Code/net/minecraft/world/entity/ai/targeting/TargetingConditions.java

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

import javax.annotation.Nullable;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.Difficulty;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.Mob;

public class TargetingConditions {
    public static final TargetingConditions DEFAULT = forCombat();
    private static final double MIN_VISIBILITY_DISTANCE_FOR_INVISIBLE_TARGET = 2.0;
    private final boolean isCombat;
    private double range = -1.0;
    private boolean checkLineOfSight = true;
    private boolean testInvisible = true;
    @Nullable
    private TargetingConditions.Selector selector;

    private TargetingConditions(boolean p_148351_) {
        this.isCombat = p_148351_;
    }

    public static TargetingConditions forCombat() {
        return new TargetingConditions(true);
    }

    public static TargetingConditions forNonCombat() {
        return new TargetingConditions(false);
    }

    public TargetingConditions copy() {
        TargetingConditions targetingconditions = this.isCombat ? forCombat() : forNonCombat();
        targetingconditions.range = this.range;
        targetingconditions.checkLineOfSight = this.checkLineOfSight;
        targetingconditions.testInvisible = this.testInvisible;
        targetingconditions.selector = this.selector;
        return targetingconditions;
    }

    public TargetingConditions range(double p_26884_) {
        this.range = p_26884_;
        return this;
    }

    public TargetingConditions ignoreLineOfSight() {
        this.checkLineOfSight = false;
        return this;
    }

    public TargetingConditions ignoreInvisibilityTesting() {
        this.testInvisible = false;
        return this;
    }

    public TargetingConditions selector(@Nullable TargetingConditions.Selector p_362620_) {
        this.selector = p_362620_;
        return this;
    }

    public boolean test(ServerLevel p_364974_, @Nullable LivingEntity p_26886_, LivingEntity p_26887_) {
        if (p_26886_ == p_26887_) {
            return false;
        } else if (!p_26887_.canBeSeenByAnyone()) {
            return false;
        } else if (this.selector != null && !this.selector.test(p_26887_, p_364974_)) {
            return false;
        } else {
            if (p_26886_ == null) {
                if (this.isCombat && (!p_26887_.canBeSeenAsEnemy() || p_364974_.getDifficulty() == Difficulty.PEACEFUL)) {
                    return false;
                }
            } else {
                if (this.isCombat && (!p_26886_.canAttack(p_26887_) || !p_26886_.canAttackType(p_26887_.getType()) || p_26886_.isAlliedTo(p_26887_))) {
                    return false;
                }

                if (this.range > 0.0) {
                    double d0 = this.testInvisible ? p_26887_.getVisibilityPercent(p_26886_) : 1.0;
                    double d1 = Math.max(this.range * d0, 2.0);
                    double d2 = p_26886_.distanceToSqr(p_26887_.getX(), p_26887_.getY(), p_26887_.getZ());
                    if (d2 > d1 * d1) {
                        return false;
                    }
                }

                if (this.checkLineOfSight && p_26886_ instanceof Mob mob && !mob.getSensing().hasLineOfSight(p_26887_)) {
                    return false;
                }
            }

            return true;
        }
    }

    @FunctionalInterface
    public interface Selector {
        boolean test(LivingEntity p_362515_, ServerLevel p_363831_);
    }
}