package net.minecraft.world.entity.ai.behavior;

import java.util.Collections;
import java.util.List;
import net.minecraft.core.BlockPos;
import net.minecraft.util.Util;
import net.minecraft.world.entity.PathfinderMob;
import net.minecraft.world.entity.ai.behavior.declarative.BehaviorBuilder;
import net.minecraft.world.entity.ai.memory.MemoryModuleType;
import net.minecraft.world.entity.ai.memory.WalkTarget;

public class InsideBrownianWalk {
	public static BehaviorControl<PathfinderMob> create(final float speedModifier) {
		return BehaviorBuilder.create(
			i -> i.group(i.absent(MemoryModuleType.WALK_TARGET))
				.apply(
					i,
					walkTarget -> (level, body, timestamp) -> {
						if (level.canSeeSky(body.blockPosition())) {
							return false;
						} else {
							BlockPos bodyPos = body.blockPosition();
							List<BlockPos> poses = (List<BlockPos>)BlockPos.betweenClosedStream(bodyPos.offset(-1, -1, -1), bodyPos.offset(1, 1, 1))
								.map(BlockPos::immutable)
								.collect(Util.toMutableList());
							Collections.shuffle(poses);
							poses.stream()
								.filter(pos -> !level.canSeeSky(pos))
								.filter(pos -> level.loadedAndEntityCanStandOn(pos, body))
								.filter(pos -> level.noCollision(body))
								.findFirst()
								.ifPresent(target -> walkTarget.set(new WalkTarget(target, speedModifier, 0)));
							return true;
						}
					}
				)
		);
	}
}