ApiBase.php

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<?php
abstract class ApiBase extends ContextSource {
    // These constants allow modules to specify exactly how to treat incoming parameters.

    // Default value of the parameter
    const PARAM_DFLT = 0;
    // Boolean, do we accept more than one item for this parameter (e.g.: titles)?
    const PARAM_ISMULTI = 1;
    // Can be either a string type (e.g.: 'integer') or an array of allowed values
    const PARAM_TYPE = 2;
    // Max value allowed for a parameter. Only applies if TYPE='integer'
    const PARAM_MAX = 3;
    // Max value allowed for a parameter for bots and sysops. Only applies if TYPE='integer'
    const PARAM_MAX2 = 4;
    // Lowest value allowed for a parameter. Only applies if TYPE='integer'
    const PARAM_MIN = 5;
    // Boolean, do we allow the same value to be set more than once when ISMULTI=true
    const PARAM_ALLOW_DUPLICATES = 6;
    // Boolean, is the parameter deprecated (will show a warning)
    const PARAM_DEPRECATED = 7;
    const PARAM_REQUIRED = 8; // Boolean, is the parameter required?
    // Boolean, if MIN/MAX are set, enforce (die) these?
    // Only applies if TYPE='integer' Use with extreme caution
    const PARAM_RANGE_ENFORCE = 9;

    const LIMIT_BIG1 = 500; // Fast query, std user limit
    const LIMIT_BIG2 = 5000; // Fast query, bot/sysop limit
    const LIMIT_SML1 = 50; // Slow query, std user limit
    const LIMIT_SML2 = 500; // Slow query, bot/sysop limit

    const GET_VALUES_FOR_HELP = 1;

    private $mMainModule;
    private $mModuleName, $mModulePrefix;
    private $mSlaveDB = null;
    private $mParamCache = array();

    public function __construct( ApiMain $mainModule, $moduleName, $modulePrefix = '' ) {
        $this->mMainModule = $mainModule;
        $this->mModuleName = $moduleName;
        $this->mModulePrefix = $modulePrefix;

        if ( !$this->isMain() ) {
            $this->setContext( $mainModule->getContext() );
        }
    }


    /************************************************************************/
    abstract public function execute();

    public function getModuleManager() {
        return null;
    }

    public function getCustomPrinter() {
        return null;
    }

    protected function getDescription() {
        return false;
    }

    protected function getExamples() {
        return false;
    }

    public function getHelpUrls() {
        return false;
    }

    protected function getAllowedParams( /* $flags = 0 */ ) {
        // int $flags is not declared because it causes "Strict standards"
        // warning. Most derived classes do not implement it.
        return false;
    }

    protected function getParamDescription() {
        return false;
    }

    public function shouldCheckMaxlag() {
        return true;
    }

    public function isReadMode() {
        return true;
    }

    public function isWriteMode() {
        return false;
    }

    public function mustBePosted() {
        return $this->needsToken() !== false;
    }

    public function needsToken() {
        return false;
    }

    protected function getWebUITokenSalt( array $params ) {
        return null;
    }

    /************************************************************************/
    public function getModuleName() {
        return $this->mModuleName;
    }

    public function getModulePrefix() {
        return $this->mModulePrefix;
    }

    public function getMain() {
        return $this->mMainModule;
    }

    public function isMain() {
        return $this === $this->mMainModule;
    }

    public function getResult() {
        // Main module has getResult() method overridden
        // Safety - avoid infinite loop:
        if ( $this->isMain() ) {
            ApiBase::dieDebug( __METHOD__, 'base method was called on main module. ' );
        }

        return $this->getMain()->getResult();
    }

    public function getResultData() {
        return $this->getResult()->getData();
    }

    protected function getDB() {
        if ( !isset( $this->mSlaveDB ) ) {
            $this->profileDBIn();
            $this->mSlaveDB = wfGetDB( DB_SLAVE, 'api' );
            $this->profileDBOut();
        }

        return $this->mSlaveDB;
    }

    public function getFinalDescription() {
        $desc = $this->getDescription();
        wfRunHooks( 'APIGetDescription', array( &$this, &$desc ) );

        return $desc;
    }

    public function getFinalParams( $flags = 0 ) {
        $params = $this->getAllowedParams( $flags );

        if ( $this->needsToken() ) {
            $params['token'] = array(
                ApiBase::PARAM_TYPE => 'string',
                ApiBase::PARAM_REQUIRED => true,
            );
        }

        wfRunHooks( 'APIGetAllowedParams', array( &$this, &$params, $flags ) );

        return $params;
    }

    public function getFinalParamDescription() {
        $desc = $this->getParamDescription();

        $tokenType = $this->needsToken();
        if ( $tokenType ) {
            if ( !isset( $desc['token'] ) ) {
                $desc['token'] = array();
            } elseif ( !is_array( $desc['token'] ) ) {
                // We ignore a plain-string token, because it's probably an
                // extension that is supplying the string for BC.
                $desc['token'] = array();
            }
            array_unshift( $desc['token'],
                "A '$tokenType' token retrieved from action=query&meta=tokens"
            );
        }

        wfRunHooks( 'APIGetParamDescription', array( &$this, &$desc ) );

        return $desc;
    }

    /************************************************************************/
    public function encodeParamName( $paramName ) {
        return $this->mModulePrefix . $paramName;
    }

    public function extractRequestParams( $parseLimit = true ) {
        // Cache parameters, for performance and to avoid bug 24564.
        if ( !isset( $this->mParamCache[$parseLimit] ) ) {
            $params = $this->getFinalParams();
            $results = array();

            if ( $params ) { // getFinalParams() can return false
                foreach ( $params as $paramName => $paramSettings ) {
                    $results[$paramName] = $this->getParameterFromSettings(
                        $paramName, $paramSettings, $parseLimit );
                }
            }
            $this->mParamCache[$parseLimit] = $results;
        }

        return $this->mParamCache[$parseLimit];
    }

    protected function getParameter( $paramName, $parseLimit = true ) {
        $params = $this->getFinalParams();
        $paramSettings = $params[$paramName];

        return $this->getParameterFromSettings( $paramName, $paramSettings, $parseLimit );
    }

    public function requireOnlyOneParameter( $params, $required /*...*/ ) {
        $required = func_get_args();
        array_shift( $required );
        $p = $this->getModulePrefix();

        $intersection = array_intersect( array_keys( array_filter( $params,
            array( $this, "parameterNotEmpty" ) ) ), $required );

        if ( count( $intersection ) > 1 ) {
            $this->dieUsage(
                "The parameters {$p}" . implode( ", {$p}", $intersection ) . ' can not be used together',
                'invalidparammix' );
        } elseif ( count( $intersection ) == 0 ) {
            $this->dieUsage(
                "One of the parameters {$p}" . implode( ", {$p}", $required ) . ' is required',
                'missingparam'
            );
        }
    }

    public function requireMaxOneParameter( $params, $required /*...*/ ) {
        $required = func_get_args();
        array_shift( $required );
        $p = $this->getModulePrefix();

        $intersection = array_intersect( array_keys( array_filter( $params,
            array( $this, "parameterNotEmpty" ) ) ), $required );

        if ( count( $intersection ) > 1 ) {
            $this->dieUsage(
                "The parameters {$p}" . implode( ", {$p}", $intersection ) . ' can not be used together',
                'invalidparammix'
            );
        }
    }

    public function requireAtLeastOneParameter( $params, $required /*...*/ ) {
        $required = func_get_args();
        array_shift( $required );
        $p = $this->getModulePrefix();

