Minimal Google OAuth2 Client Library for Deno

import GoogleOAuth2Client from 'https://deno.com/x/google_oauth2_client/mod.ts'

import type { oAuth2Config } from 'https://deno.com/x/google_oauth2_client/mod.ts'

import { getCookies, setCookie } from 'https://deno.land/std/http/cookie.ts'

const CONFIG: oAuth2Config = {
  CLIENT_ID: 'example-client-id',
  CLIENT_SECRET: 'example-client-secret',
  AUTH_ENDPOINT: 'https://accounts.google.com/o/oauth2/v2/auth',
  TOKEN_ENDPOINT: 'https://oauth2.googleapis.com/token',
  REDIRECT_URL: 'https://example.com/auth/callback', // example callback url
  SCOPES: ['https://www.googleapis.com/auth/userinfo.profile'], // example scopes
  REVOKE_TOKEN_ENDPOINT: 'https://oauth2.googleapis.com/revoke'
}

const oAuth2Client = new GoogleOAuth2Client(CONFIG)

function login() {
  const url = oAuth2Client.getRedirectUrl()

  return new Response('REDIRECTING', {
    headers: { Location: url },
    status: 307
  })
}

async function callback({ headers, url }: Headers) {
  const code = new URL(url).searchParams.get('code')!

  const { access_token, expires_in, refresh_token } = await exchangeToken(code)

  const res = Response.json({ message: 'Welcome..' })
  setCookie(res.headers, {
    name: 'access_token',
    value: access_token,
    maxAge: expires_in,
    path: '/',
    httpOnly: true,
    secure: Deno.env.get('MODE') === 'production' ? true : false
  })
}

async function logout({ headers }: Headers) {
  const { access_token } = getCookies(headers)
  await revokeAccessToken(access_token)
}