Add 'ApiMakeParserOptions' hook

[mediawiki.git] / includes / api / ApiHelp.php

<?php
/**
 *
 *
 * Created on Aug 29, 2014
 *
 * Copyright © 2014 Brad Jorsch <bjorsch@wikimedia.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

use HtmlFormatter\HtmlFormatter;

/**
 * Class to output help for an API module
 *
 * @since 1.25 completely rewritten
 * @ingroup API
 */
class ApiHelp extends ApiBase {
        public function execute() {
                $params = $this->extractRequestParams();
                $modules = [];

                foreach ( $params['modules'] as $path ) {
                        $modules[] = $this->getModuleFromPath( $path );
                }

                // Get the help
                $context = new DerivativeContext( $this->getMain()->getContext() );
                $context->setSkin( SkinFactory::getDefaultInstance()->makeSkin( 'apioutput' ) );
                $context->setLanguage( $this->getMain()->getLanguage() );
                $context->setTitle( SpecialPage::getTitleFor( 'ApiHelp' ) );
                $out = new OutputPage( $context );
                $out->setCopyrightUrl( 'https://www.mediawiki.org/wiki/Special:MyLanguage/Copyright' );
                $context->setOutput( $out );

                self::getHelp( $context, $modules, $params );

                // Grab the output from the skin
                ob_start();
                $context->getOutput()->output();
                $html = ob_get_clean();

                $result = $this->getResult();
                if ( $params['wrap'] ) {
                        $data = [
                                'mime' => 'text/html',
                                'help' => $html,
                        ];
                        ApiResult::setSubelementsList( $data, 'help' );
                        $result->addValue( null, $this->getModuleName(), $data );
                } else {
                        $result->reset();
                        $result->addValue( null, 'text', $html, ApiResult::NO_SIZE_CHECK );
                        $result->addValue( null, 'mime', 'text/html', ApiResult::NO_SIZE_CHECK );
                }
        }

        /**
         * Generate help for the specified modules
         *
         * Help is placed into the OutputPage object returned by
         * $context->getOutput().
         *
         * Recognized options include:
         *  - headerlevel: (int) Header tag level
         *  - nolead: (bool) Skip the inclusion of api-help-lead
         *  - noheader: (bool) Skip the inclusion of the top-level section headers
         *  - submodules: (bool) Include help for submodules of the current module
         *  - recursivesubmodules: (bool) Include help for submodules recursively
         *  - helptitle: (string) Title to link for additional modules' help. Should contain $1.
         *  - toc: (bool) Include a table of contents
         *
         * @param IContextSource $context
         * @param ApiBase[]|ApiBase $modules
         * @param array $options Formatting options (described above)
         * @return string
         */
        public static function getHelp( IContextSource $context, $modules, array $options ) {
                global $wgContLang;

                if ( !is_array( $modules ) ) {
                        $modules = [ $modules ];
                }

                $out = $context->getOutput();
                $out->addModuleStyles( 'mediawiki.hlist' );
                $out->addModuleStyles( 'mediawiki.apihelp' );
                if ( !empty( $options['toc'] ) ) {
                        $out->addModules( 'mediawiki.toc' );
                }
                $out->setPageTitle( $context->msg( 'api-help-title' ) );

                $cache = ObjectCache::getMainWANInstance();
                $cacheKey = null;
                if ( count( $modules ) == 1 && $modules[0] instanceof ApiMain &&
                        $options['recursivesubmodules'] && $context->getLanguage() === $wgContLang
                ) {
                        $cacheHelpTimeout = $context->getConfig()->get( 'APICacheHelpTimeout' );
                        if ( $cacheHelpTimeout > 0 ) {
                                // Get help text from cache if present
                                $cacheKey = wfMemcKey( 'apihelp', $modules[0]->getModulePath(),
                                        (int)!empty( $options['toc'] ),
                                        str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
                                $cached = $cache->get( $cacheKey );
                                if ( $cached ) {
                                        $out->addHTML( $cached );
                                        return;
                                }
                        }
                }
                if ( $out->getHTML() !== '' ) {
                        // Don't save to cache, there's someone else's content in the page
                        // already
                        $cacheKey = null;
                }