        $intersection = array_intersect(
            array_keys( array_filter( $params, array( $this, "parameterNotEmpty" ) ) ),
            $required
        );

        if ( count( $intersection ) == 0 ) {
            $this->dieUsage( "At least one of the parameters {$p}" .
                implode( ", {$p}", $required ) . ' is required', "{$p}missingparam" );
        }
    }

    private function parameterNotEmpty( $x ) {
        return !is_null( $x ) && $x !== false;
    }

    public function getTitleOrPageId( $params, $load = false ) {
        $this->requireOnlyOneParameter( $params, 'title', 'pageid' );

        $pageObj = null;
        if ( isset( $params['title'] ) ) {
            $titleObj = Title::newFromText( $params['title'] );
            if ( !$titleObj || $titleObj->isExternal() ) {
                $this->dieUsageMsg( array( 'invalidtitle', $params['title'] ) );
            }
            if ( !$titleObj->canExist() ) {
                $this->dieUsage( "Namespace doesn't allow actual pages", 'pagecannotexist' );
            }
            $pageObj = WikiPage::factory( $titleObj );
            if ( $load !== false ) {
                $pageObj->loadPageData( $load );
            }
        } elseif ( isset( $params['pageid'] ) ) {
            if ( $load === false ) {
                $load = 'fromdb';
            }
            $pageObj = WikiPage::newFromID( $params['pageid'], $load );
            if ( !$pageObj ) {
                $this->dieUsageMsg( array( 'nosuchpageid', $params['pageid'] ) );
            }
        }

        return $pageObj;
    }

    protected function getWatchlistValue( $watchlist, $titleObj, $userOption = null ) {

        $userWatching = $this->getUser()->isWatched( $titleObj, WatchedItem::IGNORE_USER_RIGHTS );

        switch ( $watchlist ) {
            case 'watch':
                return true;

            case 'unwatch':
                return false;

            case 'preferences':
                # If the user is already watching, don't bother checking
                if ( $userWatching ) {
                    return true;
                }
                # If no user option was passed, use watchdefault and watchcreations
                if ( is_null( $userOption ) ) {
                    return $this->getUser()->getBoolOption( 'watchdefault' ) ||
                        $this->getUser()->getBoolOption( 'watchcreations' ) && !$titleObj->exists();
                }

                # Watch the article based on the user preference
                return $this->getUser()->getBoolOption( $userOption );

            case 'nochange':
                return $userWatching;

            default:
                return $userWatching;
        }
    }

    protected function getParameterFromSettings( $paramName, $paramSettings, $parseLimit ) {
        // Some classes may decide to change parameter names
        $encParamName = $this->encodeParamName( $paramName );

        if ( !is_array( $paramSettings ) ) {
            $default = $paramSettings;
            $multi = false;
            $type = gettype( $paramSettings );
            $dupes = false;
            $deprecated = false;
            $required = false;
        } else {
            $default = isset( $paramSettings[self::PARAM_DFLT] )
                ? $paramSettings[self::PARAM_DFLT]
                : null;
            $multi = isset( $paramSettings[self::PARAM_ISMULTI] )
                ? $paramSettings[self::PARAM_ISMULTI]
                : false;
            $type = isset( $paramSettings[self::PARAM_TYPE] )
                ? $paramSettings[self::PARAM_TYPE]
                : null;
            $dupes = isset( $paramSettings[self::PARAM_ALLOW_DUPLICATES] )
                ? $paramSettings[self::PARAM_ALLOW_DUPLICATES]
                : false;
            $deprecated = isset( $paramSettings[self::PARAM_DEPRECATED] )
                ? $paramSettings[self::PARAM_DEPRECATED]
                : false;
            $required = isset( $paramSettings[self::PARAM_REQUIRED] )
                ? $paramSettings[self::PARAM_REQUIRED]
                : false;

            // When type is not given, and no choices, the type is the same as $default
            if ( !isset( $type ) ) {
                if ( isset( $default ) ) {
                    $type = gettype( $default );
                } else {
                    $type = 'NULL'; // allow everything
                }
            }
        }

        if ( $type == 'boolean' ) {
            if ( isset( $default ) && $default !== false ) {
                // Having a default value of anything other than 'false' is not allowed
                ApiBase::dieDebug(
                    __METHOD__,
                    "Boolean param $encParamName's default is set to '$default'. " .
                        "Boolean parameters must default to false."
                );
            }

            $value = $this->getMain()->getCheck( $encParamName );
        } elseif ( $type == 'upload' ) {
            if ( isset( $default ) ) {
                // Having a default value is not allowed
                ApiBase::dieDebug(
                    __METHOD__,
                    "File upload param $encParamName's default is set to " .
                        "'$default'. File upload parameters may not have a default." );
            }
            if ( $multi ) {
                ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
            }
            $value = $this->getMain()->getUpload( $encParamName );
            if ( !$value->exists() ) {
                // This will get the value without trying to normalize it
                // (because trying to normalize a large binary file
                // accidentally uploaded as a field fails spectacularly)
                $value = $this->getMain()->getRequest()->unsetVal( $encParamName );
                if ( $value !== null ) {
                    $this->dieUsage(
                        "File upload param $encParamName is not a file upload; " .
                            "be sure to use multipart/form-data for your POST and include " .
                            "a filename in the Content-Disposition header.",
                        "badupload_{$encParamName}"
                    );
                }
            }
        } else {
            $value = $this->getMain()->getVal( $encParamName, $default );

            if ( isset( $value ) && $type == 'namespace' ) {
                $type = MWNamespace::getValidNamespaces();
            }
            if ( isset( $value ) && $type == 'submodule' ) {
                $type = $this->getModuleManager()->getNames( $paramName );
            }
        }

        if ( isset( $value ) && ( $multi || is_array( $type ) ) ) {
            $value = $this->parseMultiValue(
                $encParamName,
                $value,
                $multi,
                is_array( $type ) ? $type : null
            );
        }

        // More validation only when choices were not given
        // choices were validated in parseMultiValue()
        if ( isset( $value ) ) {
            if ( !is_array( $type ) ) {
                switch ( $type ) {
                    case 'NULL': // nothing to do
                        break;
                    case 'string':
                        if ( $required && $value === '' ) {
                            $this->dieUsageMsg( array( 'missingparam', $paramName ) );
                        }
                        break;
                    case 'integer': // Force everything using intval() and optionally validate limits
                        $min = isset( $paramSettings[self::PARAM_MIN] ) ? $paramSettings[self::PARAM_MIN] : null;
                        $max = isset( $paramSettings[self::PARAM_MAX] ) ? $paramSettings[self::PARAM_MAX] : null;
                        $enforceLimits = isset( $paramSettings[self::PARAM_RANGE_ENFORCE] )
                            ? $paramSettings[self::PARAM_RANGE_ENFORCE] : false;

