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

import java.util.Optional;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.Mob;
import net.minecraft.world.entity.ai.behavior.declarative.BehaviorBuilder;
import net.minecraft.world.entity.ai.memory.MemoryModuleType;

public class StartAttacking {
	public static <E extends Mob> BehaviorControl<E> create(final StartAttacking.TargetFinder<E> targetFinderFunction) {
		return create((level, body) -> true, targetFinderFunction);
	}

	public static <E extends Mob> BehaviorControl<E> create(
		final StartAttacking.StartAttackingCondition<E> canAttackPredicate, final StartAttacking.TargetFinder<E> targetFinderFunction
	) {
		return BehaviorBuilder.create(
			i -> i.group(i.absent(MemoryModuleType.ATTACK_TARGET), i.registered(MemoryModuleType.CANT_REACH_WALK_TARGET_SINCE))
				.apply(i, (attackTarget, cantReachSince) -> (level, body, timestamp) -> {
					if (!canAttackPredicate.test(level, (E)body)) {
						return false;
					} else {
						Optional<? extends LivingEntity> target = targetFinderFunction.get(level, (E)body);
						if (target.isEmpty()) {
							return false;
						} else {
							LivingEntity targetEntity = (LivingEntity)target.get();
							if (!body.canAttack(targetEntity)) {
								return false;
							} else {
								attackTarget.set(targetEntity);
								cantReachSince.erase();
								return true;
							}
						}
					}
				})
		);
	}

	@FunctionalInterface
	public interface StartAttackingCondition<E> {
		boolean test(ServerLevel level, E body);
	}

	@FunctionalInterface
	public interface TargetFinder<E> {
		Optional<? extends LivingEntity> get(ServerLevel level, E body);
	}
}