ed.
	 *
	 * @since 6.9.0
	 *
	 * @return string|null Error from last attempt at parsing next block delimiter,
	 *                     or `null` if last attempt succeeded.
	 */
	public function get_last_error(): ?string {
		return $this->last_error;
	}

	/**
	 * Indicates if the last attempt to parse a block’s JSON attributes failed.
	 *
	 * @see \json_last_error()
	 *
	 * @since 6.9.0
	 *
	 * @return int JSON_ERROR_ code from last attempt to parse block JSON attributes.
	 */
	public function get_last_json_error(): int {
		return $this->last_json_error;
	}

	/**
	 * Returns the type of the block comment delimiter.
	 *
	 * One of:
	 *
	 *  - {@see self::OPENER}
	 *  - {@see self::CLOSER}
	 *  - {@see self::VOID}
	 *  - `null`
	 *
	 * @since 6.9.0
	 *
	 * @return string|null type of the block comment delimiter, if currently matched.
	 */
	public function get_delimiter_type(): ?string {
		switch ( $this->state ) {
			case self::HTML_SPAN:
				return self::VOID;

			case self::MATCHED:
				return $this->type;

			default:
				return null;
		}
	}

	/**
	 * Returns whether the delimiter contains the closing flag.
	 *
	 * This should be avoided except in cases of custom error-handling
	 * with block closers containing the void flag. For normative use,
	 * {@see self::get_delimiter_type()}.
	 *
	 * @since 6.9.0
	 *
	 * @return bool Whether the currently-matched block delimiter contains the closing flag.
	 */
	public function has_closing_flag(): bool {
		return $this->has_closing_flag;
	}

	/**
	 * Indicates if the block delimiter represents a block of the given type.
	 *
	 * Since the “core” namespace may be implicit, it’s allowable to pass
	 * either the fully-qualified block type with namespace and block name
	 * as well as the shorthand version only containing the block name, if
	 * the desired block is in the “core” namespace.
	 *
	 * Since freeform HTML content is non-block content, it has no block type.
	 * Passing the wildcard “*” will, however, return true for all block types,
	 * even the implicit freeform content, though not for spans of inner HTML.
	 *
	 * Example:
	 *
	 *     $is_core_paragraph = $processor->is_block_type( 'paragraph' );
	 *     $is_core_paragraph = $processor->is_block_type( 'core/paragraph' );
	 *     $is_formula        = $processor->is_block_type( 'math-block/formula' );
	 *
	 * @param string $block_type Block type name for the desired block.
	 *                           E.g. "paragraph", "core/paragraph", "math-blocks/formula".
	 * @return bool Whether this delimiter represents a block of the given type.
	 */
	public function is_block_type( string $block_type ): bool {
		if ( '*' === $block_type ) {
			return true;
		}

		if ( $this->is_html() ) {
			// This is a core/freeform text block, it’s special.
			if ( 0 === ( $this->open_blocks_length[0] ?? null ) ) {
				return (
					'core/freeform' === $block_type ||
					'freeform' === $block_type
				);
			}

			// Otherwise this is innerHTML and not a block.
			return false;
		}

		return $this->are_equal_block_types( $this->source_text, $this->namespace_at, $this->name_at - $this->namespace_at + $this->name_length, $block_type, 0, strlen( $block_type ) );
	}

	/**
	 * Given two spans of text, indicate if they represent identical block types.
	 *
	 * This function normalizes block types to account for implicit core namespacing.
	 *
	 * Note! This function only returns valid results when the complete block types are
	 *       represented in the span offsets and lengths. This means that the full optional
	 *       namespace and block name must be represented in the input arguments.
	 *
	 * Example:
	 *
	 *              0    5   10   15   20   25   30   35   40
	 *     $text = '<!-- wp:block --><!-- /wp:core/block -->';
	 *
	 *     true  === WP_Block_Processor::are_equal_block_types( $text, 9, 5, $text, 27, 10 );
	 *     false === WP_Block_Processor::are_equal_block_types( $text, 9, 5, 'my/block', 0, 8 );
	 *
	 * @since 6.9.0
	 *
	 * @param string $a_text   Text in which first block type appears.
	 * @param int    $a_at     Byte offset into text in which first block type starts.
	 * @param int    $a_length Byte length of first block type.
	 * @param string $b_text   Text in which second block type appears (may be the same as the first text).
	 * @param int    $b_at     Byte offset into text in which second block type starts.
	 * @param int    $b_length Byte length of second block type.
	 * @return bool Whether the spans of text represent identical block types, normalized for namespacing.
	 */
	public static function are_equal_block_types( string $a_text, int $a_at, int $a_length, string $b_text, int $b_at, int $b_length ): bool {
		$a_ns_length = strcspn( $a_text, '/', $a_at, $a_length );
		$b_ns_length = strcspn( $b_text, '/', $b_at, $b_length );