                        if ( is_array( $value ) ) {
                            $value = array_map( 'intval', $value );
                            if ( !is_null( $min ) || !is_null( $max ) ) {
                                foreach ( $value as &$v ) {
                                    $this->validateLimit( $paramName, $v, $min, $max, null, $enforceLimits );
                                }
                            }
                        } else {
                            $value = intval( $value );
                            if ( !is_null( $min ) || !is_null( $max ) ) {
                                $this->validateLimit( $paramName, $value, $min, $max, null, $enforceLimits );
                            }
                        }
                        break;
                    case 'limit':
                        if ( !$parseLimit ) {
                            // Don't do any validation whatsoever
                            break;
                        }
                        if ( !isset( $paramSettings[self::PARAM_MAX] )
                            || !isset( $paramSettings[self::PARAM_MAX2] )
                        ) {
                            ApiBase::dieDebug(
                                __METHOD__,
                                "MAX1 or MAX2 are not defined for the limit $encParamName"
                            );
                        }
                        if ( $multi ) {
                            ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
                        }
                        $min = isset( $paramSettings[self::PARAM_MIN] ) ? $paramSettings[self::PARAM_MIN] : 0;
                        if ( $value == 'max' ) {
                            $value = $this->getMain()->canApiHighLimits()
                                ? $paramSettings[self::PARAM_MAX2]
                                : $paramSettings[self::PARAM_MAX];
                            $this->getResult()->setParsedLimit( $this->getModuleName(), $value );
                        } else {
                            $value = intval( $value );
                            $this->validateLimit(
                                $paramName,
                                $value,
                                $min,
                                $paramSettings[self::PARAM_MAX],
                                $paramSettings[self::PARAM_MAX2]
                            );
                        }
                        break;
                    case 'boolean':
                        if ( $multi ) {
                            ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
                        }
                        break;
                    case 'timestamp':
                        if ( is_array( $value ) ) {
                            foreach ( $value as $key => $val ) {
                                $value[$key] = $this->validateTimestamp( $val, $encParamName );
                            }
                        } else {
                            $value = $this->validateTimestamp( $value, $encParamName );
                        }
                        break;
                    case 'user':
                        if ( is_array( $value ) ) {
                            foreach ( $value as $key => $val ) {
                                $value[$key] = $this->validateUser( $val, $encParamName );
                            }
                        } else {
                            $value = $this->validateUser( $value, $encParamName );
                        }
                        break;
                    case 'upload': // nothing to do
                        break;
                    default:
                        ApiBase::dieDebug( __METHOD__, "Param $encParamName's type is unknown - $type" );
                }
            }

            // Throw out duplicates if requested
            if ( !$dupes && is_array( $value ) ) {
                $value = array_unique( $value );
            }

            // Set a warning if a deprecated parameter has been passed
            if ( $deprecated && $value !== false ) {
                $this->setWarning( "The $encParamName parameter has been deprecated." );
            }
        } elseif ( $required ) {
            $this->dieUsageMsg( array( 'missingparam', $paramName ) );
        }

        return $value;
    }

    protected function parseMultiValue( $valueName, $value, $allowMultiple, $allowedValues ) {
        if ( trim( $value ) === '' && $allowMultiple ) {
            return array();
        }

        // This is a bit awkward, but we want to avoid calling canApiHighLimits()
        // because it unstubs $wgUser
        $valuesList = explode( '|', $value, self::LIMIT_SML2 + 1 );
        $sizeLimit = count( $valuesList ) > self::LIMIT_SML1 && $this->mMainModule->canApiHighLimits()
            ? self::LIMIT_SML2
            : self::LIMIT_SML1;

        if ( self::truncateArray( $valuesList, $sizeLimit ) ) {
            $this->setWarning( "Too many values supplied for parameter '$valueName': " .
                "the limit is $sizeLimit" );
        }

        if ( !$allowMultiple && count( $valuesList ) != 1 ) {
            // Bug 33482 - Allow entries with | in them for non-multiple values
            if ( in_array( $value, $allowedValues, true ) ) {
                return $value;
            }

            $possibleValues = is_array( $allowedValues )
                ? "of '" . implode( "', '", $allowedValues ) . "'"
                : '';
            $this->dieUsage(
                "Only one $possibleValues is allowed for parameter '$valueName'",
                "multival_$valueName"
            );
        }

        if ( is_array( $allowedValues ) ) {
            // Check for unknown values
            $unknown = array_diff( $valuesList, $allowedValues );
            if ( count( $unknown ) ) {
                if ( $allowMultiple ) {
                    $s = count( $unknown ) > 1 ? 's' : '';
                    $vals = implode( ", ", $unknown );
                    $this->setWarning( "Unrecognized value$s for parameter '$valueName': $vals" );
                } else {
                    $this->dieUsage(
                        "Unrecognized value for parameter '$valueName': {$valuesList[0]}",
                        "unknown_$valueName"
                    );
                }
            }
            // Now throw them out
            $valuesList = array_intersect( $valuesList, $allowedValues );
        }

        return $allowMultiple ? $valuesList : $valuesList[0];
    }

    protected function validateLimit( $paramName, &$value, $min, $max, $botMax = null, $enforceLimits = false ) {
        if ( !is_null( $min ) && $value < $min ) {

            $msg = $this->encodeParamName( $paramName ) . " may not be less than $min (set to $value)";
            $this->warnOrDie( $msg, $enforceLimits );
            $value = $min;
        }

        // Minimum is always validated, whereas maximum is checked only if not
        // running in internal call mode
        if ( $this->getMain()->isInternalMode() ) {
            return;
        }

        // Optimization: do not check user's bot status unless really needed -- skips db query
        // assumes $botMax >= $max
        if ( !is_null( $max ) && $value > $max ) {
            if ( !is_null( $botMax ) && $this->getMain()->canApiHighLimits() ) {
                if ( $value > $botMax ) {
                    $msg = $this->encodeParamName( $paramName ) .
                        " may not be over $botMax (set to $value) for bots or sysops";
                    $this->warnOrDie( $msg, $enforceLimits );
                    $value = $botMax;
                }
            } else {
                $msg = $this->encodeParamName( $paramName ) . " may not be over $max (set to $value) for users";
                $this->warnOrDie( $msg, $enforceLimits );
                $value = $max;
            }
        }
    }

    protected function validateTimestamp( $value, $encParamName ) {
        $unixTimestamp = wfTimestamp( TS_UNIX, $value );
        if ( $unixTimestamp === false ) {
            $this->dieUsage(
                "Invalid value '$value' for timestamp parameter $encParamName",
                "badtimestamp_{$encParamName}"
            );
        }

        return wfTimestamp( TS_MW, $unixTimestamp );
    }

    public final function validateToken( $token, array $params ) {
        $tokenType = $this->needsToken();
        $salts = ApiQueryTokens::getTokenTypeSalts();
        if ( !isset( $salts[$tokenType] ) ) {
            throw new MWException(
                "Module '{$this->getModuleName()}' tried to use token type '$tokenType' " .
                    'without registering it'
            );
        }

        if ( $this->getUser()->matchEditToken(
            $token,
            $salts[$tokenType],
            $this->getRequest()
        ) ) {
            return true;
        }

        $webUiSalt = $this->getWebUITokenSalt( $params );
        if ( $webUiSalt !== null && $this->getUser()->matchEditToken(
            $token,
            $webUiSalt,
            $this->getRequest()
        ) ) {
            return true;
        }

        return false;
    }

    private function validateUser( $value, $encParamName ) {
        $title = Title::makeTitleSafe( NS_USER, $value );
        if ( $title === null ) {
            $this->dieUsage(
                "Invalid value '$value' for user parameter $encParamName",
                "baduser_{$encParamName}"
            );
        }

        return $title->getText();
    }

    /************************************************************************/
    protected function setWatch( $watch, $titleObj, $userOption = null ) {
        $value = $this->getWatchlistValue( $watch, $titleObj, $userOption );
        if ( $value === null ) {
            return;
        }

