import Vue from 'vue'

export type AsyncComputedGetter<T> = () => Promise<T>

export interface IAsyncComputedValue<T> {
  default?: T | (() => T)
  get: AsyncComputedGetter<T>
  watch?: string[] | (() => void)
  shouldUpdate?: () => boolean
  lazy?: boolean
}

export interface AsyncComputedObject {
  [K: string]: AsyncComputedGetter<any> | IAsyncComputedValue<any>
}

export interface IASyncComputedState {
  state: 'updating' | 'success' | 'error'
  updating: boolean
  success: boolean
  error: boolean
  exception: Error | null
  update: () => void
}

declare module 'vue/types/options' {
  interface ComponentOptions<V extends Vue> {
    asyncComputed?: AsyncComputedObject
  }
}

declare module 'vue/types/vue' {
  interface Vue {
    $asyncComputed: {[K: string]: IASyncComputedState}
  }
}