[GitHub/WoltLab/WCF.git] / wcfsetup / install / files / lib / data / language / LanguageEditor.class.php

<?php

namespace wcf\data\language;

use wcf\data\DatabaseObjectEditor;
use wcf\data\IEditableCachedObject;
use wcf\data\language\category\LanguageCategory;
use wcf\data\language\category\LanguageCategoryEditor;
use wcf\data\language\item\LanguageItemEditor;
use wcf\data\language\item\LanguageItemList;
use wcf\data\page\PageEditor;
use wcf\event\language\LanguageContentCopying;
use wcf\system\cache\builder\LanguageCacheBuilder;
use wcf\system\database\util\PreparedStatementConditionBuilder;
use wcf\system\event\EventHandler;
use wcf\system\exception\SystemException;
use wcf\system\io\AtomicWriter;
use wcf\system\language\LanguageFactory;
use wcf\system\Regex;
use wcf\system\WCF;
use wcf\util\DirectoryUtil;
use wcf\util\FileUtil;
use wcf\util\StringUtil;
use wcf\util\XML;

/**
 * Provides functions to edit languages.
 *
 * @author  Alexander Ebert
 * @copyright   2001-2019 WoltLab GmbH
 * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 *
 * @method static Language    create(array $parameters = [])
 * @method      Language    getDecoratedObject()
 * @mixin       Language
 */
class LanguageEditor extends DatabaseObjectEditor implements IEditableCachedObject
{
    /**
     * @inheritDoc
     */
    protected static $baseClass = Language::class;

    /**
     * @inheritDoc
     */
    public function delete()
    {
        parent::delete();

        self::deleteLanguageFiles($this->languageID);
    }

    /**
     * Updates the language files for the given category.
     *
     * @param LanguageCategory $languageCategory
     */
    public function updateCategory(LanguageCategory $languageCategory)
    {
        $this->writeLanguageFiles([$languageCategory->languageCategoryID]);
    }

    /**
     * Write the languages files.
     *
     * @param int[] $languageCategoryIDs
     */
    protected function writeLanguageFiles(array $languageCategoryIDs)
    {
        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add("languageID = ?", [$this->languageID]);
        $conditions->add("languageCategoryID IN (?)", [$languageCategoryIDs]);

        // get language items
        $sql = "SELECT  languageItem, languageItemValue, languageCustomItemValue,
                        languageUseCustomValue, languageCategoryID
                FROM    wcf" . WCF_N . "_language_item
                " . $conditions;
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute($conditions->getParameters());
        $items = [];
        while ($row = $statement->fetchArray()) {
            $languageCategoryID = $row['languageCategoryID'];
            if (!isset($items[$languageCategoryID])) {
                $items[$languageCategoryID] = [];
            }

            $items[$languageCategoryID][$row['languageItem']] = $row['languageUseCustomValue'] ? $row['languageCustomItemValue'] : $row['languageItemValue'];
        }

        foreach ($items as $languageCategoryID => $languageItems) {
            $category = LanguageFactory::getInstance()->getCategoryByID($languageCategoryID);
            if ($category === null) {
                continue;
            }

            $filename = WCF_DIR . 'language/' . $this->languageID . '_' . $category->languageCategory . '.php';
            $writer = new AtomicWriter($filename);

            $writer->write("<?php\n/**\n* WoltLab Suite\n* language: " . $this->languageCode . "\n* encoding: UTF-8\n* category: " . $category->languageCategory . "\n* generated at " . \gmdate("r") . "\n* \n* DO NOT EDIT THIS FILE\n*/\n");
            foreach ($languageItems as $languageItem => $languageItemValue) {
                $writer->write("\$this->items['" . $languageItem . "'] = " . \var_export($languageItemValue, true) . ";\n");

                // compile dynamic language variables
                if ($category->languageCategory != 'wcf.global' && \strpos($languageItemValue, '{') !== false) {
                    try {
                        $output = LanguageFactory::getInstance()->getScriptingCompiler()->compileString(
                            $languageItem,
                            $languageItemValue
                        );
                    } catch (SystemException $e) {
                        continue;
                    } // ignore compiler errors

                    $writer->write("\$this->dynamicItems['" . $languageItem . "'] = " . \var_export($output['template'], true) . ";\n");
                }
            }

            $writer->flush();
            $writer->close();
            FileUtil::makeWritable($filename);
        }
    }

    /**
     * Exports this language.
     */
    public function export(int $packageID, bool $exportCustomValues = false)
    {
        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add("language_item.languageID = ?", [$this->languageID]);
        $conditions->add("language_item.packageID = ?", [$packageID]);

