import { System } from 'detect-collisions'
import { EventEmitter } from 'node:events'

export default class Game {
  entities = []
  tickRate = 30
  currentTick = 0

  #eventEmitter = new EventEmitter()
  #system = new System()
  #tickBudget = Math.floor(1000 / this.tickRate)

  get eventEmitter() { return this.#eventEmitter }
  get system() { return this.#system }
  get tickBudget() { return this.#tickBudget }

  spawn_entity(entity) {
    this.entities.push(entity)
    this.#system.insert(entity.collider)
    entity.game = this
  }

  async start() {
    const start = performance.now()
    await this.update()
    setTimeout(() => this.start(), Math.max(0, this.#tickBudget - (performance.now() - start)))
  }

  async update() {
    Promise.allSettled(this.entities.map((e) => e.update()))
    this.currentTick++
    this.eventEmitter.emit('tick')
  }
}