package net.minecraft.world.level.levelgen.placement;

import com.mojang.serialization.MapCodec;
import java.util.stream.Stream;
import java.util.stream.Stream.Builder;
import net.minecraft.core.BlockPos;
import net.minecraft.util.RandomSource;
import net.minecraft.util.valueproviders.ConstantInt;
import net.minecraft.util.valueproviders.IntProvider;
import net.minecraft.util.valueproviders.IntProviders;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.levelgen.Heightmap;

@Deprecated
public class CountOnEveryLayerPlacement extends PlacementModifier {
	public static final MapCodec<CountOnEveryLayerPlacement> CODEC = IntProviders.codec(0, 256)
		.fieldOf("count")
		.xmap(CountOnEveryLayerPlacement::new, c -> c.count);
	private final IntProvider count;

	private CountOnEveryLayerPlacement(final IntProvider count) {
		this.count = count;
	}

	public static CountOnEveryLayerPlacement of(final IntProvider count) {
		return new CountOnEveryLayerPlacement(count);
	}

	public static CountOnEveryLayerPlacement of(final int count) {
		return of(ConstantInt.of(count));
	}

	@Override
	public Stream<BlockPos> getPositions(final PlacementContext context, final RandomSource random, final BlockPos origin) {
		Builder<BlockPos> positions = Stream.builder();
		int layer = 0;

		boolean foundAny;
		do {
			foundAny = false;

			for (int i = 0; i < this.count.sample(random); i++) {
				int x = random.nextInt(16) + origin.getX();
				int z = random.nextInt(16) + origin.getZ();
				int startY = context.getHeight(Heightmap.Types.MOTION_BLOCKING, x, z);
				int y = findOnGroundYPosition(context, x, startY, z, layer);
				if (y != Integer.MAX_VALUE) {
					positions.add(new BlockPos(x, y, z));
					foundAny = true;
				}
			}

			layer++;
		} while (foundAny);

		return positions.build();
	}

	@Override
	public PlacementModifierType<?> type() {
		return PlacementModifierType.COUNT_ON_EVERY_LAYER;
	}

	private static int findOnGroundYPosition(final PlacementContext context, final int xStart, final int yStart, final int zStart, final int layerToPlaceOn) {
		BlockPos.MutableBlockPos currentPos = new BlockPos.MutableBlockPos(xStart, yStart, zStart);
		int currentLayer = 0;
		BlockState currentBlock = context.getBlockState(currentPos);

		for (int y = yStart; y >= context.getMinY() + 1; y--) {
			currentPos.setY(y - 1);
			BlockState belowBlock = context.getBlockState(currentPos);
			if (!isEmpty(belowBlock) && isEmpty(currentBlock) && !belowBlock.is(Blocks.BEDROCK)) {
				if (currentLayer == layerToPlaceOn) {
					return currentPos.getY() + 1;
				}

				currentLayer++;
			}

			currentBlock = belowBlock;
		}

		return Integer.MAX_VALUE;
	}

	private static boolean isEmpty(final BlockState blockState) {
		return blockState.isAir() || blockState.is(Blocks.WATER) || blockState.is(Blocks.LAVA);
	}
}