        // header
        echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<language xmlns=\"http://www.woltlab.com\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://www.woltlab.com http://www.woltlab.com/XSD/6.0/language.xsd\" languagecode=\"" . $this->languageCode . "\" languagename=\"" . $this->languageName . "\" countrycode=\"" . $this->countryCode . "\">\n";

        // get items
        $sql = "SELECT      languageItem,
                            " . ($exportCustomValues ? "CASE WHEN languageUseCustomValue > 0 THEN languageCustomItemValue ELSE languageItemValue END AS languageItemValue" : "languageItemValue") . ",
                            languageCategory
                FROM        wcf" . WCF_N . "_language_item language_item
                LEFT JOIN   wcf" . WCF_N . "_language_category language_category
                ON          language_category.languageCategoryID = language_item.languageCategoryID
                " . $conditions;
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute($conditions->getParameters());
        $items = [];
        while ($row = $statement->fetchArray()) {
            $items[$row['languageCategory']][$row['languageItem']] = $row['languageItemValue'];
        }

        // sort categories
        \ksort($items);

        foreach ($items as $category => $categoryItems) {
            // sort items
            \ksort($categoryItems);

            // category header
            echo "\t<category name=\"" . $category . "\">\n";

            // items
            foreach ($categoryItems as $item => $value) {
                echo "\t\t<item name=\"" . $item . "\"><![CDATA[" . StringUtil::escapeCDATA($value) . "]]></item>\n";
            }

            // category footer
            echo "\t</category>\n";
        }

        // add shadow values (pages)
        $pages = [];
        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add("page_content.pageID = page.pageID");
        $conditions->add("page_content.languageID = ?", [$this->languageID]);
        $conditions->add("page.packageID = ?", [$packageID]);
        $conditions->add("page.originIsSystem = ?", [1]);
        $sql = "SELECT      page.identifier, page_content.title, page_content.content
                FROM        wcf" . WCF_N . "_page page,
                            wcf" . WCF_N . "_page_content page_content
                " . $conditions . "
                ORDER BY    page.identifier";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute($conditions->getParameters());
        while ($row = $statement->fetchArray()) {
            $pages[] = $row;
        }

        if (!empty($pages)) {
            echo "\t<category name=\"shadow.invalid.page\">\n";

            foreach ($pages as $page) {
                if ($page['title']) {
                    echo "\t\t<item name=\"shadow.invalid.page." . $page['identifier'] . ".title\"><![CDATA[" . StringUtil::escapeCDATA($page['title']) . "]]></item>\n";
                }
                if ($page['content']) {
                    echo "\t\t<item name=\"shadow.invalid.page." . $page['identifier'] . ".content\"><![CDATA[" . StringUtil::escapeCDATA($page['content']) . "]]></item>\n";
                }
            }

            echo "\t</category>\n";
        }

        // add shadow values (boxes)
        $boxes = [];
        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add("box_content.boxID = box.boxID");
        $conditions->add("box_content.languageID = ?", [$this->languageID]);
        $conditions->add("box.packageID = ?", [$packageID]);
        $conditions->add("box.originIsSystem = ?", [1]);
        $sql = "SELECT      box.identifier, box_content.title, box_content.content
                FROM        wcf" . WCF_N . "_box box,
                            wcf" . WCF_N . "_box_content box_content
                " . $conditions . "
                ORDER BY    box.identifier";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute($conditions->getParameters());
        while ($row = $statement->fetchArray()) {
            $boxes[] = $row;
        }

        if (!empty($pages)) {
            echo "\t<category name=\"shadow.invalid.box\">\n";

            foreach ($boxes as $box) {
                if ($box['title']) {
                    echo "\t\t<item name=\"shadow.invalid.box." . $box['identifier'] . ".title\"><![CDATA[" . StringUtil::escapeCDATA($box['title']) . "]]></item>\n";
                }
                if ($box['content']) {
                    echo "\t\t<item name=\"shadow.invalid.box." . $box['identifier'] . ".content\"><![CDATA[" . StringUtil::escapeCDATA($box['content']) . "]]></item>\n";
                }
            }

            echo "\t</category>\n";
        }

        // footer
        echo "</language>";
    }

    /**
     * Deletes the language items from the given XML document.
     *
     * @throws  \InvalidArgumentException   if given XML document is invalid with regard to deleting language items
     * @since   5.5
     */
    protected function deleteFromXML(XML $xml, int $packageID): void
    {
        $xpath = $xml->xpath();

