ForeignResourceManager.php

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<?php
class ForeignResourceManager {
    private $defaultAlgo = 'sha384';
    private $hasErrors = false;
    private $registryFile;
    private $libDir;
    private $tmpParentDir;
    private $cacheDir;
    private $infoPrinter;
    private $errorPrinter;
    private $verbosePrinter;
    private $action;
    private $registry;

    public function __construct(
        $registryFile,
        $libDir,
        callable $infoPrinter = null,
        callable $errorPrinter = null,
        callable $verbosePrinter = null
    ) {
        $this->registryFile = $registryFile;
        $this->libDir = $libDir;
        $this->infoPrinter = $infoPrinter ?? function () {
        };
        $this->errorPrinter = $errorPrinter ?? $this->infoPrinter;
        $this->verbosePrinter = $verbosePrinter ?? function () {
        };

        // Use a temporary directory under the destination directory instead
        // of wfTempDir() because PHP's rename() does not work across file
        // systems, and the user's /tmp and $IP may be on different filesystems.
        $this->tmpParentDir = "{$this->libDir}/.foreign/tmp";

        $cacheHome = getenv( 'XDG_CACHE_HOME' ) ? realpath( getenv( 'XDG_CACHE_HOME' ) ) : false;
        $this->cacheDir = $cacheHome ? "$cacheHome/mw-foreign" : "{$this->libDir}/.foreign/cache";
    }

    public function run( $action, $module ) {
        $actions = [ 'update', 'verify', 'make-sri' ];
        if ( !in_array( $action, $actions ) ) {
            $this->error( "Invalid action.\n\nMust be one of " . implode( ', ', $actions ) . '.' );
            return false;
        }
        $this->action = $action;

        $this->registry = $this->parseBasicYaml( file_get_contents( $this->registryFile ) );
        if ( $module === 'all' ) {
            $modules = $this->registry;
        } elseif ( isset( $this->registry[ $module ] ) ) {
            $modules = [ $module => $this->registry[ $module ] ];
        } else {
            $this->error( "Unknown module name.\n\nMust be one of:\n" .
                wordwrap( implode( ', ', array_keys( $this->registry ) ), 80 ) .
                '.'
            );
            return false;
        }

        foreach ( $modules as $moduleName => $info ) {
            $this->verbose( "\n### {$moduleName}\n\n" );
            $destDir = "{$this->libDir}/$moduleName";

            if ( $this->action === 'update' ) {
                $this->output( "... updating '{$moduleName}'\n" );
                $this->verbose( "... emptying directory for $moduleName\n" );
                wfRecursiveRemoveDir( $destDir );
            } elseif ( $this->action === 'verify' ) {
                $this->output( "... verifying '{$moduleName}'\n" );
            } else {
                $this->output( "... checking '{$moduleName}'\n" );
            }

            $this->verbose( "... preparing {$this->tmpParentDir}\n" );
            wfRecursiveRemoveDir( $this->tmpParentDir );
            if ( !wfMkdirParents( $this->tmpParentDir ) ) {
                throw new Exception( "Unable to create {$this->tmpParentDir}" );
            }

            if ( !isset( $info['type'] ) ) {
                throw new Exception( "Module '$moduleName' must have a 'type' key." );
            }
            switch ( $info['type'] ) {
                case 'tar':
                    $this->handleTypeTar( $moduleName, $destDir, $info );
                    break;
                case 'file':
                    $this->handleTypeFile( $moduleName, $destDir, $info );
                    break;
                case 'multi-file':
                    $this->handleTypeMultiFile( $moduleName, $destDir, $info );
                    break;
                default:
                    throw new Exception( "Unknown type '{$info['type']}' for '$moduleName'" );
            }
        }

        $this->output( "\nDone!\n" );
        $this->cleanUp();
        if ( $this->hasErrors ) {
            // The verify mode should check all modules/files and fail after, not during.
            return false;
        }

        return true;
    }

    private function cacheKey( $src, $integrity ) {
        $key = basename( $src ) . '_' . substr( $integrity, -12 );
        $key = preg_replace( '/[.\/+?=_-]+/', '_', $key );
        return rtrim( $key, '_' );
    }

    private function cacheGet( $key ) {
        return Wikimedia\quietCall( 'file_get_contents', "{$this->cacheDir}/$key.data" );
    }

    private function cacheSet( $key, $data ) {
        wfMkdirParents( $this->cacheDir );
        file_put_contents( "{$this->cacheDir}/$key.data", $data, LOCK_EX );
    }

    private function fetch( $src, $integrity ) {
        $key = $this->cacheKey( $src, $integrity );
        $data = $this->cacheGet( $key );
        if ( $data ) {
            return $data;
        }

