package localization

// EntityDescriptor describes an entity type and its handler
// Uses type erasure to store handlers of different concrete types
type EntityDescriptor struct {
	Type      string
	Fields    []string
	Handler   any // Type-erased handler - will be cast to specific type when used
	TableName string
	IDField   string
}

// EntityRegistry holds all registered entity descriptors
var EntityRegistry = make(map[string]*EntityDescriptor)


// RegisterEntity registers a new entity type with its handler
func RegisterEntity(descriptor *EntityDescriptor) {
	EntityRegistry[descriptor.Type] = descriptor
}

// GetEntityDescriptor returns the descriptor for a given entity type
func GetEntityDescriptor(entityType string) (*EntityDescriptor, bool) {
	desc, exists := EntityRegistry[entityType]
	return desc, exists
}

// GetAllEntityTypes returns all registered entity types
func GetAllEntityTypes() []string {
	types := make([]string, 0, len(EntityRegistry))
	for entityType := range EntityRegistry {
		types = append(types, entityType)
	}
	return types
}

// GetEntityTypesForFilter filters entity types based on the filter string
func GetEntityTypesForFilter(entityTypeFilter string) []string {
	switch entityTypeFilter {
	case "all":
		return GetAllEntityTypes()
	case "site", "sites", "building", "buildings":
		return []string{"site"}
	case "heritage_title", "title", "titles":
		return []string{"heritage_title"}
	case "heritage_timeline_item", "timeline", "timeline_item", "item":
		return []string{"heritage_timeline_item"}
	case "heritage_source", "source", "sources":
		return []string{"heritage_source"}
	case "organization", "organizations", "org", "orgs":
		return []string{"organization"}
	case "geographical_feature", "geographical_features", "geo", "geofeature":
		return []string{"geographical_feature"}
	case "product", "products":
		return []string{"product"}
	default:
		return []string{entityTypeFilter}
	}
}

// GetFieldsForEntityType returns the localizable fields for an entity type
func GetFieldsForEntityType(entityType string) []string {
	if desc, exists := GetEntityDescriptor(entityType); exists {
		return desc.Fields
	}
	return []string{}
}