<?php
/**
 * @package     Joomla.Plugin
 * @subpackage  Fields.Media
 *
 * @copyright   (C) 2017 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\Form\Form;

/**
 * Fields Media Plugin
 *
 * @since  3.7.0
 */
class PlgFieldsMedia extends \Joomla\Component\Fields\Administrator\Plugin\FieldsPlugin
{
    /**
     * Transforms the field into a DOM XML element and appends it as a child on the given parent.
     *
     * @param   stdClass    $field   The field.
     * @param   DOMElement  $parent  The field node parent.
     * @param   Form        $form    The form.
     *
     * @return  DOMElement
     *
     * @since   4.0.0
     */
    public function onCustomFieldsPrepareDom($field, DOMElement $parent, Form $form)
    {
        $fieldNode = parent::onCustomFieldsPrepareDom($field, $parent, $form);

        if (!$fieldNode)
        {
            return $fieldNode;
        }

        $fieldNode->setAttribute('type', 'accessiblemedia');

        if (Factory::getApplication()->getIdentity()->authorise('core.create', 'com_media'))
        {
            $fieldNode->setAttribute('disabled', 'false');
        }

        return $fieldNode;
    }

    /**
     * Before prepares the field value.
     *
     * @param   string     $context  The context.
     * @param   \stdclass  $item     The item.
     * @param   \stdclass  $field    The field.
     *
     * @return  void
     *
     * @since   4.0.0
     */
    public function onCustomFieldsBeforePrepareField($context, $item, $field)
    {
        // Check if the field should be processed by us
        if (!$this->isTypeSupported($field->type))
        {
            return;
        }

        // Check if the field value is an old (string) value
        $field->value = $this->checkValue($field->value);
    }

    /**
     * Before prepares the field value.
     *
     * @param   string  $value  The value to check.
     *
     * @return  array  The checked value
     *
     * @since   4.0.0
     */
    private function checkValue($value)
    {
        json_decode($value);

        if (json_last_error() === JSON_ERROR_NONE)
        {
            return (array) json_decode($value, true);
        }

        return array('imagefile' => $value, 'alt_text' => '');
    }
}