effect_chain_example.ts

async function getAccessToken() {
  return Effect.runPromise(
    fetchFresh<{ access_token: string }>(
      null,
      'https://accounts.spotify.com/api/token',
      {
        method: 'POST',
        headers: {
          Authorization: `Basic ${Buffer.from(
            `${process.env.SPOTIFY_CLIENT_ID}:${process.env.SPOTIFY_CLIENT_SECRET}`
          ).toString('base64')}`,
          'Content-Type': 'application/x-www-form-urlencoded',
        },
        body: new URLSearchParams({
          grant_type: 'refresh_token',
          refresh_token: String(process.env.SPOTIFY_REFRESH_TOKEN),
        }),
      }
    )
  )
}

export async function getCurrentTrack() {
  const { access_token } = await getAccessToken()
  const program = fetchFresh<{ item: ISong }>(
    null,
    'https://api.spotify.com/v1/me/player/currently-playing',
    {
      headers: {
        Authorization: `Bearer ${access_token}`,
      },
    }
  ).pipe(
    Effect.map(({ item }) => item),
    Effect.orElseSucceed(() => null)
  )

  return Effect.runPromise(program)
}
      
export default async function Page() {
  const currentTrack = await getCurrentTrack()

  if (!currentTrack) {
    return <></>
  }
      
  return JSON.stringify(currentTrack)
}