tools: align locale diagnostics and generate native language names

tools/logging/locale.go

@@ -0,0 +1,43 @@
+package logging
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// WarnMissingTranslations groups missing keys without wrapping long key lists.
+func WarnMissingTranslations(missing map[string][]string) {
+	if message := missingTranslations(missing); message != "" {
+		Warn("Locale", "%s", message)
+	}
+}
+
+func missingTranslations(missing map[string][]string) string {
+	languages := make([]string, 0, len(missing))
+	width := len("Language")
+	for lang, keys := range missing {
+		if len(keys) > 0 {
+			languages = append(languages, lang)
+			width = max(width, len(lang))
+		}
+	}
+	if len(languages) == 0 {
+		return ""
+	}
+	sort.Strings(languages)
+	var message strings.Builder
+	fmt.Fprintf(&message, "Missing translation keys:\n%-*s  %-8s  %s\n", width, "Language", "Fallback", "Key")
+	for _, lang := range languages {
+		keys := append([]string(nil), missing[lang]...)
+		sort.Strings(keys)
+		for i, key := range keys {
+			label, fallback := "", ""
+			if i == 0 {
+				label, fallback = lang, "en-US"
+			}
+			fmt.Fprintf(&message, "%-*s  %-8s  %s\n", width, label, fallback, key)
+		}
+	}
+	return strings.TrimSuffix(message.String(), "\n")
+}