<?php

namespace SilverStripe\CMS\Model;

use SilverStripe\ORM\DataExtension;
use SilverStripe\Security\Member;

/**
 * Plug-ins for additional functionality in your SiteTree classes.
 *
 * @template T of SiteTree
 * @extends DataExtension<T>
 */
abstract class SiteTreeExtension extends DataExtension
{

    /**
     * Hook called before the page's {@link Versioned::publishSingle()} action is completed
     *
     * @param SiteTree &$original The current Live SiteTree record prior to publish
     */
    protected function onBeforePublish(&$original)
    {
    }

    /**
     * Hook called after the page's {@link Versioned::publishSingle()} action is completed
     *
     * @param SiteTree &$original The current Live SiteTree record prior to publish
     */
    protected function onAfterPublish(&$original)
    {
    }

    /**
     * Hook called before the page's {@link Versioned::doUnpublish()} action is completed
     */
    protected function onBeforeUnpublish()
    {
    }


    /**
     * Hook called after the page's {@link SiteTree::doUnpublish()} action is completed
     */
    protected function onAfterUnpublish()
    {
    }

    /**
     * Hook called to determine if a user may add children to this SiteTree object
     *
     * @see SiteTree::canAddChildren()
     *
     * @param Member $member The member to check permission against, or the currently
     * logged in user
     * @return boolean|null Return false to deny rights, or null to yield to default
     */
    public function canAddChildren($member)
    {
    }

    /**
     * Hook called to determine if a user may publish this SiteTree object
     *
     * @see SiteTree::canPublish()
     *
     * @param Member $member The member to check permission against, or the currently
     * logged in user
     * @return boolean|null Return false to deny rights, or null to yield to default
     */
    public function canPublish($member)
    {
    }

    /**
     * Hook called to modify the $base url of this page, with a given $action,
     * before {@link SiteTree::RelativeLink()} calls {@link Controller::join_links()}
     * on the $base and $action
     *
     * @param string &$link The URL of this page relative to siteroot including
     * the action
     * @param string $base The URL of this page relative to siteroot, not including
     * the action
     * @param string|boolean $action The action or subpage called on this page.
     * (Legacy support) If this is true, then do not reduce the 'home' urlsegment
     * to an empty link
     */
    public function updateRelativeLink(&$link, $base, $action)
    {
    }
}