IOConsumer<T> action) throws IOException {
    final IOConsumer<T> actualAction = toIOConsumer(action);
    of(stream).forEach(e -> Erase.accept(actualAction, e));
  }

  /**
   * Null-safe version of {@link StreamSupport#stream(java.util.Spliterator, boolean)}.
   *
   * <p>Copied from Apache Commons Lang.
   *
   * @param <T> the type of stream elements.
   * @param values the elements of the new stream, may be {@code null}.
   * @return the new stream on {@code values} or {@link Stream#empty()}.
   */
  static <T> Stream<T> of(final Iterable<T> values) {
    return values == null ? Stream.empty() : StreamSupport.stream(values.spliterator(), false);
  }

  static <T> Stream<T> of(final Stream<T> stream) {
    return stream == null ? Stream.empty() : stream;
  }

  /**
   * Null-safe version of {@link Stream#of(Object[])}.
   *
   * <p>Copied from Apache Commons Lang.
   *
   * @param <T> the type of stream elements.
   * @param values the elements of the new stream, may be {@code null}.
   * @return the new stream on {@code values} or {@link Stream#empty()}.
   */
  @SafeVarargs // Creating a stream from an array is safe
  static <T> Stream<T> of(final T... values) {
    return values == null ? Stream.empty() : Stream.of(values);
  }

  static <T> IOConsumer<T> toIOConsumer(final IOConsumer<T> action) {
    return action != null ? action : IOConsumer.noop();
  }

  private IOStreams() {
    // no instances
  }
}
