initial commit

src/i18n.ts

@@ -0,0 +1,58 @@
+import { en } from "./locales/en";
+
+type NestedStrings = { [key: string]: string | NestedStrings };
+export type Translations = NestedStrings;
+
+function getByPath(obj: Record<string, unknown>, path: string): string | undefined {
+  const parts = path.split(".");
+  let current: unknown = obj;
+  for (const part of parts) {
+    if (current == null || typeof current !== "object") return undefined;
+    current = (current as Record<string, unknown>)[part];
+  }
+  return typeof current === "string" ? current : undefined;
+}
+
+function interpolate(template: string, params: Record<string, string | number>): string {
+  return template.replace(/\{(\w+)\}/g, (_, key: string) => {
+    return key in params ? String(params[key]) : `{${key}}`;
+  });
+}
+
+const cache = new Map<string, Translations>();
+
+export async function loadTranslations(
+  lang: string,
+  kv?: { get<T>(key: string, type: "json"): Promise<T | null> },
+): Promise<Translations> {
+  if (lang === "en") return en;
+
+  const cached = cache.get(lang);
+  if (cached) return cached;
+
+  if (!kv) return en;
+
+  try {
+    const stored = await kv.get<Partial<Translations>>(`i18n:${lang}`, "json");
+    if (stored) {
+      const merged = { ...en, ...stored } as Translations;
+      cache.set(lang, merged);
+      return merged;
+    }
+  } catch {
+    // KV read failed, fall back to EN
+  }
+
+  return en;
+}
+
+export function t(
+  key: string,
+  params?: Record<string, string | number>,
+  lang?: string | null,
+  translations?: Translations,
+): string {
+  const dict = translations ?? en;
+  const raw = getByPath(dict as Record<string, unknown>, key) ?? getByPath(en as Record<string, unknown>, key) ?? key;
+  return params ? interpolate(raw, params) : raw;
+}