Merge pull request #165 from Bernhard-Krop/code-32

Fixing problems with barcode type code 32

Author: casperbakker

src/Types/TypeCode32.php

@@ -3,6 +3,9 @@
 namespace Picqer\Barcode\Types;
 
 use Picqer\Barcode\Barcode;
+use Picqer\Barcode\Exceptions\InvalidCharacterException;
+use Picqer\Barcode\Exceptions\InvalidCheckDigitException;
+use Picqer\Barcode\Exceptions\InvalidLengthException;
 
 /*
  * CODE 32 - italian pharmaceutical
@@ -47,14 +50,65 @@ class TypeCode32 extends TypeCode39
 
     public function getBarcodeData(string $code): Barcode
     {
-        $code39 = '';
+        // Validate code 32.
+        $stringLength = strlen($code);
+
+        for ($i = 0;  $i < $stringLength; ++$i) {
+            if (!is_numeric($code[$i])) {
+                throw new InvalidCharacterException('Character "' . $code[$i] . '" is not supported.');
+            }
+        }
+
+        // Prepare code 32.
+        $code          = str_pad($code, 8, '0', STR_PAD_LEFT);
+        $checksumDigit = $this->checksum_code32(substr($code, 0, 8));
+        $stringLength  = max($stringLength, 8);
+
+        if ($stringLength === 8) {
+            $code .= $checksumDigit;
+            ++$stringLength;
+        }
+        if ($stringLength !== 9) {
+            throw new InvalidLengthException('Only a code consisting of no more than 9 numbers is supported.');
+        }
+        if ($code[8] !== $checksumDigit) {
+            throw new InvalidCheckDigitException('Provided checksum digit is wrong for provided code.');
+        }
+
+        // Convert code 32 into code 39.
+        $code39   = '';
         $codeElab = $code;
-        
-        for ($e = 5; $e >= 0; $e--) {
-            $code39 .= $this->conversionTable32[intval($codeElab / pow(32,$e))];
-            $codeElab = intval($codeElab % pow(32,$e));
-	    }
-        
+
+        for ($e = 5; $e >= 0; --$e) {
+            $code39  .= $this->conversionTable32[intval($codeElab / pow(32, $e))];
+            $codeElab = $codeElab % pow(32, $e);
+        }
+
+        // Return barcode data for code 39.
         return parent::getBarcodeData($code39);
-	}
+    }
+
+
+    /**
+     * Calculate CODE 32 checksum (modulo 10).
+     *
+     * @param string $code code to represent.
+     * @return string char checksum.
+     * @protected
+     */
+    protected function checksum_code32(string $code): string
+    {
+        $s = 0;
+
+        foreach (str_split($code) as $i => $c) {
+            if (0 === $i % 2) {
+                $s += (int)$c;
+            } else {
+                $c  = 2 * (int)$c;
+                $s += (int)floor($c / 10) + ($c % 10);
+            }
+        }
+
+        return (string)$s % 10;
+    }
 }