import {compose} from '@avocado/core';
import {EventEmitter, Property} from '@avocado/mixins';

const decorate = compose(
  EventEmitter,
  Property('frequency', {
    default: 0,
  }),
);

class TickerBase {

  constructor(frequency = 0) {
    this.remainder = 0;
    this.frequency = frequency;
  }

  remaining() {
    return 1 - this.remainder / this.frequency;
  }

  reset() {
    this.remainder = 0;
  }

  tick(elapsed) {
    if (0 === this.frequency) {
      return;
    }
    this.remainder += elapsed;
    if (this.remainder >= this.frequency) {
      const ticks = Math.floor(this.remainder / this.frequency);
      if (ticks > 0) {
        this.remainder -= ticks * this.frequency;
        for (let i = 0; i < ticks; ++i) {
          this.emit('tick', this.frequency);
        }
      }
    }
  }

}

export class Ticker extends decorate(TickerBase) {}