/*
    * Copyright (C) 2026 B3Partners B.V.
    *
    * SPDX-License-Identifier: MIT
    */
   package org.tailormap.api.geotools.collection;
   
   import java.util.concurrent.atomic.AtomicInteger;
   import java.util.function.IntConsumer;
  import org.geotools.api.feature.simple.SimpleFeature;
  import org.geotools.data.simple.SimpleFeatureIterator;
  import org.geotools.feature.collection.DecoratingSimpleFeatureIterator;
  import org.jspecify.annotations.Nullable;
  
  /** A decorating feature iterator that will call a callback after a specified number of features are handled. */
  public class ProgressReportingFeatureIterator extends DecoratingSimpleFeatureIterator {
  
    private final AtomicInteger count = new AtomicInteger(0);
    private final int progressInterval;
    private final IntConsumer progressCallback;
    private SimpleFeatureIterator iterator;
  
    /**
     * Creates an iterator that reports progress after every configured number of processed features.
     *
     * @param iterator the wrapped feature iterator, must not be {@code null}
     * @param progressInterval the number of processed features between progress updates, must be greater than {@code 0}
     * @param progressCallback the callback that receives the current processed feature count; may be {@code null}
     * @throws IllegalArgumentException if {@code progressInterval <= 0}
     */
    public ProgressReportingFeatureIterator(
        SimpleFeatureIterator iterator, int progressInterval, @Nullable IntConsumer progressCallback) {
      super(iterator);
      if (progressInterval <= 0) {
        throw new IllegalArgumentException("progressInterval must be greater than 0");
      }
      this.iterator = iterator;
      this.progressInterval = progressInterval;
      this.progressCallback = progressCallback;
    }
  
    @Override
    public SimpleFeature next() {
      if (count.incrementAndGet() % progressInterval == 0) {
        if (progressCallback != null) {
          progressCallback.accept(count.get());
        }
      }
      return iterator.next();
    }
  
    @Override
    public boolean hasNext() {
      return iterator.hasNext();
    }
  
    @Override
    public void close() {
      iterator.close();
      iterator = null;
      count.set(0);
    }
  }