orizontal-tab (9)> (RFC 2616 2.2).
			 */
			$headers = preg_replace( '/\n[ \t]/', ' ', $headers );
			// Create the headers array.
			$headers = explode( "\n", $headers );
		}

		$response = array(
			'code'    => 0,
			'message' => '',
		);

		/*
		 * If a redirection has taken place, The headers for each page request may have been passed.
		 * In this case, determine the final HTTP header and parse from there.
		 */
		for ( $i = count( $headers ) - 1; $i >= 0; $i-- ) {
			if ( ! empty( $headers[ $i ] ) && ! str_contains( $headers[ $i ], ':' ) ) {
				$headers = array_splice( $headers, $i );
				break;
			}
		}

		$cookies    = array();
		$newheaders = array();
		foreach ( (array) $headers as $tempheader ) {
			if ( empty( $tempheader ) ) {
				continue;
			}

			if ( ! str_contains( $tempheader, ':' ) ) {
				$stack   = explode( ' ', $tempheader, 3 );
				$stack[] = '';
				list( , $response['code'], $response['message']) = $stack;
				continue;
			}

			list($key, $value) = explode( ':', $tempheader, 2 );

			$key   = strtolower( $key );
			$value = trim( $value );

			if ( isset( $newheaders[ $key ] ) ) {
				if ( ! is_array( $newheaders[ $key ] ) ) {
					$newheaders[ $key ] = array( $newheaders[ $key ] );
				}
				$newheaders[ $key ][] = $value;
			} else {
				$newheaders[ $key ] = $value;
			}
			if ( 'set-cookie' === $key ) {
				$cookies[] = new WP_Http_Cookie( $value, $url );
			}
		}

		// Cast the Response Code to an int.
		$response['code'] = (int) $response['code'];

		return array(
			'response' => $response,
			'headers'  => $newheaders,
			'cookies'  => $cookies,
		);
	}

	/**
	 * Takes the arguments for a ::request() and checks for the cookie array.
	 *
	 * If it's found, then it upgrades any basic name => value pairs to WP_Http_Cookie instances,
	 * which are each parsed into strings and added to the Cookie: header (within the arguments array).
	 * Edits the array by reference.
	 *
	 * @since 2.8.0
	 *
	 * @param array $r Full array of args passed into ::request()
	 */
	public static function buildCookieHeader( &$r ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.MethodNameInvalid
		if ( ! empty( $r['cookies'] ) ) {
			// Upgrade any name => value cookie pairs to WP_HTTP_Cookie instances.
			foreach ( $r['cookies'] as $name => $value ) {
				if ( ! is_object( $value ) ) {
					$r['cookies'][ $name ] = new WP_Http_Cookie(
						array(
							'name'  => $name,
							'value' => $value,
						)
					);
				}
			}

			$cookies_header = '';
			foreach ( (array) $r['cookies'] as $cookie ) {
				$cookies_header .= $cookie->getHeaderValue() . '; ';
			}

			$cookies_header         = substr( $cookies_header, 0, -2 );
			$r['headers']['cookie'] = $cookies_header;
		}
	}

	/**
	 * Decodes chunk transfer-encoding, based off the HTTP 1.1 specification.
	 *
	 * Based off the HTTP http_encoding_dechunk function.
	 *
	 * @link https://tools.ietf.org/html/rfc2616#section-19.4.6 Process for chunked decoding.
	 *
	 * @since 2.7.0
	 *
	 * @param string $body Body content.
	 * @return string Chunked decoded body on success or raw body on failure.
	 */
	public static function chunkTransferDecode( $body ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.MethodNameInvalid
		// The body is not chunked encoded or is malformed.
		if ( ! preg_match( '/^([0-9a-f]+)[^\r\n]*\r\n/i', trim( $body ) ) ) {
			return $body;
		}

		$parsed_body = '';

		// We'll be altering $body, so need a backup in case of error.
		$body_original = $body;

		while ( true ) {
			$has_chunk = (bool) preg_match( '/^([0-9a-f]+)[^\r\n]*\r\n/i', $body, $match );
			if ( ! $has_chunk || empty( $match[1] ) ) {
				return $body_original;
			}

			$length       = hexdec( $match[1] );
			$chunk_length = strlen( $match[0] );

			// Parse out the chunk of data.
			$parsed_body .= substr( $body, $chunk_length, $length );

			// Remove the chunk from the raw data.
			$body = substr( $body, $length + $chunk_length );

			// End of the document.
			if ( '0' === trim( $body ) ) {
				return $parsed_body;
			}
		}
	}