        $items = $xpath->query('/ns:language/ns:delete/ns:item');
        if (empty($items)) {
            return;
        }

        $languageItems = [];

        /** @var \DOMElement $item */
        foreach ($items as $item) {
            $itemName = $item->getAttribute('name');

            if (empty($itemName)) {
                throw new \InvalidArgumentException("The 'name' attribute is missing or empty.");
            }

            if (StringUtil::trim($itemName) !== $itemName) {
                throw new \InvalidArgumentException("The name '{$itemName}' contains leading or trailing whitespaces.");
            }

            $languageItems[] = $itemName;
        }

        if (empty($languageItems)) {
            return;
        }

        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add('packageID = ?', [$packageID]);
        $conditions->add('languageItem IN (?)', [$languageItems]);
        $conditions->add('languageID = ?', [$this->languageID]);
        $sql = "DELETE FROM wcf1_language_item
                {$conditions}";
        $statement = WCF::getDB()->prepare($sql);
        $statement->execute($conditions->getParameters());
    }

    /**
     * Checks the structure of the XML file to ensure that either the old, deprecated structure
     * with direct `category` children is used or the new structure with `import` and `delete`
     * children.
     *
     * @throws  \InvalidArgumentException   if old and new structure is mixed
     * @since   5.5
     */
    protected function validateXMLStructure(XML $xml): void
    {
        $xpath = $xml->xpath();

        $hasImport = $xpath->query('/ns:language/ns:import')->length !== 0;
        $hasDelete = $xpath->query('/ns:language/ns:delete')->length !== 0;
        $hasDirectCategories = $xpath->query('/ns:language/ns:category')->length !== 0;

        if (($hasImport || $hasDelete) && $hasDirectCategories) {
            throw new \InvalidArgumentException("'category' elements cannot be used next to 'import' and 'delete' elements.");
        }
    }

    /**
     * Imports language items from an XML file into this language.
     * Updates the relevant language files automatically.
     *
     * @param XML $xml
     * @param int $packageID
     * @param bool $updateFiles
     * @param bool $updateExistingItems
     * @throws  \InvalidArgumentException   if given XML file is invalid
     */
    public function updateFromXML(XML $xml, $packageID, $updateFiles = true, $updateExistingItems = true)
    {
        $this->validateXMLStructure($xml);

        $this->deleteFromXML($xml, $packageID);

        $xpath = $xml->xpath();
        $usedCategories = [];

        // fetch categories
        $categories = $xpath->query('/ns:language/ns:import/ns:category');
        if ($categories->length === 0) {
            // Fallback for the old, deprecated version before WSC 5.5, which only supported imports.
            $categories = $xpath->query('/ns:language/ns:category');
        }

        /** @var \DOMElement $category */
        foreach ($categories as $category) {
            $usedCategories[$category->getAttribute('name')] = 0;
        }

        if (empty($usedCategories)) {
            return;
        }

        // select existing categories
        $conditions = new PreparedStatementConditionBuilder();
        $conditions->add("languageCategory IN (?)", [\array_keys($usedCategories)]);

        $sql = "SELECT  languageCategoryID, languageCategory
                FROM    wcf" . WCF_N . "_language_category
                " . $conditions;
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute($conditions->getParameters());
        while ($row = $statement->fetchArray()) {
            $usedCategories[$row['languageCategory']] = $row['languageCategoryID'];
        }

        // create new categories
        foreach ($usedCategories as $categoryName => $categoryID) {
            if ($categoryID) {
                continue;
            }
            if (\strpos($categoryName, 'shadow.invalid') === 0) {
                continue; // ignore shadow items
            }

            /** @var LanguageCategory $category */
            $category = LanguageCategoryEditor::create([
                'languageCategory' => $categoryName,
            ]);
            $usedCategories[$categoryName] = $category->languageCategoryID;
        }

        // loop through categories to import items
        $itemData = $pageContents = $boxContents = [];
        $languageItemValues = [];

