// instantiate a pool outside of your hotpath
const baseURL = 'https://movies-api.example.com'
const pool = new Pool(baseURL)

const server = new ApolloServer({
  typeDefs,
  resolvers,
  dataSources: () => {
    return {
      moviesAPI: new MoviesAPI(baseURL, pool),
    }
  },
})

import { Pool } from 'undici'
import { HTTPDataSource } from '@llc1123/apollo-datasource-http'

const datasource = new (class MoviesAPI extends HTTPDataSource {
  constructor(baseURL: string, pool: Pool) {
    // global client options
    super(baseURL, {
      pool,
      clientOptions: {
        bodyTimeout: 5000,
        headersTimeout: 2000,
      },
      requestOptions: {
        headers: {
          'X-Client': 'client',
        },
      },
    })
  }

  onCacheKeyCalculation(request: Request): string {
    // return different key based on request options
  }

  async onRequest(request: Request): Promise<void> {
    // manipulate request before it is send
    // for example assign a AbortController signal to all requests and abort

    request.signal = this.context.abortController.signal

    setTimeout(() => {
      this.context.abortController.abort()
    }, 3000).unref()
  }

  onResponse<TResult = unknown>(request: Request, response: Response<TResult>): Response<TResult> {
    // manipulate response or handle unsuccessful response in a different way
    return super.onResponse(request, response)
  }

  onError(error: Error, request: Request): void {
    // in case of a request error
    if (error instanceof RequestError) {
      console.log(error.request, error.response)
    }
  }

  async createMovie() {
    return this.post('/movies', {
      body: {
        name: 'Dude Where\'s My Car',
      }
    })
  }

  async getMovie(id) {
    return this.get(`/movies/${id}`, {
      query: {
        a: 1,
      },
      context: {
        tracingName: 'getMovie',
      },
      headers: {
        'X-Foo': 'bar',
      },
    })
  }
})()