                $options['recursivesubmodules'] = !empty( $options['recursivesubmodules'] );
                $options['submodules'] = $options['recursivesubmodules'] || !empty( $options['submodules'] );

                // Prepend lead
                if ( empty( $options['nolead'] ) ) {
                        $msg = $context->msg( 'api-help-lead' );
                        if ( !$msg->isDisabled() ) {
                                $out->addHTML( $msg->parseAsBlock() );
                        }
                }

                $haveModules = [];
                $html = self::getHelpInternal( $context, $modules, $options, $haveModules );
                if ( !empty( $options['toc'] ) && $haveModules ) {
                        $out->addHTML( Linker::generateTOC( $haveModules, $context->getLanguage() ) );
                }
                $out->addHTML( $html );

                $helptitle = isset( $options['helptitle'] ) ? $options['helptitle'] : null;
                $html = self::fixHelpLinks( $out->getHTML(), $helptitle, $haveModules );
                $out->clearHTML();
                $out->addHTML( $html );

                if ( $cacheKey !== null ) {
                        $cache->set( $cacheKey, $out->getHTML(), $cacheHelpTimeout );
                }
        }

        /**
         * Replace Special:ApiHelp links with links to api.php
         *
         * @param string $html
         * @param string|null $helptitle Title to link to rather than api.php, must contain '$1'
         * @param array $localModules Keys are modules to link within the current page, values are ignored
         * @return string
         */
        public static function fixHelpLinks( $html, $helptitle = null, $localModules = [] ) {
                $formatter = new HtmlFormatter( $html );
                $doc = $formatter->getDoc();
                $xpath = new DOMXPath( $doc );
                $nodes = $xpath->query( '//a[@href][not(contains(@class,\'apihelp-linktrail\'))]' );
                foreach ( $nodes as $node ) {
                        $href = $node->getAttribute( 'href' );
                        do {
                                $old = $href;
                                $href = rawurldecode( $href );
                        } while ( $old !== $href );
                        if ( preg_match( '!Special:ApiHelp/([^&/|#]+)((?:#.*)?)!', $href, $m ) ) {
                                if ( isset( $localModules[$m[1]] ) ) {
                                        $href = $m[2] === '' ? '#' . $m[1] : $m[2];
                                } elseif ( $helptitle !== null ) {
                                        $href = Title::newFromText( str_replace( '$1', $m[1], $helptitle ) . $m[2] )
                                                ->getFullURL();
                                } else {
                                        $href = wfAppendQuery( wfScript( 'api' ), [
                                                'action' => 'help',
                                                'modules' => $m[1],
                                        ] ) . $m[2];
                                }
                                $node->setAttribute( 'href', $href );
                                $node->removeAttribute( 'title' );
                        }
                }

                return $formatter->getText();
        }

        /**
         * Wrap a message in HTML with a class.
         *
         * @param Message $msg
         * @param string $class
         * @param string $tag
         * @return string
         */
        private static function wrap( Message $msg, $class, $tag = 'span' ) {
                return Html::rawElement( $tag, [ 'class' => $class ],
                        $msg->parse()
                );
        }

        /**
         * Recursively-called function to actually construct the help
         *
         * @param IContextSource $context
         * @param ApiBase[] $modules
         * @param array $options
         * @param array &$haveModules
         * @return string
         */
        private static function getHelpInternal( IContextSource $context, array $modules,
                array $options, &$haveModules
        ) {
                $out = '';

                $level = empty( $options['headerlevel'] ) ? 2 : $options['headerlevel'];
                if ( empty( $options['tocnumber'] ) ) {
                        $tocnumber = [ 2 => 0 ];
                } else {
                        $tocnumber = &$options['tocnumber'];
                }

                foreach ( $modules as $module ) {
                        $tocnumber[$level]++;
                        $path = $module->getModulePath();
                        $module->setContext( $context );
                        $help = [
                                'header' => '',
                                'flags' => '',
                                'description' => '',
                                'help-urls' => '',
                                'parameters' => '',
                                'examples' => '',
                                'submodules' => '',
                        ];

