import { NextRequest, NextResponse } from 'next/server';
import { cookies } from 'next/headers';
import { jwtVerify } from 'jose';

const SESSION_COOKIE_NAME = 'auth_session';

/**
 * Proxy to protect routes with authentication
 * Reusable for other projects - just copy this file
 */
export async function proxy(request: NextRequest) {
  const { pathname } = request.nextUrl;

  // Check if authentication is enabled
  const authEnabled = !!process.env.AUTH_USERS;
  
  // If auth is not enabled, allow all requests
  if (!authEnabled) {
    return NextResponse.next();
  }

  // Public paths that don't require authentication
  const publicPaths = ['/login'];
  const isPublicPath = publicPaths.some(path => pathname.startsWith(path));

  if (isPublicPath) {
    return NextResponse.next();
  }

  // Check for session cookie
  const cookieStore = await cookies();
  const sessionCookie = cookieStore.get(SESSION_COOKIE_NAME);

  if (!sessionCookie) {
    return NextResponse.redirect(new URL('/login', request.url));
  }

  // Verify session token
  try {
    const secretKey = process.env.AUTH_SECRET || 'default-secret-change-in-production';
    const key = new TextEncoder().encode(secretKey);
    
    const { payload } = await jwtVerify(sessionCookie.value, key, {
      algorithms: ['HS256'],
    });

    // Check if session is expired
    if (payload.expiresAt && (payload.expiresAt as number) < Date.now()) {
      const response = NextResponse.redirect(new URL('/login', request.url));
      response.cookies.delete(SESSION_COOKIE_NAME);
      return response;
    }

    return NextResponse.next();
  } catch (error) {
    // Invalid token - redirect to login
    const response = NextResponse.redirect(new URL('/login', request.url));
    response.cookies.delete(SESSION_COOKIE_NAME);
    return response;
  }
}

export const config = {
  matcher: [
    /*
     * Match all request paths except for the ones starting with:
     * - _next/static (static files)
     * - _next/image (image optimization files)
     * - favicon.ico (favicon file)
     * - public folder
     */
    '/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
  ],
};