		$a_has_ns = $a_ns_length !== $a_length;
		$b_has_ns = $b_ns_length !== $b_length;

		// Both contain namespaces.
		if ( $a_has_ns && $b_has_ns ) {
			if ( $a_length !== $b_length ) {
				return false;
			}

			$a_block_type = substr( $a_text, $a_at, $a_length );

			return 0 === substr_compare( $b_text, $a_block_type, $b_at, $b_length );
		}

		if ( $a_has_ns ) {
			$b_block_type = 'core/' . substr( $b_text, $b_at, $b_length );

			return (
				strlen( $b_block_type ) === $a_length &&
				0 === substr_compare( $a_text, $b_block_type, $a_at, $a_length )
			);
		}

		if ( $b_has_ns ) {
			$a_block_type = 'core/' . substr( $a_text, $a_at, $a_length );

			return (
				strlen( $a_block_type ) === $b_length &&
				0 === substr_compare( $b_text, $a_block_type, $b_at, $b_length )
			);
		}

		// Neither contains a namespace.
		if ( $a_length !== $b_length ) {
			return false;
		}

		$a_name = substr( $a_text, $a_at, $a_length );

		return 0 === substr_compare( $b_text, $a_name, $b_at, $b_length );
	}

	/**
	 * Indicates if the matched delimiter is an opening or void delimiter of the given type,
	 * if a type is provided, otherwise if it opens any block or implicit freeform HTML content.
	 *
	 * This is a helper method to ease handling of code inspecting where blocks start, and for
	 * checking if the blocks are of a given type. The function is variadic to allow for
	 * checking if the delimiter opens one of many possible block types.
	 *
	 * To advance to the start of a block {@see self::next_block()}.
	 *
	 * Example:
	 *
	 *     $processor = new WP_Block_Processor( $html );
	 *     while ( $processor->next_delimiter() ) {
	 *         if ( $processor->opens_block( 'core/code', 'syntaxhighlighter/code' ) ) {
	 *             echo "Found code!";
	 *             continue;
	 *         }
	 *
	 *         if ( $processor->opens_block( 'core/image' ) ) {
	 *             echo "Found an image!";
	 *             continue;
	 *         }
	 *
	 *         if ( $processor->opens_block() ) {
	 *             echo "Found a new block!";
	 *         }
	 *     }
	 *
	 * @since 6.9.0
	 *
	 * @see self::is_block_type()
	 *
	 * @param string[] $block_type Optional. Is the matched block type one of these?
	 *                             If none are provided, will not test block type.
	 * @return bool Whether the matched block delimiter opens a block, and whether it
	 *              opens a block of one of the given block types, if provided.
	 */
	public function opens_block( string ...$block_type ): bool {
		// HTML spans only open implicit freeform content at the top level.
		if ( self::HTML_SPAN === $this->state && 1 !== count( $this->open_blocks_at ) ) {
			return false;
		}

		/*
		 * Because HTML spans are discovered after the next delimiter is found,
		 * the delimiter type when visiting HTML spans refers to the type of the
		 * following delimiter. Therefore the HTML case is handled by checking
		 * the state and depth of the stack of open block.
		 */
		if ( self::CLOSER === $this->type && ! $this->is_html() ) {
			return false;
		}

		if ( count( $block_type ) === 0 ) {
			return true;
		}

		return array_any( $block_type, fn( $block ) => $this->is_block_type( $block ) );
	}

	/**
	 * Indicates if the matched delimiter is an HTML span.
	 *
	 * @since 6.9.0
	 *
	 * @see self::is_non_whitespace_html()
	 *
	 * @return bool Whether the processor is matched on an HTML span.
	 */
	public function is_html(): bool {
		return self::HTML_SPAN === $this->state;
	}

