import type {
  ApolloClient,
  ApolloQueryResult,
  FetchResult,
  MutationOptions,
  Observable,
  ObservableQuery,
  OperationVariables,
  QueryOptions,
  SubscriptionOptions,
  WatchQueryOptions,
} from '@apollo/client/core/index.js'
import type { ApolloProvider } from './apollo-provider'
import type {
  VueApolloQueryDefinition,
  VueApolloSubscriptionDefinition,
} from './options'

interface SmartApollo<V> {
  skip: boolean
  refresh: () => void
  start: () => void
  stop: () => void
}

type PickedObservableQuery = Pick<ObservableQuery, 'fetchMore' |
  'subscribeToMore' |
  'refetch' |
  'setVariables' |
  'setOptions' |
  'startPolling' |
  'stopPolling'>

export interface SmartQuery<V> extends SmartApollo<V>, PickedObservableQuery {
  loading: boolean
}

export type SmartSubscription<V> = SmartApollo<V>

interface ClientOptions {
  client?: string
}

interface ApolloClientMethods {
  query: <R = any, TVariables = OperationVariables>(options: QueryOptions<TVariables> & ClientOptions) => Promise<ApolloQueryResult<R>>
  watchQuery: <R = any, TVariables = OperationVariables>(options: WatchQueryOptions<TVariables> & ClientOptions) => ObservableQuery<R, TVariables>
  mutate: <R = any, TVariables = OperationVariables>(options: MutationOptions<R, TVariables> & ClientOptions) => Promise<FetchResult<R>>
  subscribe: <R = any, TVariables = OperationVariables>(options: SubscriptionOptions<TVariables> & ClientOptions) => Observable<FetchResult<R>>
}

export interface DollarApollo<V> extends ApolloClientMethods {
  readonly vm: V
  readonly queries: Record<string, SmartQuery<V>>
  readonly subscriptions: Record<string, SmartSubscription<V>>
  readonly provider: ApolloProvider
  readonly loading: boolean

  // writeonly not yet implemented in TypeScript: https://github.com/Microsoft/TypeScript/issues/21759
  /* writeonly */ skipAllQueries: boolean
  /* writeonly */ skipAllSubscriptions: boolean
  /* writeonly */ skipAll: boolean

  getClient: <R = any>() => ApolloClient<R>

  addSmartQuery: <R = any>(key: string, options: VueApolloQueryDefinition<R>) => SmartQuery<V>
  addSmartSubscription: <R = any>(key: string, options: VueApolloSubscriptionDefinition) => SmartSubscription<V>
}