import { createServerClient } from '@supabase/ssr';
import { NextRequest, NextResponse } from 'next/server';
import {
  VIEW_TENANT_COOKIE,
  VIEW_TENANT_NAME_COOKIE,
  VIEW_TENANT_SLUG_COOKIE,
  clearedViewTenantCookieOpts,
  isAgencyRole,
  userRole,
} from '@/lib/agency';

function withSecurityHeaders(res: NextResponse, path?: string) {
  res.headers.set('X-Frame-Options', 'DENY');
  res.headers.set('X-Content-Type-Options', 'nosniff');
  res.headers.set('Referrer-Policy', 'strict-origin-when-cross-origin');
  if (!path?.startsWith('/legal')) {
    res.headers.set('X-Robots-Tag', 'noindex, nofollow');
  }
  res.headers.set(
    'Permissions-Policy',
    'camera=(), microphone=(), geolocation=()'
  );
  if (process.env.NODE_ENV === 'production') {
    res.headers.set(
      'Strict-Transport-Security',
      'max-age=63072000; includeSubDomains; preload'
    );
  }
  return res;
}

export async function middleware(req: NextRequest) {
  let res = NextResponse.next({
    request: { headers: req.headers },
  });

  // Public Supabase URL only — Docker-internal Kong rewrite made getUser() fail
  // after login (cookie set, middleware treats user as logged out → stuck verifying).
  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() {
          return req.cookies.getAll();
        },
        setAll(cookiesToSet: { name: string; value: string; options?: Record<string, unknown> }[]) {
          cookiesToSet.forEach(({ name, value }) => req.cookies.set(name, value));
          res = NextResponse.next({
            request: { headers: req.headers },
          });
          cookiesToSet.forEach(({ name, value, options }) =>
            res.cookies.set(name, value, options)
          );
        },
      },
    }
  );

  // Prefer local session from cookie. getUser() revalidates via Auth network and
  // fails in this Edge runtime when Kong/hairpin is broken → endless login loop.
  const {
    data: { session },
  } = await supabase.auth.getSession();
  const user = session?.user ?? null;

  const url = req.nextUrl.clone();
  const path = url.pathname;

  const apiKeyHeader =
    req.headers.get('x-api-key') ||
    req.headers.get('authorization')?.replace(/^Bearer\s+/i, '');
  const isApiKeyAuth =
    Boolean(apiKeyHeader) &&
    apiKeyHeader ===
      (process.env.INTEGRATIONS_API_KEY ||
        process.env.N8N_API_KEY ||
        'n8n_sec_4v_9a7d3b2c1f8e4a5d6c7b8a9e0f1a2b3c');

  // Public: login, attribution script, health, inbound webhooks (CRM), cron (Bearer CRON_SECRET), integrations (API Key)
  const isPublic =
    (isApiKeyAuth && path.startsWith('/api/')) ||
    path === '/login' ||
    path === '/api/health' ||
    path.startsWith('/api/webhooks/') ||
    path.startsWith('/api/cron/') ||
    path.startsWith('/api/integrations/') ||
    path === '/_4v_attr.js' ||
    path.startsWith('/_next') ||
    path === '/favicon.ico' ||
    path === '/favicon.png' ||
    path === '/icon.png';

  if (!user && !isPublic && (path === '/' || path.startsWith('/dashboard') || path.startsWith('/api/'))) {
    if (path.startsWith('/api/')) {
      return withSecurityHeaders(
        NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
      );
    }
    const loginUrl = req.nextUrl.clone();
    loginUrl.pathname = '/login';
    if (path.startsWith('/dashboard')) {
      loginUrl.searchParams.set('next', path);
    }
    return withSecurityHeaders(NextResponse.redirect(loginUrl));
  }

  const role = userRole(user);
  const agency = isAgencyRole(role);

  if (user && path === '/login') {
    const dashboardUrl = req.nextUrl.clone();
    dashboardUrl.pathname = agency ? '/dashboard/agencia' : '/dashboard/kpis';
    return withSecurityHeaders(NextResponse.redirect(dashboardUrl));
  }

  if (user && !agency && path.startsWith('/dashboard/agencia')) {
    const forbiddenUrl = req.nextUrl.clone();
    forbiddenUrl.pathname = '/dashboard/kpis';
    return withSecurityHeaders(NextResponse.redirect(forbiddenUrl));
  }

  if (user && !agency && path.startsWith('/api/admin/')) {
    return withSecurityHeaders(
      NextResponse.json(
        {
          error:
            'Forbidden: solo usuarios agencia (admin/team) pueden usar esta acción. Entra con marketing@4ventures.es.',
        },
        { status: 403 }
      )
    );
  }

  let tenantSlug =
    user?.user_metadata?.slug || user?.app_metadata?.slug || '4ventures-hub';
  const hostname = req.headers.get('host') || '';
  const parts = hostname.split('.');

  if (parts.length > 2) {
    const sub = parts[0].toLowerCase();
    if (
      sub !== 'app' &&
      sub !== 'git' &&
      sub !== 'supabase' &&
      sub !== 'n8n' &&
      sub !== 'n8n-agencia' &&
      sub !== 'www'
    ) {
      tenantSlug = sub;
    }
  }

  const queryTenant = url.searchParams.get('tenant');
  if (queryTenant) {
    tenantSlug = queryTenant.toLowerCase();
  } else {
    const cookieTenant = req.cookies.get('4v_tenant')?.value;
    if (cookieTenant && !user?.user_metadata?.slug) {
      tenantSlug = cookieTenant;
    }
  }

  res.headers.set('x-tenant-slug', tenantSlug);
  res.headers.set('x-user-role', role);
  if (user?.email) {
    res.headers.set('x-user-email', user.email);
  }
  res.cookies.set('4v_tenant', tenantSlug, {
    path: '/',
    maxAge: 60 * 60 * 24 * 30,
    sameSite: 'lax',
    secure: process.env.NODE_ENV === 'production',
  });

  // Clientes: no deben conservar cookies de "vista cliente" de una sesión agencia.
  if (user && !agency) {
    const hasView =
      req.cookies.get(VIEW_TENANT_COOKIE)?.value ||
      req.cookies.get(VIEW_TENANT_NAME_COOKIE)?.value;
    if (hasView) {
      const opts = clearedViewTenantCookieOpts(
        process.env.NODE_ENV === 'production'
      );
      res.cookies.set(VIEW_TENANT_COOKIE, '', opts);
      res.cookies.set(VIEW_TENANT_SLUG_COOKIE, '', opts);
      res.cookies.set(VIEW_TENANT_NAME_COOKIE, '', opts);
    }
  }

  return withSecurityHeaders(res);
}

export const config = {
  matcher: [
    '/((?!_next/static|_next/image|favicon.ico|favicon.png|icon.png|_4v_attr.js).*)',
  ],
};