import { defineMiddleware } from "astro:middleware";
import { config, isDev } from "./config.ts";

export const onRequest = isDev && defineMiddleware((context, next) => {
  const { url } = context;

  // Get the locale from the domain
  const host = context.request.headers.get("x-forwarded-host") ||
    context.request.headers.get("host") ||
    url.host;

  // Find which locale this domain corresponds to
  let domainLocale: string | undefined;
  for (const [locale, domain] of Object.entries(config.domains)) {
    const domainHost = new URL(domain as string).host;
    if (host === domainHost) {
      domainLocale = locale;
      break;
    }
  }

  // If we're on a domain-mapped locale and the path doesn't start with the locale prefix,
  // internally rewrite to add the prefix
  if (domainLocale && url.pathname === "/") {
    // Rewrite / to /{locale}/
    return context.rewrite(`/${domainLocale}/`);
  }

  // For other paths without locale prefix, also rewrite
  if (
    domainLocale && !url.pathname.startsWith(`/${domainLocale}/`) &&
    !url.pathname.startsWith(`/${domainLocale}`) &&
    !url.pathname.startsWith("/_")
  ) {
    // Check if the path starts with any other locale
    const startsWithOtherLocale = config.locales.some(
      (l: string) =>
        l !== domainLocale &&
        (url.pathname.startsWith(`/${l}/`) || url.pathname === `/${l}`),
    );

    if (!startsWithOtherLocale) {
      return context.rewrite(`/${domainLocale}${url.pathname}`);
    }
  }

  return next();
});