// Package domain contains pure domain models with no external dependencies.
// These types represent the core business concepts of the service.
package domain

import "errors"

// Domain errors - these are business-level errors that should be translated
// to appropriate HTTP status codes by the handler layer.
var (
	// ErrInvalidTheme indicates an invalid theme value was provided.
	ErrInvalidTheme = errors.New("theme must be one of: light, dark, system")

	// ErrInvalidLanguage indicates an invalid language value was provided.
	ErrInvalidLanguage = errors.New("language must be one of: en, fr, es, de, ja")

	// ErrInvalidDigest indicates an invalid digest frequency was provided.
	ErrInvalidDigest = errors.New("notifications.digest must be one of: none, daily, weekly")
)