IdentitytoolkitV3.rb

require 'google/apis/identitytoolkit_v3'
require 'googleauth'
require 'json'

# Creates user accounts with email and password
class FirebaseAccountManager
  # Konstanten ruhig in die Klassen ziehen, wenn die einen direkten Bezug haben
  SCOPE = [
    'https://www.googleapis.com/auth/firebase',
    'https://www.googleapis.com/auth/identitytoolkit',
    'https://www.googleapis.com/auth/userinfo.email'
  ].join(' ')
  CREDENTIALS_PATH = 'credentials.json'.freeze
  
  attr_accessor :service
 
  # Wenn man keyword arguments mit default values nimmt, dann hast du eine Chance die Werte zu überschreiben
  def initialize(scope: SCOPE, credentials_file: CREDENTIALS_PATH)
    authorizer = Google::Auth::ServiceAccountCredentials.make_creds(
      json_key_io: File.open(credentials_file),
      scope: scope
    )
    @service = Google::Apis::IdentitytoolkitV3::IdentityToolkitService.new
    @service.authorization = authorizer
  end

  # In solchen Situationen finde ich keyword arguments immer besser.
  def create_user(email:, password:, uid:)
    request = Google::Apis::IdentitytoolkitV3::SignupNewUserRequest.new(
      email: email,
      password: password,
      local_id: uid
    )
    @service.signup_new_user(request)
  end

  def get_user(uid)
    request = Google::Apis::IdentitytoolkitV3::GetAccountInfoRequest.new(
      local_id: [uid]
    )
    @service.get_account_info(request)
  end

  def create_if_new(uid, email, password)
    response = get_user(uid)

    # Bie collections (was `users` bestimmt ist) muss man immer aufpassen, ob man `.nil?` oder `.empty?` verwendet.
    return unless response.users.nil?

    create_user(email: email, password: password, uid: uid)
  end
end

manager = FirebaseAccountManager.new

uid = '736651e4-d0cd-4e26-b882-3d27635455bc'
email = 'peter.ullrich6@studitemps.de'
password = 'superSecret123'

response = manager.create_if_new(uid, email, password)

puts JSON.pretty_generate(response)