Chris@0: <?php
Chris@0: /**
Chris@0:  * Zend Framework (http://framework.zend.com/)
Chris@0:  *
Chris@0:  * @see       http://github.com/zendframework/zend-diactoros for the canonical source repository
Chris@0:  * @copyright Copyright (c) 2015-2016 Zend Technologies USA Inc. (http://www.zend.com)
Chris@0:  * @license   https://github.com/zendframework/zend-diactoros/blob/master/LICENSE.md New BSD License
Chris@0:  */
Chris@0: 
Chris@0: namespace Zend\Diactoros;
Chris@0: 
Chris@0: use Psr\Http\Message\StreamInterface;
Chris@0: use UnexpectedValueException;
Chris@0: 
Chris@16: use function array_pop;
Chris@16: use function implode;
Chris@16: use function ltrim;
Chris@16: use function preg_match;
Chris@16: use function sprintf;
Chris@16: use function str_replace;
Chris@16: use function ucwords;
Chris@16: 
Chris@0: /**
Chris@0:  * Provides base functionality for request and response de/serialization
Chris@0:  * strategies, including functionality for retrieving a line at a time from
Chris@0:  * the message, splitting headers from the body, and serializing headers.
Chris@0:  */
Chris@0: abstract class AbstractSerializer
Chris@0: {
Chris@0:     const CR  = "\r";
Chris@0:     const EOL = "\r\n";
Chris@0:     const LF  = "\n";
Chris@0: 
Chris@0:     /**
Chris@0:      * Retrieve a single line from the stream.
Chris@0:      *
Chris@0:      * Retrieves a line from the stream; a line is defined as a sequence of
Chris@0:      * characters ending in a CRLF sequence.
Chris@0:      *
Chris@0:      * @param StreamInterface $stream
Chris@0:      * @return string
Chris@0:      * @throws UnexpectedValueException if the sequence contains a CR or LF in
Chris@0:      *     isolation, or ends in a CR.
Chris@0:      */
Chris@0:     protected static function getLine(StreamInterface $stream)
Chris@0:     {
Chris@0:         $line    = '';
Chris@0:         $crFound = false;
Chris@0:         while (! $stream->eof()) {
Chris@0:             $char = $stream->read(1);
Chris@0: 
Chris@0:             if ($crFound && $char === self::LF) {
Chris@0:                 $crFound = false;
Chris@0:                 break;
Chris@0:             }
Chris@0: 
Chris@0:             // CR NOT followed by LF
Chris@0:             if ($crFound && $char !== self::LF) {
Chris@0:                 throw new UnexpectedValueException('Unexpected carriage return detected');
Chris@0:             }
Chris@0: 
Chris@0:             // LF in isolation
Chris@0:             if (! $crFound && $char === self::LF) {
Chris@0:                 throw new UnexpectedValueException('Unexpected line feed detected');
Chris@0:             }
Chris@0: 
Chris@0:             // CR found; do not append
Chris@0:             if ($char === self::CR) {
Chris@0:                 $crFound = true;
Chris@0:                 continue;
Chris@0:             }
Chris@0: 
Chris@0:             // Any other character: append
Chris@0:             $line .= $char;
Chris@0:         }
Chris@0: 
Chris@0:         // CR found at end of stream
Chris@0:         if ($crFound) {
Chris@0:             throw new UnexpectedValueException("Unexpected end of headers");
Chris@0:         }
Chris@0: 
Chris@0:         return $line;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Split the stream into headers and body content.
Chris@0:      *
Chris@0:      * Returns an array containing two elements
Chris@0:      *
Chris@0:      * - The first is an array of headers
Chris@0:      * - The second is a StreamInterface containing the body content
Chris@0:      *
Chris@0:      * @param StreamInterface $stream
Chris@0:      * @return array
Chris@0:      * @throws UnexpectedValueException For invalid headers.
Chris@0:      */
Chris@0:     protected static function splitStream(StreamInterface $stream)
Chris@0:     {
Chris@0:         $headers       = [];
Chris@0:         $currentHeader = false;
Chris@0: 
Chris@0:         while ($line = self::getLine($stream)) {
Chris@0:             if (preg_match(';^(?P<name>[!#$%&\'*+.^_`\|~0-9a-zA-Z-]+):(?P<value>.*)$;', $line, $matches)) {
Chris@0:                 $currentHeader = $matches['name'];
Chris@0:                 if (! isset($headers[$currentHeader])) {
Chris@0:                     $headers[$currentHeader] = [];
Chris@0:                 }
Chris@0:                 $headers[$currentHeader][] = ltrim($matches['value']);
Chris@0:                 continue;
Chris@0:             }
Chris@0: 
Chris@0:             if (! $currentHeader) {
Chris@0:                 throw new UnexpectedValueException('Invalid header detected');
Chris@0:             }
Chris@0: 
Chris@0:             if (! preg_match('#^[ \t]#', $line)) {
Chris@0:                 throw new UnexpectedValueException('Invalid header continuation');
Chris@0:             }
Chris@0: 
Chris@0:             // Append continuation to last header value found
Chris@0:             $value = array_pop($headers[$currentHeader]);
Chris@0:             $headers[$currentHeader][] = $value . ltrim($line);
Chris@0:         }
Chris@0: 
Chris@0:         // use RelativeStream to avoid copying initial stream into memory
Chris@0:         return [$headers, new RelativeStream($stream, $stream->tell())];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Serialize headers to string values.
Chris@0:      *
Chris@0:      * @param array $headers
Chris@0:      * @return string
Chris@0:      */
Chris@0:     protected static function serializeHeaders(array $headers)
Chris@0:     {
Chris@0:         $lines = [];
Chris@0:         foreach ($headers as $header => $values) {
Chris@0:             $normalized = self::filterHeader($header);
Chris@0:             foreach ($values as $value) {
Chris@0:                 $lines[] = sprintf('%s: %s', $normalized, $value);
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return implode("\r\n", $lines);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Filter a header name to wordcase
Chris@0:      *
Chris@0:      * @param string $header
Chris@0:      * @return string
Chris@0:      */
Chris@0:     protected static function filterHeader($header)
Chris@0:     {
Chris@0:         $filtered = str_replace('-', ' ', $header);
Chris@0:         $filtered = ucwords($filtered);
Chris@0:         return str_replace(' ', '-', $filtered);
Chris@0:     }
Chris@0: }