wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Lib;

use LogicException;
use MediaWiki\Registration\ExtensionRegistry;

/**
 * WikibaseSettings is a static access point to Wikibase settings defined as global state
 * (typically in LocalSettings.php).
 *
 * @note WikibaseSettings is intended for internal use by bootstrapping code. Application service
 * logic should have individual settings injected, static entry points to application logic should
 * use top level factory methods such as WikibaseRepo::getSettings() and
 * WikibaseClient::getSettings().
 *
 * @todo Move this to a separate component.
 *
 * @license GPL-2.0-or-later
 * @author Daniel Kinzler
 */
class WikibaseSettings {

    /**
     * @return bool True if and only if the Wikibase repository component is enabled on this wiki.
     */
    public static function isRepoEnabled() {
        return ExtensionRegistry::getInstance()->isLoaded( 'WikibaseRepository' );
    }

    /**
     * @return SettingsArray
     */
    public static function getRepoSettings() {
        global $wgWBRepoSettings;
        if ( !self::isRepoEnabled() ) {
            throw new LogicException( 'Cannot access repo settings: Wikibase Repository component is not enabled!' );
        }

        $repoSettings = array_merge(
            require __DIR__ . '/../config/WikibaseLib.default.php',
            require __DIR__ . '/../../repo/config/Wikibase.default.php'
        );
        // Hack to make a proper merge strategy for these configs in case they are being overriden by sysadmins
        // More info T257447
        // TODO: This should move to a proper mediawiki config handler: T258658
        $overrideArrays = [ 'entityDataFormats' ];
        $twoDArrayMerge = [ 'string-limits', 'pagePropertiesRdf' ];
        $falseMeansRemove = [ 'urlSchemes', 'canonicalLanguageCodes', 'globeUris' ];

        return self::mergeSettings(
            $repoSettings,
            $wgWBRepoSettings ?? [],
            $overrideArrays,
            $twoDArrayMerge,
            $falseMeansRemove
        );
    }

    /**
     * @return bool True if and only if the Wikibase client component is enabled on this wiki.
     */
    public static function isClientEnabled() {
        return ExtensionRegistry::getInstance()->isLoaded( 'WikibaseClient' );
    }

    /**
     * @return SettingsArray
     */
    public static function getClientSettings() {
        global $wgWBClientSettings;

        if ( !self::isClientEnabled() ) {
            throw new LogicException( 'Cannot access client settings: Wikibase Client component is not enabled!' );
        }

        $clientSettings = array_merge(
            require __DIR__ . '/../config/WikibaseLib.default.php',
            require __DIR__ . '/../../client/config/WikibaseClient.default.php'
        );

        return self::mergeSettings( $clientSettings, $wgWBClientSettings ?? [] );
    }

    /**
     * Merge two arrays of default and custom settings,
     * so that it looks like the custom settings were added on top of the default settings.
     *
     * Originally, Wikibase extensions were loaded and configured somewhat like this:
     *
     *     require_once "$IP/extensions/Wikibase/client/WikibaseClient.php";
     *     $wgWBClientSettings['repoUrl'] = 'https://pool.my.wiki';
     *
     * Here, $wgWBClientSettings would be initialized by WikibaseClient.php.
     * However, with the move to extension registration and wfLoadExtension(),
     * this is no longer possible, and $wgWBClientSettings will start out empty.
     * This method returns an array that looks like the custom settings
     * were added on top of existing default settings as above,
     * even though the default settings were in fact only loaded later.
     *
     * @param array $defaultSettings The default settings loaded from some other config file.
     * @param array $customSettings The custom settings from a configuration global.
     * @param string[] $overrideArrays
     * @param string[] $twoDArrayMerge
     * @param string[] $falseMeansRemove
     * @return SettingsArray The merged settings.
     */
    private static function mergeSettings(
        array $defaultSettings,
        array $customSettings,
        array $overrideArrays = [],
        array $twoDArrayMerge = [],
        array $falseMeansRemove = []
    ): SettingsArray {
        foreach ( $customSettings as $key => $value ) {
            $defaultValue = $defaultSettings[$key] ?? [];
            if ( is_array( $value ) && is_array( $defaultValue ) ) {
                $defaultSettings[$key] = self::mergeComplexArrays(
                    $key,
                    $value,
                    $defaultValue,
                    $twoDArrayMerge,
                    $overrideArrays,
                    $falseMeansRemove
                );
            } else {
                $defaultSettings[$key] = $value;
            }
        }

        return new SettingsArray( $defaultSettings );
    }

    private static function mergeComplexArrays(
        string $key,
        array $value,
        array $defaultValue,
        array $twoDArrayMerge,
        array $overrideArrays,
        array $falseMeansRemove
    ): array {
        if ( in_array( $key, $twoDArrayMerge ) ) {
            return wfArrayPlus2d( $value, $defaultValue );
        }
        if ( in_array( $key, $overrideArrays ) ) {
            return $value;
        }
        if ( in_array( $key, $falseMeansRemove ) ) {
            $result = array_merge( $defaultValue, $value );
            foreach ( $result as $valueKey => $valueValue ) {
                if ( $valueValue === false ) {
                    unset( $result[$valueKey] );
                    $index = array_search( $valueKey, $result );
                    if ( $index !== false ) {
                        unset( $result[$index] );
                    }
                }
            }

            // Keep the non-numeric keys but drop the numeric ones
            return array_merge( $result );
        }
        return array_merge( $defaultValue, $value );
    }
}