export default function smartClone<T extends object>(obj: any, clonedObjects = new WeakMap()) : T {
  if (obj === null || typeof obj !== 'object') {
    return obj
  }

  if (clonedObjects.has(obj)) {
    return clonedObjects.get(obj)
  }

  const constructorMap: Map<DateConstructor | RegExpConstructor | ArrayConstructor, (obj: any) => any> = new Map([
    [Date, (obj: Date) => new Date(obj.getTime())],
    [RegExp, (obj: RegExp) => new RegExp(obj)],
    [Array, (obj: any[]) => obj.map((item) => smartClone(item, clonedObjects))],
  ] as Iterable<[DateConstructor | RegExpConstructor | ArrayConstructor, (obj: any) => any]>)

  const objConstructor = obj.constructor
  const cloneConstructor = constructorMap.get(objConstructor)

  if (cloneConstructor) {
    const clone = cloneConstructor(obj)
    clonedObjects.set(obj, clone)
    return clone
  }

  const proto = Object.getPrototypeOf(obj)
  const clone = Object.create(proto)

  clonedObjects.set(obj, clone)

  Object.keys(obj).forEach((key) => {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      clone[key] = smartClone(obj[key], clonedObjects)
    }
  })

  return clone
}