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package cz.ascaria.borekboritel.controllers;

import com.jme3.math.Quaternion;
import com.jme3.math.Vector3f;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import cz.ascaria.borekboritel.Main;
import de.lessvoid.nifty.Nifty;
import de.lessvoid.nifty.elements.Element;
import de.lessvoid.nifty.screen.Screen;
import de.lessvoid.nifty.tools.SizeValue;

/**
 * Hud controller.
 * @author Ascaria
 */
public class HudController extends BaseScreenController
{
    protected Node camNode;
    protected Node targetNode;

    protected int gunSightHalfWidth = 0;
    protected int gunSightHalfHeight = 0;
    protected int screenHeight = 0;
    protected Vector3f enemyScreenCoords = new Vector3f();

    protected Element gunSight;
    protected Geometry target;

    @Override
    public void bind(Nifty nifty, Screen screen)
    {
        super.bind(nifty, screen);

        camNode = new Node();
        camNode.attachChild(targetNode = new Node());

        gunSight = screen.findElementByName("hud-gun-sight");
        gunSightHalfWidth = gunSight.getWidth() / 2;
        gunSightHalfHeight = gunSight.getHeight() / 2;

        screenHeight = settings.getHeight();

        lockTarget(null);

        Main.LOG.info("HudController");
    }

    public void lockTarget(Geometry target) {
        this.target = target;
        if(null == target) {
            projectGunSight(settings.getWidth() / 2, screenHeight / 2);
        }
    }

    public void update(float tpf) {
        if(null != target) {
            // Set starting position
            camNode.setLocalTranslation(cam.getLocation());
            camNode.setLocalRotation(cam.getRotation());

            // Look at enemy
            targetNode.lookAt(target.getWorldTranslation(), cam.getUp());
            float[] a = targetNode.getLocalRotation().toAngles(null);

            // Limit yaw
            if(a[1] > cam.getFrustumRight()) {
                a[1] = cam.getFrustumRight();
            } else if(a[1] < cam.getFrustumLeft()) {
                a[1] = cam.getFrustumLeft();
            }

            // Limit pitch
            if(a[0] > cam.getFrustumTop()) {
                a[0] = cam.getFrustumTop();
            } else if(a[0] < cam.getFrustumBottom()) {
                a[0] = cam.getFrustumBottom();
            }

            // TODO: left and right side of the screen is correct, top and bottom not.
            // TODO: if we are exactly backwards or upright on Y axis, crosshair is blinking in two positions, super twinposition :)
            targetNode.setLocalRotation(new Quaternion().fromAngles(a));

            // Move towards enemy slightly, less Z = more shaking less twinposition, more Z = no shaking more twinposition
            targetNode.setLocalTranslation(targetNode.getLocalRotation().mult(new Vector3f(0f, 0f, 0.5f)));

            cam.getScreenCoordinates(targetNode.getWorldTranslation(), enemyScreenCoords);
            projectGunSight(enemyScreenCoords.x, enemyScreenCoords.y);
        }
    }

    protected void projectGunSight(float x, float y) {
        if(null != gunSight) {
            gunSight.setConstraintX(SizeValue.px((int)x - gunSightHalfWidth));
            gunSight.setConstraintY(SizeValue.px(screenHeight - (int)y - gunSightHalfHeight));
            gunSight.getParent().layoutElements();
        }
    }
}