array transform

array_transform.php

<?php

$mailFolders = [
    'INBOX',
    'INBOX.childfolder',
    'INBOX.childfolder.subchildfolder',
    'INBOX.sent',
    'INBOX.draft'
    ];

$explodedfolders = array_map(function($folder){
    return explode($delimiter='.',$folder);
},$mailFolders);
    
//do some array / collection magic here to get the wanted result
    
    
$result = [
    
    [
        'name'=>'INBOX',
        'path'=>'INBOX',
        'children'=>[
                [
                'name'=>'childfolder',
                'path'=>'INBOX.childfolder',
                'children'=>
                    [
                        [
                            'name'=>'subchildfolder',
                            'path'=>'INBOX.childfolder.subchildfolder',
                            'children'=>[]
                        ]
                    ]
                ],
                [
                'name'=>'sent',
                'path'=>'INBOX.sent',
                'children'=>[],
                ],
                [
                'name'=>'draft',
                'path'=>'INBOX.draft',
                'children'=>[],
                ]
            ]
        ]
    ]
    
?>