@startuml error-handling
!include ../../../pipeline/diagrams/biergarten-weizen-theme.puml
skinparam sequenceMessageAlign center
skinparam maxMessageSize 200

title User Authentication Flow - Error Handling (Global Exception Filter)

participant "API\nController" as API

note over API
  API.Core's GlobalExceptionFilter catches:
  - FluentValidation.ValidationException -> 400 Bad Request\n    {message, errors} (grouped by property)
  - ConflictException -> 409 Conflict
  - NotFoundException -> 404 Not Found
  - UnauthorizedException -> 401 Unauthorized
  - ForbiddenException -> 403 Forbidden
  - Domain.Exceptions.ValidationException -> 400 Bad Request
  - Microsoft.Data.SqlClient.SqlException -> 503 Service Unavailable
  - All others -> 500 Internal Server Error
end note

note over API
  Applies uniformly across every authentication
  endpoint (registration, login, refresh, confirm,
  resend, update-username/email/password/profile,
  delete-account) - see the per-flow diagrams for
  where each exception type is thrown.
end note

@enduml