class WebAuthn::AuthenticatorData

def self.deserialize(data)
  read(data)
rescue EOFError
  raise AuthenticatorDataFormatError
end

def aaguid
  raw_aaguid = attested_credential_data.raw_aaguid
  unless raw_aaguid == WebAuthn::AuthenticatorData::AttestedCredentialData::ZEROED_AAGUID
    attested_credential_data.aaguid
  end
end

def attested_credential_data
  @attested_credential_data ||=
    AttestedCredentialData.deserialize(trailing_bytes)
rescue AttestedCredentialDataFormatError
  raise AuthenticatorDataFormatError
end

def attested_credential_data_included?
  flags.attested_credential_data_included == 1
end

def attested_credential_data_length
  if attested_credential_data_included?
    attested_credential_data.length
  else
    0
  end
end

def base_length
  RP_ID_HASH_LENGTH + FLAGS_LENGTH + SIGN_COUNT_LENGTH
end

def credential
  if attested_credential_data_included?
    attested_credential_data.credential
  end
end

def credential_backed_up?
  flags.backup_state == 1
end

def credential_backup_eligible?
  flags.backup_eligibility == 1
end

def data
  to_binary_s
end

def extension_data
  @extension_data ||= CBOR.decode(raw_extension_data)
end

def extension_data_included?
  flags.extension_data_included == 1
end

def extension_data_length
  if extension_data_included?
    raw_extension_data.length
  else
    0
  end
end

def raw_extension_data
  if extension_data_included?
    if attested_credential_data_included?
      trailing_bytes[attested_credential_data.length..-1]
    else
      trailing_bytes.snapshot
    end
  end
end

def user_flagged?
  user_present? || user_verified?
end

def user_present?
  flags.user_present == 1
end

def user_verified?
  flags.user_verified == 1
end

def valid?
  (!attested_credential_data_included? || attested_credential_data.valid?) &&
    (!extension_data_included? || extension_data) &&
    valid_length?
end

def valid_length?
  data_length == base_length + attested_credential_data_length + extension_data_length
end