        WatchAction::doWatchOrUnwatch( $value, $titleObj, $this->getUser() );
    }

    public static function truncateArray( &$arr, $limit ) {
        $modified = false;
        while ( count( $arr ) > $limit ) {
            array_pop( $arr );
            $modified = true;
        }

        return $modified;
    }

    public function getWatchlistUser( $params ) {
        if ( !is_null( $params['owner'] ) && !is_null( $params['token'] ) ) {
            $user = User::newFromName( $params['owner'], false );
            if ( !( $user && $user->getId() ) ) {
                $this->dieUsage( 'Specified user does not exist', 'bad_wlowner' );
            }
            $token = $user->getOption( 'watchlisttoken' );
            if ( $token == '' || $token != $params['token'] ) {
                $this->dieUsage(
                    'Incorrect watchlist token provided -- please set a correct token in Special:Preferences',
                    'bad_wltoken'
                );
            }
        } else {
            if ( !$this->getUser()->isLoggedIn() ) {
                $this->dieUsage( 'You must be logged-in to have a watchlist', 'notloggedin' );
            }
            if ( !$this->getUser()->isAllowed( 'viewmywatchlist' ) ) {
                $this->dieUsage( 'You don\'t have permission to view your watchlist', 'permissiondenied' );
            }
            $user = $this->getUser();
        }

        return $user;
    }

    /************************************************************************/
    public function setWarning( $warning ) {
        $result = $this->getResult();
        $data = $result->getData();
        $moduleName = $this->getModuleName();
        if ( isset( $data['warnings'][$moduleName] ) ) {
            // Don't add duplicate warnings
            $oldWarning = $data['warnings'][$moduleName]['*'];
            $warnPos = strpos( $oldWarning, $warning );
            // If $warning was found in $oldWarning, check if it starts at 0 or after "\n"
            if ( $warnPos !== false && ( $warnPos === 0 || $oldWarning[$warnPos - 1] === "\n" ) ) {
                // Check if $warning is followed by "\n" or the end of the $oldWarning
                $warnPos += strlen( $warning );
                if ( strlen( $oldWarning ) <= $warnPos || $oldWarning[$warnPos] === "\n" ) {
                    return;
                }
            }
            // If there is a warning already, append it to the existing one
            $warning = "$oldWarning\n$warning";
        }
        $msg = array();
        ApiResult::setContent( $msg, $warning );
        $result->addValue( 'warnings', $moduleName,
            $msg, ApiResult::OVERRIDE | ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
    }

    private function warnOrDie( $msg, $enforceLimits = false ) {
        if ( $enforceLimits ) {
            $this->dieUsage( $msg, 'integeroutofrange' );
        }

        $this->setWarning( $msg );
    }

    public function dieUsage( $description, $errorCode, $httpRespCode = 0, $extradata = null ) {
        Profiler::instance()->close();
        throw new UsageException(
            $description,
            $this->encodeParamName( $errorCode ),
            $httpRespCode,
            $extradata
        );
    }

    public function getErrorFromStatus( $status ) {
        if ( $status->isGood() ) {
            throw new MWException( 'Successful status passed to ApiBase::dieStatus' );
        }

        $errors = $status->getErrorsArray();
        if ( !$errors ) {
            // No errors? Assume the warnings should be treated as errors
            $errors = $status->getWarningsArray();
        }
        if ( !$errors ) {
            // Still no errors? Punt
            $errors = array( array( 'unknownerror-nocode' ) );
        }

        // Cannot use dieUsageMsg() because extensions might return custom
        // error messages.
        if ( $errors[0] instanceof Message ) {
            $msg = $errors[0];
            $code = $msg->getKey();
        } else {
            $code = array_shift( $errors[0] );
            $msg = wfMessage( $code, $errors[0] );
        }
        if ( isset( ApiBase::$messageMap[$code] ) ) {
            // Translate message to code, for backwards compatibility
            $code = ApiBase::$messageMap[$code]['code'];
        }

        return array( $code, $msg->inLanguage( 'en' )->useDatabase( false )->plain() );
    }

    public function dieStatus( $status ) {

        list( $code, $msg ) = $this->getErrorFromStatus( $status );
        $this->dieUsage( $msg, $code );
    }

    // @codingStandardsIgnoreStart Allow long lines. Cannot split these.
    public static $messageMap = array(
        // This one MUST be present, or dieUsageMsg() will recurse infinitely
        'unknownerror' => array( 'code' => 'unknownerror', 'info' => "Unknown error: \"\$1\"" ),
        'unknownerror-nocode' => array( 'code' => 'unknownerror', 'info' => 'Unknown error' ),

        // Messages from Title::getUserPermissionsErrors()
        'ns-specialprotected' => array(
            'code' => 'unsupportednamespace',
            'info' => "Pages in the Special namespace can't be edited"
        ),
        'protectedinterface' => array(
            'code' => 'protectednamespace-interface',
            'info' => "You're not allowed to edit interface messages"
        ),
        'namespaceprotected' => array(
            'code' => 'protectednamespace',
            'info' => "You're not allowed to edit pages in the \"\$1\" namespace"
        ),
        'customcssprotected' => array(
            'code' => 'customcssprotected',
            'info' => "You're not allowed to edit custom CSS pages"
        ),
        'customjsprotected' => array(
            'code' => 'customjsprotected',
            'info' => "You're not allowed to edit custom JavaScript pages"
        ),
        'cascadeprotected' => array(
            'code' => 'cascadeprotected',
            'info' => "The page you're trying to edit is protected because it's included in a cascade-protected page"
        ),
        'protectedpagetext' => array(
            'code' => 'protectedpage',
            'info' => "The \"\$1\" right is required to edit this page"
        ),
        'protect-cantedit' => array(
            'code' => 'cantedit',
            'info' => "You can't protect this page because you can't edit it"
        ),
        'deleteprotected' => array(
            'code' => 'cantedit',
            'info' => "You can't delete this page because it has been protected"
        ),
        'badaccess-group0' => array(
            'code' => 'permissiondenied',
            'info' => "Permission denied"
        ), // Generic permission denied message
        'badaccess-groups' => array(
            'code' => 'permissiondenied',
            'info' => "Permission denied"
        ),
        'titleprotected' => array(
            'code' => 'protectedtitle',
            'info' => "This title has been protected from creation"
        ),
        'nocreate-loggedin' => array(
            'code' => 'cantcreate',
            'info' => "You don't have permission to create new pages"
        ),
        'nocreatetext' => array(
            'code' => 'cantcreate-anon',
            'info' => "Anonymous users can't create new pages"
        ),
        'movenologintext' => array(
            'code' => 'cantmove-anon',
            'info' => "Anonymous users can't move pages"
        ),
        'movenotallowed' => array(
            'code' => 'cantmove',
            'info' => "You don't have permission to move pages"
        ),
        'confirmedittext' => array(
            'code' => 'confirmemail',
            'info' => "You must confirm your email address before you can edit"
        ),
        'blockedtext' => array(
            'code' => 'blocked',
            'info' => "You have been blocked from editing"
        ),
        'autoblockedtext' => array(
            'code' => 'autoblocked',
            'info' => "Your IP address has been blocked automatically, because it was used by a blocked user"
        ),

