Merge "Update docs/hooks.txt for ShowSearchHitTitle"

[mediawiki.git] / includes / media / SVG.php

<?php
/**
 * Handler for SVG images.
 *
 * 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
 * @ingroup Media
 */
use Wikimedia\ScopedCallback;

/**
 * Handler for SVG images.
 *
 * @ingroup Media
 */
class SvgHandler extends ImageHandler {
        const SVG_METADATA_VERSION = 2;

        /** @var array A list of metadata tags that can be converted
         *  to the commonly used exif tags. This allows messages
         *  to be reused, and consistent tag names for {{#formatmetadata:..}}
         */
        private static $metaConversion = [
                'originalwidth' => 'ImageWidth',
                'originalheight' => 'ImageLength',
                'description' => 'ImageDescription',
                'title' => 'ObjectName',
        ];

        function isEnabled() {
                global $wgSVGConverters, $wgSVGConverter;
                if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
                        wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );

                        return false;
                } else {
                        return true;
                }
        }

        public function mustRender( $file ) {
                return true;
        }

        function isVectorized( $file ) {
                return true;
        }

        /**
         * @param File $file
         * @return bool
         */
        function isAnimatedImage( $file ) {
                # @todo Detect animated SVGs
                $metadata = $file->getMetadata();
                if ( $metadata ) {
                        $metadata = $this->unpackMetadata( $metadata );
                        if ( isset( $metadata['animated'] ) ) {
                                return $metadata['animated'];
                        }
                }

                return false;
        }

        /**
         * Which languages (systemLanguage attribute) is supported.
         *
         * @note This list is not guaranteed to be exhaustive.
         * To avoid OOM errors, we only look at first bit of a file.
         * Thus all languages on this list are present in the file,
         * but its possible for the file to have a language not on
         * this list.
         *
         * @param File $file
         * @return array Array of language codes, or empty if no language switching supported.
         */
        public function getAvailableLanguages( File $file ) {
                $metadata = $file->getMetadata();
                $langList = [];
                if ( $metadata ) {
                        $metadata = $this->unpackMetadata( $metadata );
                        if ( isset( $metadata['translations'] ) ) {
                                foreach ( $metadata['translations'] as $lang => $langType ) {
                                        if ( $langType === SVGReader::LANG_FULL_MATCH ) {
                                                $langList[] = $lang;
                                        }
                                }
                        }
                }
                return $langList;
        }

        /**
         * What language to render file in if none selected.
         *
         * @param File $file
         * @return string Language code.
         */
        public function getDefaultRenderLanguage( File $file ) {
                return 'en';
        }

        /**
         * We do not support making animated svg thumbnails
         * @param File $file
         * @return bool
         */
        function canAnimateThumbnail( $file ) {
                return false;
        }

        /**
         * @param File $image
         * @param array $params
         * @return bool
         */
        function normaliseParams( $image, &$params ) {
                global $wgSVGMaxSize;
                if ( !parent::normaliseParams( $image, $params ) ) {
                        return false;
                }
                # Don't make an image bigger than wgMaxSVGSize on the smaller side
                if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
                        if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
                                $srcWidth = $image->getWidth( $params['page'] );
                                $srcHeight = $image->getHeight( $params['page'] );
                                $params['physicalWidth'] = $wgSVGMaxSize;
                                $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
                        }
                } else {
                        if ( $params['physicalHeight'] > $wgSVGMaxSize ) {
                                $srcWidth = $image->getWidth( $params['page'] );
                                $srcHeight = $image->getHeight( $params['page'] );
                                $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
                                $params['physicalHeight'] = $wgSVGMaxSize;
                        }
                }

                return true;
        }

        /**
         * @param File $image
         * @param string $dstPath
         * @param string $dstUrl
         * @param array $params
         * @param int $flags
         * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
         */
        function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
                if ( !$this->normaliseParams( $image, $params ) ) {
                        return new TransformParameterError( $params );
                }
                $clientWidth = $params['width'];
                $clientHeight = $params['height'];
                $physicalWidth = $params['physicalWidth'];
                $physicalHeight = $params['physicalHeight'];
                $lang = isset( $params['lang'] ) ? $params['lang'] : $this->getDefaultRenderLanguage( $image );

                if ( $flags & self::TRANSFORM_LATER ) {
                        return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
                }

                $metadata = $this->unpackMetadata( $image->getMetadata() );
                if ( isset( $metadata['error'] ) ) { // sanity check
                        $err = wfMessage( 'svg-long-error', $metadata['error']['message'] );

                        return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
                }

                if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
                        return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
                                wfMessage( 'thumbnail_dest_directory' ) );
                }

                $srcPath = $image->getLocalRefPath();
                if ( $srcPath === false ) { // Failed to get local copy
                        wfDebugLog( 'thumbnail',
                                sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
                                        wfHostname(), $image->getName() ) );

