import { System } from '../core/System.ts';
import { SystemName } from '../core/Constants.ts';
import type { Entity } from '../core/Entity.ts';

export interface SkillEffect {
  lifetime: number;
  time: number;
  type?: string;
  x?: number;
  y?: number;
  angle?: number;
  range?: number;
  coneAngle?: number;
  caster?: Entity;
  startX?: number;
  startY?: number;
  speed?: number;
  onUpdate?: (deltaTime: number) => void;
  onComplete?: () => void;
}

/**
 * System responsible for tracking and updating temporary active skill effects like fire breath or pounce trails.
 */
export class SkillEffectSystem extends System {
  activeEffects: SkillEffect[];

  constructor() {
    super(SystemName.SKILL_EFFECT);
    this.requiredComponents = [];
    this.priority = 50;
    this.activeEffects = [];
  }

  /**
   * Update all active effects, removing them when their lifetime expires.
   * @param deltaTime - Time elapsed since last frame in seconds
   * @param _entities - Filtered entities
   */
  process(deltaTime: number, _entities: Entity[]): void {
    for (let i = this.activeEffects.length - 1; i >= 0; i--) {
      const effect = this.activeEffects[i];
      effect.lifetime -= deltaTime;
      effect.time += deltaTime;

      if (effect.onUpdate) {
        effect.onUpdate(deltaTime);
      }

      if (effect.lifetime <= 0) {
        if (effect.onComplete) {
          effect.onComplete();
        }
        this.activeEffects.splice(i, 1);
      }
    }
  }

  /**
   * Add a new visual skill effect to the system.
   * @param effect - The effect data object
   */
  addEffect(effect: SkillEffect): void {
    this.activeEffects.push(effect);
  }

  /**
   * Get the list of currently active skill effects.
   * @returns Array of active effects
   */
  getEffects(): SkillEffect[] {
    return this.activeEffects;
  }
}