<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2013 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Form\Field;

use Joomla\CMS\Component\ComponentHelper;
use Joomla\CMS\Factory;
use Joomla\CMS\Helper\TagsHelper;
use Joomla\CMS\Language\Multilanguage;
use Joomla\Database\ParameterType;
use Joomla\Utilities\ArrayHelper;

// phpcs:disable PSR1.Files.SideEffects
\defined('_JEXEC') or die;
// phpcs:enable PSR1.Files.SideEffects

/**
 * List of Tags field.
 *
 * @since  3.1
 */
class TagField extends ListField
{
    /**
     * A flexible tag list that respects access controls
     *
     * @var    string
     * @since  3.1
     */
    public $type = 'Tag';

    /**
     * Flag to work with nested tag field
     *
     * @var    boolean
     * @since  3.1
     */
    public $isNested = null;

    /**
     * com_tags parameters
     *
     * @var    \Joomla\Registry\Registry
     * @since  3.1
     */
    protected $comParams = null;

    /**
     * Name of the layout being used to render the field
     *
     * @var    string
     * @since  4.0.0
     */
    protected $layout = 'joomla.form.field.tag';

    /**
     * Constructor
     *
     * @since  3.1
     */
    public function __construct()
    {
        parent::__construct();

        // Load com_tags config
        $this->comParams = ComponentHelper::getParams('com_tags');
    }

    /**
     * Method to get the field input for a tag field.
     *
     * @return  string  The field input.
     *
     * @since   3.1
     */
    protected function getInput()
    {
        $data = $this->collectLayoutData();

        if (!\is_array($this->value) && !empty($this->value)) {
            if ($this->value instanceof TagsHelper) {
                if (empty($this->value->tags)) {
                    $this->value = [];
                } else {
                    $this->value = $this->value->tags;
                }
            }

            // String in format 2,5,4
            if (\is_string($this->value)) {
                $this->value = explode(',', $this->value);
            }

            // Integer is given
            if (\is_int($this->value)) {
                $this->value = [$this->value];
            }

            $data['value'] = $this->value;
        }

        $data['remoteSearch']  = $this->isRemoteSearch();
        $data['options']       = $this->getOptions();
        $data['isNested']      = $this->isNested();
        $data['allowCustom']   = $this->allowCustom();
        $data['minTermLength'] = (int) $this->comParams->get('min_term_length', 3);

        return $this->getRenderer($this->layout)->render($data);
    }

    /**
     * Method to get a list of tags
     *
     * @return  object[]  The field option objects.
     *
     * @since   3.1
     */
    protected function getOptions()
    {
        $published = (string) $this->element['published'] ?: [0, 1];
        $app       = Factory::getApplication();
        $language  = null;
        $options   = [];

        // This limit is only used with isRemoteSearch
        $prefillLimit   = 30;
        $isRemoteSearch = $this->isRemoteSearch();

        $db    = $this->getDatabase();
        $query = $db->getQuery(true)
            ->select(
                [
                    $db->quoteName('a.id', 'value'),
                    $db->quoteName('a.path'),
                    $db->quoteName('a.title', 'text'),
                    $db->quoteName('a.level'),
                    $db->quoteName('a.published'),
                    $db->quoteName('a.lft'),
                ]
            )
            ->from($db->quoteName('#__tags', 'a'));

        // Limit Options in multilanguage
        if ($app->isClient('site') && Multilanguage::isEnabled()) {
            if (ComponentHelper::getParams('com_tags')->get('tag_list_language_filter') === 'current_language') {
                $language = [$app->getLanguage()->getTag(), '*'];
            }
        } elseif (!empty($this->element['language'])) {
            // Filter language
            if (strpos($this->element['language'], ',') !== false) {
                $language = explode(',', $this->element['language']);
            } else {
                $language = [$this->element['language']];
            }
        }

        if ($language) {
            $query->whereIn($db->quoteName('a.language'), $language, ParameterType::STRING);
        }

        $query->where($db->quoteName('a.lft') . ' > 0');

        // Filter on the published state
        if (is_numeric($published)) {
            $published = (int) $published;
            $query->where($db->quoteName('a.published') . ' = :published')
                ->bind(':published', $published, ParameterType::INTEGER);
        } elseif (\is_array($published)) {
            $published = ArrayHelper::toInteger($published);
            $query->whereIn($db->quoteName('a.published'), $published);
        }

