import { 
  createClient, 
  defaultExchanges, 
  dedupExchange, 
  cacheExchange, 
  fetchExchange, 
  errorExchange, 
  subscriptionExchange,
  CombinedError,
  Operation, 
  Exchange
} from 'urql';
import { makeOperation } from '@urql/core';
import { devtoolsExchange } from '@urql/devtools'
import { authExchange } from '@urql/exchange-auth';
import { SubscriptionClient } from 'subscriptions-transport-ws'
import { pipe, tap } from 'wonka'

import { getAuthData, authLogout } from "./auth"
import { GQL_BASE_URL, WS_BASE_URL } from './conf'
import { useNotifyToast } from './composables'

const { toastError } = useNotifyToast();


const subscriptionClient = new SubscriptionClient( WS_BASE_URL, { 
  reconnect: true,
  lazy: true,
  connectionParams: () => {
    const authData = getAuthData();
    return {
      headers: {
        ...(authData?.auth?.token && {
        'x-felicity-user-id': "felicity-user-x",
        'x-felicity-role': "felicity-role-x",
        'Authorization': `Bearer ${authData?.auth?.token}`
      })
      },
    }
  }, 
});


const getAuth = async ({ authState }) => {
  const authData = getAuthData();

  if (!authState) {
    if (authData?.auth?.token) {
      return { token: authData?.auth?.token };
    }
    return null;
  }

  if(authState.token) {
    return { token: authState.token };
  }


  toastError("Faied to get Auth Data. Login");

  authLogout();

  return null;
};

const addAuthToOperation = ({ authState, operation }) => {
  if (!authState || !authState.token) {
    return operation;
  }

  const fetchOptions =
    typeof operation.context.fetchOptions === 'function'
      ? operation.context.fetchOptions()
      : operation.context.fetchOptions || {};

  return makeOperation(operation?.kind, operation, {
    ...operation.context,
    fetchOptions: {
      ...fetchOptions,
      headers: {
        ...fetchOptions.headers,
        Authorization: `Bearer ${authState.token}`,
      },
      credentials: 'include',
    },
  });
};

const didAuthError = (error: any ) => {
  if(!error.graphQLErrors|| error.graphQLErrors.length ===0){
    return error.message == "[Network] Failed to fetch"
  }
  return error.graphQLErrors.some((e: any) => e.extensions?.code === 'FORBIDDEN');
};

const willAuthError = (authState: any) => {
  if (!authState || "/* JWT is expired */") return true;
  return false;
}

const resultInterceptorExchange: Exchange = ({ forward }) => (ops$) => pipe(ops$, forward,
  tap((operationResult) => {}),
);

export const urqlClient = createClient({
  url: GQL_BASE_URL,
   ...(('process.env.DEV') && { exchanges: [devtoolsExchange, ...defaultExchanges] }),
  exchanges: [
    dedupExchange,
    cacheExchange,
    errorExchange({
      onError: (error: CombinedError, operation: Operation) => {
        let isAuthError = false;

        if(!error.graphQLErrors || error.graphQLErrors.length ===0){
          isAuthError = error.message === "[Network] Failed to fetch";
        }else{
          isAuthError = error.graphQLErrors.some(e => e.extensions?.code === 'FORBIDDEN');
        }
        if (isAuthError) {
          toastError("Unknown Network Error Encountered")
          authLogout();
        }
      },
    }),
    authExchange({
      addAuthToOperation,
      willAuthError,
      didAuthError,
      getAuth,
    }),
    resultInterceptorExchange,
    fetchExchange,
    subscriptionExchange({
      forwardSubscription: operation => subscriptionClient.request(operation) as any
    }),
  ],  
  fetchOptions: () => {
    const authData = getAuthData();
    return {
      headers: {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET, POST, PATCH, PUT, DELETE, OPTIONS',
        'Access-Control-Allow-Headers': 'Origin, Content-Type, X-Auth-Token',
        ...(authData?.auth?.token && {
          'x-felicity-user-id': "felicity-user-x",
          'x-felicity-role': "felicity-role-x",
          'Authorization': `Bearer ${authData?.auth?.token}`
        }),
      },
    };
  },
});