<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Mime;

/**
 * Support class for MultiPart Mime Messages
 */
class Mime
{
    const TYPE_OCTETSTREAM = 'application/octet-stream';
    const TYPE_TEXT = 'text/plain';
    const TYPE_HTML = 'text/html';
    const ENCODING_7BIT = '7bit';
    const ENCODING_8BIT = '8bit';
    const ENCODING_QUOTEDPRINTABLE = 'quoted-printable';
    const ENCODING_BASE64 = 'base64';
    const DISPOSITION_ATTACHMENT = 'attachment';
    const DISPOSITION_INLINE = 'inline';
    const LINELENGTH = 72;
    const LINEEND = "\n";
    const MULTIPART_ALTERNATIVE = 'multipart/alternative';
    const MULTIPART_MIXED = 'multipart/mixed';
    const MULTIPART_RELATED = 'multipart/related';

    protected $boundary;
    protected static $makeUnique = 0;

    // lookup-Tables for QuotedPrintable
    public static $qpKeys = array(
        "\x00","\x01","\x02","\x03","\x04","\x05","\x06","\x07",
        "\x08","\x09","\x0A","\x0B","\x0C","\x0D","\x0E","\x0F",
        "\x10","\x11","\x12","\x13","\x14","\x15","\x16","\x17",
        "\x18","\x19","\x1A","\x1B","\x1C","\x1D","\x1E","\x1F",
        "\x7F","\x80","\x81","\x82","\x83","\x84","\x85","\x86",
        "\x87","\x88","\x89","\x8A","\x8B","\x8C","\x8D","\x8E",
        "\x8F","\x90","\x91","\x92","\x93","\x94","\x95","\x96",
        "\x97","\x98","\x99","\x9A","\x9B","\x9C","\x9D","\x9E",
        "\x9F","\xA0","\xA1","\xA2","\xA3","\xA4","\xA5","\xA6",
        "\xA7","\xA8","\xA9","\xAA","\xAB","\xAC","\xAD","\xAE",
        "\xAF","\xB0","\xB1","\xB2","\xB3","\xB4","\xB5","\xB6",
        "\xB7","\xB8","\xB9","\xBA","\xBB","\xBC","\xBD","\xBE",
        "\xBF","\xC0","\xC1","\xC2","\xC3","\xC4","\xC5","\xC6",
        "\xC7","\xC8","\xC9","\xCA","\xCB","\xCC","\xCD","\xCE",
        "\xCF","\xD0","\xD1","\xD2","\xD3","\xD4","\xD5","\xD6",
        "\xD7","\xD8","\xD9","\xDA","\xDB","\xDC","\xDD","\xDE",
        "\xDF","\xE0","\xE1","\xE2","\xE3","\xE4","\xE5","\xE6",
        "\xE7","\xE8","\xE9","\xEA","\xEB","\xEC","\xED","\xEE",
        "\xEF","\xF0","\xF1","\xF2","\xF3","\xF4","\xF5","\xF6",
        "\xF7","\xF8","\xF9","\xFA","\xFB","\xFC","\xFD","\xFE",
        "\xFF"
    );

    public static $qpReplaceValues = array(
        "=00","=01","=02","=03","=04","=05","=06","=07",
        "=08","=09","=0A","=0B","=0C","=0D","=0E","=0F",
        "=10","=11","=12","=13","=14","=15","=16","=17",
        "=18","=19","=1A","=1B","=1C","=1D","=1E","=1F",
        "=7F","=80","=81","=82","=83","=84","=85","=86",
        "=87","=88","=89","=8A","=8B","=8C","=8D","=8E",
        "=8F","=90","=91","=92","=93","=94","=95","=96",
        "=97","=98","=99","=9A","=9B","=9C","=9D","=9E",
        "=9F","=A0","=A1","=A2","=A3","=A4","=A5","=A6",
        "=A7","=A8","=A9","=AA","=AB","=AC","=AD","=AE",
        "=AF","=B0","=B1","=B2","=B3","=B4","=B5","=B6",
        "=B7","=B8","=B9","=BA","=BB","=BC","=BD","=BE",
        "=BF","=C0","=C1","=C2","=C3","=C4","=C5","=C6",
        "=C7","=C8","=C9","=CA","=CB","=CC","=CD","=CE",
        "=CF","=D0","=D1","=D2","=D3","=D4","=D5","=D6",
        "=D7","=D8","=D9","=DA","=DB","=DC","=DD","=DE",
        "=DF","=E0","=E1","=E2","=E3","=E4","=E5","=E6",
        "=E7","=E8","=E9","=EA","=EB","=EC","=ED","=EE",
        "=EF","=F0","=F1","=F2","=F3","=F4","=F5","=F6",
        "=F7","=F8","=F9","=FA","=FB","=FC","=FD","=FE",
        "=FF"
    );