	/**
	 * Determines whether an HTTP API request to the given URL should be blocked.
	 *
	 * Those who are behind a proxy and want to prevent access to certain hosts may do so. This will
	 * prevent plugins from working and core functionality, if you don't include `api.wordpress.org`.
	 *
	 * You block external URL requests by defining `WP_HTTP_BLOCK_EXTERNAL` as true in your `wp-config.php`
	 * file and this will only allow localhost and your site to make requests. The constant
	 * `WP_ACCESSIBLE_HOSTS` will allow additional hosts to go through for requests. The format of the
	 * `WP_ACCESSIBLE_HOSTS` constant is a comma separated list of hostnames to allow, wildcard domains
	 * are supported, eg `*.wordpress.org` will allow for all subdomains of `wordpress.org` to be contacted.
	 *
	 * @since 2.8.0
	 *
	 * @link https://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
	 * @link https://core.trac.wordpress.org/ticket/14636 Allow wildcard domains in WP_ACCESSIBLE_HOSTS
	 *
	 * @param string $uri URI of url.
	 * @return bool True to block, false to allow.
	 */
	public function block_request( $uri ) {
		// We don't need to block requests, because nothing is blocked.
		if ( ! defined( 'WP_HTTP_BLOCK_EXTERNAL' ) || ! WP_HTTP_BLOCK_EXTERNAL ) {
			return false;
		}

		$check = parse_url( $uri );
		if ( ! $check ) {
			return true;
		}

		$home = parse_url( get_option( 'siteurl' ) );

		// Don't block requests back to ourselves by default.
		if ( 'localhost' === $check['host'] || ( isset( $home['host'] ) && $home['host'] === $check['host'] ) ) {
			/**
			 * Filters whether to block local HTTP API requests.
			 *
			 * A local request is one to `localhost` or to the same host as the site itself.
			 *
			 * @since 2.8.0
			 *
			 * @param bool $block Whether to block local requests. Default false.
			 */
			return apply_filters( 'block_local_requests', false );
		}

		if ( ! defined( 'WP_ACCESSIBLE_HOSTS' ) ) {
			return true;
		}

		static $accessible_hosts = null;
		static $wildcard_regex   = array();
		if ( null === $accessible_hosts ) {
			$accessible_hosts = preg_split( '|,\s*|', WP_ACCESSIBLE_HOSTS );

			if ( str_contains( WP_ACCESSIBLE_HOSTS, '*' ) ) {
				$wildcard_regex = array();
				foreach ( $accessible_hosts as $host ) {
					$wildcard_regex[] = str_replace( '\*', '.+', preg_quote( $host, '/' ) );
				}
				$wildcard_regex = '/^(' . implode( '|', $wildcard_regex ) . ')$/i';
			}
		}

		if ( ! empty( $wildcard_regex ) ) {
			return ! preg_match( $wildcard_regex, $check['host'] );
		} else {
			return ! in_array( $check['host'], $accessible_hosts, true ); // Inverse logic, if it's in the array, then don't block it.
		}
	}

	/**
	 * Used as a wrapper for PHP's parse_url() function that handles edgecases in < PHP 5.4.7.
	 *
	 * @deprecated 4.4.0 Use wp_parse_url()
	 * @see wp_parse_url()
	 *
	 * @param string $url The URL to parse.
	 * @return bool|array False on failure; Array of URL components on success;
	 *                    See parse_url()'s return values.
	 */
	protected static function parse_url( $url ) {
		_deprecated_function( __METHOD__, '4.4.0', 'wp_parse_url()' );
		return wp_parse_url( $url );
	}

	/**
	 * Converts a relative URL to an absolute URL relative to a given URL.
	 *
	 * If an Absolute URL is provided, no processing of that URL is done.
	 *
	 * @since 3.4.0
	 *
	 * @param string $maybe_relative_path The URL which might be relative.
	 * @param string $url                 The URL which $maybe_relative_path is relative to.
	 * @return string An Absolute URL, in a failure condition where the URL cannot be parsed, the relative URL will be returned.
	 */
	public static function make_absolute_url( $maybe_relative_path, $url ) {
		if ( empty( $url ) ) {
			return $maybe_relative_path;
		}

		$url_parts = wp_parse_url( $url );
		if ( ! $url_parts ) {
			return $maybe_relative_path;
		}

		$relative_url_parts = wp_parse_url( $maybe_relative_path );
		if ( ! $relative_url_parts ) {
			return $maybe_relative_path;
		}

		// Check for a scheme on the 'relative' URL.
		if ( ! empty( $relative_url_parts['scheme'] ) ) {
			return $maybe_relative_path;
		}

		$absolute_path = $url_parts['scheme'] . '://';