                        if ( empty( $options['noheader'] ) || !empty( $options['toc'] ) ) {
                                $anchor = $path;
                                $i = 1;
                                while ( isset( $haveModules[$anchor] ) ) {
                                        $anchor = $path . '|' . ++$i;
                                }

                                if ( $module->isMain() ) {
                                        $headerContent = $context->msg( 'api-help-main-header' )->parse();
                                        $headerAttr = [
                                                'class' => 'apihelp-header',
                                        ];
                                } else {
                                        $name = $module->getModuleName();
                                        $headerContent = $module->getParent()->getModuleManager()->getModuleGroup( $name ) .
                                                "=$name";
                                        if ( $module->getModulePrefix() !== '' ) {
                                                $headerContent .= ' ' .
                                                        $context->msg( 'parentheses', $module->getModulePrefix() )->parse();
                                        }
                                        // Module names are always in English and not localized,
                                        // so English language and direction must be set explicitly,
                                        // otherwise parentheses will get broken in RTL wikis
                                        $headerAttr = [
                                                'class' => 'apihelp-header apihelp-module-name',
                                                'dir' => 'ltr',
                                                'lang' => 'en',
                                        ];
                                }

                                $headerAttr['id'] = $anchor;

                                $haveModules[$anchor] = [
                                        'toclevel' => count( $tocnumber ),
                                        'level' => $level,
                                        'anchor' => $anchor,
                                        'line' => $headerContent,
                                        'number' => implode( '.', $tocnumber ),
                                        'index' => false,
                                ];
                                if ( empty( $options['noheader'] ) ) {
                                        $help['header'] .= Html::element(
                                                'h' . min( 6, $level ),
                                                $headerAttr,
                                                $headerContent
                                        );
                                }
                        } else {
                                $haveModules[$path] = true;
                        }

                        $links = [];
                        $any = false;
                        for ( $m = $module; $m !== null; $m = $m->getParent() ) {
                                $name = $m->getModuleName();
                                if ( $name === 'main_int' ) {
                                        $name = 'main';
                                }

                                if ( count( $modules ) === 1 && $m === $modules[0] &&
                                        !( !empty( $options['submodules'] ) && $m->getModuleManager() )
                                ) {
                                        $link = Html::element( 'b', null, $name );
                                } else {
                                        $link = SpecialPage::getTitleFor( 'ApiHelp', $m->getModulePath() )->getLocalURL();
                                        $link = Html::element( 'a',
                                                [ 'href' => $link, 'class' => 'apihelp-linktrail' ],
                                                $name
                                        );
                                        $any = true;
                                }
                                array_unshift( $links, $link );
                        }
                        if ( $any ) {
                                $help['header'] .= self::wrap(
                                        $context->msg( 'parentheses' )
                                                ->rawParams( $context->getLanguage()->pipeList( $links ) ),
                                        'apihelp-linktrail', 'div'
                                );
                        }

                        $flags = $module->getHelpFlags();
                        $help['flags'] .= Html::openElement( 'div',
                                [ 'class' => 'apihelp-block apihelp-flags' ] );
                        $msg = $context->msg( 'api-help-flags' );
                        if ( !$msg->isDisabled() ) {
                                $help['flags'] .= self::wrap(
                                        $msg->numParams( count( $flags ) ), 'apihelp-block-head', 'div'
                                );
                        }
                        $help['flags'] .= Html::openElement( 'ul' );
                        foreach ( $flags as $flag ) {
                                $help['flags'] .= Html::rawElement( 'li', null,
                                        self::wrap( $context->msg( "api-help-flag-$flag" ), "apihelp-flag-$flag" )
                                );
                        }
                        $sourceInfo = $module->getModuleSourceInfo();
                        if ( $sourceInfo ) {
                                if ( isset( $sourceInfo['namemsg'] ) ) {
                                        $extname = $context->msg( $sourceInfo['namemsg'] )->text();
                                } else {
                                        $extname = $sourceInfo['name'];
                                }
                                $help['flags'] .= Html::rawElement( 'li', null,
                                        self::wrap(
                                                $context->msg( 'api-help-source', $extname, $sourceInfo['name'] ),
                                                'apihelp-source'
                                        )
                                );

