<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Mime
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/**
 * @see Zend_Mime
 */
require_once 'Zend/Mime.php';

/**
 * @category   Zend
 * @package    Zend_Mime
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Mime_Decode
{
    /**
     * Explode MIME multipart string into seperate parts
     *
     * Parts consist of the header and the body of each MIME part.
     *
     * @param  string $body     raw body of message
     * @param  string $boundary boundary as found in content-type
     * @return array parts with content of each part, empty if no parts found
     * @throws Zend_Exception
     */
    public static function splitMime($body, $boundary)
    {
        // TODO: we're ignoring \r for now - is this function fast enough and is it safe to asume noone needs \r?
        $body = str_replace("\r", '', $body);

        $start = 0;
        $res = array();
        // find every mime part limiter and cut out the
        // string before it.
        // the part before the first boundary string is discarded:
        $p = strpos($body, '--' . $boundary . "\n", $start);
        if ($p === false) {
            // no parts found!
            return array();
        }

        // position after first boundary line
        $start = $p + 3 + strlen($boundary);

        while (($p = strpos($body, '--' . $boundary . "\n", $start)) !== false) {
            $res[] = substr($body, $start, $p-$start);
            $start = $p + 3 + strlen($boundary);
        }

        // no more parts, find end boundary
        $p = strpos($body, '--' . $boundary . '--', $start);
        if ($p===false) {
            throw new Zend_Exception('Not a valid Mime Message: End Missing');
        }

        // the remaining part also needs to be parsed:
        $res[] = substr($body, $start, $p-$start);
        return $res;
    }

    /**
     * decodes a mime encoded String and returns a
     * struct of parts with header and body
     *
     * @param  string $message  raw message content
     * @param  string $boundary boundary as found in content-type
     * @param  string $EOL EOL string; defaults to {@link Zend_Mime::LINEEND}
     * @return array|null parts as array('header' => array(name => value), 'body' => content), null if no parts found
     * @throws Zend_Exception
     */
    public static function splitMessageStruct($message, $boundary, $EOL = Zend_Mime::LINEEND)
    {
        $parts = self::splitMime($message, $boundary);
        if (count($parts) <= 0) {
            return null;
        }
        $result = array();
        foreach ($parts as $part) {
            self::splitMessage($part, $headers, $body, $EOL);
            $result[] = array('header' => $headers,
                              'body'   => $body    );
        }
        return $result;
    }

    /**
     * split a message in header and body part, if no header or an
     * invalid header is found $headers is empty
     *
     * The charset of the returned headers depend on your iconv settings.
     *
     * @param  string $message raw message with header and optional content
     * @param  array  $headers output param, array with headers as array(name => value)
     * @param  string $body    output param, content of message
     * @param  string $EOL EOL string; defaults to {@link Zend_Mime::LINEEND}
     * @return null
     */
    public static function splitMessage($message, &$headers, &$body, $EOL = Zend_Mime::LINEEND)
    {
        // check for valid header at first line
        $firstline = strtok($message, "\n");
        if (!preg_match('%^[^\s]+[^:]*:%', $firstline)) {
            $headers = array();
            // TODO: we're ignoring \r for now - is this function fast enough and is it safe to asume noone needs \r?
            $body = str_replace(array("\r", "\n"), array('', $EOL), $message);
            return;
        }

        // find an empty line between headers and body
        // default is set new line
        if (strpos($message, $EOL . $EOL)) {
            list($headers, $body) = explode($EOL . $EOL, $message, 2);
        // next is the standard new line
        } else if ($EOL != "\r\n" && strpos($message, "\r\n\r\n")) {
            list($headers, $body) = explode("\r\n\r\n", $message, 2);
        // next is the other "standard" new line
        } else if ($EOL != "\n" && strpos($message, "\n\n")) {
            list($headers, $body) = explode("\n\n", $message, 2);
        // at last resort find anything that looks like a new line
        } else {
            @list($headers, $body) = @preg_split("%([\r\n]+)\\1%U", $message, 2);
        }

        $headers = iconv_mime_decode_headers($headers, ICONV_MIME_DECODE_CONTINUE_ON_ERROR);

        if ($headers === false ) {
            // an error occurs during the decoding
            return;
        }

        // normalize header names
        foreach ($headers as $name => $header) {
            $lower = strtolower($name);
            if ($lower == $name) {
                continue;
            }
            unset($headers[$name]);
            if (!isset($headers[$lower])) {
                $headers[$lower] = $header;
                continue;
            }
            if (is_array($headers[$lower])) {
                $headers[$lower][] = $header;
                continue;
            }
            $headers[$lower] = array($headers[$lower], $header);
        }
    }

    /**
     * split a content type in its different parts
     *
     * @param  string $type       content-type
     * @param  string $wantedPart the wanted part, else an array with all parts is returned
     * @return string|array wanted part or all parts as array('type' => content-type, partname => value)
     */
    public static function splitContentType($type, $wantedPart = null)
    {
        return self::splitHeaderField($type, $wantedPart, 'type');
    }

    /**
     * split a header field like content type in its different parts
     *
     * @param  string $type       header field
     * @param  string $wantedPart the wanted part, else an array with all parts is returned
     * @param  string $firstName  key name for the first part
     * @return string|array wanted part or all parts as array($firstName => firstPart, partname => value)
     * @throws Zend_Exception
     */
    public static function splitHeaderField($field, $wantedPart = null, $firstName = 0)
    {
        $wantedPart = strtolower($wantedPart);
        $firstName = strtolower($firstName);

        // special case - a bit optimized
        if ($firstName === $wantedPart) {
            $field = strtok($field, ';');
            return $field[0] == '"' ? substr($field, 1, -1) : $field;
        }

        $field = $firstName . '=' . $field;
        if (!preg_match_all('%([^=\s]+)\s*=\s*("[^"]+"|[^;]+)(;\s*|$)%', $field, $matches)) {
            throw new Zend_Exception('not a valid header field');
        }

        if ($wantedPart) {
            foreach ($matches[1] as $key => $name) {
                if (strcasecmp($name, $wantedPart)) {
                    continue;
                }
                if ($matches[2][$key][0] != '"') {
                    return $matches[2][$key];
                }
                return substr($matches[2][$key], 1, -1);
            }
            return null;
        }

        $split = array();
        foreach ($matches[1] as $key => $name) {
            $name = strtolower($name);
            if ($matches[2][$key][0] == '"') {
                $split[$name] = substr($matches[2][$key], 1, -1);
            } else {
                $split[$name] = $matches[2][$key];
            }
        }

        return $split;
    }

    /**
     * decode a quoted printable encoded string
     *
     * The charset of the returned string depends on your iconv settings.
     *
     * @param  string encoded string
     * @return string decoded string
     */
    public static function decodeQuotedPrintable($string)
    {
        return iconv_mime_decode($string, ICONV_MIME_DECODE_CONTINUE_ON_ERROR);
    }
}
