move mbstring operations to separate handler class

composer.json

@@ -41,10 +41,11 @@
 	"prefer-stable": true,
 	"require": {
 		"php": "^8.2",
-		"ext-mbstring": "*",
 		"chillerlan/php-settings-container": "^3.1"
 	},
 	"require-dev": {
+		"ext-iconv": "*",
+		"ext-mbstring": "*",
 		"chillerlan/php-authenticator": "^5.1",
 		"phan/phan": "^5.4",
 		"phpunit/phpunit": "^10.5",
@@ -55,7 +56,8 @@
 	"suggest": {
 		"chillerlan/php-authenticator": "Yet another Google authenticator! Also creates URIs for mobile apps.",
 		"setasign/fpdf": "Required to use the QR FPDF output.",
-		"simple-icons/simple-icons": "SVG icons that you can use to embed as logos in the QR Code"
+		"simple-icons/simple-icons": "SVG icons that you can use to embed as logos in the QR Code",
+		"symfony/polyfill-mbstring": "^1.24"
 	},
 	"autoload": {
 		"psr-4": {

src/Common/CharacterEncodingHandlerInterface.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * Interface CharacterEncodingHandlerInterface
+ *
+ * @created      11.01.2024
+ * @author       smiley <[email protected]>
+ * @copyright    2024 smiley
+ * @license      MIT
+ */
+
+namespace chillerlan\QRCode\Common;
+
+/**
+ * Handles all multibyte character encoding/conversion operations
+ */
+interface CharacterEncodingHandlerInterface{
+
+	/**
+	 * Get the string length
+	 */
+	public static function getCharCount(string $string, string $encoding = null):int;
+
+	/**
+	 * Gets the internal character encoding
+	 */
+	public static function getInternalEncoding():string;
+
+	/**
+	 * Converts the given `$string` to `$to_encoding`, optionally using the given encoding(s) in `$from_encoding`
+	 *
+	 * @throws \RuntimeException if an error occurred
+	 */
+	public static function convertEncoding(string $string, string $to_encoding, array|string $from_encoding = null):string;
+
+}

src/Common/EncodingHandlerTrait.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * Trait EncodingHandlerTrait
+ *
+ * @created      12.01.2024
+ * @author       smiley <[email protected]>
+ * @copyright    2024 smiley
+ * @license      MIT
+ */
+
+namespace chillerlan\QRCode\Common;
+
+use chillerlan\QRCode\QRCodeException;
+use Symfony\Polyfill\Mbstring\Mbstring;
+use Throwable;
+use function class_exists;
+use function extension_loaded;
+
+trait EncodingHandlerTrait{
+
+	protected static CharacterEncodingHandlerInterface $encodingHandler;
+
+	/**
+	 * @throws \chillerlan\QRCode\QRCodeException
+	 */
+	protected static function getEncodingHandler():string{
+
+		try{
+			return match(true){
+				extension_loaded('mbstring')                               => MBStringHandler::class,
+				extension_loaded('iconv') && class_exists(Mbstring::class) => MBStringHandler::class,
+				extension_loaded('iconv')                                  => IconvHandler::class,
+			};
+		}
+		catch(Throwable){
+			throw new QRCodeException('no character encoding handler available');
+		}
+
+	}
+
+	/**
+	 * We're setting an instance here so that the IDE stops yelling at the FQN
+	 */
+	protected function setEncodingHandler():void{
+		static::$encodingHandler = new (static::getEncodingHandler());
+	}
+
+}

src/Common/IconvHandler.php

@@ -0,0 +1,60 @@
+<?php
+/**
+ * Class IconvHandler
+ *
+ * @created      12.01.2024
+ * @author       smiley <[email protected]>
+ * @copyright    2024 smiley
+ * @license      MIT
+ *
+ * @noinspection PhpComposerExtensionStubsInspection
+ */
+
+namespace chillerlan\QRCode\Common;
+
+use RuntimeException;
+use function iconv_get_encoding;
+use function iconv_strlen;
+use function is_array;
+use function is_string;
+
+/**
+ * Handles iconv encoding operations (will probably fail)
+ */
+class IconvHandler implements CharacterEncodingHandlerInterface{
+
+	/**
+	 * @inheritDoc
+	 */
+	public static function getCharCount(string $string, string $encoding = null):int{
+		return iconv_strlen($string, $encoding);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public static function getInternalEncoding():string{
+		return iconv_get_encoding('internal_encoding');
+	}
+
+	/**
+	 * @inheritDoc
+	 * @todo
+	 */
+	public static function convertEncoding(string $string, string $to_encoding, array|string $from_encoding = null):string{
+
+		// we don't have detect_encoding here, so we pick the first item, otherwise set to internal
+		if(is_array($from_encoding)){
+			$from_encoding = ($from_encoding[0] ?? self::getInternalEncoding());
+		}
+
+		$str = iconv($from_encoding, $to_encoding, $string);
+
+		if(!is_string($str)){
+			throw new RuntimeException('iconv error');
+		}
+
+		return $str;
+	}
+
+}