                                $link = SpecialPage::getTitleFor( 'Version', 'License/' . $sourceInfo['name'] );
                                if ( isset( $sourceInfo['license-name'] ) ) {
                                        $msg = $context->msg( 'api-help-license', $link, $sourceInfo['license-name'] );
                                } elseif ( SpecialVersion::getExtLicenseFileName( dirname( $sourceInfo['path'] ) ) ) {
                                        $msg = $context->msg( 'api-help-license-noname', $link );
                                } else {
                                        $msg = $context->msg( 'api-help-license-unknown' );
                                }
                                $help['flags'] .= Html::rawElement( 'li', null,
                                        self::wrap( $msg, 'apihelp-license' )
                                );
                        } else {
                                $help['flags'] .= Html::rawElement( 'li', null,
                                        self::wrap( $context->msg( 'api-help-source-unknown' ), 'apihelp-source' )
                                );
                                $help['flags'] .= Html::rawElement( 'li', null,
                                        self::wrap( $context->msg( 'api-help-license-unknown' ), 'apihelp-license' )
                                );
                        }
                        $help['flags'] .= Html::closeElement( 'ul' );
                        $help['flags'] .= Html::closeElement( 'div' );

                        foreach ( $module->getFinalDescription() as $msg ) {
                                $msg->setContext( $context );
                                $help['description'] .= $msg->parseAsBlock();
                        }

                        $urls = $module->getHelpUrls();
                        if ( $urls ) {
                                $help['help-urls'] .= Html::openElement( 'div',
                                        [ 'class' => 'apihelp-block apihelp-help-urls' ]
                                );
                                $msg = $context->msg( 'api-help-help-urls' );
                                if ( !$msg->isDisabled() ) {
                                        $help['help-urls'] .= self::wrap(
                                                $msg->numParams( count( $urls ) ), 'apihelp-block-head', 'div'
                                        );
                                }
                                if ( !is_array( $urls ) ) {
                                        $urls = [ $urls ];
                                }
                                $help['help-urls'] .= Html::openElement( 'ul' );
                                foreach ( $urls as $url ) {
                                        $help['help-urls'] .= Html::rawElement( 'li', null,
                                                Html::element( 'a', [ 'href' => $url ], $url )
                                        );
                                }
                                $help['help-urls'] .= Html::closeElement( 'ul' );
                                $help['help-urls'] .= Html::closeElement( 'div' );
                        }

                        $params = $module->getFinalParams( ApiBase::GET_VALUES_FOR_HELP );
                        $dynamicParams = $module->dynamicParameterDocumentation();
                        $groups = [];
                        if ( $params || $dynamicParams !== null ) {
                                $help['parameters'] .= Html::openElement( 'div',
                                        [ 'class' => 'apihelp-block apihelp-parameters' ]
                                );
                                $msg = $context->msg( 'api-help-parameters' );
                                if ( !$msg->isDisabled() ) {
                                        $help['parameters'] .= self::wrap(
                                                $msg->numParams( count( $params ) ), 'apihelp-block-head', 'div'
                                        );
                                }
                                $help['parameters'] .= Html::openElement( 'dl' );

                                $descriptions = $module->getFinalParamDescription();

                                foreach ( $params as $name => $settings ) {
                                        if ( !is_array( $settings ) ) {
                                                $settings = [ ApiBase::PARAM_DFLT => $settings ];
                                        }

                                        $help['parameters'] .= Html::element( 'dt', null,
                                                $module->encodeParamName( $name ) );