        // Miscellaneous interface messages
        'actionthrottledtext' => array(
            'code' => 'ratelimited',
            'info' => "You've exceeded your rate limit. Please wait some time and try again"
        ),
        'alreadyrolled' => array(
            'code' => 'alreadyrolled',
            'info' => "The page you tried to rollback was already rolled back"
        ),
        'cantrollback' => array(
            'code' => 'onlyauthor',
            'info' => "The page you tried to rollback only has one author"
        ),
        'readonlytext' => array(
            'code' => 'readonly',
            'info' => "The wiki is currently in read-only mode"
        ),
        'sessionfailure' => array(
            'code' => 'badtoken',
            'info' => "Invalid token" ),
        'cannotdelete' => array(
            'code' => 'cantdelete',
            'info' => "Couldn't delete \"\$1\". Maybe it was deleted already by someone else"
        ),
        'notanarticle' => array(
            'code' => 'missingtitle',
            'info' => "The page you requested doesn't exist"
        ),
        'selfmove' => array( 'code' => 'selfmove', 'info' => "Can't move a page to itself"
        ),
        'immobile_namespace' => array(
            'code' => 'immobilenamespace',
            'info' => "You tried to move pages from or to a namespace that is protected from moving"
        ),
        'articleexists' => array(
            'code' => 'articleexists',
            'info' => "The destination article already exists and is not a redirect to the source article"
        ),
        'protectedpage' => array(
            'code' => 'protectedpage',
            'info' => "You don't have permission to perform this move"
        ),
        'hookaborted' => array(
            'code' => 'hookaborted',
            'info' => "The modification you tried to make was aborted by an extension hook"
        ),
        'cantmove-titleprotected' => array(
            'code' => 'protectedtitle',
            'info' => "The destination article has been protected from creation"
        ),
        'imagenocrossnamespace' => array(
            'code' => 'nonfilenamespace',
            'info' => "Can't move a file to a non-file namespace"
        ),
        'imagetypemismatch' => array(
            'code' => 'filetypemismatch',
            'info' => "The new file extension doesn't match its type"
        ),
        // 'badarticleerror' => shouldn't happen
        // 'badtitletext' => shouldn't happen
        'ip_range_invalid' => array( 'code' => 'invalidrange', 'info' => "Invalid IP range" ),
        'range_block_disabled' => array(
            'code' => 'rangedisabled',
            'info' => "Blocking IP ranges has been disabled"
        ),
        'nosuchusershort' => array(
            'code' => 'nosuchuser',
            'info' => "The user you specified doesn't exist"
        ),
        'badipaddress' => array( 'code' => 'invalidip', 'info' => "Invalid IP address specified" ),
        'ipb_expiry_invalid' => array( 'code' => 'invalidexpiry', 'info' => "Invalid expiry time" ),
        'ipb_already_blocked' => array(
            'code' => 'alreadyblocked',
            'info' => "The user you tried to block was already blocked"
        ),
        'ipb_blocked_as_range' => array(
            'code' => 'blockedasrange',
            'info' => "IP address \"\$1\" was blocked as part of range \"\$2\". You can't unblock the IP individually, but you can unblock the range as a whole."
        ),
        'ipb_cant_unblock' => array(
            'code' => 'cantunblock',
            'info' => "The block you specified was not found. It may have been unblocked already"
        ),
        'mailnologin' => array(
            'code' => 'cantsend',
            'info' => "You are not logged in, you do not have a confirmed email address, or you are not allowed to send email to other users, so you cannot send email"
        ),
        'ipbblocked' => array(
            'code' => 'ipbblocked',
            'info' => 'You cannot block or unblock users while you are yourself blocked'
        ),
        'ipbnounblockself' => array(
            'code' => 'ipbnounblockself',
            'info' => 'You are not allowed to unblock yourself'
        ),
        'usermaildisabled' => array(
            'code' => 'usermaildisabled',
            'info' => "User email has been disabled"
        ),
        'blockedemailuser' => array(
            'code' => 'blockedfrommail',
            'info' => "You have been blocked from sending email"
        ),
        'notarget' => array(
            'code' => 'notarget',
            'info' => "You have not specified a valid target for this action"
        ),
        'noemail' => array(
            'code' => 'noemail',
            'info' => "The user has not specified a valid email address, or has chosen not to receive email from other users"
        ),
        'rcpatroldisabled' => array(
            'code' => 'patroldisabled',
            'info' => "Patrolling is disabled on this wiki"
        ),
        'markedaspatrollederror-noautopatrol' => array(
            'code' => 'noautopatrol',
            'info' => "You don't have permission to patrol your own changes"
        ),
        'delete-toobig' => array(
            'code' => 'bigdelete',
            'info' => "You can't delete this page because it has more than \$1 revisions"
        ),
        'movenotallowedfile' => array(
            'code' => 'cantmovefile',
            'info' => "You don't have permission to move files"
        ),
        'userrights-no-interwiki' => array(
            'code' => 'nointerwikiuserrights',
            'info' => "You don't have permission to change user rights on other wikis"
        ),
        'userrights-nodatabase' => array(
            'code' => 'nosuchdatabase',
            'info' => "Database \"\$1\" does not exist or is not local"
        ),
        'nouserspecified' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
        'noname' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
        'summaryrequired' => array( 'code' => 'summaryrequired', 'info' => 'Summary required' ),
        'import-rootpage-invalid' => array(
            'code' => 'import-rootpage-invalid',
            'info' => 'Root page is an invalid title'
        ),
        'import-rootpage-nosubpage' => array(
            'code' => 'import-rootpage-nosubpage',
            'info' => 'Namespace "$1" of the root page does not allow subpages'
        ),

