import {compose} from '@avocado/core';
import {Trait} from '@avocado/entity';
import {Property} from '@avocado/mixins';
import {Ticker} from '@avocado/timing';

const decorate = compose(
)

export class Emitter extends decorate(Trait) {

  initialize() {
    this.emitters = {};
    this.ticker = new Ticker(1 / 10);
    this.ticker.on('tick', (elapsed) => {
      this.updateFrequency();
      for (const key in this.emitters) {
        const emitter = this.emitters[key];
        emitter.tick(elapsed);
      }
    });
  }

  static addEmitter(emitter) {
    if (!this._emitters) {
      this._emitters = [];
    }
    this._emitters.push(emitter);
  }

  static particleCount() {
    let particleCount = 0;
    if (!this._emitters) {
      return particleCount;
    }
    for (let i = 0; i < this._emitters.length; i++) {
      const emitter = this._emitters[i];
      particleCount += emitter.particleCount;
    }
    return particleCount;
  }

  static removeEmitter(emitter) {
    const index = this._emitters.indexOf(emitter);
    if (-1 === index) {
      return;
    }
    this._emitters.splice(index, 1);
  }

  updateFrequency() {
    const particleCount = this.constructor.particleCount();
    const updatesPerSecond = Math.max(15, (60 - (particleCount / 10)));
    this.ticker.frequency = 1 / updatesPerSecond;
  }

  hooks() {
    return {

      afterDestructionTickers: () => {
        return (elapsed) => {
          for (const key in this.emitters) {
            const emitter = this.emitters[key];
            this.ticker.tick(elapsed);
            if (!emitter.hasParticles()) {
              emitter.destroy();
              delete this.emitters[key];
            }
          }
          return 0 === Object.keys(this.emitters).length;
        };
      },

    }
  }

  methods() {
    return {

      addEmitter: (key, emitter) => {
        this.emitters[key] = emitter;
        this.constructor.addEmitter(emitter);
      },

      addEmitterRenderer: (key, renderer) => {
        if (!this.emitters[key]) {
          return;
        }
        this.emitters[key].addRenderer(renderer);
      },

      emitParticle: (key, ...args) => {
        if (!this.emitters[key]) {
          return;
        }
        this.emitters[key].emit(...args);
      },

    }
  }

  renderTick(elapsed) {
    this.ticker.tick(elapsed);
  }

}