are not allowed to make proxied oEmbed requests.' ), array( 'status' => rest_authorization_required_code() ) );
		}
		return true;
	}

	/**
	 * Callback for the proxy API endpoint.
	 *
	 * Returns the JSON object for the proxied item.
	 *
	 * @since 4.8.0
	 *
	 * @see WP_oEmbed::get_html()
	 * @global WP_Embed   $wp_embed   WordPress Embed object.
	 * @global WP_Scripts $wp_scripts
	 *
	 * @param WP_REST_Request $request Full data about the request.
	 * @return object|WP_Error oEmbed response data or WP_Error on failure.
	 */
	public function get_proxy_item( $request ) {
		global $wp_embed, $wp_scripts;

		$args = $request->get_params();

		// Serve oEmbed data from cache if set.
		unset( $args['_wpnonce'] );
		$cache_key = 'oembed_' . md5( serialize( $args ) );
		$data      = get_transient( $cache_key );
		if ( ! empty( $data ) ) {
			return $data;
		}

		$url = $request['url'];
		unset( $args['url'] );

		// Copy maxwidth/maxheight to width/height since WP_oEmbed::fetch() uses these arg names.
		if ( isset( $args['maxwidth'] ) ) {
			$args['width'] = $args['maxwidth'];
		}
		if ( isset( $args['maxheight'] ) ) {
			$args['height'] = $args['maxheight'];
		}

		// Short-circuit process for URLs belonging to the current site.
		$data = get_oembed_response_data_for_url( $url, $args );

		if ( $data ) {
			return $data;
		}

		$data = _wp_oembed_get_object()->get_data( $url, $args );

		if ( false === $data ) {
			// Try using a classic embed, instead.
			/* @var WP_Embed $wp_embed */
			$html = $wp_embed->get_embed_handler_html( $args, $url );

			if ( $html ) {
				// Check if any scripts were enqueued by the shortcode, and include them in the response.
				$enqueued_scripts = array();

				foreach ( $wp_scripts->queue as $script ) {
					$enqueued_scripts[] = $wp_scripts->registered[ $script ]->src;
				}

				return (object) array(
					'provider_name' => __( 'Embed Handler' ),
					'html'          => $html,
					'scripts'       => $enqueued_scripts,
				);
			}

			return new WP_Error( 'oembed_invalid_url', get_status_header_desc( 404 ), array( 'status' => 404 ) );
		}

		/** This filter is documented in wp-includes/class-wp-oembed.php */
		$data->html = apply_filters( 'oembed_result', _wp_oembed_get_object()->data2html( (object) $data, $url ), $url, $args );

		/**
		 * Filters the oEmbed TTL value (time to live).
		 *
		 * Similar to the {@see 'oembed_ttl'} filter, but for the REST API
		 * oEmbed proxy endpoint.
		 *
		 * @since 4.8.0
		 *
		 * @param int    $time    Time to live (in seconds).
		 * @param string $url     The attempted embed URL.
		 * @param array  $args    An array of embed request arguments.
		 */
		$ttl = apply_filters( 'rest_oembed_ttl', DAY_IN_SECONDS, $url, $args );

		set_transient( $cache_key, $data, $ttl );

		return $data;
	}
}
ng '\\'
     * @param list<string>|string $paths  The PSR-4 base directories
     *
     * @throws \InvalidArgumentException
     *
     * @return void
     */
    public function setPsr4($prefix, $paths)
    {
        if (!$prefix) {
            $this->fallbackDirsPsr4 = (array) $paths;
        } else {
            $length = strlen($prefix);
            if ('\\' !== $prefix[$length - 1]) {
                throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
            }
            $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
            $this->prefixDirsPsr4[$prefix] = (array) $paths;
        }
    }

    /**
     * Turns on searching the include path for class files.
     *
     * @param bool $useIncludePath
     *
     * @return void
     */
    public function setUseIncludePath($useIncludePath)
    {
        $this->useIncludePath = $useIncludePath;
    }

    /**
     * Can be used to check if the autoloader uses the include path to check
     * for classes.
     *
     * @return bool
     */
    public function getUseIncludePath()
    {
        return $this->useIncludePath;
    }

    /**
     * Turns off searching the prefix and fallback directories for classes
     * that have not been registered with the class map.
     *
     * @param bool $classMapAuthoritative
     *
     * @return void
     */
    public function setClassMapAuthoritative($classMapAuthoritative)
    {
        $this->classMapAuthoritative = $classMapAuthoritative;
    }

    /**
     * Should class lookup fail if not found in the current class map?
     *
     * @return bool
     */
    public function isClassMapAuthoritative()
    {
        return $this->classMapAuthoritative;
    }

