<?php

namespace wcf\data\smiley\category;

use wcf\data\category\AbstractDecoratedCategory;
use wcf\data\ITraversableObject;
use wcf\data\smiley\Smiley;
use wcf\data\smiley\SmileyCache;
use wcf\system\exception\SystemException;
use wcf\system\WCF;

/**
 * Represents a smiley category.
 *
 * @author  Tim Duesterhus, Alexander Ebert
 * @copyright   2001-2019 WoltLab GmbH
 * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 * @package WoltLabSuite\Core\Data\Smiley\Category
 *
 * @method      SmileyCategory[]    getChildCategories()
 * @method      SmileyCategory[]    getAllChildCategories()
 * @method      SmileyCategory      getParentCategory()
 * @method      SmileyCategory[]    getParentCategories()
 * @method static SmileyCategory|null getCategory($categoryID)
 */
class SmileyCategory extends AbstractDecoratedCategory implements \Countable, ITraversableObject
{
    /**
     * current iterator index
     * @var int
     */
    protected $index = 0;

    /**
     * list of index to object relation
     * @var int[]
     */
    protected $indexToObject;

    /**
     * list of assigned smilies
     * @var Smiley[]
     */
    public $smilies;

    /**
     * Loads associated smilies from cache.
     */
    public function loadSmilies()
    {
        if ($this->smilies === null) {
            $this->smilies = SmileyCache::getInstance()->getCategorySmilies($this->categoryID ?: null);
            $this->indexToObject = \array_keys($this->smilies);
        }
    }

    /**
     * @inheritDoc
     */
    public function count()
    {
        return \count($this->smilies);
    }

    /**
     * @inheritDoc
     * @return  Smiley
     */
    public function current()
    {
        $objectID = $this->indexToObject[$this->index];

        return $this->smilies[$objectID];
    }

    /**
     * CAUTION: This methods does not return the current iterator index,
     * rather than the object key which maps to that index.
     *
     * @see \Iterator::key()
     */
    public function key()
    {
        return $this->indexToObject[$this->index];
    }

    /**
     * @inheritDoc
     */
    public function next()
    {
        $this->index++;
    }

    /**
     * @inheritDoc
     */
    public function rewind()
    {
        $this->index = 0;
    }

    /**
     * @inheritDoc
     */
    public function valid()
    {
        return isset($this->indexToObject[$this->index]);
    }

    /**
     * @inheritDoc
     */
    public function seek($index)
    {
        $this->index = $index;

        if (!$this->valid()) {
            throw new \OutOfBoundsException();
        }
    }

    /**
     * @inheritDoc
     */
    public function seekTo($objectID)
    {
        $this->index = \array_search($objectID, $this->indexToObject);

        if ($this->index === false) {
            throw new SystemException("object id '" . $objectID . "' is invalid");
        }
    }

    /**
     * @inheritDoc
     * @return  Smiley|null
     */
    public function search($objectID)
    {
        try {
            $this->seekTo($objectID);

            return $this->current();
        } catch (SystemException $e) {
            return;
        }
    }

    /**
     * Returns the category's name.
     *
     * @return  string
     */
    public function __toString()
    {
        return WCF::getLanguage()->get($this->title);
    }
}