import SAT from 'sat'
import SATX from './satx.js'
import { Vector2 } from 'three'

export default class Projectile {
  id = crypto.randomUUID()
  after = null
  speed = 1000
  radius = 5
  owner = null
  onCollide = null
  visualHeight = 50

  #position = new Vector2()
  #dest = null
  #game = null
  
  get collider() {
    return new SAT.Circle(new SAT.Vector(this.x, this.y), this.radius)
  }

  constructor(...options) {
    Object.entries(options).forEach((value, key) => this[key] = value)
  }

  get game() { return this.#game }
  get position() { return this.#position }
  get x() { return this.position.x }
  get y() { return this.position.y }
  set game(value) { this.#game = value }
  set x(value) { this.position.x = value }
  set y(value) { this.position.y = value }
  set destination(value) { this.#dest = value }

  checkCollisions() {
    (this.game?.entities ?? []).filter((e) => e.id != this.id).forEach((e) => {
      if (e.id == this.owner) { return }

      if (SATX.collideObject(this.collider, e.collider)) {
        this.onCollide(this, e)
      }
    })
  }

  checkIfArrived() {
    if (!this.#position.equals(this.#dest)) { return }

    if (this.after != null) {
      this.after(this)
    }

    this.despawn()
  }

  despawn() {
    this.game?.despawn(this)
  }

  state() {
    return {
      ...this,
      position: {
        x: this.x,
        y: this.y,
      },
    }
  }

  takeStep() {
    const speed = (this.speed / (this.game?.tickBudget ?? 1000))
    const destination = this.#dest
    const difference = destination.clone().sub(this.position)
    const distance = difference.length()
    const direction = difference.clone().normalize()
    const stepTaken = this.position.clone().add(direction.multiplyScalar(speed))
    const position = distance <= speed ? destination : stepTaken

    this.position.copy(position)
  }

  update() {
    this.takeStep()
    if (this.onCollide != null) { this.checkCollisions() }
    this.checkIfArrived()
  }
}