content: /*
   * Copyright 2015, 2024 StreamEx contributors
   *
   * 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 one.util.streamex;
  
  import one.util.streamex.Internals.TailSpliterator;
  
  import java.util.Spliterator;
  import java.util.function.Consumer;
  
  /**
   * @author Tagir Valeev
   *
   * @param <T> type of the elements
   */
  /* package */class TailConcatSpliterator<T> implements TailSpliterator<T> {
      private Spliterator<T> left, right;
      private int characteristics;
      private long size;
  
      @SuppressWarnings("unchecked")
      public TailConcatSpliterator(Spliterator<? extends T> left, Spliterator<? extends T> right) {
          this.left = (Spliterator<T>) left;
          this.right = (Spliterator<T>) right;
          this.characteristics = left.characteristics() & right.characteristics() & (ORDERED | SIZED | SUBSIZED);
          this.size = left.estimateSize() + right.estimateSize();
          if (this.size < 0) {
              this.size = Long.MAX_VALUE;
              this.characteristics &= (~SIZED) & (~SUBSIZED);
          }
      }
  
      @Override
      public boolean tryAdvance(Consumer<? super T> action) {
          if (left != null) {
              if (left.tryAdvance(action)) {
                  if (size > 0 && size != Long.MAX_VALUE)
                      size--;
                  return true;
              }
              left = null;
          }
          if (right != null)
              right = TailSpliterator.tryAdvanceWithTail(right, action);
          return right != null;
      }
  
      @Override
      public Spliterator<T> tryAdvanceOrTail(Consumer<? super T> action) {
          if (left == null || !left.tryAdvance(action)) {
              Spliterator<T> s = right;
              right = null;
              return s;
          }
          if (size > 0 && size != Long.MAX_VALUE)
              size--;
          return this;
      }
  
      @Override
      public void forEachRemaining(Consumer<? super T> action) {
          if (left != null)
              left.forEachRemaining(action);
          if (right != null)
              TailSpliterator.forEachWithTail(right, action);
      }
  
      @Override
      public Spliterator<T> forEachOrTail(Consumer<? super T> action) {
          if (left != null)
              left.forEachRemaining(action);
          Spliterator<T> s = right;
          right = null;
          return s;
      }
  
      @Override
      public Spliterator<T> trySplit() {
          if (left == null)
              return right.trySplit();
          Spliterator<T> s = left;
          left = null;
          return s;
      }
  
      @Override
      public long estimateSize() {
          if (left == null)
              return right == null ? 0 : right.estimateSize();
          return size;
      }
  
      @Override
      public int characteristics() {
          return characteristics;
      }
  }
  