Mobile App Auth
  Logged Out*
    authentication method -> Authentication Method?

  Logged In
    log out -> Logging Out

  Logging Out
    done -> Logged Out
    failed -> Logging Out Error

  Logging Out Error

  Authentication Method?
    password auth? -> Verify User Password
    biometric auth? -> Supports Biometric Authentication?

  Supports Biometric Authentication?
    supports biometric authentication? -> Has Stored Biometric Credentials For Username?
    does not support biometric authentication? -> Verify User Password

  Biometric Authentication
    Has Stored Biometric Credentials For Username?
      has credentials in keychain for username? -> User Selected Biometric Authentication?
      does not have credentials in keychain for username? -> Empty Biometric Credentials For Username

    User Selected Biometric Authentication?
      user selected biometric authentication? -> Biometric Authentication Method Selected
      user chose password authentication? -> Verify User Password

    Biometric Authentication Method Selected
      # via biometric authentication
      log in -> Prompt For Biometric Authentication
      # remove biometric authentication for this username
      reset -> Resetting Biometric Credentials for Username

    Prompt For Biometric Authentication
      credentials are correct? -> Logged In
      credentials are incorrect? -> Saved Biometric Credentials Error

    Saved Biometric Credentials Error
      # try new password
      log in -> Empty Biometric Credentials For Username
      try password authentication -> Password Authentication Selected

    Empty Biometric Credentials For Username
      # attempt authentication
      log in -> Saving Biometric Credentials For Username

    Saving Biometric Credentials For Username
      # attempt authentication
      log in -> Prompt For Biometric Authentication

    Resetting Biometric Credentials for Username
      # deleted
      reset -> Empty Biometric Credentials For Username

  User Password Authentication
    Password Authentication Selected
      login -> Verify User Password
    Verify User Password
      credentials are correct? -> Logged In
      credentials are incorrect? -> Bad Credentials
    Bad Credentials
      reset -> Logged Out