// ESM type definitions for ngraph.events
// Project: https://github.com/anvaka/ngraph.events
// Definitions by: Tobias Kopelke <https://github.com/lordnox>

// define keys that are allowed as event names
export type EventKey = string | number | symbol
// define basic function that is allowed for event listeners
export type EventCallback = (...args: any[]) => void

// defined additional event properties that will be added by eventify
export interface EventedType {
  on: (eventName: EventKey, callback: EventCallback, ctx?: any) => this
  off: (eventName?: EventKey, callback?: EventCallback) => this
  fire: (eventName: EventKey, ...args: any[]) => this
}

// extend generic object type as Generic but remove the on, off, fire properties
export default function eventify<Type extends {}>(subject: Type & {
  on?: never
  off?: never
  fire?: never
}): EventedType & Type