_functions.php

<?php
namespace Poirot\Connection\Http
{
    use Poirot\Stream\Interfaces\iStreamable;
    use Poirot\Stream\Streamable\STemporary;


    /**
     * Parse Header line
     *
     * @param string $headers
     *
     * @return false|array[string 'label', string 'value']
     */
    function parseHeaderLines($headers)
    {
        if (! preg_match_all('/.*[\n]?/', $headers, $lines) )
            throw new \InvalidArgumentException('Error Parsing Request Message.');

        $lines = $lines[0];

        $headers = array();
        foreach ($lines as $line)
            $headers += splitLabelValue($line);


        return $headers;
    }

    /**
     * Parse Header line
     *
     * - name MUST be composed of printable US-ASCII characters (i.e.,
     *   characters that have values between 33 and 126, inclusive),
     *   except colon.
     *
     * @param string $line
     *
     * @return array['label' => 'value_line']
     */
    function splitLabelValue($line)
    {
        if (! preg_match('/^(?P<label>[^()><@,;:\"\\/\[\]?=}{ \t]+):(?P<value>.*)$/', $line, $matches) )
            if ($matches === false || !isset($matches['label']) || !isset($matches['value']) )
                throw new \InvalidArgumentException(sprintf(
                    'Invalid Header (%s).'
                    , $line
                ));

        return array( $matches['label'] => trim($matches['value'], "\r\n") );
    }


    /**
     * Parse Response Headers
     *
     * @param string $httpMessage
     *
     * @return array['version'=>string, 'status'=>int, 'reason'=>string, 'headers'=>array(key=>val)]
     */
    function parseResponseHeaders($httpMessage)
    {
        if (! preg_match_all('/.*[\r\n]?/', $httpMessage, $lines) )
            throw new \InvalidArgumentException('Error Parsing Request Message.');

        $lines = $lines[0];

        $firstLine = array_shift($lines);

        $regex   = '/^HTTP\/(?P<version>1\.[01]) (?P<status>\d{3})(?:[ ]+(?P<reason>.*))?$/';
        $matches = array();
        if (!preg_match($regex, $firstLine, $matches))
            throw new \InvalidArgumentException(
                'A valid response status line was not found in the provided string.'
                . ' response:'
                . $httpMessage
            );


        // ...

        $return = array();

        $return['version'] = $matches['version'];
        $return['status']  = (int) $matches['status'];
        $return['reason']  = (isset($matches['reason']) ? $matches['reason'] : '');
        // headers:
        $return['headers'] = array();
        while ($nextLine = array_shift($lines)) {
            if (trim($nextLine) == '')
                // headers end
                break;

            if (! preg_match('/^(?P<label>[^()><@,;:\"\\/\[\]?=}{ \t]+):(?P<value>.*)$/', $nextLine, $matches))
                throw new \InvalidArgumentException(
                    'Valid Header not found: '.$nextLine
                );

            $return['headers'][$matches['label']] = trim($matches['value']);
        }

        // sort headers
        ksort($return['headers']);
        
        return $return;
    }

    /**
     * Parse Status Line From Request
     *
     * @param string $httpMessage
     *
     * @return array['version'=>string, 'status'=>int, 'reason'=>string, 'headers'=>array(key=>val)]
     */
    function parseStatusLine($httpMessage)
    {
        if (! preg_match_all('/.*[\r\n]?/', $httpMessage, $lines) )
            throw new \InvalidArgumentException('Error Parsing Request Message.');

        $lines = $lines[0];

        $firstLine = array_shift($lines);

        $regex   = '/^HTTP\/(?P<version>1\.[01]) (?P<status>\d{3})(?:[ ]+(?P<reason>.*))?$/';
        $matches = array();
        if (! preg_match($regex, $firstLine, $matches) )
            throw new \InvalidArgumentException(
                'A valid response status line was not found in the provided string.'
                . ' response:'
                . $httpMessage
            );

        return [
            'version' => $matches['version'],
            'status'  => (int) $matches['status'],
            'reason'  => $matches['reason'],
        ];
    }

    /**
     * Parse Request Message Expresssion
     *
     * @param string $request
     *
     * @return array
     */
    function parseRequest($request)
    {
        if (! preg_match_all('/.*[\n]?/', $request, $lines) )
            throw new \InvalidArgumentException('Error Parsing Request Message.');

        $lines = $lines[0];

        // request line:
        $firstLine = array_shift($lines);
        $matches = null;
        $methods = '\w+';
        $regex     = '#^(?P<method>' . $methods . ')\s(?P<uri>[^ ]*)(?:\sHTTP\/(?P<version>\d+\.\d+)){0,1}#';
        if (! preg_match($regex, $firstLine, $matches) )
            throw new \InvalidArgumentException(
                'A valid request line was not found in the provided message.'
            );

        $return = array();

        $return['method'] = $matches['method'];
        $return['uri']    = $matches['uri'];

        if (isset($matches['version']))
            $return['version'] = $matches['version'];

        // headers:
        while ($nextLine = array_shift($lines)) {
            if (trim($nextLine) == '')
                // headers end
                break;

            if (! preg_match('/^(?P<label>[^()><@,;:\"\\/\[\]?=}{ \t]+):(?P<value>.*)$/', $nextLine, $matches))
                throw new \InvalidArgumentException(
                    'Valid Header not found: '.$nextLine
                );

            $return['headers'][$matches['label']] = trim($matches['value']);
        }

        // body:
        parse_str(urldecode(implode("\r\n", $lines)), $output);
        $return['body'] = $output;
        return $return;
    }

    /**
     * Read and Skip Headers Of Http Message
     * 
     * @param iStreamable|string $message
     * 
     * @return string Headers of http message
     * @throws \Exception
     */
    function readAndSkipHeaders($message)
    {
        if (! $message instanceof iStreamable ) {
            $message = (string) $message;
            $message = new STemporary($message);
        }
        
        $stream = $message;
        if ( $stream->getCurrOffset() > 0 ) {
            if (! $stream->resource()->isSeekable() )
                throw new \Exception(sprintf(
                    'Reading Headers Must Start From Begining Of Request Stream Or Stream Been Seekable; current offset is: (%s).'
                    , $stream->getCurrOffset()
                ));
            else
                $stream->seek(0);
        }

        $headers = '';
        ## 255 can be vary, its each header length.
        while(! $stream->isEOF() && ($line = $stream->readLine("\r\n")) !== null ) {
            $break = false;
            $headers .= $line."\r\n";
            if (trim($line) === '')
                ## http headers part read complete
                $break = true;

            if ($break) break;
        }

        return $headers;
    }
}