        /** @var \DOMElement $category */
        foreach ($categories as $category) {
            $categoryName = $category->getAttribute('name');
            $elements = $xpath->query('child::*', $category);

            if ($categoryName == 'shadow.invalid.page') {
                /** @var \DOMElement $element */
                foreach ($elements as $element) {
                    if (
                        \preg_match(
                            '/^shadow\.invalid\.page\.(.*)\.(title|content)/',
                            $element->getAttribute('name'),
                            $match
                        )
                    ) {
                        if (!isset($pageContents[$match[1]])) {
                            $pageContents[$match[1]] = [];
                        }
                        $pageContents[$match[1]][$match[2]] = $element->nodeValue;
                    }
                }
            } elseif ($categoryName == 'shadow.invalid.box') {
                /** @var \DOMElement $element */
                foreach ($elements as $element) {
                    if (
                        \preg_match(
                            '/^shadow\.invalid\.box\.(.*)\.(title|content)/',
                            $element->getAttribute('name'),
                            $match
                        )
                    ) {
                        if (!isset($boxContents[$match[1]])) {
                            $boxContents[$match[1]] = [];
                        }
                        $boxContents[$match[1]][$match[2]] = $element->nodeValue;
                    }
                }
            } else {
                $categoryID = $usedCategories[$categoryName];

                /** @var \DOMElement $element */
                foreach ($elements as $element) {
                    $itemName = $element->getAttribute('name');

                    self::validateItemName($itemName, $categoryName);

                    $itemValue = $element->nodeValue;

                    $itemData[] = $this->languageID;
                    $itemData[] = $itemName;
                    $itemData[] = $itemValue;
                    $itemData[] = $categoryID;
                    if ($packageID) {
                        if ($packageID == -1) {
                            throw new \BadMethodCallException('Specifying `-1` as the packageID is no longer supported.');
                        }

                        $itemData[] = $packageID;
                    }

                    if ($updateExistingItems) {
                        $languageItemValues[$itemName] = $itemValue;
                    }
                }
            }
        }

        // save items
        if (!empty($itemData)) {
            // select phrases that have custom versions that might get disabled during the update
            if ($updateExistingItems) {
                $conditions = new PreparedStatementConditionBuilder();
                $conditions->add("languageItem IN (?)", [\array_keys($languageItemValues)]);
                $conditions->add("languageID = ?", [$this->languageID]);
                if ($packageID > 0) {
                    $conditions->add("packageID = ?", [$packageID]);
                }
                $conditions->add("(languageUseCustomValue = ? OR isCustomLanguageItem = ?)", [1, 1]);

                $sql = "SELECT  languageItemID, languageItem, languageItemValue, isCustomLanguageItem
                        FROM    wcf" . WCF_N . "_language_item
                        " . $conditions;
                $statement = WCF::getDB()->prepareStatement($sql);
                $statement->execute($conditions->getParameters());
                $updateValues = $customLanguageItemIDs = [];
                while ($row = $statement->fetchArray()) {
                    if ($row['isCustomLanguageItem']) {
                        $customLanguageItemIDs[] = $row['languageItemID'];
                    }

                    // also save old values of custom language items
                    if ($row['isCustomLanguageItem'] || $row['languageItemValue'] != $languageItemValues[$row['languageItem']]) {
                        $updateValues[] = $row['languageItemID'];
                    }
                }

                if (!empty($updateValues)) {
                    $sql = "UPDATE  wcf" . WCF_N . "_language_item
                            SET     languageItemOldValue = languageItemValue,
                                    languageCustomItemDisableTime = ?,
                                    languageUseCustomValue = ?
                            WHERE   languageItemID = ?";
                    $statement = WCF::getDB()->prepareStatement($sql);

                    WCF::getDB()->beginTransaction();
                    foreach ($updateValues as $languageItemID) {
                        $statement->execute([
                            TIME_NOW,
                            0,
                            $languageItemID,
                        ]);
                    }
                    WCF::getDB()->commitTransaction();
                }

                // make custom language items normal ones
                if (!empty($customLanguageItemIDs)) {
                    $sql = "UPDATE  wcf" . WCF_N . "_language_item
                            SET     isCustomLanguageItem = ?,
                                    languageItemOriginIsSystem = ?,
                                    packageID = ?
                            WHERE   languageItemID = ?";
                    $statement = WCF::getDB()->prepareStatement($sql);

                    WCF::getDB()->beginTransaction();
                    foreach ($updateValues as $languageItemID) {
                        $statement->execute([
                            0,
                            1,
                            $packageID,
                            $languageItemID,
                        ]);
                    }
                    WCF::getDB()->commitTransaction();
                }
            }

            // insert/update a maximum of 50 items per run (prevents issues with max_allowed_packet)
            $step = $packageID ? 5 : 4;
            WCF::getDB()->beginTransaction();
            for ($i = 0, $length = \count($itemData); $i < $length; $i += 50 * $step) {
                $parameters = \array_slice($itemData, $i, 50 * $step);
                $repeat = \count($parameters) / $step;

