#include "crawl.hpp"

#include <type_traits>

#include <function_ref.hpp>

#include "engine/displacement.hpp"

namespace devilution {
namespace {

bool CrawlFlipsX(Displacement mirrored, tl::function_ref<bool(Displacement)> function)
{
	for (const Displacement displacement : { mirrored.flipX(), mirrored }) {
		if (!function(displacement))
			return false;
	}
	return true;
}

bool CrawlFlipsY(Displacement mirrored, tl::function_ref<bool(Displacement)> function)
{
	for (const Displacement displacement : { mirrored, mirrored.flipY() }) {
		if (!function(displacement))
			return false;
	}
	return true;
}

bool CrawlFlipsXY(Displacement mirrored, tl::function_ref<bool(Displacement)> function)
{
	for (const Displacement displacement : { mirrored.flipX(), mirrored, mirrored.flipXY(), mirrored.flipY() }) {
		if (!function(displacement))
			return false;
	}
	return true;
}

} // namespace

bool DoCrawl(unsigned radius, tl::function_ref<bool(Displacement)> function)
{
	if (radius == 0)
		return function(Displacement { 0, 0 });

	if (!CrawlFlipsY({ 0, static_cast<int>(radius) }, function))
		return false;
	for (unsigned i = 1; i < radius; i++) {
		if (!CrawlFlipsXY({ static_cast<int>(i), static_cast<int>(radius) }, function))
			return false;
	}
	if (radius > 1) {
		if (!CrawlFlipsXY({ static_cast<int>(radius) - 1, static_cast<int>(radius) - 1 }, function))
			return false;
	}
	if (!CrawlFlipsX({ static_cast<int>(radius), 0 }, function))
		return false;
	for (unsigned i = 1; i < radius; i++) {
		if (!CrawlFlipsXY({ static_cast<int>(radius), static_cast<int>(i) }, function))
			return false;
	}
	return true;
}

bool DoCrawl(unsigned minRadius, unsigned maxRadius, tl::function_ref<bool(Displacement)> function)
{
	for (unsigned i = minRadius; i <= maxRadius; i++) {
		if (!DoCrawl(i, function))
			return false;
	}
	return true;
}

} // namespace devilution