                                        // Add description
                                        $description = [];
                                        if ( isset( $descriptions[$name] ) ) {
                                                foreach ( $descriptions[$name] as $msg ) {
                                                        $msg->setContext( $context );
                                                        $description[] = $msg->parseAsBlock();
                                                }
                                        }

                                        // Add usage info
                                        $info = [];

                                        // Required?
                                        if ( !empty( $settings[ApiBase::PARAM_REQUIRED] ) ) {
                                                $info[] = $context->msg( 'api-help-param-required' )->parse();
                                        }

                                        // Custom info?
                                        if ( !empty( $settings[ApiBase::PARAM_HELP_MSG_INFO] ) ) {
                                                foreach ( $settings[ApiBase::PARAM_HELP_MSG_INFO] as $i ) {
                                                        $tag = array_shift( $i );
                                                        $info[] = $context->msg( "apihelp-{$path}-paraminfo-{$tag}" )
                                                                ->numParams( count( $i ) )
                                                                ->params( $context->getLanguage()->commaList( $i ) )
                                                                ->params( $module->getModulePrefix() )
                                                                ->parse();
                                                }
                                        }

                                        // Type documentation
                                        if ( !isset( $settings[ApiBase::PARAM_TYPE] ) ) {
                                                $dflt = isset( $settings[ApiBase::PARAM_DFLT] )
                                                        ? $settings[ApiBase::PARAM_DFLT]
                                                        : null;
                                                if ( is_bool( $dflt ) ) {
                                                        $settings[ApiBase::PARAM_TYPE] = 'boolean';
                                                } elseif ( is_string( $dflt ) || is_null( $dflt ) ) {
                                                        $settings[ApiBase::PARAM_TYPE] = 'string';
                                                } elseif ( is_int( $dflt ) ) {
                                                        $settings[ApiBase::PARAM_TYPE] = 'integer';
                                                }
                                        }
                                        if ( isset( $settings[ApiBase::PARAM_TYPE] ) ) {
                                                $type = $settings[ApiBase::PARAM_TYPE];
                                                $multi = !empty( $settings[ApiBase::PARAM_ISMULTI] );
                                                $hintPipeSeparated = true;
                                                $count = ApiBase::LIMIT_SML2 + 1;

                                                if ( is_array( $type ) ) {
                                                        $count = count( $type );
                                                        $links = isset( $settings[ApiBase::PARAM_VALUE_LINKS] )
                                                                ? $settings[ApiBase::PARAM_VALUE_LINKS]
                                                                : [];
                                                        $type = array_map( function ( $v ) use ( $links ) {
                                                                $ret = wfEscapeWikiText( $v );
                                                                if ( isset( $links[$v] ) ) {
                                                                        $ret = "[[{$links[$v]}|$ret]]";
                                                                }
                                                                return $ret;
                                                        }, $type );
                                                        $i = array_search( '', $type, true );
                                                        if ( $i === false ) {
                                                                $type = $context->getLanguage()->commaList( $type );
                                                        } else {
                                                                unset( $type[$i] );
                                                                $type = $context->msg( 'api-help-param-list-can-be-empty' )
                                                                        ->numParams( count( $type ) )
                                                                        ->params( $context->getLanguage()->commaList( $type ) )
                                                                        ->parse();
                                                        }
                                                        $info[] = $context->msg( 'api-help-param-list' )
                                                                ->params( $multi ? 2 : 1 )
                                                                ->params( $type )
                                                                ->parse();
                                                        $hintPipeSeparated = false;
                                                } else {
                                                        switch ( $type ) {
                                                                case 'submodule':
                                                                        $groups[] = $name;
                                                                        if ( isset( $settings[ApiBase::PARAM_SUBMODULE_MAP] ) ) {
                                                                                $map = $settings[ApiBase::PARAM_SUBMODULE_MAP];
                                                                                ksort( $map );
                                                                                $submodules = [];
                                                                                foreach ( $map as $v => $m ) {
                                                                                        $submodules[] = "[[Special:ApiHelp/{$m}|{$v}]]";
                                                                                }
                                                                        } else {
                                                                                $submodules = $module->getModuleManager()->getNames( $name );
                                                                                sort( $submodules );
                                                                                $prefix = $module->isMain()
                                                                                        ? '' : ( $module->getModulePath() . '+' );
                                                                                $submodules = array_map( function ( $name ) use ( $prefix ) {
                                                                                        return "[[Special:ApiHelp/{$prefix}{$name}|{$name}]]";
                                                                                }, $submodules );
                                                                        }
                                                                        $count = count( $submodules );
                                                                        $info[] = $context->msg( 'api-help-param-list' )
                                                                                ->params( $multi ? 2 : 1 )
                                                                                ->params( $context->getLanguage()->commaList( $submodules ) )
                                                                                ->parse();
                                                                        $hintPipeSeparated = false;
                                                                        // No type message necessary, we have a list of values.
                                                                        $type = null;
                                                                        break;

