package usecase

import (
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/promptkit/internal/capacity"
)

// CapacityError identifies bounded admission rejected for one selected backend.
type CapacityError struct {
	BackendID string
}

func (e *CapacityError) Error() string {
	if e == nil || strings.TrimSpace(e.BackendID) == "" {
		return capacity.ErrCapacityExceeded.Error()
	}
	return fmt.Sprintf("backend %q admission: %v", e.BackendID, capacity.ErrCapacityExceeded)
}

func (e *CapacityError) Unwrap() error {
	return capacity.ErrCapacityExceeded
}