    public static $qpKeysString =
         "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F\x7F\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8A\x8B\x8C\x8D\x8E\x8F\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9A\x9B\x9C\x9D\x9E\x9F\xA0\xA1\xA2\xA3\xA4\xA5\xA6\xA7\xA8\xA9\xAA\xAB\xAC\xAD\xAE\xAF\xB0\xB1\xB2\xB3\xB4\xB5\xB6\xB7\xB8\xB9\xBA\xBB\xBC\xBD\xBE\xBF\xC0\xC1\xC2\xC3\xC4\xC5\xC6\xC7\xC8\xC9\xCA\xCB\xCC\xCD\xCE\xCF\xD0\xD1\xD2\xD3\xD4\xD5\xD6\xD7\xD8\xD9\xDA\xDB\xDC\xDD\xDE\xDF\xE0\xE1\xE2\xE3\xE4\xE5\xE6\xE7\xE8\xE9\xEA\xEB\xEC\xED\xEE\xEF\xF0\xF1\xF2\xF3\xF4\xF5\xF6\xF7\xF8\xF9\xFA\xFB\xFC\xFD\xFE\xFF";

    /**
     * Check if the given string is "printable"
     *
     * Checks that a string contains no unprintable characters. If this returns
     * false, encode the string for secure delivery.
     *
     * @param string $str
     * @return bool
     */
    public static function isPrintable($str)
    {
        return (strcspn($str, static::$qpKeysString) == strlen($str));
    }

    /**
     * Encode a given string with the QUOTED_PRINTABLE mechanism and wrap the lines.
     *
     * @param string $str
     * @param int $lineLength Defaults to {@link LINELENGTH}
     * @param string $lineEnd Defaults to {@link LINEEND}
     * @return string
     */
    public static function encodeQuotedPrintable($str,
        $lineLength = self::LINELENGTH,
        $lineEnd = self::LINEEND)
    {
        $out = '';
        $str = self::_encodeQuotedPrintable($str);

        // Split encoded text into separate lines
        while ($str) {
            $ptr = strlen($str);
            if ($ptr > $lineLength) {
                $ptr = $lineLength;
            }

            // Ensure we are not splitting across an encoded character
            $pos = strrpos(substr($str, 0, $ptr), '=');
            if ($pos !== false && $pos >= $ptr - 2) {
                $ptr = $pos;
            }

            // Check if there is a space at the end of the line and rewind
            if ($ptr > 0 && $str[$ptr - 1] == ' ') {
                --$ptr;
            }

            // Add string and continue
            $out .= substr($str, 0, $ptr) . '=' . $lineEnd;
            $str = substr($str, $ptr);
        }

        $out = rtrim($out, $lineEnd);
        $out = rtrim($out, '=');
        return $out;
    }

    /**
     * Converts a string into quoted printable format.
     *
     * @param  string $str
     * @return string
     */
    private static function _encodeQuotedPrintable($str)
    {
        $str = str_replace('=', '=3D', $str);
        $str = str_replace(static::$qpKeys, static::$qpReplaceValues, $str);
        $str = rtrim($str);
        return $str;
    }

    /**
     * Encode a given string with the QUOTED_PRINTABLE mechanism for Mail Headers.
     *
     * Mail headers depend on an extended quoted printable algorithm otherwise
     * a range of bugs can occur.
     *
     * @param string $str
     * @param string $charset
     * @param int $lineLength Defaults to {@link LINELENGTH}
     * @param string $lineEnd Defaults to {@link LINEEND}
     * @return string
     */
    public static function encodeQuotedPrintableHeader($str, $charset,
        $lineLength = self::LINELENGTH,
        $lineEnd = self::LINEEND)
    {
        // Reduce line-length by the length of the required delimiter, charsets and encoding
        $prefix = sprintf('=?%s?Q?', $charset);
        $lineLength = $lineLength-strlen($prefix)-3;

        $str = self::_encodeQuotedPrintable($str);

        // Mail-Header required chars have to be encoded also:
        $str = str_replace(array('?', ' ', '_'), array('=3F', '=20', '=5F'), $str);

        // initialize first line, we need it anyways
        $lines = array(0 => "");

