// Package ports defines the storage-agnostic boundaries used by the user
// service.
package ports

import (
	"errors"
	"fmt"
)

var (
	// ErrNotFound reports that a requested source-of-truth record does not
	// exist in the dependency behind the port.
	ErrNotFound = errors.New("ports: record not found")

	// ErrConflict reports that a create or update cannot be applied because the
	// dependency state conflicts with the requested mutation.
	ErrConflict = errors.New("ports: conflict")

	// ErrInvalidPageToken reports that a supplied pagination token cannot be
	// decoded or does not match the expected filter set.
	ErrInvalidPageToken = errors.New("ports: invalid page token")
)

var (
	// ErrUserNameConflict reports that a mutation specifically failed because
	// the auto-generated `user_name` lookup is already owned by another user.
	// The sentinel still matches ErrConflict via errors.Is so callers can
	// preserve the stable public conflict semantics while collecting more
	// precise observability.
	ErrUserNameConflict = fmt.Errorf("%w: user name conflict", ErrConflict)
)