WP_REST_URL_Details_Controller::get_remote_url() WordPress Method

	private function get_remote_url( $url ) {

		/*
		 * Provide a modified UA string to workaround web properties which block WordPress "Pingbacks".
		 * Why? The UA string used for pingback requests contains `WordPress/` which is very similar
		 * to that used as the default UA string by the WP HTTP API. Therefore requests from this
		 * REST endpoint are being unintentionally blocked as they are misidentified as pingback requests.
		 * By slightly modifying the UA string, but still retaining the "WordPress" identification (via "WP")
		 * we are able to work around this issue.
		 * Example UA string: `WP-URLDetails/5.9-alpha-51389 (+http://localhost:8888)`.
		*/
		$modified_user_agent = 'WP-URLDetails/' . get_bloginfo( 'version' ) . ' (+' . get_bloginfo( 'url' ) . ')';

		$args = array(
			'limit_response_size' => 150 * KB_IN_BYTES,
			'user-agent'          => $modified_user_agent,
		);

		/**
		 * Filters the HTTP request args for URL data retrieval.
		 *
		 * Can be used to adjust response size limit and other WP_Http::request() args.
		 *
		 * @since 5.9.0
		 *
		 * @param array  $args Arguments used for the HTTP request.
		 * @param string $url  The attempted URL.
		 */
		$args = apply_filters( 'rest_url_details_http_request_args', $args, $url );

		$response = wp_safe_remote_get( $url, $args );

		if ( WP_Http::OK !== wp_remote_retrieve_response_code( $response ) ) {
			// Not saving the error response to cache since the error might be temporary.
			return new WP_Error(
				'no_response',
				__( 'URL not found. Response returned a non-200 status code for this URL.' ),
				array( 'status' => WP_Http::NOT_FOUND )
			);
		}

		$remote_body = wp_remote_retrieve_body( $response );

		if ( empty( $remote_body ) ) {
			return new WP_Error(
				'no_content',
				__( 'Unable to retrieve body from response at this URL.' ),
				array( 'status' => WP_Http::NOT_FOUND )
			);
		}

		return $remote_body;
	}