                $placeholders = \substr(
                    \str_repeat('(?, ?, ?, ?' . ($packageID ? ', ?' : '') . '),', $repeat),
                    0,
                    -1
                );
                $sql = "INSERT" . (!$updateExistingItems ? " IGNORE" : "") . " INTO wcf" . WCF_N . "_language_item
                                    (languageID, languageItem, languageItemValue, languageCategoryID" . ($packageID ? ", packageID" : "") . ")
                        VALUES      {$placeholders}";

                if ($updateExistingItems) {
                    if ($packageID > 0) {
                        // do not update anything if language item is owned by a different package
                        $sql .= "
                            ON DUPLICATE KEY UPDATE languageItemValue = IF(packageID = " . $packageID . ", IF(languageItemOriginIsSystem = 0, languageItemValue, VALUES(languageItemValue)), languageItemValue),
                                                    languageCategoryID = IF(packageID = " . $packageID . ", VALUES(languageCategoryID), languageCategoryID)";
                    } else {
                        // skip package id check during WCFSetup (packageID = 0) or if using the ACP form (packageID = -1)
                        $sql .= "
                            ON DUPLICATE KEY UPDATE languageItemValue = IF(languageItemOriginIsSystem = 0, languageItemValue, VALUES(languageItemValue)),
                                                    languageCategoryID = VALUES(languageCategoryID)";
                    }
                }

                $statement = WCF::getDB()->prepareStatement($sql);
                $statement->execute($parameters);
            }
            WCF::getDB()->commitTransaction();
        }

        // save page content
        if (!empty($pageContents)) {
            // get page ids
            $pageIDs = [];
            $conditions = new PreparedStatementConditionBuilder();
            $conditions->add("identifier IN (?)", [\array_keys($pageContents)]);
            $sql = "SELECT  pageID, identifier
                    FROM    wcf" . WCF_N . "_page
                    " . $conditions;
            $statement = WCF::getDB()->prepareStatement($sql);
            $statement->execute($conditions->getParameters());
            while ($row = $statement->fetchArray()) {
                $pageIDs[$row['identifier']] = $row['pageID'];
            }

            $sql = "INSERT IGNORE INTO  wcf1_page_content
                                        (pageID, languageID, title, content, metaDescription, customURL, hasEmbeddedObjects)
                    SELECT              pageID, ?, title, content, metaDescription, CASE WHEN customURL <> '' THEN CONCAT(customURL, '_', ?) ELSE '' END, hasEmbeddedObjects
                    FROM                wcf1_page_content
                    WHERE               pageID = ?
                                    AND languageID = ?";
            $createLanguageVersionStatement = WCF::getDB()->prepare($sql);
            $sql = "UPDATE  wcf" . WCF_N . "_page_content
                    SET     title = ?
                    WHERE   pageID = ?
                        AND languageID = ?";
            $updateTitleStatement = WCF::getDB()->prepareStatement($sql);
            $sql = "UPDATE  wcf" . WCF_N . "_page_content
                    SET     content = ?
                    WHERE   pageID = ?
                        AND languageID = ?";
            $updateContentStatement = WCF::getDB()->prepareStatement($sql);

            foreach ($pageContents as $identifier => $pageContent) {
                if (!isset($pageIDs[$identifier])) {
                    continue; // unknown page
                }

                $createLanguageVersionStatement->execute([
                    $this->languageID,
                    $this->languageID,
                    $pageIDs[$identifier],
                    LanguageFactory::getInstance()->getDefaultLanguageID(),
                ]);
                if (isset($pageContent['title'])) {
                    $updateTitleStatement->execute([$pageContent['title'], $pageIDs[$identifier], $this->languageID]);
                }
                if (isset($pageContent['content'])) {
                    $updateContentStatement->execute([
                        $pageContent['content'],
                        $pageIDs[$identifier],
                        $this->languageID,
                    ]);
                }
            }
        }

        // save box content
        if (!empty($boxContents)) {
            // get box ids
            $boxIDs = [];
            $conditions = new PreparedStatementConditionBuilder();
            $conditions->add("identifier IN (?)", [\array_keys($boxContents)]);
            $sql = "SELECT  boxID, identifier
                    FROM    wcf" . WCF_N . "_box
                    " . $conditions;
            $statement = WCF::getDB()->prepareStatement($sql);
            $statement->execute($conditions->getParameters());
            while ($row = $statement->fetchArray()) {
                $boxIDs[$row['identifier']] = $row['boxID'];
            }

