import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';

export function middleware(request: NextRequest) {
    const pathname = request.nextUrl.pathname;

    // Check if the pathname already has a locale
    const pathnameHasLocale = /^\/(?:en|zh-TW|zh-CN)(?:\/|$)/.test(pathname);

    // If it doesn't have a locale and it's not a static file or API route
    if (
        !pathnameHasLocale &&
        !pathname.startsWith('/_next') &&
        !pathname.startsWith('/api') &&
        !pathname.includes('.')
    ) {
        // Default to zh-CN locale
        const url = request.nextUrl.clone();
        url.pathname = `/zh-CN${pathname}`;
        return NextResponse.redirect(url);
    }

    return NextResponse.next();
}

export const config = {
    matcher: [
        // Skip all internal paths (_next)
        '/((?!_next/static|_next/image|favicon.ico).*)',
    ],
};