src/Common/MBStringHandler.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * Class MBStringHandler
+ *
+ * @created      11.01.2024
+ * @author       smiley <[email protected]>
+ * @copyright    2024 smiley
+ * @license      MIT
+ *
+ * @noinspection PhpComposerExtensionStubsInspection
+ */
+
+namespace chillerlan\QRCode\Common;
+
+use RuntimeException;
+use function is_string;
+use function mb_convert_encoding;
+use function mb_internal_encoding;
+use function mb_strlen;
+
+/**
+ * Handles mbstring encoding operations
+ */
+class MBStringHandler implements CharacterEncodingHandlerInterface{
+
+	/**
+	 * @inheritDoc
+	 */
+	public static function getCharCount(string $string, string $encoding = null):int{
+		return mb_strlen($string, $encoding);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public static function getInternalEncoding():string{
+		return mb_internal_encoding();
+	}
+
+	/**
+	 * @inheritDoc
+	 * @see \mb_detect_encoding()
+	 */
+	public static function convertEncoding(string $string, string $to_encoding, array|string $from_encoding = null):string{
+		$str =  mb_convert_encoding($string, $to_encoding, $from_encoding);
+
+		if(!is_string($str)){
+			throw new RuntimeException('mb_convert_encoding error');
+		}
+
+		return $str;
+	}
+
+}

src/Data/ECI.php

@@ -10,8 +10,8 @@
 
 namespace chillerlan\QRCode\Data;
 
-use chillerlan\QRCode\Common\{BitBuffer, ECICharset, Mode};
-use function mb_convert_encoding, mb_detect_encoding, mb_internal_encoding, sprintf;
+use chillerlan\QRCode\Common\{BitBuffer, ECICharset, EncodingHandlerTrait, Mode};
+use function sprintf;
 
 /**
  * Adds an ECI Designator
@@ -21,6 +21,7 @@
  * Please note that you have to take care for the correct data encoding when adding with QRCode::add*Segment()
  */
 final class ECI extends QRDataModeAbstract{
+	use EncodingHandlerTrait;
 
 	/**
 	 * @inheritDoc
@@ -43,6 +44,8 @@ public function __construct(int $encoding){
 		}
 
 		$this->encoding = $encoding;
+
+		$this->setEncodingHandler();
 	}
 
 	/**
@@ -142,14 +145,12 @@ public static function decodeSegment(BitBuffer $bitBuffer, int $versionNumber):s
 			// upon decoding. I have seen ISO-8859-1 used as well as
 			// Shift_JIS -- without anything like an ECI designator to
 			// give a hint.
-			$encoding = mb_detect_encoding($data, ['ISO-8859-1', 'Windows-1252', 'SJIS', 'UTF-8'], true);
-
-			if($encoding === false){
-				throw new QRCodeDataException('could not determine encoding in ECI mode'); // @codeCoverageIgnore
-			}
+			$encoding = ['ISO-8859-1', 'Windows-1252', 'SJIS', 'UTF-8'];
 		}
 
-		return mb_convert_encoding($data, mb_internal_encoding(), $encoding);
+		$to_encoding = self::$encodingHandler::getInternalEncoding();
+
+		return self::$encodingHandler::convertEncoding($data, $to_encoding, $encoding);
 	}
 
 }

src/Data/Hanzi.php

@@ -12,8 +12,7 @@
 
 use chillerlan\QRCode\Common\{BitBuffer, Mode};
 use Throwable;
-use function chr, implode, intdiv, is_string, mb_convert_encoding, mb_detect_encoding,
-	mb_detect_order, mb_internal_encoding, mb_strlen, ord, sprintf, strlen;
+use function chr, implode, intdiv, ord, sprintf, strlen;
 