            $sql = "INSERT IGNORE INTO  wcf" . WCF_N . "_box_content
                                        (boxID, languageID)
                    VALUES              (?, ?)";
            $createLanguageVersionStatement = WCF::getDB()->prepareStatement($sql);
            $sql = "UPDATE  wcf" . WCF_N . "_box_content
                    SET     title = ?
                    WHERE   boxID = ?
                        AND languageID = ?";
            $updateTitleStatement = WCF::getDB()->prepareStatement($sql);
            $sql = "UPDATE  wcf" . WCF_N . "_box_content
                    SET     content = ?
                    WHERE   boxID = ?
                        AND languageID = ?";
            $updateContentStatement = WCF::getDB()->prepareStatement($sql);

            foreach ($boxContents as $identifier => $boxContent) {
                if (!isset($boxIDs[$identifier])) {
                    continue; // unknown box
                }

                $createLanguageVersionStatement->execute([$boxIDs[$identifier], $this->languageID]);
                if (isset($boxContent['title'])) {
                    $updateTitleStatement->execute([$boxContent['title'], $boxIDs[$identifier], $this->languageID]);
                }
                if (isset($boxContent['content'])) {
                    $updateContentStatement->execute([$boxContent['content'], $boxIDs[$identifier], $this->languageID]);
                }
            }
        }

        // update the relevant language files
        if ($updateFiles) {
            self::deleteLanguageFiles($this->languageID);
        }

        // delete relevant template compilations
        $this->deleteCompiledTemplates();
    }

    /**
     * Verifies that the given variable is a valid variable within the given category.
     * Throws an exception otherwise.
     *
     * @since 5.4
     */
    final public static function validateItemName(string $itemName, string $categoryName): void
    {
        // Safeguard against malformed phrases, an empty name has a strange side effect.
        if (empty($itemName)) {
            throw new \InvalidArgumentException("The name attribute is missing or empty.");
        }

        if ($itemName !== $categoryName && \strpos($itemName, $categoryName . '.') !== 0) {
            throw new \InvalidArgumentException(WCF::getLanguage()->getDynamicVariable(
                'wcf.acp.language.import.error.categoryMismatch',
                [
                    'categoryName' => $categoryName,
                    'languageItem' => $itemName,
                ]
            ));
        }

        if (StringUtil::trim($itemName) !== $itemName) {
            throw new \InvalidArgumentException("The name '{$itemName}' contains leading or trailing whitespaces.");
        }
    }

    /**
     * Deletes the language cache.
     *
     * @param string $languageID
     * @param string $category
     */
    public static function deleteLanguageFiles($languageID = '.*', $category = '.*')
    {
        if ($category != '.*') {
            $category = \preg_quote($category, '~');
        }
        if ($languageID != '.*') {
            $languageID = \intval($languageID);
        }

        DirectoryUtil::getInstance(WCF_DIR . 'language/')->removePattern(new Regex($languageID . '_' . $category . '\.php$'));
    }

    /**
     * Deletes relevant template compilations.
     */
    public function deleteCompiledTemplates()
    {
        // templates
        DirectoryUtil::getInstance(WCF_DIR . 'templates/compiled/')->removePattern(new Regex('.*_' . $this->languageID . '_.*\.php$'));
        // acp templates
        DirectoryUtil::getInstance(WCF_DIR . 'acp/templates/compiled/')->removePattern(new Regex('.*_' . $this->languageID . '_.*\.php$'));
    }

    /**
     * Updates all language files of the given package id.
     */
    public static function updateAll()
    {
        self::deleteLanguageFiles();
    }

    /**
     * Takes an XML object and returns the specific language code.
     *
     * @param XML $xml
     * @return  string
     * @throws  SystemException
     */
    public static function readLanguageCodeFromXML(XML $xml)
    {
        $rootNode = $xml->xpath()->query('/ns:language')->item(0);
        $attributes = $xml->xpath()->query('attribute::*', $rootNode);
        foreach ($attributes as $attribute) {
            if ($attribute->name == 'languagecode') {
                return $attribute->value;
            }
        }

        throw new SystemException("missing attribute 'languagecode' in language file");
    }

    /**
     * Takes an XML object and returns the specific language name.
     *
     * @param XML $xml
     * @return  string      language name
     * @throws  SystemException
     */
    public static function readLanguageNameFromXML(XML $xml)
    {
        $rootNode = $xml->xpath()->query('/ns:language')->item(0);
        $attributes = $xml->xpath()->query('attribute::*', $rootNode);
        foreach ($attributes as $attribute) {
            if ($attribute->name == 'languagename') {
                return $attribute->value;
            }
        }

        throw new SystemException("missing attribute 'languagename' in language file");
    }

