threejs-test/src/game/EntityFactory.js

import { Transform } from '../components/Transform.js';
import { Velocity } from '../components/Velocity.js';
import { MeshComponent } from '../components/MeshComponent.js';
import { Collidable } from '../components/Collidable.js';
import { Health } from '../components/Health.js';
import { Invincibility } from '../components/Invincibility.js';
import { PlayerTag, CoinTag, ObstacleTag, BoundaryConstrained } from '../components/Tags.js';
import { GameConfig } from './GameConfig.js';

/**
 * EntityFactory - creates pre-configured game entities with appropriate components.
 * Centralizes entity creation logic for consistency.
 * 
 * @typedef {import('../ecs/World.js').EntityId} EntityId
 */
export class EntityFactory {
  /**
   * @param {import('../ecs/World.js').World} world - The ECS world
   * @param {THREE.Scene} scene - The Three.js scene
   */
  constructor(world, scene) {
    /** @type {import('../ecs/World.js').World} */
    this.world = world;
    
    /** @type {THREE.Scene} */
    this.scene = scene;
    
    /** @type {number} Size of the game ground/play area */
    this.groundSize = 30;
  }

  /**
   * Create the player entity
   * @returns {EntityId} The player entity ID
   */
  createPlayer() {
    const entity = this.world.createEntity();

    // Create mesh
    const geometry = new window.THREE.BoxGeometry(1, 1, 1);
    const material = new window.THREE.MeshStandardMaterial({
      color: 0x4169E1,
      metalness: 0.3,
      roughness: 0.4
    });
    const mesh = new window.THREE.Mesh(geometry, material);
    mesh.castShadow = true;
    mesh.receiveShadow = true;
    this.scene.add(mesh);

    // Add components
    this.world.addComponent(entity, new Transform(0, 0.5, 0));
    this.world.addComponent(entity, new Velocity());
    this.world.addComponent(entity, new MeshComponent(mesh));
    this.world.addComponent(entity, new Collidable(0, 'player')); // Player center point (original behavior)
    this.world.addComponent(entity, new Health(100));
    // Invincibility starts inactive until first damage
    this.world.addComponent(entity, new Invincibility(GameConfig.INVINCIBILITY_DURATION, false));
    this.world.addComponent(entity, new PlayerTag());
    this.world.addComponent(entity, new BoundaryConstrained(this.groundSize));

    return entity;
  }

  /**
   * Create a collectible coin entity
   * @param {number} [index=0] - Unique index for animation offset
   * @returns {EntityId} The coin entity ID
   */
  createCoin(index = 0) {
    const entity = this.world.createEntity();

    // Create mesh
    const geometry = new window.THREE.SphereGeometry(0.3, 16, 16);
    const material = new window.THREE.MeshStandardMaterial({
      color: 0xFFD700,
      metalness: 0.8,
      roughness: 0.2,
      emissive: 0xFFD700,
      emissiveIntensity: 0.3
    });
    const mesh = new window.THREE.Mesh(geometry, material);
    mesh.castShadow = true;
    mesh.receiveShadow = true;
    this.scene.add(mesh);

    // Random position
    const x = (Math.random() - 0.5) * (this.groundSize - 4);
    const z = (Math.random() - 0.5) * (this.groundSize - 4);

    // Add components
    this.world.addComponent(entity, new Transform(x, 0.5, z));
    this.world.addComponent(entity, new MeshComponent(mesh));
    this.world.addComponent(entity, new Collidable(0.8, 'coin'));
    this.world.addComponent(entity, new CoinTag(index));

    return entity;
  }

  /**
   * Create an obstacle entity
   * @returns {EntityId} The obstacle entity ID
   */
  createObstacle() {
    const entity = this.world.createEntity();

    // Create mesh
    const geometry = new window.THREE.BoxGeometry(1.5, 2, 1.5);
    const material = new window.THREE.MeshStandardMaterial({
      color: 0xFF4500,
      metalness: 0.3,
      roughness: 0.7
    });
    const mesh = new window.THREE.Mesh(geometry, material);
    mesh.castShadow = true;
    mesh.receiveShadow = true;
    this.scene.add(mesh);

    // Random position (away from center)
    let posX, posZ;
    do {
      posX = (Math.random() - 0.5) * (this.groundSize - 4);
      posZ = (Math.random() - 0.5) * (this.groundSize - 4);
    } while (Math.abs(posX) < 3 && Math.abs(posZ) < 3);

    // Random velocity
    const velocity = new Velocity(
      (Math.random() - 0.5) * 0.05,
      0,
      (Math.random() - 0.5) * 0.05
    );

    // Add components
    this.world.addComponent(entity, new Transform(posX, 1, posZ));
    this.world.addComponent(entity, velocity);
    this.world.addComponent(entity, new MeshComponent(mesh));
    this.world.addComponent(entity, new Collidable(1.5, 'obstacle'));
    this.world.addComponent(entity, new ObstacleTag());
    this.world.addComponent(entity, new BoundaryConstrained(this.groundSize));

    return entity;
  }

  /**
   * Remove entity and its mesh from scene
   * @param {EntityId} entityId - The entity to destroy
   */
  destroyEntity(entityId) {
    // Remove mesh from scene if it exists
    const meshComp = this.world.getComponent(entityId, MeshComponent);
    if (meshComp) {
      this.scene.remove(meshComp.mesh);
      meshComp.mesh.geometry.dispose();
      meshComp.mesh.material.dispose();
    }

    // Remove entity from world
    this.world.removeEntity(entityId);
  }
}