	/**
	 * Indicates if the matched delimiter is an HTML span and comprises more
	 * than whitespace characters, i.e. contains real content.
	 *
	 * Many block serializers introduce newlines between block delimiters,
	 * so the presence of top-level non-block content does not imply that
	 * there are “real” freeform HTML blocks. Checking if there is content
	 * beyond whitespace is a more certain check, such as for determining
	 * whether to load CSS for the freeform or fallback block type.
	 *
	 * @since 6.9.0
	 *
	 * @see self::is_html()
	 *
	 * @return bool Whether the currently-matched delimiter is an HTML
	 *              span containing non-whitespace text.
	 */
	public function is_non_whitespace_html(): bool {
		if ( ! $this->is_html() ) {
			return false;
		}

		$length = $this->matched_delimiter_at - $this->after_previous_delimiter;

		$whitespace_length = strspn(
			$this->source_text,
			" \t\f\r\n",
			$this->after_previous_delimiter,
			$length
		);

		return $whitespace_length !== $length;
	}

	/**
	 * Returns the string content of a matched HTML span, or `null` otherwise.
	 *
	 * @since 6.9.0
	 *
	 * @return string|null Raw HTML content, or `null` if not currently matched on HTML.
	 */
	public function get_html_content(): ?string {
		if ( ! $this->is_html() ) {
			return null;
		}

		return substr(
			$this->source_text,
			$this->after_previous_delimiter,
			$this->matched_delimiter_at - $this->after_previous_delimiter
		);
	}

	/**
	 * Allocates a substring for the block type and returns the fully-qualified
	 * name, including the namespace, if matched on a delimiter, otherwise `null`.
	 *
	 * This function is like {@see self::get_printable_block_type()} but when
	 * paused on a freeform HTML block, will return `null` instead of “core/freeform”.
	 * The `null` behavior matches what {@see \parse_blocks()} returns but may not
	 * be as useful as having a string value.
	 *
	 * This function allocates a substring for the given block type. This
	 * allocation will be small and likely fine in most cases, but it's
	 * preferable to call {@see self::is_block_type()} if only needing
	 * to know whether the delimiter is for a given block type, as that
	 * function is more efficient for this purpose and avoids the allocation.
	 *
	 * Example:
	 *
	 *     // Avoid.
	 *     'core/paragraph' = $processor->get_block_type();
	 *
	 *     // Prefer.
	 *     $processor->is_block_type( 'core/paragraph' );
	 *     $processor->is_block_type( 'paragraph' );
	 *     $processor->is_block_type( 'core/freeform' );
	 *
	 *     // Freeform HTML content has no block type.
	 *     $processor = new WP_Block_Processor( 'non-block content' );
	 *     $processor->next_token();
	 *     null === $processor->get_block_type();
	 *
	 * @since 6.9.0
	 *
	 * @see self::are_equal_block_types()
	 *
	 * @return string|null Fully-qualified block namespace and type, e.g. "core/paragraph",
	 *                     if matched on an explicit delimiter, otherwise `null`.
	 */
	public function get_block_type(): ?string {
		if (
			self::READY === $this->state ||
			self::COMPLETE === $this->state ||
			self::INCOMPLETE_INPUT === $this->state
		) {
			return null;
		}

		// This is a core/freeform text block, it’s special.
		if ( $this->is_html() ) {
			return null;
		}

		$block_type = substr( $this->source_text, $this->namespace_at, $this->name_at - $this->namespace_at + $this->name_length );
		return self::normalize_block_type( $block_type );
	}