        $req = MWHttpRequest::factory( $src, [ 'method' => 'GET', 'followRedirects' => false ] );
        if ( !$req->execute()->isOK() ) {
            throw new Exception( "Failed to download resource at {$src}" );
        }
        if ( $req->getStatus() !== 200 ) {
            throw new Exception( "Unexpected HTTP {$req->getStatus()} response from {$src}" );
        }
        $data = $req->getContent();
        $algo = $integrity === null ? $this->defaultAlgo : explode( '-', $integrity )[0];
        $actualIntegrity = $algo . '-' . base64_encode( hash( $algo, $data, true ) );
        if ( $integrity === $actualIntegrity ) {
            $this->verbose( "... passed integrity check for {$src}\n" );
            $this->cacheSet( $key, $data );
        } elseif ( $this->action === 'make-sri' ) {
            $this->output( "Integrity for {$src}\n\tintegrity: ${actualIntegrity}\n" );
        } else {
            throw new Exception( "Integrity check failed for {$src}\n" .
                "\tExpected: {$integrity}\n" .
                "\tActual: {$actualIntegrity}"
            );
        }
        return $data;
    }

    private function handleTypeFile( $moduleName, $destDir, array $info ) {
        if ( !isset( $info['src'] ) ) {
            throw new Exception( "Module '$moduleName' must have a 'src' key." );
        }
        $data = $this->fetch( $info['src'], $info['integrity'] ?? null );
        $dest = $info['dest'] ?? basename( $info['src'] );
        $path = "$destDir/$dest";
        if ( $this->action === 'verify' && sha1_file( $path ) !== sha1( $data ) ) {
            throw new Exception( "File for '$moduleName' is different." );
        }
        if ( $this->action === 'update' ) {
            wfMkdirParents( $destDir );
            file_put_contents( "$destDir/$dest", $data );
        }
    }

    private function handleTypeMultiFile( $moduleName, $destDir, array $info ) {
        if ( !isset( $info['files'] ) ) {
            throw new Exception( "Module '$moduleName' must have a 'files' key." );
        }
        foreach ( $info['files'] as $dest => $file ) {
            if ( !isset( $file['src'] ) ) {
                throw new Exception( "Module '$moduleName' file '$dest' must have a 'src' key." );
            }
            $data = $this->fetch( $file['src'], $file['integrity'] ?? null );
            $path = "$destDir/$dest";
            if ( $this->action === 'verify' && sha1_file( $path ) !== sha1( $data ) ) {
                throw new Exception( "File '$dest' for '$moduleName' is different." );
            } elseif ( $this->action === 'update' ) {
                wfMkdirParents( $destDir );
                file_put_contents( "$destDir/$dest", $data );
            }
        }
    }

    private function handleTypeTar( $moduleName, $destDir, array $info ) {
        $info += [ 'src' => null, 'integrity' => null, 'dest' => null ];
        if ( $info['src'] === null ) {
            throw new Exception( "Module '$moduleName' must have a 'src' key." );
        }
        // Download the resource to a temporary file and open it
        $data = $this->fetch( $info['src'], $info['integrity' ] );
        $tmpFile = "{$this->tmpParentDir}/$moduleName.tar";
        $this->verbose( "... writing '$moduleName' src to $tmpFile\n" );
        file_put_contents( $tmpFile, $data );
        $p = new PharData( $tmpFile );
        $tmpDir = "{$this->tmpParentDir}/$moduleName";
        $p->extractTo( $tmpDir );
        unset( $data, $p );

