/**
 * Synology SSO 로그인 시작
 * GET /api/auth/synology
 * 
 * Synology SSO Server OAuth 2.0 인증 페이지로 리다이렉트
 */
export default defineEventHandler(async (event) => {
  const config = useRuntimeConfig()
  
  if (!config.synologyServerUrl || !config.synologyClientId) {
    throw createError({ 
      statusCode: 500, 
      message: 'Synology SSO가 설정되지 않았습니다.' 
    })
  }
  
  // Synology SSO Server OAuth 인증 URL
  const authUrl = new URL(`${config.synologyServerUrl}/webman/sso/SSOOauth.cgi`)
  authUrl.searchParams.set('response_type', 'code')
  authUrl.searchParams.set('client_id', config.synologyClientId)
  authUrl.searchParams.set('redirect_uri', config.synologyRedirectUri)
  authUrl.searchParams.set('scope', 'user_id')
  authUrl.searchParams.set('state', crypto.randomUUID())
  
  return sendRedirect(event, authUrl.toString())
})