src/entities/Enemy.js

import * as THREE from "three";

export class Enemy {
  constructor(hp, speed, reward, pathPoints, scene) {
    this.hp = hp;
    this.maxHp = hp;
    // Keep original speed as baseSpeed; speed becomes derived
    this.baseSpeed = speed;
    this.reward = reward;
    this.currentSeg = 0;
    this.pathPoints = pathPoints;
    this.scene = scene;
    this.position = pathPoints[0].clone();
    this.target = pathPoints[1].clone();

    // Slow status (non-stacking, refreshes on re-hit)
    this.slowMult = 1.0; // 0.6 means 40% slow
    this.slowRemaining = 0.0; // seconds remaining

    // Mesh
    const geo = new THREE.ConeGeometry(0.6, 1.6, 6);
    const mat = new THREE.MeshStandardMaterial({
      color: 0xff5555,
      roughness: 0.7,
    });
    const mesh = new THREE.Mesh(geo, mat);
    mesh.castShadow = true;
    mesh.position.copy(this.position);
    mesh.rotation.x = Math.PI;

    // Health bar
    const hbBgGeo = new THREE.PlaneGeometry(1.2, 0.15);
    const hbBgMat = new THREE.MeshBasicMaterial({
      color: 0x000000,
      side: THREE.DoubleSide,
      depthWrite: false,
      depthTest: false, // ensure bar not occluded by ground
      transparent: true,
      opacity: 0.8,
    });
    const hbBg = new THREE.Mesh(hbBgGeo, hbBgMat);
    // Lift the bar higher so it's clearly above the enemy and ground
    // Keep it centered in local Z; we'll face it to camera each frame
    hbBg.position.set(0, 2.0, 0.0);
    // Remove fixed -90deg pitch; use camera-facing billboard instead
    hbBg.rotation.set(0, 0, 0);
    // Billboard: always face the active camera
    hbBg.onBeforeRender = (renderer, scene, camera) => {
      hbBg.quaternion.copy(camera.quaternion);
    };

    const hbGeo = new THREE.PlaneGeometry(1.2, 0.15);
    const hbMat = new THREE.MeshBasicMaterial({
      color: 0x00ff00,
      side: THREE.DoubleSide,
      depthWrite: false,
      depthTest: false, // ensure bar not occluded by ground
      transparent: true,
      opacity: 0.95,
    });
    const hb = new THREE.Mesh(hbGeo, hbMat);
    // Slight offset to avoid z-fighting with bg
    hb.position.set(0, 0.002, 0);
    hbBg.add(hb);
    mesh.add(hbBg);

    // Ensure bars render above the enemy and ground
    mesh.renderOrder = 1;
    hbBg.renderOrder = 2000;
    hb.renderOrder = 2001;

    this.mesh = mesh;
    this.hbBg = hbBg;
    this.hb = hb;

    // For validation: briefly show bars at spawn so we can confirm visibility.
    // This will be overridden as soon as takeDamage() runs or update() enforces state.
    this.hbBg.visible = true;

    scene.add(mesh);
  }

  takeDamage(dmg) {
    this.hp -= dmg;
    this.hp = Math.max(this.hp, 0);
    const ratio = Math.max(0, Math.min(1, this.hp / this.maxHp));
    this.hb.scale.x = ratio;
    this.hb.position.x = -0.6 * (1 - ratio) + 0; // anchor left

    // Show bar only when not at full health and still alive
    this.hbBg.visible = this.hp > 0 && this.hp < this.maxHp;
  }

  applySlow(mult, duration) {
    // Non-stacking: overwrite multiplier and refresh duration
    this.slowMult = mult;
    this.slowRemaining = duration;
  }

  isDead() {
    return this.hp <= 0;
  }

  update(dt) {
    // Tick slow timer
    if (this.slowRemaining > 0) {
      this.slowRemaining -= dt;
      if (this.slowRemaining <= 0) {
        this.slowRemaining = 0;
        this.slowMult = 1.0;
      }
    }

    const toTarget = new THREE.Vector3().subVectors(this.target, this.position);
    const dist = toTarget.length();
    const epsilon = 0.01;

    if (dist < epsilon) {
      // Advance to next waypoint
      this.currentSeg++;
      if (this.currentSeg >= this.pathPoints.length - 1) {
        // Reached end
        return "end";
      }
      this.position.copy(this.target);
      this.target = this.pathPoints[this.currentSeg + 1].clone();
    } else {
      toTarget.normalize();
      const effectiveSpeed =
        this.baseSpeed * (this.slowRemaining > 0 ? this.slowMult : 1.0);
      this.position.addScaledVector(toTarget, effectiveSpeed * dt);
    }

    this.mesh.position.copy(this.position);

    // Keep health bar visibility consistent (in case hp changes elsewhere)
    if (this.hbBg) {
      // Only show when damaged; if you don't see bars, they will appear after first damage.
      this.hbBg.visible = this.hp > 0 && this.hp < this.maxHp;
    }

    // Face movement direction
    if (toTarget.lengthSq() > 0.0001) {
      const angle = Math.atan2(
        this.target.x - this.position.x,
        this.target.z - this.position.z
      );
      this.mesh.rotation.y = angle;
    }

    return "ok";
  }

  destroy() {
    this.scene.remove(this.mesh);
  }
}