import {
  createAuth0Client,
  Auth0Client,
  GetTokenSilentlyOptions,
  IdToken,
  LogoutOptions,
  RedirectLoginOptions,
  User
} from '@auth0/auth0-spa-js'
import { Ref, ref } from 'vue'

/** Define a default action to perform after authentication */
const DEFAULT_REDIRECT_CALLBACK = (_: any) =>
  window.history.replaceState({}, document.title, window.location.pathname)

interface Client {
  loading: Ref<boolean>
  isAuthenticated: Ref<boolean>
  user: Ref<User | undefined>
  auth0Client?: Promise<Auth0Client>
  error: Ref
  handleRedirectCallback: () => Promise<void>
  loginWithRedirect: (o: RedirectLoginOptions) => Promise<void>
  getIdTokenClaims: () => Promise<void | IdToken | undefined>
  getTokenSilently: (o: GetTokenSilentlyOptions) => Promise<string | void>
  logout: (o: LogoutOptions) => Promise<void>
}

let instance: Client

const params = (new URL(window.location.href)).searchParams
const domain = params.get('domain') || 'unbound.eu.auth0.com'

export const useAuth = (onRedirectCallback: (appState?: any) => void = DEFAULT_REDIRECT_CALLBACK) => {
  if (instance) {
    return instance
  }
  const options = {
    domain,
    clientId: 'orQfnvCPUR5C3mJkKoiWLQHOVQsBn60e',
    authorizationParams: {
      audience: 'http://dancefinder.unbound.se',
      redirect_uri: window.location.origin
    }
  }

  instance = {
    loading: ref(true),
    isAuthenticated: ref(false),
    user: ref(undefined),
    auth0Client: undefined,
    error: ref(null),
    /** Handles the callback when logging in using a redirect */
    handleRedirectCallback: () => {
      instance.loading.value = true
      return instance.auth0Client!.then(client => client.handleRedirectCallback())
        .then(() => {
          return instance.auth0Client?.then(client => client.getUser())
            .then((user) => {
              instance.user.value = user
              instance.isAuthenticated.value = true
              instance.error.value = null
            }
            )
        })
        .catch((e) => {
          instance.error.value = e
        })
        .finally(() => {
          instance.loading.value = false
        })
    },
    /** Authenticates the user using the redirect method */
    loginWithRedirect: (o: RedirectLoginOptions) => {
      return instance.auth0Client!.then(client => client.loginWithRedirect(o))
        .catch((e) => {
          instance.error.value = e
        })
    },
    /** Returns all the claims present in the ID token */
    getIdTokenClaims: () => {
      return instance.auth0Client!.then(client => client.getIdTokenClaims())
    },
    /** Returns the access token. If the token is invalid or missing, a new one is retrieved */
    getTokenSilently: (o: GetTokenSilentlyOptions) => {
      return instance.auth0Client!.then((client) => {
        return client.getTokenSilently(o).catch((e) => {
          instance.error.value = e
        })
      })
    },
    /** Logs the user out and removes their session on the authorization server */
    logout: (o: LogoutOptions) => {
      return instance.auth0Client!.then(client => client.logout(o))
    }
  }

  const fetchUser = () => {
    return instance.auth0Client!.then(client => client.isAuthenticated())
      .then((a) => {
        instance.auth0Client?.then(client => client.getUser()
          .then((u) => {
            instance.isAuthenticated.value = a
            instance.user.value = u
            instance.error.value = null
          }))
      })
  }
  // Create a new instance of the SDK client using members of the given options object
  instance.auth0Client = createAuth0Client(options)
  instance.auth0Client
    .then((client) => {
      instance.loading.value = true
      // If the user is returning to the app after authentication..
      if (
        window.location.search.includes('state=') && (
          window.location.search.includes('code=') ||
          window.location.search.includes('error=')
        )
      ) {
        // handle the redirect and retrieve tokens
        return client.handleRedirectCallback()
          .then((result) => {
            // Notify subscribers that the redirect callback has happened, passing the appState
            // (useful for retrieving any pre-authentication state)
            onRedirectCallback(result.appState)
            // Initialize our internal authentication state
            return fetchUser()
          })
      } else {
        return fetchUser()
      }
    })
    .catch((e) => {
      instance.error.value = e
    })
    .finally(() => {
      instance.loading.value = false
    })
  return instance
}