    /**
     * Takes an XML object and returns the specific country code.
     *
     * @param XML $xml
     * @return  string      country code
     * @throws  SystemException
     */
    public static function readCountryCodeFromXML(XML $xml)
    {
        $rootNode = $xml->xpath()->query('/ns:language')->item(0);
        $attributes = $xml->xpath()->query('attribute::*', $rootNode);
        foreach ($attributes as $attribute) {
            if ($attribute->name == 'countrycode') {
                return $attribute->value;
            }
        }

        throw new SystemException("missing attribute 'countrycode' in language file");
    }

    /**
     * Imports language items from an XML file into a new or a current language.
     * Updates the relevant language files automatically.
     *
     * @param XML $xml
     * @param int $packageID
     * @param Language $source
     * @return  LanguageEditor
     */
    public static function importFromXML(XML $xml, $packageID, ?Language $source = null)
    {
        $languageCode = self::readLanguageCodeFromXML($xml);

        // try to find an existing language with the given language code
        $language = LanguageFactory::getInstance()->getLanguageByCode($languageCode);

        // create new language
        if ($language === null) {
            $countryCode = self::readCountryCodeFromXML($xml);
            $languageName = self::readLanguageNameFromXML($xml);
            $language = self::create([
                'countryCode' => $countryCode,
                'languageCode' => $languageCode,
                'languageName' => $languageName,
            ]);

            if ($source) {
                $sourceEditor = new self($source);
                $sourceEditor->copy($language);
            }
        }

        // import xml
        $languageEditor = new self($language);
        $languageEditor->updateFromXML($xml, $packageID);

        // return language object
        return $languageEditor;
    }

    /**
     * Copies all language variables from current language to language specified as $destination.
     * Caution: This method expects that target language does not have any items!
     *
     * @param Language $destination
     */
    public function copy(Language $destination)
    {
        $sql = "INSERT INTO wcf" . WCF_N . "_language_item
                            (languageID, languageItem, languageItemValue, languageItemOriginIsSystem, languageCategoryID, packageID)
                SELECT      ?, languageItem, languageItemValue, languageItemOriginIsSystem, languageCategoryID, packageID
                FROM        wcf" . WCF_N . "_language_item
                WHERE       languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([
            $destination->languageID,
            $this->languageID,
        ]);
    }

    /**
     * Updates the language items of a language category.
     *
     * @param array $items
     * @param LanguageCategory $category
     * @param int $packageID
     * @param array $useCustom
     */
    public function updateItems(
        array $items,
        LanguageCategory $category,
        $packageID = PACKAGE_ID,
        array $useCustom = []
    ) {
        if (empty($items)) {
            return;
        }

        // find existing language items
        $languageItemList = new LanguageItemList();
        $languageItemList->getConditionBuilder()->add("language_item.languageItem IN (?)", [\array_keys($items)]);
        $languageItemList->getConditionBuilder()->add("languageID = ?", [$this->languageID]);
        $languageItemList->readObjects();

        foreach ($languageItemList->getObjects() as $languageItem) {
            $languageItemEditor = new LanguageItemEditor($languageItem);
            $languageItemEditor->update([
                'languageCustomItemValue' => $items[$languageItem->languageItem],
                'languageUseCustomValue' => isset($useCustom[$languageItem->languageItem]) ? 1 : 0,
            ]);

            // remove updated items, leaving items to be created within
            unset($items[$languageItem->languageItem]);
        }

        // create remaining items
        if (!empty($items)) {
            // bypass LanguageItemEditor::create() for performance reasons
            $sql = "INSERT INTO wcf" . WCF_N . "_language_item
                                (languageID, languageItem, languageItemValue, languageItemOriginIsSystem, languageCategoryID, packageID)
                    VALUES      (?, ?, ?, ?, ?, ?)";
            $statement = WCF::getDB()->prepareStatement($sql);

            foreach ($items as $itemName => $itemValue) {
                $statement->execute([
                    $this->languageID,
                    $itemName,
                    $itemValue,
                    0,
                    $category->languageCategoryID,
                    $packageID,
                ]);
            }
        }

        // update the relevant language files
        self::deleteLanguageFiles($this->languageID, $category->languageCategory);

        // delete relevant template compilations
        $this->deleteCompiledTemplates();
    }

    /**
     * Sets current language as default language.
     */
    public function setAsDefault()
    {
        // remove default flag from all languages
        $sql = "UPDATE  wcf" . WCF_N . "_language
                SET     isDefault = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([0]);

        // set current language as default language
        $this->update(['isDefault' => 1]);

