import { createDep, Dep } from './dep'
import { toReactive } from './reactive'
import { activeEffect, track, trackEffects } from './effect'

export interface Ref<T = any> {
  value: T
}

export function ref(value?: unknown) {
  return createRef(value, false)
}
function createRef(rawValue: unknown, shallow: boolean) {
  if (isRef(rawValue)) {
    return rawValue
  }
  return new RefImpl(rawValue, shallow)
}
class RefImpl<T> {
  private _value: T
  public dep?: Dep = undefined
  public readonly __v_isRef = true
  constructor(
    value: T,
    public readonly __v_isShallow: boolean
  ) {
    this._value = __v_isShallow ? value : toReactive(value)
  }
  get value() {
    trackRefValue(this)
    return this._value
  }
  set value(newValue) {}
}
export function trackRefValue(ref) {
  if (activeEffect) {
    trackEffects(ref.dep || (ref.dep = createDep()))
  }
}
//是否为ref
export function isRef(r: any): r is Ref {
  return !!(r && r.__v_isRef === true)
}