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

import java.util.Optional;
import net.minecraft.util.Mth;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.Mob;
import net.minecraft.world.phys.Vec3;

public class LookControl implements Control {
	protected final Mob mob;
	protected float yMaxRotSpeed;
	protected float xMaxRotAngle;
	protected int lookAtCooldown;
	protected double wantedX;
	protected double wantedY;
	protected double wantedZ;

	public LookControl(Mob mob) {
		this.mob = mob;
	}

	/**
	 * Sets the mob's look vector
	 */
	public void setLookAt(Vec3 lookVector) {
		this.setLookAt(lookVector.x, lookVector.y, lookVector.z);
	}

	/**
	 * Sets the controlling mob's look vector to the provided entity's location
	 */
	public void setLookAt(Entity entity) {
		this.setLookAt(entity.getX(), getWantedY(entity), entity.getZ());
	}

	/**
	 * Sets position to look at using entity
	 */
	public void setLookAt(Entity entity, float deltaYaw, float deltaPitch) {
		this.setLookAt(entity.getX(), getWantedY(entity), entity.getZ(), deltaYaw, deltaPitch);
	}

	public void setLookAt(double x, double y, double z) {
		this.setLookAt(x, y, z, this.mob.getHeadRotSpeed(), this.mob.getMaxHeadXRot());
	}

	/**
	 * Sets position to look at
	 */
	public void setLookAt(double x, double y, double z, float deltaYaw, float deltaPitch) {
		this.wantedX = x;
		this.wantedY = y;
		this.wantedZ = z;
		this.yMaxRotSpeed = deltaYaw;
		this.xMaxRotAngle = deltaPitch;
		this.lookAtCooldown = 2;
	}

	/**
	 * Updates look
	 */
	public void tick() {
		if (this.resetXRotOnTick()) {
			this.mob.setXRot(0.0F);
		}

		if (this.lookAtCooldown > 0) {
			this.lookAtCooldown--;
			this.getYRotD().ifPresent(float_ -> this.mob.yHeadRot = this.rotateTowards(this.mob.yHeadRot, float_, this.yMaxRotSpeed));
			this.getXRotD().ifPresent(float_ -> this.mob.setXRot(this.rotateTowards(this.mob.getXRot(), float_, this.xMaxRotAngle)));
		} else {
			this.mob.yHeadRot = this.rotateTowards(this.mob.yHeadRot, this.mob.yBodyRot, 10.0F);
		}

		this.clampHeadRotationToBody();
	}

	protected void clampHeadRotationToBody() {
		if (!this.mob.getNavigation().isDone()) {
			this.mob.yHeadRot = Mth.rotateIfNecessary(this.mob.yHeadRot, this.mob.yBodyRot, this.mob.getMaxHeadYRot());
		}
	}

	protected boolean resetXRotOnTick() {
		return true;
	}

	public boolean isLookingAtTarget() {
		return this.lookAtCooldown > 0;
	}

	public double getWantedX() {
		return this.wantedX;
	}

	public double getWantedY() {
		return this.wantedY;
	}

	public double getWantedZ() {
		return this.wantedZ;
	}

	protected Optional<Float> getXRotD() {
		double d = this.wantedX - this.mob.getX();
		double e = this.wantedY - this.mob.getEyeY();
		double f = this.wantedZ - this.mob.getZ();
		double g = Math.sqrt(d * d + f * f);
		return !(Math.abs(e) > 1.0E-5F) && !(Math.abs(g) > 1.0E-5F) ? Optional.empty() : Optional.of((float)(-(Mth.atan2(e, g) * 180.0F / (float)Math.PI)));
	}

	protected Optional<Float> getYRotD() {
		double d = this.wantedX - this.mob.getX();
		double e = this.wantedZ - this.mob.getZ();
		return !(Math.abs(e) > 1.0E-5F) && !(Math.abs(d) > 1.0E-5F) ? Optional.empty() : Optional.of((float)(Mth.atan2(e, d) * 180.0F / (float)Math.PI) - 90.0F);
	}

	/**
	 * Rotate as much as possible from {@code from} to {@code to} within the bounds of {@code maxDelta}
	 */
	protected float rotateTowards(float from, float to, float maxDelta) {
		float f = Mth.degreesDifference(from, to);
		float g = Mth.clamp(f, -maxDelta, maxDelta);
		return from + g;
	}

	private static double getWantedY(Entity entity) {
		return entity instanceof LivingEntity ? entity.getEyeY() : (entity.getBoundingBox().minY + entity.getBoundingBox().maxY) / 2.0;
	}
}