import ApolloClient, { FetchPolicy } from "apollo-client"
import { HttpLink } from "apollo-link-http"
import { InMemoryCache, NormalizedCacheObject } from "apollo-cache-inmemory"
// import { setContext } from "apollo-link-context"
import ActionCable from "action-cable-react-jwt"
import ActionCableLink from "graphql-ruby-client/dist/subscriptions/ActionCableLink"
import { ApolloLink } from "apollo-link"
import { handleAuthentication, refreshToken } from "utils/oauth"
import { Observable } from "apollo-link"
import { onError } from "apollo-link-error"
import config from "config"

const promiseToObservable = (promise: Promise<any>) =>
  new Observable((subscriber: any) => {
    promise.then(
      value => {
        if (subscriber.closed) return
        subscriber.next(value)
        subscriber.complete()
      },
      error => subscriber.error(error)
    )
  })

const defaultOptions = {
  watchQuery: {
    fetchPolicy: "cache-and-network" as FetchPolicy
  }
}

const getTokens = async () => {
  const token = localStorage.getItem("token")
  const freshToken = localStorage.getItem("refresh_token")
  if (token && freshToken) {
    await refreshToken()
  } else {
    await handleAuthentication()
  }

  const authorization = token ? `Bearer: ${token}` : ""
  return token ? { authorization: authorization } : {}
}

const setTokenForOperation = async (operation: any) => {
  return operation.setContext({
    headers: {
      // eslint-disable-next-line
      ...(await getTokens())
    }
  })
}

const hasSubscriptionOperation = ({ query: { definitions } }: any) => {
  return definitions.some(({ kind, operation }: any) => {
    return kind === "OperationDefinition" && operation === "subscription"
  })
}

const createActionCableLink = () => {
  const token = localStorage.getItem("token")
  console.log('createActionCableLink: ', token)
  const cable = ActionCable.createConsumer("ws://localhost:3004/cable", token)
  return new ActionCableLink({ cable })
}

const createLinkWithToken = () =>
  new ApolloLink(
    (operation, forward) =>
      new Observable(observer => {
        let handle: any
        Promise.resolve(operation)
          .then(setTokenForOperation)
          .then(() => {
            handle = forward(operation).subscribe({
              next: observer.next.bind(observer),
              error: observer.error.bind(observer),
              complete: observer.complete.bind(observer)
            })
          })
          .catch(observer.error.bind(observer))
        return () => {
          if (handle) handle.unsubscribe()
        }
      })
  )

const createErrorLink = () =>
  onError(({ networkError, operation, forward }: any): any => {
    if (networkError) {
      switch (networkError.statusCode) {
        case 401:
          const token = localStorage.getItem("token")
          const freshToken = localStorage.getItem("refresh_token")
          if (token && freshToken) {
            return promiseToObservable(refreshToken()).flatMap(() => forward(operation))
          } else {
            return promiseToObservable(handleAuthentication()).flatMap(() => forward(operation))
          }
        default:
      }
    }
  })

const createHttpLink = (fetch = undefined, uri = config.api.baseUrl) =>
  new HttpLink({
    fetch,
    uri
  })

export const createClient = ({ fetch = undefined, uri = config.api.baseUrl }): ApolloClient<NormalizedCacheObject> => {
  const cache = new InMemoryCache()

  const client = new ApolloClient({
    link: ApolloLink.from([
      createErrorLink(),
      createLinkWithToken(),
      ApolloLink.split(hasSubscriptionOperation, createActionCableLink(), createHttpLink(fetch, uri)),
    ])  ,
    cache,
    defaultOptions
  })

  return client
}

export default createClient