import { NextResponse } from "next/server";
import type { NextRequest } from "next/server";
import { resolvePublicPath, toInternalPath, toPublicFromInternal, type Locale } from "./i18n/routes";

function localeFromPath(pathname: string): Locale {
  if (pathname === "/en" || pathname.startsWith("/en/")) return "en";
  const resolved = resolvePublicPath(pathname);
  if (resolved) return resolved.locale;
  if (pathname === "/de" || pathname.startsWith("/de/")) return "de";
  return "de";
}

function withLocale(response: NextResponse, pathname: string) {
  response.headers.set("x-locale", localeFromPath(pathname));
  return response;
}

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

  if (pathname === "/de" || pathname.startsWith("/de/")) {
    const publicPath = toPublicFromInternal(pathname);
    if (publicPath && publicPath !== pathname) {
      const url = request.nextUrl.clone();
      url.pathname = publicPath;
      return withLocale(NextResponse.redirect(url), publicPath);
    }
  }

  const internal = toInternalPath(pathname);
  if (internal && internal !== pathname) {
    const url = request.nextUrl.clone();
    url.pathname = internal;
    return withLocale(NextResponse.rewrite(url), pathname);
  }

  return withLocale(NextResponse.next(), pathname);
}

export const config = {
  matcher: [
    "/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp|ico|txt|xml)$).*)",
  ],
};