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

import com.google.common.collect.ImmutableSet;
import java.util.Optional;
import java.util.Set;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.ai.memory.MemoryModuleType;
import net.minecraft.world.entity.ai.memory.NearestVisibleLivingEntities;

public abstract class NearestVisibleLivingEntitySensor extends Sensor<LivingEntity> {
	protected abstract boolean isMatchingEntity(ServerLevel level, LivingEntity entity, LivingEntity target);

	protected abstract MemoryModuleType<LivingEntity> getMemory();

	@Override
	public Set<MemoryModuleType<?>> requires() {
		return ImmutableSet.of(this.getMemory());
	}

	@Override
	protected void doTick(ServerLevel level, LivingEntity entity) {
		entity.getBrain().setMemory(this.getMemory(), this.getNearestEntity(level, entity));
	}

	private Optional<LivingEntity> getNearestEntity(ServerLevel level, LivingEntity enttiy) {
		return this.getVisibleEntities(enttiy)
			.flatMap(nearestVisibleLivingEntities -> nearestVisibleLivingEntities.findClosest(livingEntity2 -> this.isMatchingEntity(level, enttiy, livingEntity2)));
	}

	protected Optional<NearestVisibleLivingEntities> getVisibleEntities(LivingEntity entity) {
		return entity.getBrain().getMemory(MemoryModuleType.NEAREST_VISIBLE_LIVING_ENTITIES);
	}
}