Internationalization Guide

# Internationalization Guide for Google Antigravity

Master i18n in Google Antigravity IDE. This guide covers translations, locale detection, and formatting.

## next-intl Setup

```typescript
// i18n.ts
import { getRequestConfig } from "next-intl/server";

export default getRequestConfig(async ({ locale }) => ({
  messages: (await import(`./messages/${locale}.json`)).default
}));

// messages/en.json
{
  "common": {
    "welcome": "Welcome, {name}!",
    "items": "{count, plural, =0 {No items} =1 {One item} other {# items}}"
  },
  "auth": {
    "login": "Log in",
    "logout": "Log out",
    "signUp": "Sign up"
  }
}
```

## Using Translations

```typescript
"use client";

import { useTranslations } from "next-intl";

export function WelcomeBanner({ userName }: { userName: string }) {
  const t = useTranslations("common");

  return (
    <div>
      <h1>{t("welcome", { name: userName })}</h1>
      <p>{t("items", { count: 5 })}</p>
    </div>
  );
}
```

## Date and Number Formatting

```typescript
import { useFormatter } from "next-intl";

export function ProductPrice({ price, date }: { price: number; date: Date }) {
  const format = useFormatter();

  return (
    <div>
      <span>{format.number(price, { style: "currency", currency: "USD" })}</span>
      <span>{format.dateTime(date, { dateStyle: "medium" })}</span>
      <span>{format.relativeTime(date)}</span>
    </div>
  );
}
```

## Locale Switching

```typescript
"use client";

import { useLocale } from "next-intl";
import { useRouter, usePathname } from "next/navigation";

export function LocaleSwitcher() {
  const locale = useLocale();
  const router = useRouter();
  const pathname = usePathname();

  const switchLocale = (newLocale: string) => {
    router.push(pathname.replace(`/${locale}`, `/${newLocale}`));
  };

  return (
    <select value={locale} onChange={(e) => switchLocale(e.target.value)}>
      <option value="en">English</option>
      <option value="es">Español</option>
      <option value="fr">Français</option>
    </select>
  );
}
```

## Best Practices

1. **Use ICU format** - Handles plurals and formatting
2. **Externalize strings** - No hardcoded text
3. **Test all locales** - Verify translations work

Google Antigravity IDE provides i18n scaffolding.