import { NextRequest, NextResponse } from 'next/server';

const config = {
  matcher: [
    /*
     * Match all paths except for:
     * 1. /api routes
     * 2. /_next (Next.js internals)
     * 3. /_static (inside /public)
     * 4. all root files inside /public (e.g. /favicon.ico)
     */
    '/((?!api/|_next/|_static/|_vercel|[\\w-]+\\.\\w+).*)',
  ],
};

export default async function middleware(req: NextRequest) {
  const url = req.nextUrl;
  const response = NextResponse.next();

  // Maximum size to prevent cookie chunking - make it even more conservative
  const MAX_COOKIE_SIZE = 3000; // even more conservative limit in bytes
  
  // Function to set all required nextAuth environment variables
  const setNextAuthEnvVars = () => {
    // Set strict cookie size limits
    process.env.NEXTAUTH_COOKIE_SIZE_LIMIT = String(MAX_COOKIE_SIZE);
    
    // Force cookie compression to reduce size
    process.env.NEXTAUTH_COOKIES_CHUNKING = 'false'; // Disable chunking and force smaller cookies
    process.env.NEXTAUTH_COOKIES_CHUNKING_SIZE = String(MAX_COOKIE_SIZE);
    
    // Set secure cookie settings
    process.env.NEXTAUTH_COOKIES_SECURE = 'true';
    process.env.NEXTAUTH_COOKIES_SAMESITE = 'none';
    
    // Disable unnecessary callbacks that might increase cookie size
    process.env.NEXTAUTH_DISABLE_CALLBACK = 'true';
    process.env.NEXTAUTH_DISABLE_JWT_CALLBACK = 'true';
    process.env.NEXTAUTH_JWT_STORE_RAW_TOKEN = 'false';
    
    // Strongly enforce JWT max age
    process.env.NEXTAUTH_JWT_MAX_AGE = String(12 * 60 * 60); // 12 hours in seconds
  };

  // Set environment variables for all routes
  setNextAuthEnvVars();

  // Detect refresh token errors in cookies and clean them up
  const checkForErrorsAndCleanup = () => {
    const cookies = req.cookies;
    const cookieNames = Object.keys(cookies.getAll());
    
    // Check for error param in URL that would indicate token refresh errors
    if (url.pathname.includes('/signin') && url.searchParams.has('error')) {
      // Clean up all auth cookies to ensure a fresh start
      const allAuthCookies = cookieNames.filter(name => 
        name.includes('auth') || 
        name.includes('keycloak') || 
        name.includes('session') ||
        name.includes('KEYCLOAK') ||
        name.includes('KC_')
      );
      
      allAuthCookies.forEach(name => {
        response.cookies.delete(name);
      });
      
      // Special header to indicate a serious error that requires full cleanup
      response.headers.set('X-Auth-Error-Recovery', 'true');
    }
  };
  
  // Check for and clean up error cookies
  checkForErrorsAndCleanup();

  // Special handling for loggedout page to clean up cookies
  if (url.pathname === '/loggedout') {
    // Check if we're preserving SSO or doing a full logout
    const preserveSso = url.searchParams.get('preserveSso') === 'true';
    
    console.log(`Middleware detected logout (preserveSso: ${preserveSso})`);
    
    if (preserveSso) {
      // Only clean up NextAuth cookies but preserve Keycloak SSO cookies
      const nextAuthCookies = [
        'next-auth.session-token', 
        'next-auth.csrf-token', 
        'next-auth.callback-url',
        '__Secure-next-auth.session-token',
        '__Host-next-auth.csrf-token'
      ];
      
      nextAuthCookies.forEach(name => {
        response.cookies.delete(name);
      });
      
      // Also delete any chunked cookies
      const cookieNames = Object.keys(req.cookies.getAll());
      const chunkedCookies = cookieNames.filter(name => /next-auth.*\.\d+$/.test(name));
      chunkedCookies.forEach(name => {
        response.cookies.delete(name);
      });
    } else {
      // Full logout - clear all auth-related cookies
      const authCookies = [
        'next-auth.session-token', 
        'next-auth.csrf-token', 
        'next-auth.callback-url',
        '__Secure-next-auth.session-token',
        '__Host-next-auth.csrf-token',
        'KEYCLOAK_SESSION',
        'KEYCLOAK_IDENTITY',
        'KC_RESTART',
        'JSESSIONID'
      ];
      
      authCookies.forEach(name => {
        response.cookies.delete(name);
      });
      
      // Also delete any chunked cookies
      const cookieNames = Object.keys(req.cookies.getAll());
      const chunkedCookies = cookieNames.filter(name => 
        /next-auth.*\.\d+$/.test(name) || 
        /KEYCLOAK.*/.test(name) || 
        /KC_.*/.test(name)
      );
      chunkedCookies.forEach(name => {
        response.cookies.delete(name);
      });
    }
  }
  
  // For sign-in page, add header if fresh login is requested
  if (url.pathname === '/api/auth/signin' && url.searchParams.get('fresh') === 'true') {
    response.headers.set('X-Auth-Fresh-Login', 'true');
  }

  return response;
}

export { config };