                                                                case 'namespace':
                                                                        $namespaces = MWNamespace::getValidNamespaces();
                                                                        $count = count( $namespaces );
                                                                        $info[] = $context->msg( 'api-help-param-list' )
                                                                                ->params( $multi ? 2 : 1 )
                                                                                ->params( $context->getLanguage()->commaList( $namespaces ) )
                                                                                ->parse();
                                                                        $hintPipeSeparated = false;
                                                                        // No type message necessary, we have a list of values.
                                                                        $type = null;
                                                                        break;

                                                                case 'tags':
                                                                        $tags = ChangeTags::listExplicitlyDefinedTags();
                                                                        $count = count( $tags );
                                                                        $info[] = $context->msg( 'api-help-param-list' )
                                                                                ->params( $multi ? 2 : 1 )
                                                                                ->params( $context->getLanguage()->commaList( $tags ) )
                                                                                ->parse();
                                                                        $hintPipeSeparated = false;
                                                                        $type = null;
                                                                        break;

                                                                case 'limit':
                                                                        if ( isset( $settings[ApiBase::PARAM_MAX2] ) ) {
                                                                                $info[] = $context->msg( 'api-help-param-limit2' )
                                                                                        ->numParams( $settings[ApiBase::PARAM_MAX] )
                                                                                        ->numParams( $settings[ApiBase::PARAM_MAX2] )
                                                                                        ->parse();
                                                                        } else {
                                                                                $info[] = $context->msg( 'api-help-param-limit' )
                                                                                        ->numParams( $settings[ApiBase::PARAM_MAX] )
                                                                                        ->parse();
                                                                        }
                                                                        break;

                                                                case 'integer':
                                                                        // Possible messages:
                                                                        // api-help-param-integer-min,
                                                                        // api-help-param-integer-max,
                                                                        // api-help-param-integer-minmax
                                                                        $suffix = '';
                                                                        $min = $max = 0;
                                                                        if ( isset( $settings[ApiBase::PARAM_MIN] ) ) {
                                                                                $suffix .= 'min';
                                                                                $min = $settings[ApiBase::PARAM_MIN];
                                                                        }
                                                                        if ( isset( $settings[ApiBase::PARAM_MAX] ) ) {
                                                                                $suffix .= 'max';
                                                                                $max = $settings[ApiBase::PARAM_MAX];
                                                                        }
                                                                        if ( $suffix !== '' ) {
                                                                                $info[] =
                                                                                        $context->msg( "api-help-param-integer-$suffix" )
                                                                                                ->params( $multi ? 2 : 1 )
                                                                                                ->numParams( $min, $max )
                                                                                                ->parse();
                                                                        }
                                                                        break;

                                                                case 'upload':
                                                                        $info[] = $context->msg( 'api-help-param-upload' )
                                                                                ->parse();
                                                                        // No type message necessary, api-help-param-upload should handle it.
                                                                        $type = null;
                                                                        break;

