feat: add core i18n runtime and catalogs

lib/i18n/format.ts

@@ -0,0 +1,72 @@
+import type { TranslationValues } from "./types";
+
+const PLURAL_PATTERN = /\{(\w+),\s*plural,\s*one\s*\{([^{}]*)\}\s*other\s*\{([^{}]*)\}\s*\}/g;
+const VALUE_PATTERN = /\{(\w+)\}/g;
+
+export function interpolateMessage(
+  message: string,
+  values: TranslationValues = {},
+  locale = "tr",
+): string {
+  const pluralized = message.replace(
+    PLURAL_PATTERN,
+    (_match, key: string, one: string, other: string) => {
+      const count = Number(values[key] ?? 0);
+      const category = new Intl.PluralRules(toIntlLocale(locale)).select(count);
+      const template = category === "one" ? one : other;
+      return template.replaceAll("#", String(count));
+    },
+  );
+
+  return pluralized.replace(VALUE_PATTERN, (_match, key: string) => {
+    const value = values[key];
+    if (value === null || value === undefined) return "";
+    if (value instanceof Date) return formatDate(value, locale);
+    return String(value);
+  });
+}
+
+export function formatDate(
+  value: Date | string | number,
+  locale: string,
+  options: Intl.DateTimeFormatOptions = { day: "2-digit", month: "long", year: "numeric" },
+): string {
+  return new Intl.DateTimeFormat(toIntlLocale(locale), options).format(new Date(value));
+}
+
+export function formatDateTime(
+  value: Date | string | number,
+  locale: string,
+  options: Intl.DateTimeFormatOptions = {
+    day: "2-digit",
+    month: "long",
+    year: "numeric",
+    hour: "2-digit",
+    minute: "2-digit",
+  },
+): string {
+  return new Intl.DateTimeFormat(toIntlLocale(locale), options).format(new Date(value));
+}
+
+export function formatNumber(
+  value: number,
+  locale: string,
+  options?: Intl.NumberFormatOptions,
+): string {
+  return new Intl.NumberFormat(toIntlLocale(locale), options).format(value);
+}
+
+export function formatMoney(
+  amountMinor: number,
+  currency: string,
+  locale: string,
+): string {
+  return new Intl.NumberFormat(toIntlLocale(locale), {
+    style: "currency",
+    currency,
+  }).format(amountMinor / 100);
+}
+
+export function toIntlLocale(locale: string): string {
+  return locale === "tr" ? "tr-TR" : locale === "en" ? "en-US" : locale;
+}