        $this->clearCache();
    }

    /**
     * Clears language cache.
     */
    public function clearCache()
    {
        LanguageCacheBuilder::getInstance()->reset();
    }

    /**
     * Enables the multilingualism feature for given languages.
     *
     * @param array $languageIDs
     */
    public static function enableMultilingualism(array $languageIDs = [])
    {
        $sql = "UPDATE  wcf" . WCF_N . "_language
                SET     hasContent = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([0]);

        if (!empty($languageIDs)) {
            $sql = '';
            $statementParameters = [];
            foreach ($languageIDs as $languageID) {
                if (!empty($sql)) {
                    $sql .= ',';
                }
                $sql .= '?';
                $statementParameters[] = $languageID;
            }

            $sql = "UPDATE  wcf" . WCF_N . "_language
                    SET     hasContent = ?
                    WHERE   languageID IN (" . $sql . ")";
            $statement = WCF::getDB()->prepareStatement($sql);
            \array_unshift($statementParameters, 1);
            $statement->execute($statementParameters);
        }
    }

    /**
     * @inheritDoc
     */
    public static function resetCache()
    {
        LanguageFactory::getInstance()->clearCache();
    }

    /**
     * Copies all cms contents (article, box, media, page) from given source language to language specified as $destinationLanguageID.
     *
     * @param int $sourceLanguageID
     * @param int $destinationLanguageID
     */
    public static function copyLanguageContent($sourceLanguageID, $destinationLanguageID)
    {
        // article content
        $sql = "INSERT IGNORE INTO  wcf" . WCF_N . "_article_content
                                    (articleID, languageID, title, teaser, content, imageID, hasEmbeddedObjects)
                SELECT              articleID, ?, title, teaser, content, imageID, hasEmbeddedObjects
                FROM                wcf" . WCF_N . "_article_content
                WHERE               languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([$destinationLanguageID, $sourceLanguageID]);

        // box content
        $sql = "INSERT IGNORE INTO  wcf" . WCF_N . "_box_content
                                    (boxID, languageID, title, content, imageID, hasEmbeddedObjects)
                SELECT              boxID, ?, title, content, imageID, hasEmbeddedObjects
                FROM                wcf" . WCF_N . "_box_content
                WHERE               languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([$destinationLanguageID, $sourceLanguageID]);

        // create tpl files
        $sql = "SELECT  *
                FROM    wcf" . WCF_N . "_box_content
                WHERE   boxID IN (
                            SELECT  boxID
                            FROM    wcf" . WCF_N . "_box
                            WHERE   boxType = ?
                        )
                    AND languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute(['tpl', $destinationLanguageID]);
        while ($row = $statement->fetchArray()) {
            \file_put_contents(
                WCF_DIR . 'templates/__cms_box_' . $row['boxID'] . '_' . $destinationLanguageID . '.tpl',
                $row['content']
            );
        }

        // media content
        $sql = "INSERT IGNORE INTO  wcf" . WCF_N . "_media_content
                                    (mediaID, languageID, title, caption, altText)
                SELECT              mediaID, ?, title, caption, altText
                FROM                wcf" . WCF_N . "_media_content
                WHERE               languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([$destinationLanguageID, $sourceLanguageID]);

        // page content
        $sql = "INSERT IGNORE INTO  wcf" . WCF_N . "_page_content
                                    (pageID, languageID, title, content, metaDescription, customURL, hasEmbeddedObjects)
                SELECT              pageID, ?, title, content, metaDescription, CASE WHEN customURL <> '' THEN CONCAT(customURL, '_', ?) ELSE '' END, hasEmbeddedObjects
                FROM                wcf" . WCF_N . "_page_content
                WHERE               languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute([$destinationLanguageID, $destinationLanguageID, $sourceLanguageID]);

        // create tpl files
        $sql = "SELECT  *
                FROM    wcf" . WCF_N . "_page_content
                WHERE   pageID IN (
                            SELECT  pageID
                            FROM    wcf" . WCF_N . "_page
                            WHERE   pageType = ?
                        )
                    AND languageID = ?";
        $statement = WCF::getDB()->prepareStatement($sql);
        $statement->execute(['tpl', $destinationLanguageID]);
        while ($row = $statement->fetchArray()) {
            \file_put_contents(
                WCF_DIR . 'templates/__cms_page_' . $row['pageID'] . '_' . $destinationLanguageID . '.tpl',
                $row['content']
            );
        }

        PageEditor::resetCache();

        EventHandler::getInstance()->fire(new LanguageContentCopying(
            new Language($sourceLanguageID),
            new Language($destinationLanguageID)
        ));
    }
}