feat: public API, SEO and existing surfaces

internal/domain/site/sitePublicURL.go

@@ -0,0 +1,22 @@
+package site
+
+import "strings"
+
+func (s Site) PublicURL(lang string, slug string) *string {
+	if s.PublicURLPattern == nil || lang == "" {
+		return nil
+	}
+	filled := strings.NewReplacer(LangPlaceholder, lang, SlugPlaceholder, slug).Replace(*s.PublicURLPattern)
+	return &filled
+}
+
+func (s Site) ArticleURL(lang string, slug string) (string, bool) {
+	if localized := s.PublicURL(lang, slug); localized != nil {
+		return *localized, true
+	}
+	return s.LegacyURL(slug), false
+}
+
+func (s Site) LegacyURL(slug string) string {
+	return s.BaseURL + "/" + slug
+}