import { getEntityDef } from './constants.js';

/**
 * A world entity: enemy or pickup. Holds a stub state machine good enough to
 * validate sprites + shooting now. Full enemy AI (patrol/chase/attack) plugs
 * into `update()` and the `state` transitions later.
 */
export class Entity {
  constructor(spawn) {
    this.x = spawn.x;
    this.y = spawn.y;
    this.type = spawn.type;
    this.def =
      getEntityDef(spawn.type) ??
      { type: spawn.type, name: spawn.type, color: 0xff00ff, isEnemy: false, health: 0 };
    this.health = this.def.health;
    this.state = 'idle'; // 'idle' | 'hurt' | 'dead' | 'collected'
    /** Ms remaining in a transient state (e.g. the hurt flinch flash). */
    this.stateTimer = 0;
  }

  get isEnemy() {
    return this.def.isEnemy;
  }

  /** Still rendered and interactable? Dead enemies and collected items aren't. */
  get active() {
    return this.state !== 'dead' && this.state !== 'collected';
  }

  /** Stub billboard color, brightened briefly while flinching from a hit. */
  get renderColor() {
    if (this.state === 'hurt') return 0xffffff;
    return this.def.color;
  }

  /** Apply damage (enemies only). Returns true if this shot killed it. */
  damage(amount) {
    if (!this.isEnemy || !this.active) return false;
    this.health -= amount;
    if (this.health <= 0) {
      this.state = 'dead';
      return true;
    }
    this.state = 'hurt';
    this.stateTimer = 120;
    return false;
  }

  collect() {
    if (!this.isEnemy) this.state = 'collected';
  }

  update(deltaMs) {
    if (this.stateTimer > 0) {
      this.stateTimer -= deltaMs;
      if (this.stateTimer <= 0 && this.state === 'hurt') {
        this.state = 'idle';
      }
    }
    // TODO: enemy AI (patrol/chase/attack/pathfinding) hooks in here.
  }
}