import { EventHandler } from './types'

export type EventTarget = Element | Record<string, unknown>

export interface HandlerObject {
  guid: number
  type: string
  originType: string
  handler: EventHandler<any, any>
  data?: any
  selector?: string
  namespace?: string
}

export interface Data {
  handler?: EventHandler<any, any>
  events: {
    [type: string]: {
      handlers: HandlerObject[]
      delegateCount: number
    }
  }
}

const cache: WeakMap<EventTarget, Data> = new WeakMap()

export function ensure(target: EventTarget) {
  if (!cache.has(target)) {
    cache.set(target, { events: Object.create(null) })
  }
  return cache.get(target)!
}

export function get(target: EventTarget) {
  return cache.get(target)
}

export function remove(target: EventTarget) {
  return cache.delete(target)
}