CakePHP copy subtree from one parent to another

<?php
// copy a subtree from one parent to another.  only works 5 levels deep
function admin_clone_subtree($source_parent_id, $target_parent_id) {
    // find all pages from the source id
    $source_parent_node = $this->Page->find('first', array('conditions' => array('Page.id' => $source_parent_id))); // find the source parent page
    $pages_to_copy = $this->Page->find('threaded', array('conditions' => array('Page.lft >=' => $source_parent_node['Page']['lft'], 'Page.rght <=' => $source_parent_node['Page']['rght'], 'Page.id <>' => $source_parent_id)));
    $id_map = array();
    $target_parent_node = $this->Page->find('first', array('conditions' => array('Page.id' => $target_parent_id))); // find the target parent page
    foreach ($pages_to_copy as $page) {
        // insert the page as a new page
        $old_id = $page['Page']['id'];
        unset($page['Page']['id']);
        unset($page['Page']['lft']);
        unset($page['Page']['rght']);
        unset($page['Page']['created']);
        unset($page['Page']['modified']);
        $page['Page']['parent_id'] = $target_parent_id; // make it a child of the new root parent
        $this->Page->create();
        $this->Page->save($page);
        $id_map[$old_id] = $this->Page->id;
        foreach ($page['children'] as $page1) {
            // insert the page as a new page
            $old_id = $page1['Page']['id'];
            unset($page1['Page']['id']);
            unset($page1['Page']['lft']);
            unset($page1['Page']['rght']);
            unset($page1['Page']['created']);
            unset($page1['Page']['modified']);
            $page1['Page']['parent_id'] = $id_map[$page1['Page']['parent_id']]; // find the new parent_id
            $this->Page->create();
            $this->Page->save($page1);
            $id_map[$old_id] = $this->Page->id;
            foreach ($page1['children'] as $page2) {
                // insert the page as a new page
                $old_id = $page2['Page']['id'];
                unset($page2['Page']['id']);
                unset($page2['Page']['lft']);
                unset($page2['Page']['rght']);
                unset($page2['Page']['created']);
                unset($page2['Page']['modified']);
                $page2['Page']['parent_id'] = $id_map[$page2['Page']['parent_id']]; // find the new parent_id
                $this->Page->create();
                $this->Page->save($page2);
                $id_map[$old_id] = $this->Page->id;
                foreach ($page2['children'] as $page3) {
                    // insert the page as a new page
                    $old_id = $page3['Page']['id'];
                    unset($page3['Page']['id']);
                    unset($page3['Page']['lft']);
                    unset($page3['Page']['rght']);
                    unset($page3['Page']['created']);
                    unset($page3['Page']['modified']);
                    $page3['Page']['parent_id'] = $id_map[$page3['Page']['parent_id']]; // find the new parent_id
                    $this->Page->create();
                    $this->Page->save($page3);
                    $id_map[$old_id] = $this->Page->id;
                    foreach ($page3['children'] as $page4) {
                        // insert the page as a new page
                        $old_id = $page4['Page']['id'];
                        unset($page4['Page']['id']);
                        unset($page4['Page']['lft']);
                        unset($page4['Page']['rght']);
                        unset($page4['Page']['created']);
                        unset($page4['Page']['modified']);
                        $page4['Page']['parent_id'] = $id_map[$page4['Page']['parent_id']]; // find the new parent_id
                        $this->Page->create();
                        $this->Page->save($page4);
                        $id_map[$old_id] = $this->Page->id;
                    }
                }
            }
        }
    }
    $this->Session->setFlash('Pages cloned successfully', 'success');
    $this->redirect(array('action'=>'index'));
}
?>