        // API-specific messages
        'readrequired' => array(
            'code' => 'readapidenied',
            'info' => "You need read permission to use this module"
        ),
        'writedisabled' => array(
            'code' => 'noapiwrite',
            'info' => "Editing of this wiki through the API is disabled. Make sure the \$wgEnableWriteAPI=true; statement is included in the wiki's LocalSettings.php file"
        ),
        'writerequired' => array(
            'code' => 'writeapidenied',
            'info' => "You're not allowed to edit this wiki through the API"
        ),
        'missingparam' => array( 'code' => 'no$1', 'info' => "The \$1 parameter must be set" ),
        'invalidtitle' => array( 'code' => 'invalidtitle', 'info' => "Bad title \"\$1\"" ),
        'nosuchpageid' => array( 'code' => 'nosuchpageid', 'info' => "There is no page with ID \$1" ),
        'nosuchrevid' => array( 'code' => 'nosuchrevid', 'info' => "There is no revision with ID \$1" ),
        'nosuchuser' => array( 'code' => 'nosuchuser', 'info' => "User \"\$1\" doesn't exist" ),
        'invaliduser' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
        'invalidexpiry' => array( 'code' => 'invalidexpiry', 'info' => "Invalid expiry time \"\$1\"" ),
        'pastexpiry' => array( 'code' => 'pastexpiry', 'info' => "Expiry time \"\$1\" is in the past" ),
        'create-titleexists' => array(
            'code' => 'create-titleexists',
            'info' => "Existing titles can't be protected with 'create'"
        ),
        'missingtitle-createonly' => array(
            'code' => 'missingtitle-createonly',
            'info' => "Missing titles can only be protected with 'create'"
        ),
        'cantblock' => array( 'code' => 'cantblock',
            'info' => "You don't have permission to block users"
        ),
        'canthide' => array(
            'code' => 'canthide',
            'info' => "You don't have permission to hide user names from the block log"
        ),
        'cantblock-email' => array(
            'code' => 'cantblock-email',
            'info' => "You don't have permission to block users from sending email through the wiki"
        ),
        'unblock-notarget' => array(
            'code' => 'notarget',
            'info' => "Either the id or the user parameter must be set"
        ),
        'unblock-idanduser' => array(
            'code' => 'idanduser',
            'info' => "The id and user parameters can't be used together"
        ),
        'cantunblock' => array(
            'code' => 'permissiondenied',
            'info' => "You don't have permission to unblock users"
        ),
        'cannotundelete' => array(
            'code' => 'cantundelete',
            'info' => "Couldn't undelete: the requested revisions may not exist, or may have been undeleted already"
        ),
        'permdenied-undelete' => array(
            'code' => 'permissiondenied',
            'info' => "You don't have permission to restore deleted revisions"
        ),
        'createonly-exists' => array(
            'code' => 'articleexists',
            'info' => "The article you tried to create has been created already"
        ),
        'nocreate-missing' => array(
            'code' => 'missingtitle',
            'info' => "The article you tried to edit doesn't exist"
        ),
        'nosuchrcid' => array(
            'code' => 'nosuchrcid',
            'info' => "There is no change with rcid \"\$1\""
        ),
        'protect-invalidaction' => array(
            'code' => 'protect-invalidaction',
            'info' => "Invalid protection type \"\$1\""
        ),
        'protect-invalidlevel' => array(
            'code' => 'protect-invalidlevel',
            'info' => "Invalid protection level \"\$1\""
        ),
        'toofewexpiries' => array(
            'code' => 'toofewexpiries',
            'info' => "\$1 expiry timestamps were provided where \$2 were needed"
        ),
        'cantimport' => array(
            'code' => 'cantimport',
            'info' => "You don't have permission to import pages"
        ),
        'cantimport-upload' => array(
            'code' => 'cantimport-upload',
            'info' => "You don't have permission to import uploaded pages"
        ),
        'importnofile' => array( 'code' => 'nofile', 'info' => "You didn't upload a file" ),
        'importuploaderrorsize' => array(
            'code' => 'filetoobig',
            'info' => 'The file you uploaded is bigger than the maximum upload size'
        ),
        'importuploaderrorpartial' => array(
            'code' => 'partialupload',
            'info' => 'The file was only partially uploaded'
        ),
        'importuploaderrortemp' => array(
            'code' => 'notempdir',
            'info' => 'The temporary upload directory is missing'
        ),
        'importcantopen' => array(
            'code' => 'cantopenfile',
            'info' => "Couldn't open the uploaded file"
        ),
        'import-noarticle' => array(
            'code' => 'badinterwiki',
            'info' => 'Invalid interwiki title specified'
        ),
        'importbadinterwiki' => array(
            'code' => 'badinterwiki',
            'info' => 'Invalid interwiki title specified'
        ),
        'import-unknownerror' => array(
            'code' => 'import-unknownerror',
            'info' => "Unknown error on import: \"\$1\""
        ),
        'cantoverwrite-sharedfile' => array(
            'code' => 'cantoverwrite-sharedfile',
            'info' => 'The target file exists on a shared repository and you do not have permission to override it'
        ),
        'sharedfile-exists' => array(
            'code' => 'fileexists-sharedrepo-perm',
            'info' => 'The target file exists on a shared repository. Use the ignorewarnings parameter to override it.'
        ),
        'mustbeposted' => array(
            'code' => 'mustbeposted',
            'info' => "The \$1 module requires a POST request"
        ),
        'show' => array(
            'code' => 'show',
            'info' => 'Incorrect parameter - mutually exclusive values may not be supplied'
        ),
        'specialpage-cantexecute' => array(
            'code' => 'specialpage-cantexecute',
            'info' => "You don't have permission to view the results of this special page"
        ),
        'invalidoldimage' => array(
            'code' => 'invalidoldimage',
            'info' => 'The oldimage parameter has invalid format'
        ),
        'nodeleteablefile' => array(
            'code' => 'nodeleteablefile',
            'info' => 'No such old version of the file'
        ),
        'fileexists-forbidden' => array(
            'code' => 'fileexists-forbidden',
            'info' => 'A file with name "$1" already exists, and cannot be overwritten.'
        ),
        'fileexists-shared-forbidden' => array(
            'code' => 'fileexists-shared-forbidden',
            'info' => 'A file with name "$1" already exists in the shared file repository, and cannot be overwritten.'
        ),
        'filerevert-badversion' => array(
            'code' => 'filerevert-badversion',
            'info' => 'There is no previous local version of this file with the provided timestamp.'
        ),

        // ApiEditPage messages
        'noimageredirect-anon' => array(
            'code' => 'noimageredirect-anon',
            'info' => "Anonymous users can't create image redirects"
        ),
        'noimageredirect-logged' => array(
            'code' => 'noimageredirect',
            'info' => "You don't have permission to create image redirects"
        ),
        'spamdetected' => array(
            'code' => 'spamdetected',
            'info' => "Your edit was refused because it contained a spam fragment: \"\$1\""
        ),
        'contenttoobig' => array(
            'code' => 'contenttoobig',
            'info' => "The content you supplied exceeds the article size limit of \$1 kilobytes"
        ),
        'noedit-anon' => array( 'code' => 'noedit-anon', 'info' => "Anonymous users can't edit pages" ),
        'noedit' => array( 'code' => 'noedit', 'info' => "You don't have permission to edit pages" ),
        'wasdeleted' => array(
            'code' => 'pagedeleted',
            'info' => "The page has been deleted since you fetched its timestamp"
        ),
        'blankpage' => array(
            'code' => 'emptypage',
            'info' => "Creating new, empty pages is not allowed"
        ),
        'editconflict' => array( 'code' => 'editconflict', 'info' => "Edit conflict detected" ),
        'hashcheckfailed' => array( 'code' => 'badmd5', 'info' => "The supplied MD5 hash was incorrect" ),
        'missingtext' => array(
            'code' => 'notext',
            'info' => "One of the text, appendtext, prependtext and undo parameters must be set"
        ),
        'emptynewsection' => array(
            'code' => 'emptynewsection',
            'info' => 'Creating empty new sections is not possible.'
        ),
        'revwrongpage' => array(
            'code' => 'revwrongpage',
            'info' => "r\$1 is not a revision of \"\$2\""
        ),
        'undo-failure' => array(
            'code' => 'undofailure',
            'info' => 'Undo failed due to conflicting intermediate edits'
        ),
        'content-not-allowed-here' => array(
            'code' => 'contentnotallowedhere',
            'info' => 'Content model "$1" is not allowed at title "$2"'
        ),

        // Messages from WikiPage::doEit()
        'edit-hook-aborted' => array(
            'code' => 'edit-hook-aborted',
            'info' => "Your edit was aborted by an ArticleSave hook"
        ),
        'edit-gone-missing' => array(
            'code' => 'edit-gone-missing',
            'info' => "The page you tried to edit doesn't seem to exist anymore"
        ),
        'edit-conflict' => array( 'code' => 'editconflict', 'info' => "Edit conflict detected" ),
        'edit-already-exists' => array(
            'code' => 'edit-already-exists',
            'info' => 'It seems the page you tried to create already exist'
        ),

        // uploadMsgs
        'invalid-file-key' => array( 'code' => 'invalid-file-key', 'info' => 'Not a valid file key' ),
        'nouploadmodule' => array( 'code' => 'nouploadmodule', 'info' => 'No upload module set' ),
        'uploaddisabled' => array(
            'code' => 'uploaddisabled',
            'info' => 'Uploads are not enabled. Make sure $wgEnableUploads is set to true in LocalSettings.php and the PHP ini setting file_uploads is true'
        ),
        'copyuploaddisabled' => array(
            'code' => 'copyuploaddisabled',
            'info' => 'Uploads by URL is not enabled. Make sure $wgAllowCopyUploads is set to true in LocalSettings.php.'
        ),
        'copyuploadbaddomain' => array(
            'code' => 'copyuploadbaddomain',
            'info' => 'Uploads by URL are not allowed from this domain.'
        ),
        'copyuploadbadurl' => array(
            'code' => 'copyuploadbadurl',
            'info' => 'Upload not allowed from this URL.'
        ),

