class Selenium::WebDriver::Credential

def as_json(*)
  credential_data = {'credentialId' => Credential.encode(id),
                     'isResidentCredential' => resident_credential?,
                     'rpId' => rp_id,
                     'privateKey' => Credential.encode(private_key),
                     'signCount' => sign_count}
  credential_data['userHandle'] = Credential.encode(user_handle) if user_handle
  credential_data
end

def decode(base64)
  Base64.urlsafe_decode64(base64).unpack('C*')
end

def encode(byte_array)
  Base64.urlsafe_encode64(byte_array&.pack('C*'))
end

def from_json(opts)
  user_handle = opts['userHandle'] ? decode(opts['userHandle']) : nil
  new(id: decode(opts['credentialId']),
      resident_credential: opts['isResidentCredential'],
      rp_id: opts['rpId'],
      private_key: opts['privateKey'],
      sign_count: opts['signCount'],
      user_handle: user_handle)
end

def initialize(id:, resident_credential:, rp_id:, private_key:, **opts)
  @id = id
  @resident_credential = resident_credential
  @rp_id = rp_id
  @user_handle = opts.delete(:user_handle) { nil }
  @private_key = private_key
  @sign_count = opts.delete(:sign_count) { 0 }
  raise ArgumentError, "Invalid arguments: #{opts.keys}" unless opts.empty?
end

def non_resident(**opts)
  Credential.new(resident_credential: false, **opts)
end

def resident(**opts)
  Credential.new(resident_credential: true, **opts)
end