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

// 🌍 1. Importamos el motor de idiomas
import createIntlMiddleware from 'next-intl/middleware';
import { routing } from './i18n/routing';

// Configuramos el proxy de next-intl
const handleI18nRouting = createIntlMiddleware(routing);

// 🔒 2. Llave de seguridad del CMS
const secretKey = process.env.SESSION_SECRET || "FLUX_SUPER_SECRET_KEY_2026_ARCHITECTURE";
const encodedKey = new TextEncoder().encode(secretKey);

// 🔥 AHORA SE LLAMA "proxy" EN LUGAR DE "middleware" 🔥
export async function proxy(request: NextRequest) {
  const path = request.nextUrl.pathname;
  
  // --------------------------------------------------------
  // ZONA ROJA: CENTRO DE MANDO (Seguridad estricta, sin idiomas)
  // --------------------------------------------------------
  if (path.startsWith('/hq-command')) {
    const isPublicHQRoute = path === '/hq-command/login' || path === '/hq-command/setup';
    const cookie = request.cookies.get('flux_session')?.value;

    // Si intenta entrar al dashboard sin pase
    if (!isPublicHQRoute && !cookie) {
      return NextResponse.redirect(new URL('/hq-command/login', request.url));
    }

    // Verificamos el pase
    if (cookie) {
      try {
        await jwtVerify(cookie, encodedKey);
        // Si tiene pase y está en el login, lo mandamos al dashboard
        if (isPublicHQRoute) {
          return NextResponse.redirect(new URL('/hq-command/dashboard', request.url));
        }
        const authedRes = NextResponse.next();
        authedRes.headers.set('X-Robots-Tag', 'noindex, nofollow');
        return authedRes;
      } catch (error) {
        // Pase falso o expirado
        if (!isPublicHQRoute) {
          return NextResponse.redirect(new URL('/hq-command/login', request.url));
        }
      }
    }
    const hqRes = NextResponse.next();
    hqRes.headers.set('X-Robots-Tag', 'noindex, nofollow');
    return hqRes;
  }

  // --------------------------------------------------------
  // ZONA VERDE: WEB PÚBLICA (Motor de Traducciones i18n)
  // --------------------------------------------------------
  // Si el usuario no va al CMS, le pasamos el control a next-intl
  // para que gestione los prefijos /en/, /it/, /vec/, etc.
  const response = handleI18nRouting(request);

  // Belt-and-suspenders fix for the "redirect to :3000" bug behind Nginx.
  // next-intl can occasionally compose absolute redirect URLs using the
  // container's internal port (PORT=3000 from the Dockerfile) instead of
  // the public-facing host. We sanitise any Location header before sending
  // it back to the browser.
  const location = response.headers.get('Location');
  if (location) {
    const cleaned = sanitizeRedirectLocation(location, request);
    if (cleaned !== location) {
      response.headers.set('Location', cleaned);
    }
  }

  // ── Cache-Control on public pages ────────────────────────────────────
  // Marketing pages (home, applications, news, heritage) are dynamic per
  // request but the rendered HTML is the same for every visitor — no auth
  // gating, no per-user data. So we let Nginx and the browser cache them
  // briefly, falling back to a stale copy for up to 5 minutes while a
  // refresh happens in the background. Result: first hit on a URL renders
  // freshly (~150-300ms), every subsequent hit within 60s comes from cache
  // (<10ms). Big perceived-speed boost without breaking ISR semantics.
  if (isCacheablePublicPath(path) && !hasAuthCookie(request)) {
    response.headers.set(
      "Cache-Control",
      "public, s-maxage=60, stale-while-revalidate=300"
    );
  }

  return response;
}

// Pages we're happy to cache at the edge: locale-prefixed marketing routes.
// /parts is intentionally excluded — it's the auth-gated B2B portal and its
// HTML changes per logged-in user.
function isCacheablePublicPath(path: string): boolean {
  if (path.startsWith("/hq-command")) return false;
  if (path.startsWith("/api")) return false;
  if (path.startsWith("/_next")) return false;
  // Per-locale public pages
  if (/^\/(en|it|vec|es|de)\/parts(\/|$)/.test(path)) return false;
  if (/^\/(en|it|vec|es|de)(\/applications|\/news|\/heritage|\/?$)/.test(path)) return true;
  // Root redirect to /en — also cacheable
  if (path === "/") return true;
  return false;
}

function hasAuthCookie(request: NextRequest): boolean {
  return Boolean(
    request.cookies.get("flux_session")?.value ||
    request.cookies.get("flux_b2b_session")?.value
  );
}

function sanitizeRedirectLocation(location: string, request: NextRequest): string {
  try {
    const forwardedHost =
      request.headers.get('x-forwarded-host') || request.headers.get('host');
    const forwardedProto =
      request.headers.get('x-forwarded-proto') ||
      (request.nextUrl.protocol ? request.nextUrl.protocol.replace(':', '') : 'https');

    // Relative redirect — leave alone.
    if (!/^https?:\/\//i.test(location)) return location;

    const url = new URL(location);
    const internalPorts = new Set(['3000', '80']);
    const isInternalHost = url.hostname === '0.0.0.0' || url.hostname === 'localhost' || url.hostname === 'app';
    const isInternalPort = url.port && internalPorts.has(url.port);

    if (forwardedHost && (isInternalHost || isInternalPort)) {
      const [hostOnly] = forwardedHost.split(':');
      url.hostname = hostOnly;
      url.port = '';
      url.protocol = `${forwardedProto}:`;
      return url.toString();
    }

    // Same host, just a stray internal port — strip it.
    if (url.port === '3000') {
      url.port = '';
      return url.toString();
    }

    return location;
  } catch {
    return location;
  }
}

// --------------------------------------------------------
// OPTIMIZACIÓN EXTREMA DEL MATCHER
// --------------------------------------------------------
export const config = {
  // Coincide con TODAS las rutas de la aplicación EXCEPTO:
  // - /api (nuestras rutas backend)
  // - /_next/static y /_next/image (archivos internos de React/Next)
  // - Archivos estáticos como .jpg, .png, .mp4, .glb, .svg (.*\\..*)
  // IMPORTANTE: Al ignorar los estáticos, las fotos y videos del CMS cargarán rapidísimo.
  matcher: ['/((?!api|_next/static|_next/image|.*\\..*).*)'],
};