        'filename-tooshort' => array(
            'code' => 'filename-tooshort',
            'info' => 'The filename is too short'
        ),
        'filename-toolong' => array( 'code' => 'filename-toolong', 'info' => 'The filename is too long' ),
        'illegal-filename' => array(
            'code' => 'illegal-filename',
            'info' => 'The filename is not allowed'
        ),
        'filetype-missing' => array(
            'code' => 'filetype-missing',
            'info' => 'The file is missing an extension'
        ),

        'mustbeloggedin' => array( 'code' => 'mustbeloggedin', 'info' => 'You must be logged in to $1.' )
    );
    // @codingStandardsIgnoreEnd

    public function dieReadOnly() {
        $parsed = $this->parseMsg( array( 'readonlytext' ) );
        $this->dieUsage( $parsed['info'], $parsed['code'], /* http error */ 0,
            array( 'readonlyreason' => wfReadOnlyReason() ) );
    }

    public function dieUsageMsg( $error ) {
        # most of the time we send a 1 element, so we might as well send it as
        # a string and make this an array here.
        if ( is_string( $error ) ) {
            $error = array( $error );
        }
        $parsed = $this->parseMsg( $error );
        $this->dieUsage( $parsed['info'], $parsed['code'] );
    }

    public function dieUsageMsgOrDebug( $error ) {
        if ( $this->getConfig()->get( 'DebugAPI' ) !== true ) {
            $this->dieUsageMsg( $error );
        }

        if ( is_string( $error ) ) {
            $error = array( $error );
        }
        $parsed = $this->parseMsg( $error );
        $this->setWarning( '$wgDebugAPI: ' . $parsed['code'] . ' - ' . $parsed['info'] );
    }

    protected function dieContinueUsageIf( $condition ) {
        if ( $condition ) {
            $this->dieUsage(
                'Invalid continue param. You should pass the original value returned by the previous query',
                'badcontinue' );
        }
    }

    public function parseMsg( $error ) {
        $error = (array)$error; // It seems strings sometimes make their way in here
        $key = array_shift( $error );

        // Check whether the error array was nested
        // array( array( <code>, <params> ), array( <another_code>, <params> ) )
        if ( is_array( $key ) ) {
            $error = $key;
            $key = array_shift( $error );
        }

        if ( isset( self::$messageMap[$key] ) ) {
            return array(
                'code' => wfMsgReplaceArgs( self::$messageMap[$key]['code'], $error ),
                'info' => wfMsgReplaceArgs( self::$messageMap[$key]['info'], $error )
            );
        }

        // If the key isn't present, throw an "unknown error"
        return $this->parseMsg( array( 'unknownerror', $key ) );
    }

    protected static function dieDebug( $method, $message ) {
        throw new MWException( "Internal error in $method: $message" );
    }

    /************************************************************************/
    public function makeHelpMsg() {
        static $lnPrfx = "\n  ";

        $msg = $this->getFinalDescription();

        if ( $msg !== false ) {

            if ( !is_array( $msg ) ) {
                $msg = array(
                    $msg
                );
            }
            $msg = $lnPrfx . implode( $lnPrfx, $msg ) . "\n";

            $msg .= $this->makeHelpArrayToString( $lnPrfx, false, $this->getHelpUrls() );

            if ( $this->isReadMode() ) {
                $msg .= "\nThis module requires read rights";
            }
            if ( $this->isWriteMode() ) {
                $msg .= "\nThis module requires write rights";
            }
            if ( $this->mustBePosted() ) {
                $msg .= "\nThis module only accepts POST requests";
            }
            if ( $this->isReadMode() || $this->isWriteMode() ||
                $this->mustBePosted()
            ) {
                $msg .= "\n";
            }

            // Parameters
            $paramsMsg = $this->makeHelpMsgParameters();
            if ( $paramsMsg !== false ) {
                $msg .= "Parameters:\n$paramsMsg";
            }

            $examples = $this->getExamples();
            if ( $examples ) {
                if ( !is_array( $examples ) ) {
                    $examples = array(
                        $examples
                    );
                }
                $msg .= "Example" . ( count( $examples ) > 1 ? 's' : '' ) . ":\n";
                foreach ( $examples as $k => $v ) {
                    if ( is_numeric( $k ) ) {
                        $msg .= "  $v\n";
                    } else {
                        if ( is_array( $v ) ) {
                            $msgExample = implode( "\n", array_map( array( $this, 'indentExampleText' ), $v ) );
                        } else {
                            $msgExample = "  $v";
                        }
                        $msgExample .= ":";
                        $msg .= wordwrap( $msgExample, 100, "\n" ) . "\n    $k\n";
                    }
                }
            }
        }

        return $msg;
    }

    private function indentExampleText( $item ) {
        return "  " . $item;
    }

    protected function makeHelpArrayToString( $prefix, $title, $input ) {
        if ( $input === false ) {
            return '';
        }
        if ( !is_array( $input ) ) {
            $input = array( $input );
        }

        if ( count( $input ) > 0 ) {
            if ( $title ) {
                $msg = $title . ( count( $input ) > 1 ? 's' : '' ) . ":\n  ";
            } else {
                $msg = '  ';
            }
            $msg .= implode( $prefix, $input ) . "\n";

            return $msg;
        }

        return '';
    }

    public function makeHelpMsgParameters() {
        $params = $this->getFinalParams( ApiBase::GET_VALUES_FOR_HELP );
        if ( $params ) {

            $paramsDescription = $this->getFinalParamDescription();
            $msg = '';
            $paramPrefix = "\n" . str_repeat( ' ', 24 );
            $descWordwrap = "\n" . str_repeat( ' ', 28 );
            foreach ( $params as $paramName => $paramSettings ) {
                $desc = isset( $paramsDescription[$paramName] ) ? $paramsDescription[$paramName] : '';
                if ( is_array( $desc ) ) {
                    $desc = implode( $paramPrefix, $desc );
                }

                //handle shorthand
                if ( !is_array( $paramSettings ) ) {
                    $paramSettings = array(
                        self::PARAM_DFLT => $paramSettings,
                    );
                }

                //handle missing type
                if ( !isset( $paramSettings[ApiBase::PARAM_TYPE] ) ) {
                    $dflt = isset( $paramSettings[ApiBase::PARAM_DFLT] )
                        ? $paramSettings[ApiBase::PARAM_DFLT]
                        : null;
                    if ( is_bool( $dflt ) ) {
                        $paramSettings[ApiBase::PARAM_TYPE] = 'boolean';
                    } elseif ( is_string( $dflt ) || is_null( $dflt ) ) {
                        $paramSettings[ApiBase::PARAM_TYPE] = 'string';
                    } elseif ( is_int( $dflt ) ) {
                        $paramSettings[ApiBase::PARAM_TYPE] = 'integer';
                    }
                }

                if ( isset( $paramSettings[self::PARAM_DEPRECATED] )
                    && $paramSettings[self::PARAM_DEPRECATED]
                ) {
                    $desc = "DEPRECATED! $desc";
                }

                if ( isset( $paramSettings[self::PARAM_REQUIRED] )
                    && $paramSettings[self::PARAM_REQUIRED]
                ) {
                    $desc .= $paramPrefix . "This parameter is required";
                }

