export default defineNuxtRouteMiddleware(async (to) => {
  // Skip auth for SSR
  if (import.meta.server) return;

  // Check if auth is required (default true unless explicitly set to false)
  const isAuthRequired = to.meta.auth !== false;
  
  if (!isAuthRequired) {
    console.log('[MIDDLEWARE] Auth not required for route:', to.path);
    return;
  }

  // Skip auth check if we're already on the login page to prevent redirect loops
  if (to.path === '/login' || to.path.startsWith('/auth')) {
    return;
  }

  console.log('[MIDDLEWARE] Checking authentication for route:', to.path);

  // Use a cached auth state to avoid excessive API calls
  const nuxtApp = useNuxtApp();
  const cacheKey = 'auth:session:cache';
  const cacheExpiry = 5 * 60 * 1000; // 5 minutes cache (increased from 30 seconds)
  
  // Check if we have a cached session
  const cachedSession = nuxtApp.payload.data?.[cacheKey];
  const now = Date.now();
  
  if (cachedSession && cachedSession.timestamp && (now - cachedSession.timestamp) < cacheExpiry) {
    console.log('[MIDDLEWARE] Using cached session');
    if (cachedSession.authenticated && cachedSession.user) {
      // Store auth state for components
      if (!nuxtApp.payload.data) {
        nuxtApp.payload.data = {};
      }
      nuxtApp.payload.data.authState = {
        user: cachedSession.user,
        authenticated: cachedSession.authenticated,
        groups: cachedSession.groups || []
      };
      return;
    }
    return navigateTo('/login');
  }

  try {
    // Check Keycloak authentication via session API with timeout and retries
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 10000); // 10 second timeout (increased from 5)
    
    const sessionData = await $fetch('/api/auth/session', {
      signal: controller.signal,
      retry: 2, // Increased retry count
      retryDelay: 1000, // Increased retry delay
      onRetry: ({ retries }: { retries: number }) => {
        console.log(`[MIDDLEWARE] Retrying auth check (attempt ${retries + 1})`)
      }
    }) as any;
    
    clearTimeout(timeout);
    
    // Cache the session data
    if (!nuxtApp.payload.data) {
      nuxtApp.payload.data = {};
    }
    
    nuxtApp.payload.data[cacheKey] = {
      ...sessionData,
      timestamp: now
    };
    
    // Store auth state for components
    nuxtApp.payload.data.authState = {
      user: sessionData.user,
      authenticated: sessionData.authenticated,
      groups: sessionData.groups || []
    };
    
    console.log('[MIDDLEWARE] Session check result:', {
      authenticated: sessionData.authenticated,
      hasUser: !!sessionData.user,
      userId: sessionData.user?.id,
      groups: sessionData.groups || []
    });

    if (sessionData.authenticated && sessionData.user) {
      console.log('[MIDDLEWARE] User authenticated, allowing access');
      
      // Check for any auth errors from authorization middleware
      if (nuxtApp.payload.authError) {
        const toast = useToast();
        toast.error(String(nuxtApp.payload.authError));
        delete nuxtApp.payload.authError;
      }
      
      return;
    }

    console.log('[MIDDLEWARE] No valid authentication found, redirecting to login');
    return navigateTo('/login');
    
  } catch (error: any) {
    console.error('[MIDDLEWARE] Auth check failed:', error);
    
    // If it's a network error or timeout, check if we have a recent cached session
    if (error.name === 'AbortError' || error.code === 'ECONNREFUSED' || error.code === 'ETIMEDOUT') {
      console.log('[MIDDLEWARE] Network error, checking for recent cache');
      const recentCache = nuxtApp.payload.data?.[cacheKey];
      if (recentCache && recentCache.timestamp && (now - recentCache.timestamp) < 30 * 60 * 1000) { // 30 minutes grace period
        console.log('[MIDDLEWARE] Using recent cache despite network error (age:', Math.round((now - recentCache.timestamp) / 1000), 'seconds)');
        if (recentCache.authenticated && recentCache.user) {
          // Store auth state for components
          if (!nuxtApp.payload.data) {
            nuxtApp.payload.data = {};
          }
          nuxtApp.payload.data.authState = {
            user: recentCache.user,
            authenticated: recentCache.authenticated,
            groups: recentCache.groups || []
          };
          
          // Show a warning toast if cache is older than 10 minutes
          if ((now - recentCache.timestamp) > 10 * 60 * 1000) {
            const toast = useToast();
            toast.warning('Network connectivity issue - using cached authentication');
          }
          
          return;
        }
      }
    }
    
    return navigateTo('/login');
  }
});