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

import java.util.EnumSet;
import java.util.List;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.EntityTypes;
import net.minecraft.world.entity.animal.equine.Llama;
import net.minecraft.world.entity.decoration.LeashFenceKnotEntity;
import net.minecraft.world.phys.Vec3;

public class LlamaFollowCaravanGoal extends Goal {
	public final Llama llama;
	private double speedModifier;
	private static final int CARAVAN_LIMIT = 8;
	private int distCheckCounter;

	public LlamaFollowCaravanGoal(final Llama llama, final double speedModifier) {
		this.llama = llama;
		this.speedModifier = speedModifier;
		this.setFlags(EnumSet.of(Goal.Flag.MOVE));
	}

	@Override
	public boolean canUse() {
		if (!this.llama.isLeashed() && !this.llama.inCaravan()) {
			List<Entity> llamas = this.llama
				.level()
				.getEntities(this.llama, this.llama.getBoundingBox().inflate(9.0, 4.0, 9.0), e -> e.is(EntityTypes.LLAMA) || e.is(EntityTypes.TRADER_LLAMA));
			Llama closest = null;
			double closestDistSquare = Double.MAX_VALUE;

			for (Entity entity : llamas) {
				Llama candidate = (Llama)entity;
				if (candidate.inCaravan() && !candidate.hasCaravanTail()) {
					double distSquare = this.llama.distanceToSqr(candidate);
					if (!(distSquare > closestDistSquare)) {
						closestDistSquare = distSquare;
						closest = candidate;
					}
				}
			}

			if (closest == null) {
				for (Entity entityx : llamas) {
					Llama candidate = (Llama)entityx;
					if (candidate.isLeashed() && !candidate.hasCaravanTail()) {
						double distSquare = this.llama.distanceToSqr(candidate);
						if (!(distSquare > closestDistSquare)) {
							closestDistSquare = distSquare;
							closest = candidate;
						}
					}
				}
			}

			if (closest == null) {
				return false;
			} else if (closestDistSquare < 4.0) {
				return false;
			} else if (!closest.isLeashed() && !this.firstIsLeashed(closest, 1)) {
				return false;
			} else {
				this.llama.joinCaravan(closest);
				return true;
			}
		} else {
			return false;
		}
	}

	@Override
	public boolean canContinueToUse() {
		if (this.llama.inCaravan() && this.llama.getCaravanHead().isAlive() && this.firstIsLeashed(this.llama, 0)) {
			double distSqr = this.llama.distanceToSqr(this.llama.getCaravanHead());
			if (distSqr > 676.0) {
				if (this.speedModifier <= 3.0) {
					this.speedModifier *= 1.2;
					this.distCheckCounter = reducedTickDelay(40);
					return true;
				}

				if (this.distCheckCounter == 0) {
					return false;
				}
			}

			if (this.distCheckCounter > 0) {
				this.distCheckCounter--;
			}

			return true;
		} else {
			return false;
		}
	}

	@Override
	public void stop() {
		this.llama.leaveCaravan();
		this.speedModifier = 2.1;
	}

	@Override
	public void tick() {
		if (this.llama.inCaravan()) {
			if (!(this.llama.getLeashHolder() instanceof LeashFenceKnotEntity)) {
				Llama follows = this.llama.getCaravanHead();
				double distanceTo = this.llama.distanceTo(follows);
				float wantedDistance = 2.0F;
				Vec3 delta = new Vec3(follows.getX() - this.llama.getX(), follows.getY() - this.llama.getY(), follows.getZ() - this.llama.getZ())
					.normalize()
					.scale(Math.max(distanceTo - 2.0, 0.0));
				this.llama.getNavigation().moveTo(this.llama.getX() + delta.x, this.llama.getY() + delta.y, this.llama.getZ() + delta.z, this.speedModifier);
			}
		}
	}

	private boolean firstIsLeashed(final Llama currentMob, int counter) {
		if (counter > 8) {
			return false;
		} else if (currentMob.inCaravan()) {
			return currentMob.getCaravanHead().isLeashed() ? true : this.firstIsLeashed(currentMob.getCaravanHead(), ++counter);
		} else {
			return false;
		}
	}
}