    /**
     * APCu prefix to use to cache found/not-found classes, if the extension is enabled.
     *
     * @param string|null $apcuPrefix
     *
     * @return void
     */
    public function setApcuPrefix($apcuPrefix)
    {
        $this->apcuPrefix = function_exists('apcu_fetch') && filter_var(ini_get('apc.enabled'), FILTER_VALIDATE_BOOLEAN) ? $apcuPrefix : null;
    }

    /**
     * The APCu prefix in use, or null if APCu caching is not enabled.
     *
     * @return string|null
     */
    public function getApcuPrefix()
    {
        return $this->apcuPrefix;
    }

    /**
     * Registers this instance as an autoloader.
     *
     * @param bool $prepend Whether to prepend the autoloader or not
     *
     * @return void
     */
    public function register($prepend = false)
    {
        spl_autoload_register(array($this, 'loadClass'), true, $prepend);

        if (null === $this->vendorDir) {
            return;
        }

        if ($prepend) {
            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
        } else {
            unset(self::$registeredLoaders[$this->vendorDir]);
            self::$registeredLoaders[$this->vendorDir] = $this;
        }
    }

    /**
     * Unregisters this instance as an autoloader.
     *
     * @return void
     */
    public function unregister()
    {
        spl_autoload_unregister(array($this, 'loadClass'));

        if (null !== $this->vendorDir) {
            unset(self::$registeredLoaders[$this->vendorDir]);
        }
    }

    /**
     * Loads the given class or interface.
     *
     * @param  string    $class The name of the class
     * @return true|null True if loaded, null otherwise
     */
    public function loadClass($class)
    {
        if ($file = $this->findFile($class)) {
            $includeFile = self::$includeFile;
            $includeFile($file);

            return true;
        }

        return null;
    }

    /**
     * Finds the path to the file where the class is defined.
     *
     * @param string $class The name of the class
     *
     * @return string|false The path if found, false otherwise
     */
    public function findFile($class)
    {
        // class map lookup
        if (isset($this->classMap[$class])) {
            return $this->classMap[$class];
        }
        if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
            return false;
        }
        if (null !== $this->apcuPrefix) {
            $file = apcu_fetch($this->apcuPrefix.$class, $hit);
            if ($hit) {
                return $file;
            }
        }

        $file = $this->findFileWithExtension($class, '.php');

        // Search for Hack files if we are running on HHVM
        if (false === $file && defined('HHVM_VERSION')) {
            $file = $this->findFileWithExtension($class, '.hh');
        }

        if (null !== $this->apcuPrefix) {
            apcu_add($this->apcuPrefix.$class, $file);
        }

        if (false === $file) {
            // Remember that this class does not exist.
            $this->missingClasses[$class] = true;
        }

        return $file;
    }

    /**
     * Returns the currently registered loaders keyed by their corresponding vendor directories.
     *
     * @return array<string, self>
     */
    public static function getRegisteredLoaders()
    {
        return self::$registeredLoaders;
    }

    /**
     * @param  string       $class
     * @param  string       $ext
     * @return string|false
     */
    private function findFileWithExtension($class, $ext)
    {
        // PSR-4 lookup
        $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;

        $first = $class[0];
        if (isset($this->prefixLengthsPsr4[$first])) {
            $subPath = $class;
            while (false !== $lastPos = strrpos($subPath, '\\')) {
                $subPath = substr($subPath, 0, $lastPos);
                $search = $subPath . '\\';
                if (isset($this->prefixDirsPsr4[$search])) {
                    $pathEnd = DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $lastPos + 1);
                    foreach ($this->prefixDirsPsr4[$search] as $dir) {
                        if (file_exists($file = $dir . $pathEnd)) {
                            return $file;
                        }
                    }
                }
            }
        }

        // PSR-4 fallback dirs
        foreach ($this->fallbackDirsPsr4 as $dir) {
            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
                return $file;
            }
        }

        // PSR-0 lookup
        if (false !== $pos = strrpos($class, '\\')) {
            // namespaced class name
            $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
                . strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
        } else {
            // PEAR-like class name
            $logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
        }

        if (isset($this->prefixesPsr0[$first])) {
            foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
                if (0 === strpos($class, $prefix)) {
                    foreach ($dirs as $dir) {
                        if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
                            return $file;
                        }
                    }
                }
            }
        }

        // PSR-0 fallback dirs
        foreach ($this->fallbackDirsPsr0 as $dir) {
            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
                return $file;
            }
        }

        // PSR-0 include paths.
        if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
            return $file;
        }

        return false;
    }

    /**
     * @return void
     */
    private static function initializeIncludeClosure()
    {
        if (self::$includeFile !== null) {
            return;
        }

        /**
         * Scope isolated include.
         *
         * Prevents access to $this/self from included files.
         *
         * @param  string $file
         * @return void
         */
        self::$includeFile = \Closure::bind(static function($file) {
            include $file;
        }, null, null);
    }
}