        if ( $info['dest'] === null ) {
            // Default: Replace the entire directory
            $toCopy = [ $tmpDir => $destDir ];
        } else {
            // Expand and normalise the 'dest' entries
            $toCopy = [];
            foreach ( $info['dest'] as $fromSubPath => $toSubPath ) {
                // Use glob() to expand wildcards and check existence
                $fromPaths = glob( "{$tmpDir}/{$fromSubPath}", GLOB_BRACE );
                if ( !$fromPaths ) {
                    throw new Exception( "Path '$fromSubPath' of '$moduleName' not found." );
                }
                foreach ( $fromPaths as $fromPath ) {
                    $toCopy[$fromPath] = $toSubPath === null
                        ? "$destDir/" . basename( $fromPath )
                        : "$destDir/$toSubPath/" . basename( $fromPath );
                }
            }
        }
        foreach ( $toCopy as $from => $to ) {
            if ( $this->action === 'verify' ) {
                $this->verbose( "... verifying $to\n" );
                if ( is_dir( $from ) ) {
                    $rii = new RecursiveIteratorIterator( new RecursiveDirectoryIterator(
                        $from,
                        RecursiveDirectoryIterator::SKIP_DOTS
                    ) );
                    foreach ( $rii as $file ) {
                        $remote = $file->getPathname();
                        $local = strtr( $remote, [ $from => $to ] );
                        if ( sha1_file( $remote ) !== sha1_file( $local ) ) {
                            $this->error( "File '$local' is different." );
                            $this->hasErrors = true;
                        }
                    }
                } elseif ( sha1_file( $from ) !== sha1_file( $to ) ) {
                    $this->error( "File '$to' is different." );
                    $this->hasErrors = true;
                }
            } elseif ( $this->action === 'update' ) {
                $this->verbose( "... moving $from to $to\n" );
                wfMkdirParents( dirname( $to ) );
                if ( !rename( $from, $to ) ) {
                    throw new Exception( "Could not move $from to $to." );
                }
            }
        }
    }

    private function verbose( $text ) {
        ( $this->verbosePrinter )( $text );
    }

    private function output( $text ) {
        ( $this->infoPrinter )( $text );
    }

    private function error( $text ) {
        ( $this->errorPrinter )( $text );
    }

    private function cleanUp() {
        wfRecursiveRemoveDir( $this->tmpParentDir );

        // Prune the cache of files we don't recognise.
        $knownKeys = [];
        foreach ( $this->registry as $info ) {
            if ( $info['type'] === 'file' || $info['type'] === 'tar' ) {
                $knownKeys[] = $this->cacheKey( $info['src'], $info['integrity'] );
            } elseif ( $info['type'] === 'multi-file' ) {
                foreach ( $info['files'] as $file ) {
                    $knownKeys[] = $this->cacheKey( $file['src'], $file['integrity'] );
                }
            }
        }
        foreach ( glob( "{$this->cacheDir}/*" ) as $cacheFile ) {
            if ( !in_array( basename( $cacheFile, '.data' ), $knownKeys ) ) {
                unlink( $cacheFile );
            }
        }
    }

    private function parseBasicYaml( $input ) {
        $lines = explode( "\n", $input );
        $root = [];
        $stack = [ &$root ];
        $prev = 0;
        foreach ( $lines as $i => $text ) {
            $line = $i + 1;
            $trimmed = ltrim( $text, ' ' );
            if ( $trimmed === '' || $trimmed[0] === '#' ) {
                continue;
            }
            $indent = strlen( $text ) - strlen( $trimmed );
            if ( $indent % 2 !== 0 ) {
                throw new Exception( __METHOD__ . ": Odd indentation on line $line." );
            }
            $depth = $indent === 0 ? 0 : ( $indent / 2 );
            if ( $depth < $prev ) {
                // Close previous branches we can't re-enter
                array_splice( $stack, $depth + 1 );
            }
            if ( !array_key_exists( $depth, $stack ) ) {
                throw new Exception( __METHOD__ . ": Too much indentation on line $line." );
            }
            if ( strpos( $trimmed, ':' ) === false ) {
                throw new Exception( __METHOD__ . ": Missing colon on line $line." );
            }
            $dest =& $stack[ $depth ];
            if ( $dest === null ) {
                // Promote from null to object
                $dest = [];
            }
            list( $key, $val ) = explode( ':', $trimmed, 2 );
            $val = ltrim( $val, ' ' );
            if ( $val !== '' ) {
                // Add string
                $dest[ $key ] = $val;
            } else {
                // Add null (may become an object later)
                $val = null;
                $stack[] = &$val;
                $dest[ $key ] = &$val;
            }
            $prev = $depth;
            unset( $dest, $val );
        }
        return $root;
    }
}