/**
* @param string $str
* @return string
*/
function Utf7to8($str)
{
if (!ConvertUtils::IsUtf7($str)) {
return $str;
}
$array = array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, 63, -1, -1, -1, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
$result = '';
$error = '';
$strlen = strlen($str);
for ($i = 0; $strlen > 0; $i++, $strlen--) {
$char = $str[$i];
if ($char == '&') {
$i++;
$strlen--;
$char = isset($str[$i]) ? $str[$i] : null;
if ($char === null) {
break;
}
if ($strlen && $char == '-') {
$result .= '&';
continue;
}
$ch = 0;
$k = 10;
for (; $strlen > 0; $i++, $strlen--) {
$char = $str[$i];
$b = $array[ord($char)];
if (ord($char) & 0x80 || $b == -1) {
break;
}
if ($k > 0) {
$ch |= $b << $k;
$k -= 6;
} else {
$ch |= $b >> -$k;
if ($ch < 0x80) {
if (0x20 <= $ch && $ch < 0x7f) {
return $error;
}
$result .= chr($ch);
} else {
if ($ch < 0x800) {
$result .= chr(0xc0 | $ch >> 6);
$result .= chr(0x80 | $ch & 0x3f);
} else {
$result .= chr(0xe0 | $ch >> 12);
$result .= chr(0x80 | $ch >> 6 & 0x3f);
$result .= chr(0x80 | $ch & 0x3f);
}
}
$ch = $b << 16 + $k & 0xffff;
$k += 10;
}
}
if ($ch || $k < 6) {
return $error;
}
if (!$strlen || $char != '-') {
return $error;
}
if ($strlen > 2 && $str[$i + 1] == '&' && $str[$i + 2] != '-') {
return $error;
}
} else {
if (ord($char) < 0x20 || ord($char) >= 0x7f) {
return $error;
} else {
$result .= $char;
}
}
}
return $result;
}
