sub2api/backend/internal/service/usage_log_helpers.go

package service

import "strings"

func optionalTrimmedStringPtr(raw string) *string {
	trimmed := strings.TrimSpace(raw)
	if trimmed == "" {
		return nil
	}
	return &trimmed
}

// optionalNonEqualStringPtr returns a pointer to value if it is non-empty and
// differs from compare; otherwise nil. Used to store upstream_model only when
// it differs from the requested model.
func optionalNonEqualStringPtr(value, compare string) *string {
	if value == "" || value == compare {
		return nil
	}
	return &value
}

func forwardResultBillingModel(requestedModel, upstreamModel string) string {
	if trimmed := strings.TrimSpace(requestedModel); trimmed != "" {
		return trimmed
	}
	return strings.TrimSpace(upstreamModel)
}