if some checkboxes are 'checked' then check javascript

<!--
if all checkboxes are not 'checkecd' then check all
if some are 'checked' then check all
if all are 'checked' then uncheck all
-->

const btn = document.querySelector('button');
        btn.addEventListener('click',()=>{
            const allboxes = document.querySelectorAll('input[type="checkbox"]');
            allboxes.forEach(box => {
                if(!box.checked){
                    box.checked = true;
                } else {
                    box.checked = false;
                }
            })
        })

<button>select all</button>
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">
    <input type="checkbox">

my code is not working as desire if all checkboxes are not 'checkecd' then check all if some are 'checked' then check all if all are 'checked' then uncheck all