	/**
	 * Allocates a printable substring for the block type and returns the fully-qualified
	 * name, including the namespace, if matched on a delimiter or freeform block, otherwise `null`.
	 *
	 * This function is like {@see self::get_block_type()} but when paused on a freeform
	 * HTML block, will return “core/freeform” instead of `null`. The `null` behavior matches
	 * what {@see \parse_blocks()} returns but may not be as useful as having a string value.
	 *
	 * This function allocates a substring for the given block type. This
	 * allocation will be small and likely fine in most cases, but it's
	 * preferable to call {@see self::is_block_type()} if only needing
	 * to know whether the delimiter is for a given block type, as that
	 * function is more efficient for this purpose and avoids the allocation.
	 *
	 * Example:
	 *
	 *     // Avoid.
	 *     'core/paragraph' = $processor->get_printable_block_type();
	 *
	 *     // Prefer.
	 *     $processor->is_block_type( 'core/paragraph' );
	 *     $processor->is_block_type( 'paragraph' );
	 *     $processor->is_block_type( 'core/freeform' );
	 *
	 *     // Freeform HTML content is given an implicit type.
	 *     $processor = new WP_Block_Processor( 'non-block content' );
	 *     $processor->next_token();
	 *     'core/freeform' === $processor->get_printable_block_type();
	 *
	 * @since 6.9.0
	 *
	 * @see self::are_equal_block_types()
	 *
	 * @return string|null Fully-qualified block namespace and type, e.g. "core/paragraph",
	 *                     if matched on an explicit delimiter or freeform block, otherwise `null`.
	 */
	public function get_printable_block_type(): ?string {
		if (
			self::READY === $this->state ||
			self::COMPLETE === $this->state ||
			self::INCOMPLETE_INPUT === $this->state
		) {
			return null;
		}

		// This is a core/freeform text block, it’s special.
		if ( $this->is_html() ) {
			return 1 === count( $this->open_blocks_at )
				? 'core/freeform'
				: '#innerHTML';
		}

		$block_type = substr( $this->source_text, $this->namespace_at, $this->name_at - $this->namespace_at + $this->name_length );
		return self::normalize_block_type( $block_type );
	}

	/**
	 * Normalizes a block name to ensure that missing implicit “core” namespaces are present.
	 *
	 * Example:
	 *
	 *     'core/paragraph' === WP_Block_Processor::normalize_block_byte( 'paragraph' );
	 *     'core/paragraph' === WP_Block_Processor::normalize_block_byte( 'core/paragraph' );
	 *     'my/paragraph'   === WP_Block_Processor::normalize_block_byte( 'my/paragraph' );
	 *
	 * @since 6.9.0
	 *
	 * @param string $block_type Valid block name, potentially without a namespace.
	 * @return string Fully-qualified block type including namespace.
	 */
	public static function normalize_block_type( string $block_type ): string {
		return str_contains( $block_type, '/' )
			? $block_type
			: "core/{$block_type}";
	}

	/**
	 * Returns a lazy wrapper around the block attributes, which can be used
	 * for efficiently interacting with the JSON attributes.
	 *
	 * This stub hints that there should be a lazy interface for parsing
	 * block attributes but doesn’t define it. It serves both as a placeholder
	 * for one to come as well as a guard against implementing an eager
	 * function in its place.
	 *
	 * @throws Exception This function is a stub for subclasses to implement
	 *                   when providing streaming attribute parsing.
	 *
	 * @since 6.9.0
	 *
	 * @see self::allocate_and_return_parsed_attributes()
	 *
	 * @return never
	 */
	public function get_attributes() {
		throw new Exception( 'Lazy attribute parsing not yet supported' );
	}

	/**
	 * Attempts to parse and return the entire JSON attributes from the delimiter,
	 * allocating memory and processing the JSON span in the process.
	 *
	 * This does not return any parsed attributes for a closing block delimiter
	 * even if there is a span of JSON content; this JSON is a parsing error.
	 *
	 * Consider calling {@see static::get_attributes()} instead if it's not
	 * necessary to read all the attributes at the same time, as that provides
	 * a more efficient mechanism for typical use cases.
	 *
	 * Since the JSON span inside the comment delimiter may not be valid JSON,
	 * this function will return `null` if it cannot parse the span and set the
	 * {@see static::get_last_json_error()} to the appropriate JSON_ERROR_ constant.
	 *
	 * If the delimiter contains no JSON span, it will also return `null`,
	 * but the last error will be set to {@see \JSON_ERROR_NONE}.
	 *
	 * Example:
	 *
	 *     $processor = new WP_Block_Processor( '<!-- wp:image {"url": "https://wordpress.org/favicon.ico"} -->' );
	 *     $processor->next_delimiter();
	 *     $memory_hungry_and_slow_attributes = $processor->allocate_and_return_parsed_attributes();
	 *     $memory_hungry_and_slow_attributes === array( 'url' => 'https://wordpress.org/favicon.ico' );
	 *
	 *     $processor = new WP_Block_Processor( '<!-- /wp:image {"url": "https://wordpress.org/favicon.ico"} -->' );
	 *     $processor->next_delimiter();
	 *     null            = $processor->allocate_and_return_parsed_attributes();
	 *     JSON_ERROR_NONE = $processor->get_last_json_error();
	 *
	 *     $processor = new WP_Block_Processor( '<!-- wp:separator {} /-->' );
	 *     $processor->next_delimiter();
	 *     array() === $processor->allocate_and_return_parsed_attributes();
	 *
	 *     $processor = new WP_Block_Processor( '<!-- wp:separator /-->' );
	 *     $processor->next_delimiter();
	 *     null = $processor->allocate_and_return_parsed_attributes();
	 *
	 *     $processor = new WP_Block_Processor( '<!-- wp:image {"url} -->' );
	 *     $processor->next_delimiter();
	 *     null                 = $processor->allocate_and_return_parsed_attributes();
	 *     JSON_ERROR_CTRL_CHAR = $processor->get_last_json_error();
	 *
	 * @since 6.9.0
	 *
	 * @return array|null Parsed JSON attributes, if present and valid, otherwise `null`.
	 */
	public function allocate_and_return_parsed_attributes(): ?array {
		$this->last_json_error = JSON_ERROR_NONE;