                        return new MediaTransformError( 'thumbnail_error',
                                $params['width'], $params['height'],
                                wfMessage( 'filemissing' )
                        );
                }

                // Make a temp dir with a symlink to the local copy in it.
                // This plays well with rsvg-convert policy for external entities.
                // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
                $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
                $lnPath = "$tmpDir/" . basename( $srcPath );
                $ok = mkdir( $tmpDir, 0771 ) && symlink( $srcPath, $lnPath );
                /** @noinspection PhpUnusedLocalVariableInspection */
                $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
                        MediaWiki\suppressWarnings();
                        unlink( $lnPath );
                        rmdir( $tmpDir );
                        MediaWiki\restoreWarnings();
                } );
                if ( !$ok ) {
                        wfDebugLog( 'thumbnail',
                                sprintf( 'Thumbnail failed on %s: could not link %s to %s',
                                        wfHostname(), $lnPath, $srcPath ) );
                        return new MediaTransformError( 'thumbnail_error',
                                $params['width'], $params['height'],
                                wfMessage( 'thumbnail-temp-create' )
                        );
                }

                $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
                if ( $status === true ) {
                        return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
                } else {
                        return $status; // MediaTransformError
                }
        }

        /**
         * Transform an SVG file to PNG
         * This function can be called outside of thumbnail contexts
         * @param string $srcPath
         * @param string $dstPath
         * @param string $width
         * @param string $height
         * @param bool|string $lang Language code of the language to render the SVG in
         * @throws MWException
         * @return bool|MediaTransformError
         */
        public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
                global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
                $err = false;
                $retval = '';
                if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
                        if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
                                // This is a PHP callable
                                $func = $wgSVGConverters[$wgSVGConverter][0];
                                $args = array_merge( [ $srcPath, $dstPath, $width, $height, $lang ],
                                        array_slice( $wgSVGConverters[$wgSVGConverter], 1 ) );
                                if ( !is_callable( $func ) ) {
                                        throw new MWException( "$func is not callable" );
                                }
                                $err = call_user_func_array( $func, $args );
                                $retval = (bool)$err;
                        } else {
                                // External command
                                $cmd = str_replace(
                                        [ '$path/', '$width', '$height', '$input', '$output' ],
                                        [ $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
                                                intval( $width ),
                                                intval( $height ),
                                                wfEscapeShellArg( $srcPath ),
                                                wfEscapeShellArg( $dstPath ) ],
                                        $wgSVGConverters[$wgSVGConverter]
                                );

                                $env = [];
                                if ( $lang !== false ) {
                                        $env['LANG'] = $lang;
                                }

                                wfDebug( __METHOD__ . ": $cmd\n" );
                                $err = wfShellExecWithStderr( $cmd, $retval, $env );
                        }
                }
                $removed = $this->removeBadFile( $dstPath, $retval );
                if ( $retval != 0 || $removed ) {
                        $this->logErrorForExternalProcess( $retval, $err, $cmd );
                        return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
                }

                return true;
        }

        public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
                $im = new Imagick( $srcPath );
                $im->setImageFormat( 'png' );
                $im->setBackgroundColor( 'transparent' );
                $im->setImageDepth( 8 );

                if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
                        return 'Could not resize image';
                }
                if ( !$im->writeImage( $dstPath ) ) {
                        return "Could not write to $dstPath";
                }
        }

        /**
         * @param File|FSFile $file
         * @param string $path Unused
         * @param bool|array $metadata
         * @return array
         */
        function getImageSize( $file, $path, $metadata = false ) {
                if ( $metadata === false && $file instanceof File ) {
                        $metadata = $file->getMetadata();
                }
                $metadata = $this->unpackMetadata( $metadata );

                if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
                        return [ $metadata['width'], $metadata['height'], 'SVG',
                                "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
                } else { // error
                        return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
                }
        }

        function getThumbType( $ext, $mime, $params = null ) {
                return [ 'png', 'image/png' ];
        }

        /**
         * Subtitle for the image. Different from the base
         * class so it can be denoted that SVG's have
         * a "nominal" resolution, and not a fixed one,
         * as well as so animation can be denoted.
         *
         * @param File $file
         * @return string
         */
        function getLongDesc( $file ) {
                global $wgLang;

                $metadata = $this->unpackMetadata( $file->getMetadata() );
                if ( isset( $metadata['error'] ) ) {
                        return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
                }

                $size = $wgLang->formatSize( $file->getSize() );

                if ( $this->isAnimatedImage( $file ) ) {
                        $msg = wfMessage( 'svg-long-desc-animated' );
                } else {
                        $msg = wfMessage( 'svg-long-desc' );
                }

