/*
 * #%L
 * Image processing operations for SciJava Ops.
 * %%
 * Copyright (C) 2014 - 2024 SciJava developers.
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package org.scijava.ops.image.stats;

import java.util.function.BiFunction;

import net.imglib2.Dimensions;
import net.imglib2.RandomAccessibleInterval;
import net.imglib2.loops.LoopBuilder;
import net.imglib2.type.numeric.RealType;

import org.scijava.function.Computers;
import org.scijava.ops.spi.Op;
import org.scijava.ops.spi.OpDependency;

/**
 * Op to calculate the {@code stats.sumOfInverses}.
 *
 * @author Gabriel Selzer
 * @param <I> input type
 * @param <O> output type
 * @implNote op names='stats.sumOfInverses', priority='100.'
 */
public class DefaultSumOfInverses<I extends RealType<I>, O extends RealType<O>>
	implements Computers.Arity2<RandomAccessibleInterval<I>, O, O>
{

	@OpDependency(name = "create.img")
	private BiFunction<Dimensions, O, RandomAccessibleInterval<O>> imgCreator;

	// TODO: Can we lift this? Would require making a RAI of Doubles.
	@OpDependency(name = "math.reciprocal")
	private Computers.Arity2<I, Double, O> reciprocalOp;

	@OpDependency(name = "stats.sum")
	private Computers.Arity1<RandomAccessibleInterval<O>, O> sumOp;

	/**
	 * TODO
	 *
	 * @param input the input data to iterate over
	 * @param dbzValue the value to use for the inverse when the input data is
	 *          zero
	 * @param output the output buffer
	 */
	@Override
	public void compute(final RandomAccessibleInterval<I> input, final O dbzValue,
		final O output)
	{
        var tmpImg = imgCreator.apply(input, output);
		// TODO: Can we lift this? Would require making a RAI of Doubles.
		LoopBuilder.setImages(input, tmpImg).multiThreaded().forEachPixel((inPixel,
			outPixel) -> {
			reciprocalOp.compute(inPixel, dbzValue.getRealDouble(), outPixel);
		});
		sumOp.compute(tmpImg, output);
	}
}