        // Split encoded text into separate lines
        $tmp = "";
        while (strlen($str) > 0) {
            $currentLine = max(count($lines)-1, 0);
            $token       = static::getNextQuotedPrintableToken($str);
            $str         = substr($str, strlen($token));

            $tmp .= $token;
            if ($token == '=20') {
                // only if we have a single char token or space, we can append the
                // tempstring it to the current line or start a new line if necessary.
                if (strlen($lines[$currentLine] . $tmp) > $lineLength) {
                    $lines[$currentLine+1] = $tmp;
                } else {
                    $lines[$currentLine] .= $tmp;
                }
                $tmp = "";
            }
            // don't forget to append the rest to the last line
            if (strlen($str) == 0) {
                $lines[$currentLine] .= $tmp;
            }
        }

        // assemble the lines together by pre- and appending delimiters, charset, encoding.
        for ($i = 0, $count = count($lines); $i < $count; $i++) {
            $lines[$i] = " " . $prefix . $lines[$i] . "?=";
        }
        $str = trim(implode($lineEnd, $lines));
        return $str;
    }

    /**
     * Retrieves the first token from a quoted printable string.
     *
     * @param  string $str
     * @return string
     */
    private static function getNextQuotedPrintableToken($str)
    {
        if (substr($str, 0, 1) == "=") {
            $token = substr($str, 0, 3);
        } else {
            $token = substr($str, 0, 1);
        }
        return $token;
    }

    /**
     * Encode a given string in mail header compatible base64 encoding.
     *
     * @param string $str
     * @param string $charset
     * @param int $lineLength Defaults to {@link LINELENGTH}
     * @param string $lineEnd Defaults to {@link LINEEND}
     * @return string
     */
    public static function encodeBase64Header($str,
        $charset,
        $lineLength = self::LINELENGTH,
        $lineEnd = self::LINEEND)
    {
        $prefix = '=?' . $charset . '?B?';
        $suffix = '?=';
        $remainingLength = $lineLength - strlen($prefix) - strlen($suffix);

        $encodedValue = static::encodeBase64($str, $remainingLength, $lineEnd);
        $encodedValue = str_replace($lineEnd, $suffix . $lineEnd . ' ' . $prefix, $encodedValue);
        $encodedValue = $prefix . $encodedValue . $suffix;
        return $encodedValue;
    }

    /**
     * Encode a given string in base64 encoding and break lines
     * according to the maximum linelength.
     *
     * @param string $str
     * @param int $lineLength Defaults to {@link LINELENGTH}
     * @param string $lineEnd Defaults to {@link LINEEND}
     * @return string
     */
    public static function encodeBase64($str,
        $lineLength = self::LINELENGTH,
        $lineEnd = self::LINEEND)
    {
        return rtrim(chunk_split(base64_encode($str), $lineLength, $lineEnd));
    }

    /**
     * Constructor
     *
     * @param null|string $boundary
     * @access public
     */
    public function __construct($boundary = null)
    {
        // This string needs to be somewhat unique
        if ($boundary === null) {
            $this->boundary = '=_' . md5(microtime(1) . static::$makeUnique++);
        } else {
            $this->boundary = $boundary;
        }
    }

    /**
     * Encode the given string with the given encoding.
     *
     * @param string $str
     * @param string $encoding
     * @param string $EOL EOL string; defaults to {@link LINEEND}
     * @return string
     */
    public static function encode($str, $encoding, $EOL = self::LINEEND)
    {
        switch ($encoding) {
            case self::ENCODING_BASE64:
                return static::encodeBase64($str, self::LINELENGTH, $EOL);

            case self::ENCODING_QUOTEDPRINTABLE:
                return static::encodeQuotedPrintable($str, self::LINELENGTH, $EOL);

            default:
                /**
                 * @todo 7Bit and 8Bit is currently handled the same way.
                 */
                return $str;
        }
    }

    /**
     * Return a MIME boundary
     *
     * @access public
     * @return string
     */
    public function boundary()
    {
        return $this->boundary;
    }

    /**
     * Return a MIME boundary line
     *
     * @param string $EOL Defaults to {@link LINEEND}
     * @access public
     * @return string
     */
    public function boundaryLine($EOL = self::LINEEND)
    {
        return $EOL . '--' . $this->boundary . $EOL;
    }

    /**
     * Return MIME ending
     *
     * @param string $EOL Defaults to {@link LINEEND}
     * @access public
     * @return string
     */
    public function mimeEnd($EOL = self::LINEEND)
    {
        return $EOL . '--' . $this->boundary . '--' . $EOL;
    }
}