                $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );

                return $msg->parse();
        }

        /**
         * @param File|FSFile $file
         * @param string $filename
         * @return string Serialised metadata
         */
        function getMetadata( $file, $filename ) {
                $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
                try {
                        $metadata += SVGMetadataExtractor::getMetadata( $filename );
                } catch ( Exception $e ) { // @todo SVG specific exceptions
                        // File not found, broken, etc.
                        $metadata['error'] = [
                                'message' => $e->getMessage(),
                                'code' => $e->getCode()
                        ];
                        wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
                }

                return serialize( $metadata );
        }

        function unpackMetadata( $metadata ) {
                MediaWiki\suppressWarnings();
                $unser = unserialize( $metadata );
                MediaWiki\restoreWarnings();
                if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
                        return $unser;
                } else {
                        return false;
                }
        }

        function getMetadataType( $image ) {
                return 'parsed-svg';
        }

        function isMetadataValid( $image, $metadata ) {
                $meta = $this->unpackMetadata( $metadata );
                if ( $meta === false ) {
                        return self::METADATA_BAD;
                }
                if ( !isset( $meta['originalWidth'] ) ) {
                        // Old but compatible
                        return self::METADATA_COMPATIBLE;
                }

                return self::METADATA_GOOD;
        }

        protected function visibleMetadataFields() {
                $fields = [ 'objectname', 'imagedescription' ];

                return $fields;
        }

        /**
         * @param File $file
         * @param bool|IContextSource $context Context to use (optional)
         * @return array|bool
         */
        function formatMetadata( $file, $context = false ) {
                $result = [
                        'visible' => [],
                        'collapsed' => []
                ];
                $metadata = $file->getMetadata();
                if ( !$metadata ) {
                        return false;
                }
                $metadata = $this->unpackMetadata( $metadata );
                if ( !$metadata || isset( $metadata['error'] ) ) {
                        return false;
                }

                /* @todo Add a formatter
                $format = new FormatSVG( $metadata );
                $formatted = $format->getFormattedData();
                */

                // Sort fields into visible and collapsed
                $visibleFields = $this->visibleMetadataFields();

                $showMeta = false;
                foreach ( $metadata as $name => $value ) {
                        $tag = strtolower( $name );
                        if ( isset( self::$metaConversion[$tag] ) ) {
                                $tag = strtolower( self::$metaConversion[$tag] );
                        } else {
                                // Do not output other metadata not in list
                                continue;
                        }
                        $showMeta = true;
                        self::addMeta( $result,
                                in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
                                'exif',
                                $tag,
                                $value
                        );
                }

                return $showMeta ? $result : false;
        }

        /**
         * @param string $name Parameter name
         * @param mixed $value Parameter value
         * @return bool Validity
         */
        public function validateParam( $name, $value ) {
                if ( in_array( $name, [ 'width', 'height' ] ) ) {
                        // Reject negative heights, widths
                        return ( $value > 0 );
                } elseif ( $name == 'lang' ) {
                        // Validate $code
                        if ( $value === '' || !Language::isValidBuiltInCode( $value ) ) {
                                wfDebug( "Invalid user language code\n" );

                                return false;
                        }

                        return true;
                }

                // Only lang, width and height are acceptable keys
                return false;
        }

        /**
         * @param array $params Name=>value pairs of parameters
         * @return string Filename to use
         */
        public function makeParamString( $params ) {
                $lang = '';
                if ( isset( $params['lang'] ) && $params['lang'] !== 'en' ) {
                        $params['lang'] = strtolower( $params['lang'] );
                        $lang = "lang{$params['lang']}-";
                }
                if ( !isset( $params['width'] ) ) {
                        return false;
                }

                return "$lang{$params['width']}px";
        }

        public function parseParamString( $str ) {
                $m = false;
                if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/', $str, $m ) ) {
                        return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
                } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
                        return [ 'width' => $m[1], 'lang' => 'en' ];
                } else {
                        return false;
                }
        }

        public function getParamMap() {
                return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
        }

        /**
         * @param array $params
         * @return array
         */
        function getScriptParams( $params ) {
                $scriptParams = [ 'width' => $params['width'] ];
                if ( isset( $params['lang'] ) ) {
                        $scriptParams['lang'] = $params['lang'];
                }

                return $scriptParams;
        }

        public function getCommonMetaArray( File $file ) {
                $metadata = $file->getMetadata();
                if ( !$metadata ) {
                        return [];
                }
                $metadata = $this->unpackMetadata( $metadata );
                if ( !$metadata || isset( $metadata['error'] ) ) {
                        return [];
                }
                $stdMetadata = [];
                foreach ( $metadata as $name => $value ) {
                        $tag = strtolower( $name );
                        if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
                                // Skip these. In the exif metadata stuff, it is assumed these
                                // are measured in px, which is not the case here.
                                continue;
                        }
                        if ( isset( self::$metaConversion[$tag] ) ) {
                                $tag = self::$metaConversion[$tag];
                                $stdMetadata[$tag] = $value;
                        }
                }

                return $stdMetadata;
        }
}