        $query->order($db->quoteName('a.lft') . ' ASC');

        // Preload only active values and 30 most used tags or fill up
        if ($isRemoteSearch) {
            // Load the most $prefillLimit used tags
            $topQuery = $db->getQuery(true)
                ->select($db->quoteName('tag_id'))
                ->from($db->quoteName('#__contentitem_tag_map'))
                ->group($db->quoteName('tag_id'))
                ->order('count(*)')
                ->setLimit($prefillLimit);

            $db->setQuery($topQuery);
            $topIds = $db->loadColumn();

            // Merge the used values into the most used tags
            if (!empty($this->value) && \is_array($this->value)) {
                $topIds = array_unique(array_merge($topIds, $this->value));
            }

            // Set the default limit for the main query
            $query->setLimit($prefillLimit);

            if (!empty($topIds)) {
                // Filter the ids to the most used tags and the selected tags
                $preQuery = clone $query;
                $preQuery->clear('limit')
                    ->whereIn($db->quoteName('a.id'), $topIds);

                $db->setQuery($preQuery);

                try {
                    $options = $db->loadObjectList();
                } catch (\RuntimeException $e) {
                    return [];
                }

                // Limit the main query to the missing amount of tags
                $count        = \count($options);
                $prefillLimit -= $count;
                $query->setLimit($prefillLimit);

                // Exclude the already loaded tags from the main query
                if ($count > 0) {
                    $query->whereNotIn($db->quoteName('a.id'), ArrayHelper::getColumn($options, 'value'));
                }
            }
        }

        // Only execute the query if we need more tags not already loaded by the $preQuery query
        if (!$isRemoteSearch || $prefillLimit > 0) {
            // Get the options.
            $db->setQuery($query);

            try {
                $options = array_merge($options, $db->loadObjectList());
            } catch (\RuntimeException $e) {
                return [];
            }
        }

        // Block the possibility to set a tag as it own parent
        if ($this->form->getName() === 'com_tags.tag') {
            $id   = (int) $this->form->getValue('id', null, 0);

            foreach ($options as $option) {
                if ($option->value == $id) {
                    $option->disable = true;
                }
            }
        }

        // Merge any additional options in the XML definition.
        $options = array_merge(parent::getOptions(), $options);

        // Prepare nested data
        if ($this->isNested()) {
            $this->prepareOptionsNested($options);
        } else {
            $options = TagsHelper::convertPathsToNames($options);
        }

        return $options;
    }

    /**
     * Add "-" before nested tags, depending on level
     *
     * @param   object[]  &$options  Array of tags
     *
     * @return  object[]  The field option objects.
     *
     * @since   3.1
     */
    protected function prepareOptionsNested(&$options)
    {
        if ($options) {
            foreach ($options as &$option) {
                $repeat       = (isset($option->level) && $option->level - 1 >= 0) ? $option->level - 1 : 0;
                $option->text = str_repeat('- ', $repeat) . $option->text;
            }
        }

        return $options;
    }

    /**
     * Determine if the field has to be tagnested
     *
     * @return  boolean
     *
     * @since   3.1
     */
    public function isNested()
    {
        if ($this->isNested === null) {
            // If mode="nested" || ( mode not set & config = nested )
            if (
                isset($this->element['mode']) && (string) $this->element['mode'] === 'nested'
                || !isset($this->element['mode']) && $this->comParams->get('tag_field_ajax_mode', 1) == 0
            ) {
                $this->isNested = true;
            }
        }

        return $this->isNested;
    }

    /**
     * Determines if the field allows or denies custom values
     *
     * @return  boolean
     */
    public function allowCustom()
    {
        if ($this->element['custom'] && \in_array((string) $this->element['custom'], ['0', 'false', 'deny'])) {
            return false;
        }

        return $this->getCurrentUser()->authorise('core.create', 'com_tags');
    }

    /**
     * Check whether need to enable AJAX search
     *
     * @return  boolean
     *
     * @since   4.0.0
     */
    public function isRemoteSearch()
    {
        if ($this->element['remote-search']) {
            return !\in_array((string) $this->element['remote-search'], ['0', 'false', '']);
        }

        return $this->comParams->get('tag_field_ajax_mode', 1) == 1;
    }
}
