// allow decorating function promise function call
// before/after execution, or in case of error
type DecoratedSlot = 'before' | 'success' | 'error'
type DecoratedFunction = {
  (...args: any): any
  before?: (...args: any) => any
  success?: (...args: any) => any
  error?: (...args: any) => any
  original?: (...args: any) => any
}
export function decorate<
  Target extends Object,
  Method extends keyof Target,
  Slot extends DecoratedSlot,
  Func = Target[Method] extends (...args: any) => any ? Target[Method] : any,
  Param = Func extends (...args: any) => any ? Parameters<Func> : never,
  Return = Func extends (...args: any) => any ? Awaited<ReturnType<Func>> : never,
  Callback = Slot extends 'before'
    ? (this: Target, ...args: Param[]) => any
    : Slot extends 'success'
    ? (this: Target, arg: Return) => any
    : (this: Target, error: Error) => any
>(target: Target, type: Slot, method: Method, callback: Callback) {
  const original = target[method] as unknown as DecoratedFunction
  if (!original.original) {
    const decorated: DecoratedFunction = async function (this: Target, ...args: Param[]) {
      try {
        await decorated.before?.apply(this, args)
        const result = await original.apply(this, args)
        await decorated.success?.call(this, result)
        return result
      } catch (e) {
        if (decorated.error) {
          await decorated.error.call(this, e)
        } else {
          throw e
        }
      }
    }
    decorated.original = original
    Object.defineProperty(target, method, {
      value: decorated,
      writable: false,
      enumerable: false
    })
  }
  const decorated = target[method] as unknown as DecoratedFunction
  if (typeof callback == 'function') decorated[type] = callback as unknown as (...args: any) => any
}