 /**
  * Hanzi (simplified Chinese) mode, GBT18284-2000: 13-bit double-byte characters from the GB2312/GB18030 character set
@@ -52,7 +51,7 @@ final class Hanzi extends QRDataModeAbstract{
 	 * @inheritDoc
 	 */
 	protected function getCharCount():int{
-		return mb_strlen($this->data, self::ENCODING);
+		return self::$encodingHandler::getCharCount($this->data, self::ENCODING);
 	}
 
 	/**
@@ -66,25 +65,9 @@ public function getLengthInBits():int{
 	 * @inheritDoc
 	 */
 	public static function convertEncoding(string $string):string{
-		mb_detect_order([mb_internal_encoding(), 'UTF-8', 'GB2312', 'GB18030', 'CP936', 'EUC-CN', 'HZ']);
+		$encodings = [self::$encodingHandler::getInternalEncoding(), 'UTF-8', 'GB2312', 'GB18030', 'CP936', 'EUC-CN', 'HZ'];
 
-		$detected = mb_detect_encoding($string, null, true);
-
-		if($detected === false){
-			throw new QRCodeDataException('mb_detect_encoding error');
-		}
-
-		if($detected === self::ENCODING){
-			return $string;
-		}
-
-		$string = mb_convert_encoding($string, self::ENCODING, $detected);
-
-		if(!is_string($string)){
-			throw new QRCodeDataException('mb_convert_encoding error');
-		}
-
-		return $string;
+		return self::$encodingHandler::convertEncoding($string, self::ENCODING, $encodings);
 	}
 
 	/**
@@ -199,7 +182,9 @@ public static function decodeSegment(BitBuffer $bitBuffer, int $versionNumber):s
 			$length--;
 		}
 
-		return mb_convert_encoding(implode($buffer), mb_internal_encoding(), self::ENCODING);
+		$to_encoding = self::$encodingHandler::getInternalEncoding();
+
+		return self::$encodingHandler::convertEncoding(implode($buffer), $to_encoding, self::ENCODING);
 	}
 
 }

src/Data/Kanji.php

@@ -12,8 +12,7 @@
 
 use chillerlan\QRCode\Common\{BitBuffer, Mode};
 use Throwable;
-use function chr, implode, intdiv, is_string, mb_convert_encoding, mb_detect_encoding,
-	mb_detect_order, mb_internal_encoding, mb_strlen, ord, sprintf, strlen;
+use function chr, implode, intdiv, ord, sprintf, strlen;
 
 /**
  * Kanji mode: 13-bit double-byte characters from the Shift-JIS character set
@@ -45,7 +44,7 @@ final class Kanji extends QRDataModeAbstract{
 	 * @inheritDoc
 	 */
 	protected function getCharCount():int{
-		return mb_strlen($this->data, self::ENCODING);
+		return self::$encodingHandler::getCharCount($this->data, self::ENCODING);
 	}
 
 	/**
@@ -59,25 +58,9 @@ public function getLengthInBits():int{
 	 * @inheritDoc
 	 */
 	public static function convertEncoding(string $string):string{
-		mb_detect_order([mb_internal_encoding(), 'UTF-8', 'SJIS', 'SJIS-2004']);
+		$encodings = [self::$encodingHandler::getInternalEncoding(), 'UTF-8', 'SJIS', 'SJIS-2004'];
 
-		$detected = mb_detect_encoding($string, null, true);
-
-		if($detected === false){
-			throw new QRCodeDataException('mb_detect_encoding error');
-		}
-
-		if($detected === self::ENCODING){
-			return $string;
-		}
-
-		$string = mb_convert_encoding($string, self::ENCODING, $detected);
-
-		if(!is_string($string)){
-			throw new QRCodeDataException(sprintf('invalid encoding: %s', $detected));
-		}
-
-		return $string;
+		return self::$encodingHandler::convertEncoding($string, self::ENCODING, $encodings);
 	}
 
 	/**
@@ -185,7 +168,9 @@ public static function decodeSegment(BitBuffer $bitBuffer, int $versionNumber):s
 			$length--;
 		}
 
-		return mb_convert_encoding(implode($buffer), mb_internal_encoding(), self::ENCODING);
+		$to_encoding = self::$encodingHandler::getInternalEncoding();
+
+		return self::$encodingHandler::convertEncoding(implode($buffer), $to_encoding, self::ENCODING);
 	}
 
 }