		// Schemeless URLs will make it this far, so we check for a host in the relative URL
		// and convert it to a protocol-URL.
		if ( isset( $relative_url_parts['host'] ) ) {
			$absolute_path .= $relative_url_parts['host'];
			if ( isset( $relative_url_parts['port'] ) ) {
				$absolute_path .= ':' . $relative_url_parts['port'];
			}
		} else {
			$absolute_path .= $url_parts['host'];
			if ( isset( $url_parts['port'] ) ) {
				$absolute_path .= ':' . $url_parts['port'];
			}
		}

		// Start off with the absolute URL path.
		$path = ! empty( $url_parts['path'] ) ? $url_parts['path'] : '/';

		// If it's a root-relative path, then great.
		if ( ! empty( $relative_url_parts['path'] ) && '/' === $relative_url_parts['path'][0] ) {
			$path = $relative_url_parts['path'];

			// Else it's a relative path.
		} elseif ( ! empty( $relative_url_parts['path'] ) ) {
			// Strip off any file components from the absolute path.
			$path = substr( $path, 0, strrpos( $path, '/' ) + 1 );

			// Build the new path.
			$path .= $relative_url_parts['path'];

			// Strip all /path/../ out of the path.
			while ( strpos( $path, '../' ) > 1 ) {
				$path = preg_replace( '![^/]+/\.\./!', '', $path );
			}

			// Strip any final leading ../ from the path.
			$path = preg_replace( '!^/(\.\./)+!', '', $path );
		}

		// Add the query string.
		if ( ! empty( $relative_url_parts['query'] ) ) {
			$path .= '?' . $relative_url_parts['query'];
		}

		// Add the fragment.
		if ( ! empty( $relative_url_parts['fragment'] ) ) {
			$path .= '#' . $relative_url_parts['fragment'];
		}

		return $absolute_path . '/' . ltrim( $path, '/' );
	}

	/**
	 * Handles an HTTP redirect and follows it if appropriate.
	 *
	 * @since 3.7.0
	 *
	 * @param string $url      The URL which was requested.
	 * @param array  $args     The arguments which were used to make the request.
	 * @param array  $response The response of the HTTP request.
	 * @return array|false|WP_Error An HTTP API response array if the redirect is successfully followed,
	 *                              false if no redirect is present, or a WP_Error object if there's an error.
	 */
	public static function handle_redirects( $url, $args, $response ) {
		// If no redirects are present, or, redirects were not requested, perform no action.
		if ( ! isset( $response['headers']['location'] ) || 0 === $args['_redirection'] ) {
			return false;
		}

		// Only perform redirections on redirection http codes.
		if ( $response['response']['code'] > 399 || $response['response']['code'] < 300 ) {
			return false;
		}

		// Don't redirect if we've run out of redirects.
		if ( $args['redirection']-- <= 0 ) {
			return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
		}

		$redirect_location = $response['headers']['location'];

		// If there were multiple Location headers, use the last header specified.
		if ( is_array( $redirect_location ) ) {
			$redirect_location = array_pop( $redirect_location );
		}

		$redirect_location = WP_Http::make_absolute_url( $redirect_location, $url );

		// POST requests should not POST to a redirected location.
		if ( 'POST' === $args['method'] ) {
			if ( in_array( $response['response']['code'], array( 302, 303 ), true ) ) {
				$args['method'] = 'GET';
			}
		}

		// Include valid cookies in the redirect process.
		if ( ! empty( $response['cookies'] ) ) {
			foreach ( $response['cookies'] as $cookie ) {
				if ( $cookie->test( $redirect_location ) ) {
					$args['cookies'][] = $cookie;
				}
			}
		}

		return wp_remote_request( $redirect_location, $args );
	}

	/**
	 * Determines if a specified string represents an IP address or not.
	 *
	 * This function also detects the type of the IP address, returning either
	 * '4' or '6' to represent an IPv4 and IPv6 address respectively.
	 * This does not verify if the IP is a valid IP, only that it appears to be
	 * an IP address.
	 *
	 * @link http://home.deds.nl/~aeron/regex/ for IPv6 regex.
	 *
	 * @since 3.7.0
	 *
	 * @param string $maybe_ip A suspected IP address.
	 * @return int|false Upon success, '4' or '6' to represent an IPv4 or IPv6 address, false upon failure.
	 */
	public static function is_ip_address( $maybe_ip ) {
		if ( preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/', $maybe_ip ) ) {
			return 4;
		}

		if ( str_contains( $maybe_ip, ':' ) && preg_match( '/^(((?=.*(::))(?!.*\3.+\3))\3?|([\dA-F]{1,4}(\3|:\b|$)|\2))(?4){5}((?4){2}|(((2[0-4]|1\d|[1-9])?\d|25[0-5])\.?\b){4})$/i', trim( $maybe_ip, ' []' ) ) ) {
			return 6;
		}

		return false;
	}
}