<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_fields
 *
 * @copyright   (C) 2019 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\Component\Fields\Administrator\Field;

\defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\Form\Field\ListField;
use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Language\Text;
use Joomla\Component\Fields\Administrator\Helper\FieldsHelper;

/**
 * Fields Subfields. Represents a list field with the options being all possible
 * custom field types, except the 'subform' custom field type.
 *
 * @since  4.0.0
 */
class SubfieldsField extends ListField
{
	/**
	 * The name of this Field type.
	 *
	 * @var string
	 *
	 * @since 4.0.0
	 */
	public $type = 'Subfields';

	/**
	 * Configuration option for this field type to could filter the displayed custom field instances
	 * by a given context. Default value empty string. If given empty string, displays all custom fields.
	 *
	 * @var string
	 *
	 * @since 4.0.0
	 */
	protected $context = '';

	/**
	 * Array to do a fast in-memory caching of all custom field items. Used to not bother the
	 * FieldsHelper with a call every time this field is being rendered.
	 *
	 * @var array
	 *
	 * @since 4.0.0
	 */
	protected static $customFieldsCache = array();

	/**
	 * Method to get the field options.
	 *
	 * @return  array  The field option objects.
	 *
	 * @since   4.0.0
	 */
	protected function getOptions()
	{
		$options = parent::getOptions();

		// Check whether we have a result for this context yet
		if (!isset(static::$customFieldsCache[$this->context]))
		{
			static::$customFieldsCache[$this->context] = FieldsHelper::getFields($this->context);
		}

		// Iterate over the custom fields for this context
		foreach (static::$customFieldsCache[$this->context] as $customField)
		{
			// Skip our own subform type. We won't have subform in subform.
			if ($customField->type == 'subform')
			{
				continue;
			}

			$options[] = HTMLHelper::_(
				'select.option',
				$customField->id,
				($customField->title . ' (' . $customField->type . ')')
			);
		}

		// Sorting the fields based on the text which is displayed
		usort(
			$options,
			function ($a, $b)
			{
				return strcmp($a->text, $b->text);
			}
		);

		if (count($options) == 0)
		{
			Factory::getApplication()->enqueueMessage(Text::_('COM_FIELDS_NO_FIELDS_TO_CREATE_SUBFORM_FIELD_WARNING'), 'warning');
		}

		return $options;
	}

	/**
	 * Method to attach a JForm object to the field.
	 *
	 * @param   \SimpleXMLElement  $element  The SimpleXMLElement object representing the `<field>` tag for the form field object.
	 * @param   mixed              $value    The form field value to validate.
	 * @param   string             $group    The field name group control value. This acts as an array container for the field.
	 *                                       For example if the field has name="foo" and the group value is set to "bar" then the
	 *                                       full field name would end up being "bar[foo]".
	 *
	 * @return  boolean  True on success.
	 *
	 * @since   4.0.0
	 */
	public function setup(\SimpleXMLElement $element, $value, $group = null)
	{
		$return = parent::setup($element, $value, $group);

		if ($return)
		{
			$this->context = (string) $this->element['context'];
		}

		return $return;
	}
}