		if ( self::CLOSER === $this->type || $this->is_html() || 0 === $this->json_length ) {
			return null;
		}

		$json_span = substr( $this->source_text, $this->json_at, $this->json_length );
		$parsed    = json_decode( $json_span, null, 512, JSON_OBJECT_AS_ARRAY | JSON_INVALID_UTF8_SUBSTITUTE );

		$last_error            = json_last_error();
		$this->last_json_error = $last_error;

		return ( JSON_ERROR_NONE === $last_error && is_array( $parsed ) )
			? $parsed
			: null;
	}

	/**
	 * Returns the span representing the currently-matched delimiter, if matched, otherwise `null`.
	 *
	 * Example:
	 *
	 *     $processor = new WP_Block_Processor( '<!-- wp:void /-->' );
	 *     null     === $processor->get_span();
	 *
	 *     $processor->next_delimiter();
	 *     WP_HTML_Span( 0, 17 ) === $processor->get_span();
	 *
	 * @since 6.9.0
	 *
	 * @return WP_HTML_Span|null Span of text in source text spanning matched delimiter.
	 */
	public function get_span(): ?WP_HTML_Span {
		switch ( $this->state ) {
			case self::HTML_SPAN:
				return new WP_HTML_Span( $this->after_previous_delimiter, $this->matched_delimiter_at - $this->after_previous_delimiter );

			case self::MATCHED:
				return new WP_HTML_Span( $this->matched_delimiter_at, $this->matched_delimiter_length );

			default:
				return null;
		}
	}

	//
	// Constant declarations that would otherwise pollute the top of the class.
	//

	/**
	 * Indicates that the block comment delimiter closes an open block.
	 *
	 * @see self::$type
	 *
	 * @since 6.9.0
	 */
	const CLOSER = 'closer';

	/**
	 * Indicates that the block comment delimiter opens a block.
	 *
	 * @see self::$type
	 *
	 * @since 6.9.0
	 */
	const OPENER = 'opener';

	/**
	 * Indicates that the block comment delimiter represents a void block
	 * with no inner content of any kind.
	 *
	 * @see self::$type
	 *
	 * @since 6.9.0
	 */
	const VOID = 'void';

	/**
	 * Indicates that the processor is ready to start parsing but hasn’t yet begun.
	 *
	 * @see self::$state
	 *
	 * @since 6.9.0
	 */
	const READY = 'processor-ready';

	/**
	 * Indicates that the processor is matched on an explicit block delimiter.
	 *
	 * @see self::$state
	 *
	 * @since 6.9.0
	 */
	const MATCHED = 'processor-matched';

	/**
	 * Indicates that the processor is matched on the opening of an implicit freeform delimiter.
	 *
	 * @see self::$state
	 *
	 * @since 6.9.0
	 */
	const HTML_SPAN = 'processor-html-span';

	/**
	 * Indicates that the parser started parsing a block comment delimiter, but
	 * the input document ended before it could finish. The document was likely truncated.
	 *
	 * @see self::$state
	 *
	 * @since 6.9.0
	 */
	const INCOMPLETE_INPUT = 'incomplete-input';

