import { System } from '../core/System.js';
import { Palette } from '../core/Palette.js';
import { SystemName, ComponentType, VFXType } from '../core/Constants.js';

export class VFXSystem extends System {
  constructor() {
    super(SystemName.VFX);
    this.requiredComponents = [];
    this.priority = 40;
    this.particles = [];
  }

  process(deltaTime, _entities) {
    const playerController = this.engine.systems.find(s => s.name === SystemName.PLAYER_CONTROLLER);
    const player = playerController ? playerController.getPlayerEntity() : null;
    const playerPos = player ? player.getComponent(ComponentType.POSITION) : null;

    for (let i = this.particles.length - 1; i >= 0; i--) {
      const p = this.particles[i];

      // Update lifetime
      p.lifetime -= deltaTime;
      if (p.lifetime <= 0) {
        this.particles.splice(i, 1);
        continue;
      }

      // Behavior logic
      if (p.type === VFXType.ABSORPTION && playerPos) {
        // Attract to player
        const dx = playerPos.x - p.x;
        const dy = playerPos.y - p.y;
        const dist = Math.sqrt(dx * dx + dy * dy);

        if (dist > 5) {
          p.vx += (dx / dist) * 800 * deltaTime;
          p.vy += (dy / dist) * 800 * deltaTime;
          // Add some drag to make it smooth
          p.vx *= 0.95;
          p.vy *= 0.95;
        } else {
          // Arrived
          this.particles.splice(i, 1);
          continue;
        }
      } else {
        // Basic drag for impact particles
        p.vx *= 0.9;
        p.vy *= 0.9;
      }

      // Update position
      p.x += p.vx * deltaTime;
      p.y += p.vy * deltaTime;
    }
  }

  createImpact(x, y, color = Palette.WHITE, angle = null) {
    const count = 8;
    for (let i = 0; i < count; i++) {
      let vx, vy;
      if (angle !== null) {
        // Splash in the direction of hit + some spread
        const spread = (Math.random() - 0.5) * 2;
        const speed = 50 + Math.random() * 150;
        vx = Math.cos(angle + spread) * speed;
        vy = Math.sin(angle + spread) * speed;
      } else {
        vx = (Math.random() - 0.5) * 150;
        vy = (Math.random() - 0.5) * 150;
      }

      this.particles.push({
        x,
        y,
        vx,
        vy,
        lifetime: 0.2 + Math.random() * 0.3,
        size: 1 + Math.random() * 2,
        color: color,
        type: VFXType.IMPACT
      });
    }
  }

  createAbsorption(x, y, color = Palette.CYAN) {
    for (let i = 0; i < 12; i++) {
      // Start with a small explosion then attract
      this.particles.push({
        x,
        y,
        vx: (Math.random() - 0.5) * 100,
        vy: (Math.random() - 0.5) * 100,
        lifetime: 1.5,
        size: 2,
        color: color,
        type: VFXType.ABSORPTION
      });
    }
  }

  getParticles() {
    return this.particles;
  }
}