* @copyright 2015 Smiley * @license MIT */ namespace chillerlan\QRCode\Data; use chillerlan\QRCode\Common\{BitBuffer, Mode}; use function ceil, intdiv, preg_match, strpos; /** * Alphanumeric mode: 0 to 9, A to Z, space, $ % * + - . / : * * ISO/IEC 18004:2000 Section 8.3.3 * ISO/IEC 18004:2000 Section 8.4.3 */ final class AlphaNum extends QRDataModeAbstract{ /** * ISO/IEC 18004:2000 Table 5 * * @var string */ private const CHAR_MAP = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:'; /** * @inheritDoc */ public const DATAMODE = Mode::ALPHANUM; /** * @inheritDoc */ public function getLengthInBits():int{ return (int)ceil($this->getCharCount() * (11 / 2)); } /** * @inheritDoc */ public static function validateString(string $string):bool{ return (bool)preg_match('/^[A-Z\d %$*+-.:\/]+$/', $string); } /** * @inheritDoc */ public function write(BitBuffer $bitBuffer, int $versionNumber):QRDataModeInterface{ $len = $this->getCharCount(); $bitBuffer ->put(self::DATAMODE, 4) ->put($len, $this::getLengthBits($versionNumber)) ; // encode 2 characters in 11 bits for($i = 0; ($i + 1) < $len; $i += 2){ $bitBuffer->put( ($this->ord($this->data[$i]) * 45 + $this->ord($this->data[($i + 1)])), 11, ); } // encode a remaining character in 6 bits if($i < $len){ $bitBuffer->put($this->ord($this->data[$i]), 6); } return $this; } /** * @inheritDoc * * @throws \chillerlan\QRCode\Data\QRCodeDataException */ public static function decodeSegment(BitBuffer $bitBuffer, int $versionNumber):string{ $length = $bitBuffer->read(self::getLengthBits($versionNumber)); $result = ''; // Read two characters at a time while($length > 1){ if($bitBuffer->available() < 11){ throw new QRCodeDataException('not enough bits available'); // @codeCoverageIgnore } $nextTwoCharsBits = $bitBuffer->read(11); $result .= self::chr(intdiv($nextTwoCharsBits, 45)); $result .= self::chr($nextTwoCharsBits % 45); $length -= 2; } if($length === 1){ // special case: one character left if($bitBuffer->available() < 6){ throw new QRCodeDataException('not enough bits available'); // @codeCoverageIgnore } $result .= self::chr($bitBuffer->read(6)); } return $result; } /** * @throws \chillerlan\QRCode\Data\QRCodeDataException */ private function ord(string $chr):int{ /** @phan-suppress-next-line PhanParamSuspiciousOrder */ $ord = strpos(self::CHAR_MAP, $chr); if($ord === false){ throw new QRCodeDataException('invalid character'); // @codeCoverageIgnore } return $ord; } /** * @throws \chillerlan\QRCode\Data\QRCodeDataException */ private static function chr(int $ord):string{ if($ord < 0 || $ord > 44){ throw new QRCodeDataException('invalid character code'); // @codeCoverageIgnore } return self::CHAR_MAP[$ord]; } }