                                                                case 'string':
                                                                case 'text':
                                                                        // Displaying a type message here would be useless.
                                                                        $type = null;
                                                                        break;
                                                        }
                                                }

                                                // Add type. Messages for grep: api-help-param-type-limit
                                                // api-help-param-type-integer api-help-param-type-boolean
                                                // api-help-param-type-timestamp api-help-param-type-user
                                                // api-help-param-type-password
                                                if ( is_string( $type ) ) {
                                                        $msg = $context->msg( "api-help-param-type-$type" );
                                                        if ( !$msg->isDisabled() ) {
                                                                $info[] = $msg->params( $multi ? 2 : 1 )->parse();
                                                        }
                                                }

                                                if ( $multi ) {
                                                        $extra = [];
                                                        if ( $hintPipeSeparated ) {
                                                                $extra[] = $context->msg( 'api-help-param-multi-separate' )->parse();
                                                        }
                                                        if ( $count > ApiBase::LIMIT_SML1 ) {
                                                                $extra[] = $context->msg( 'api-help-param-multi-max' )
                                                                        ->numParams( ApiBase::LIMIT_SML1, ApiBase::LIMIT_SML2 )
                                                                        ->parse();
                                                        }
                                                        if ( $extra ) {
                                                                $info[] = implode( ' ', $extra );
                                                        }
                                                }
                                        }

                                        // Add default
                                        $default = isset( $settings[ApiBase::PARAM_DFLT] )
                                                ? $settings[ApiBase::PARAM_DFLT]
                                                : null;
                                        if ( $default === '' ) {
                                                $info[] = $context->msg( 'api-help-param-default-empty' )
                                                        ->parse();
                                        } elseif ( $default !== null && $default !== false ) {
                                                $info[] = $context->msg( 'api-help-param-default' )
                                                        ->params( wfEscapeWikiText( $default ) )
                                                        ->parse();
                                        }

                                        if ( !array_filter( $description ) ) {
                                                $description = [ self::wrap(
                                                        $context->msg( 'api-help-param-no-description' ),
                                                        'apihelp-empty'
                                                ) ];
                                        }

                                        // Add "deprecated" flag
                                        if ( !empty( $settings[ApiBase::PARAM_DEPRECATED] ) ) {
                                                $help['parameters'] .= Html::openElement( 'dd',
                                                        [ 'class' => 'info' ] );
                                                $help['parameters'] .= self::wrap(
                                                        $context->msg( 'api-help-param-deprecated' ),
                                                        'apihelp-deprecated', 'strong'
                                                );
                                                $help['parameters'] .= Html::closeElement( 'dd' );
                                        }

                                        if ( $description ) {
                                                $description = implode( '', $description );
                                                $description = preg_replace( '!\s*</([oud]l)>\s*<\1>\s*!', "\n", $description );
                                                $help['parameters'] .= Html::rawElement( 'dd',
                                                        [ 'class' => 'description' ], $description );
                                        }

                                        foreach ( $info as $i ) {
                                                $help['parameters'] .= Html::rawElement( 'dd', [ 'class' => 'info' ], $i );
                                        }
                                }

                                if ( $dynamicParams !== null ) {
                                        $dynamicParams = ApiBase::makeMessage( $dynamicParams, $context, [
                                                $module->getModulePrefix(),
                                                $module->getModuleName(),
                                                $module->getModulePath()
                                        ] );
                                        $help['parameters'] .= Html::element( 'dt', null, '*' );
                                        $help['parameters'] .= Html::rawElement( 'dd',
                                                [ 'class' => 'description' ], $dynamicParams->parse() );
                                }

                                $help['parameters'] .= Html::closeElement( 'dl' );
                                $help['parameters'] .= Html::closeElement( 'div' );
                        }