	/**
	 * Indicates that the processor has finished parsing and has nothing left to scan.
	 *
	 * @see self::$state
	 *
	 * @since 6.9.0
	 */
	const COMPLETE = 'processor-complete';
}
ly_filters( 'http_response', $response, $args, $url );
	}

	/**
	 * Uses the POST HTTP method.
	 *
	 * Used for sending data that is expected to be in the body.
	 *
	 * @since 2.7.0
	 *
	 * @param string       $url  The request URL.
	 * @param string|array $args Optional. Override the defaults.
	 * @return array|WP_Error Array containing 'headers', 'body', 'response', 'cookies', 'filename'.
	 *                        A WP_Error instance upon error. See WP_Http::response() for details.
	 */
	public function post( $url, $args = array() ) {
		$defaults    = array( 'method' => 'POST' );
		$parsed_args = wp_parse_args( $args, $defaults );
		return $this->request( $url, $parsed_args );
	}

	/**
	 * Uses the GET HTTP method.
	 *
	 * Used for sending data that is expected to be in the body.
	 *
	 * @since 2.7.0
	 *
	 * @param string       $url  The request URL.
	 * @param string|array $args Optional. Override the defaults.
	 * @return array|WP_Error Array containing 'headers', 'body', 'response', 'cookies', 'filename'.
	 *                        A WP_Error instance upon error. See WP_Http::response() for details.
	 */
	public function get( $url, $args = array() ) {
		$defaults    = array( 'method' => 'GET' );
		$parsed_args = wp_parse_args( $args, $defaults );
		return $this->request( $url, $parsed_args );
	}

	/**
	 * Uses the HEAD HTTP method.
	 *
	 * Used for sending data that is expected to be in the body.
	 *
	 * @since 2.7.0
	 *
	 * @param string       $url  The request URL.
	 * @param string|array $args Optional. Override the defaults.
	 * @return array|WP_Error Array containing 'headers', 'body', 'response', 'cookies', 'filename'.
	 *                        A WP_Error instance upon error. See WP_Http::response() for details.
	 */
	public function head( $url, $args = array() ) {
		$defaults    = array( 'method' => 'HEAD' );
		$parsed_args = wp_parse_args( $args, $defaults );
		return $this->request( $url, $parsed_args );
	}

	/**
	 * Parses the responses and splits the parts into headers and body.
	 *
	 * @since 2.7.0
	 *
	 * @param string $response The full response string.
	 * @return array {
	 *     Array with response headers and body.
	 *
	 *     @type string $headers HTTP response headers.
	 *     @type string $body    HTTP response body.
	 * }
	 */
	public static function processResponse( $response ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.MethodNameInvalid
		$response = explode( "\r\n\r\n", $response, 2 );

		return array(
			'headers' => $response[0],
			'body'    => $response[1] ?? '',
		);
	}

	/**
	 * Transforms header string into an array.
	 *
	 * @since 2.7.0
	 *
	 * @param string|array $headers The original headers. If a string is passed, it will be converted
	 *                              to an array. If an array is passed, then it is assumed to be
	 *                              raw header data with numeric keys with the headers as the values.
	 *                              No headers must be passed that were already processed.
	 * @param string       $url     Optional. The URL that was requested. Default empty.
	 * @return array {
	 *     Processed string headers. If duplicate headers are encountered,
	 *     then a numbered array is returned as the value of that header-key.
	 *
	 *     @type array            $response {
	 *         @type int    $code    The response status code. Default 0.
	 *         @type string $message The response message. Default empty.
	 *     }
	 *     @type array            $newheaders The processed header data as a multidimensional array.
	 *     @type WP_Http_Cookie[] $cookies    If the original headers contain the 'Set-Cookie' key,
	 *                                        an array containing `WP_Http_Cookie` objects is returned.
	 * }
	 */
	public static function processHeaders( $headers, $url = '' ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.MethodNameInvalid
		// Split headers, one per array element.
		if ( is_string( $headers ) ) {
			// Tolerate line terminator: CRLF = LF (RFC 2616 19.3).
			$headers = str_replace( "\r\n", "\n", $headers );
			/*
			 * Unfold folded header fields. LWS = [CRLF] 1*( SP | HT ) <US-ASCII SP, space (32)>,
			 * <US-ASCII HT, horizontal-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, -1, $segment_replacement_count );
				if ( 0 === $segment_replacement_count ) {
					break;
				}
			}

			// 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 = self::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;
	}
}