                $type = isset( $paramSettings[self::PARAM_TYPE] )
                    ? $paramSettings[self::PARAM_TYPE]
                    : null;
                if ( isset( $type ) ) {
                    $hintPipeSeparated = true;
                    $multi = isset( $paramSettings[self::PARAM_ISMULTI] )
                        ? $paramSettings[self::PARAM_ISMULTI]
                        : false;
                    if ( $multi ) {
                        $prompt = 'Values (separate with \'|\'): ';
                    } else {
                        $prompt = 'One value: ';
                    }

                    if ( $type === 'submodule' ) {
                        $type = $this->getModuleManager()->getNames( $paramName );
                        sort( $type );
                    }
                    if ( is_array( $type ) ) {
                        $choices = array();
                        $nothingPrompt = '';
                        foreach ( $type as $t ) {
                            if ( $t === '' ) {
                                $nothingPrompt = 'Can be empty, or ';
                            } else {
                                $choices[] = $t;
                            }
                        }
                        $desc .= $paramPrefix . $nothingPrompt . $prompt;
                        $choicesstring = implode( ', ', $choices );
                        $desc .= wordwrap( $choicesstring, 100, $descWordwrap );
                        $hintPipeSeparated = false;
                    } else {
                        switch ( $type ) {
                            case 'namespace':
                                // Special handling because namespaces are
                                // type-limited, yet they are not given
                                $desc .= $paramPrefix . $prompt;
                                $desc .= wordwrap( implode( ', ', MWNamespace::getValidNamespaces() ),
                                    100, $descWordwrap );
                                $hintPipeSeparated = false;
                                break;
                            case 'limit':
                                $desc .= $paramPrefix . "No more than {$paramSettings[self::PARAM_MAX]}";
                                if ( isset( $paramSettings[self::PARAM_MAX2] ) ) {
                                    $desc .= " ({$paramSettings[self::PARAM_MAX2]} for bots)";
                                }
                                $desc .= ' allowed';
                                break;
                            case 'integer':
                                $s = $multi ? 's' : '';
                                $hasMin = isset( $paramSettings[self::PARAM_MIN] );
                                $hasMax = isset( $paramSettings[self::PARAM_MAX] );
                                if ( $hasMin || $hasMax ) {
                                    if ( !$hasMax ) {
                                        $intRangeStr = "The value$s must be no less than " .
                                            "{$paramSettings[self::PARAM_MIN]}";
                                    } elseif ( !$hasMin ) {
                                        $intRangeStr = "The value$s must be no more than " .
                                            "{$paramSettings[self::PARAM_MAX]}";
                                    } else {
                                        $intRangeStr = "The value$s must be between " .
                                            "{$paramSettings[self::PARAM_MIN]} and {$paramSettings[self::PARAM_MAX]}";
                                    }

                                    $desc .= $paramPrefix . $intRangeStr;
                                }
                                break;
                            case 'upload':
                                $desc .= $paramPrefix . "Must be posted as a file upload using multipart/form-data";
                                break;
                        }
                    }

                    if ( $multi ) {
                        if ( $hintPipeSeparated ) {
                            $desc .= $paramPrefix . "Separate values with '|'";
                        }

                        $isArray = is_array( $type );
                        if ( !$isArray
                            || $isArray && count( $type ) > self::LIMIT_SML1
                        ) {
                            $desc .= $paramPrefix . "Maximum number of values " .
                                self::LIMIT_SML1 . " (" . self::LIMIT_SML2 . " for bots)";
                        }
                    }
                }

                $default = isset( $paramSettings[self::PARAM_DFLT] ) ? $paramSettings[self::PARAM_DFLT] : null;
                if ( !is_null( $default ) && $default !== false ) {
                    $desc .= $paramPrefix . "Default: $default";
                }

                $msg .= sprintf( "  %-19s - %s\n", $this->encodeParamName( $paramName ), $desc );
            }

            return $msg;
        }

        return false;
    }

    /************************************************************************/
    private $mTimeIn = 0, $mModuleTime = 0;

    public function getModuleProfileName( $db = false ) {
        if ( $db ) {
            return 'API:' . $this->mModuleName . '-DB';
        }

        return 'API:' . $this->mModuleName;
    }

    public function profileIn() {
        if ( $this->mTimeIn !== 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called twice without calling profileOut()' );
        }
        $this->mTimeIn = microtime( true );
        wfProfileIn( $this->getModuleProfileName() );
    }

    public function profileOut() {
        if ( $this->mTimeIn === 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called without calling profileIn() first' );
        }
        if ( $this->mDBTimeIn !== 0 ) {
            ApiBase::dieDebug(
                __METHOD__,
                'Must be called after database profiling is done with profileDBOut()'
            );
        }

        $this->mModuleTime += microtime( true ) - $this->mTimeIn;
        $this->mTimeIn = 0;
        wfProfileOut( $this->getModuleProfileName() );
    }

    public function safeProfileOut() {
        if ( $this->mTimeIn !== 0 ) {
            if ( $this->mDBTimeIn !== 0 ) {
                $this->profileDBOut();
            }
            $this->profileOut();
        }
    }

    public function getProfileTime() {
        if ( $this->mTimeIn !== 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called without calling profileOut() first' );
        }

        return $this->mModuleTime;
    }

    private $mDBTimeIn = 0, $mDBTime = 0;

    public function profileDBIn() {
        if ( $this->mTimeIn === 0 ) {
            ApiBase::dieDebug(
                __METHOD__,
                'Must be called while profiling the entire module with profileIn()'
            );
        }
        if ( $this->mDBTimeIn !== 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called twice without calling profileDBOut()' );
        }
        $this->mDBTimeIn = microtime( true );
        wfProfileIn( $this->getModuleProfileName( true ) );
    }

    public function profileDBOut() {
        if ( $this->mTimeIn === 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Must be called while profiling ' .
                'the entire module with profileIn()' );
        }
        if ( $this->mDBTimeIn === 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called without calling profileDBIn() first' );
        }

        $time = microtime( true ) - $this->mDBTimeIn;
        $this->mDBTimeIn = 0;

        $this->mDBTime += $time;
        $this->getMain()->mDBTime += $time;
        wfProfileOut( $this->getModuleProfileName( true ) );
    }

    public function getProfileDBTime() {
        if ( $this->mDBTimeIn !== 0 ) {
            ApiBase::dieDebug( __METHOD__, 'Called without calling profileDBOut() first' );
        }

        return $this->mDBTime;
    }

    protected function logFeatureUsage( $feature ) {
        $request = $this->getRequest();
        $s = '"' . addslashes( $feature ) . '"' .
            ' "' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) . '"' .
            ' "' . $request->getIP() . '"' .
            ' "' . addslashes( $request->getHeader( 'Referer' ) ) . '"' .
            ' "' . addslashes( $request->getHeader( 'User-agent' ) ) . '"';
        wfDebugLog( 'api-feature-usage', $s, 'private' );
    }

    /************************************************************************/

    const PROP_ROOT = 'ROOT';
    const PROP_LIST = 'LIST';
    const PROP_TYPE = 0;
    const PROP_NULLABLE = 1;

    public function getVersion() {
        wfDeprecated( __METHOD__, '1.21' );
        return '';
    }

    protected function getResultProperties() {
        wfDeprecated( __METHOD__, '1.24' );
        return false;
    }

    public function getFinalResultProperties() {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    protected static function addTokenProperties( &$props, $tokenFunctions ) {
        wfDeprecated( __METHOD__, '1.24' );
    }

    public function getRequireOnlyOneParameterErrorMessages( $params ) {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function getRequireMaxOneParameterErrorMessages( $params ) {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function getRequireAtLeastOneParameterErrorMessages( $params ) {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function getTitleOrPageIdErrorMessage() {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function getPossibleErrors() {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function getFinalPossibleErrors() {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

    public function parseErrors( $errors ) {
        wfDeprecated( __METHOD__, '1.24' );
        return array();
    }

}