                        $examples = $module->getExamplesMessages();
                        if ( $examples ) {
                                $help['examples'] .= Html::openElement( 'div',
                                        [ 'class' => 'apihelp-block apihelp-examples' ] );
                                $msg = $context->msg( 'api-help-examples' );
                                if ( !$msg->isDisabled() ) {
                                        $help['examples'] .= self::wrap(
                                                $msg->numParams( count( $examples ) ), 'apihelp-block-head', 'div'
                                        );
                                }

                                $help['examples'] .= Html::openElement( 'dl' );
                                foreach ( $examples as $qs => $msg ) {
                                        $msg = ApiBase::makeMessage( $msg, $context, [
                                                $module->getModulePrefix(),
                                                $module->getModuleName(),
                                                $module->getModulePath()
                                        ] );

                                        $link = wfAppendQuery( wfScript( 'api' ), $qs );
                                        $sandbox = SpecialPage::getTitleFor( 'ApiSandbox' )->getLocalURL() . '#' . $qs;
                                        $help['examples'] .= Html::rawElement( 'dt', null, $msg->parse() );
                                        $help['examples'] .= Html::rawElement( 'dd', null,
                                                Html::element( 'a', [ 'href' => $link ], "api.php?$qs" ) . ' ' .
                                                Html::rawElement( 'a', [ 'href' => $sandbox ],
                                                        $context->msg( 'api-help-open-in-apisandbox' )->parse() )
                                        );
                                }
                                $help['examples'] .= Html::closeElement( 'dl' );
                                $help['examples'] .= Html::closeElement( 'div' );
                        }

                        $subtocnumber = $tocnumber;
                        $subtocnumber[$level + 1] = 0;
                        $suboptions = [
                                'submodules' => $options['recursivesubmodules'],
                                'headerlevel' => $level + 1,
                                'tocnumber' => &$subtocnumber,
                                'noheader' => false,
                        ] + $options;

                        if ( $options['submodules'] && $module->getModuleManager() ) {
                                $manager = $module->getModuleManager();
                                $submodules = [];
                                foreach ( $groups as $group ) {
                                        $names = $manager->getNames( $group );
                                        sort( $names );
                                        foreach ( $names as $name ) {
                                                $submodules[] = $manager->getModule( $name );
                                        }
                                }
                                $help['submodules'] .= self::getHelpInternal(
                                        $context,
                                        $submodules,
                                        $suboptions,
                                        $haveModules
                                );
                        }

                        $module->modifyHelp( $help, $suboptions, $haveModules );

                        Hooks::run( 'APIHelpModifyOutput', [ $module, &$help, $suboptions, &$haveModules ] );

                        $out .= implode( "\n", $help );
                }

                return $out;
        }

        public function shouldCheckMaxlag() {
                return false;
        }

        public function isReadMode() {
                return false;
        }

        public function getCustomPrinter() {
                $params = $this->extractRequestParams();
                if ( $params['wrap'] ) {
                        return null;
                }

                $main = $this->getMain();
                $errorPrinter = $main->createPrinterByName( $main->getParameter( 'format' ) );
                return new ApiFormatRaw( $main, $errorPrinter );
        }

        public function getAllowedParams() {
                return [
                        'modules' => [
                                ApiBase::PARAM_DFLT => 'main',
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'submodules' => false,
                        'recursivesubmodules' => false,
                        'wrap' => false,
                        'toc' => false,
                ];
        }

        protected function getExamplesMessages() {
                return [
                        'action=help'
                                => 'apihelp-help-example-main',
                        'action=help&modules=query&submodules=1'
                                => 'apihelp-help-example-submodules',
                        'action=help&recursivesubmodules=1'
                                => 'apihelp-help-example-recursive',
                        'action=help&modules=help'
                                => 'apihelp-help-example-help',
                        'action=help&modules=query+info|query+categorymembers'
                                => 'apihelp-help-example-query',
                ];
        }

        public function getHelpUrls() {
                return [
                        'https://www.mediawiki.org/wiki/API:Main_page',
                        'https://www.mediawiki.org/wiki/API:FAQ',
                        'https://www.mediawiki.org/wiki/API:Quick_start_guide',
                ];
        }
}