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   1  <?php
   2  
   3  /**
   4  * @package   s9e\TextFormatter
   5  * @copyright Copyright (c) 2010-2022 The s9e authors
   6  * @license   http://www.opensource.org/licenses/mit-license.php The MIT License
   7  */
   8  namespace s9e\TextFormatter\Configurator\TemplateNormalizations;
   9  
  10  use DOMElement;
  11  use DOMText;
  12  
  13  class OptimizeChooseText extends AbstractChooseOptimization
  14  {
  15      /**
  16      * Adjust length of the text nodes of current xsl:choose element's branches
  17      *
  18      * @param  string  $childType Either firstChild or lastChild
  19      * @param  integer $pos
  20      * @param  integer $len
  21      * @return void
  22      */
  23  	protected function adjustTextNodes($childType, $pos, $len = PHP_INT_MAX)
  24      {
  25          foreach ($this->getBranches() as $branch)
  26          {
  27              $node            = $branch->$childType;
  28              $node->nodeValue = substr($node->textContent, $pos, $len);
  29          }
  30      }
  31  
  32      /**
  33      * Compute the number of leading characters common to all strings
  34      *
  35      * @param  string[] $strings
  36      * @return integer
  37      */
  38  	protected function getPrefixLength(array $strings)
  39      {
  40          $i      = 0;
  41          $len    = 0;
  42          $maxLen = min(array_map('strlen', $strings));
  43          while ($i < $maxLen)
  44          {
  45              $c = $strings[0][$i];
  46              foreach ($strings as $string)
  47              {
  48                  if ($string[$i] !== $c)
  49                  {
  50                      break 2;
  51                  }
  52              }
  53              $len = ++$i;
  54          }
  55  
  56          return $len;
  57      }
  58  
  59      /**
  60      * Get the text content of the firstChild/lastChild of each branch if they are all text nodes
  61      *
  62      * @param  string   $childType Either firstChild or lastChild
  63      * @return string[]            List of strings or an empty array
  64      */
  65  	protected function getTextContent($childType)
  66      {
  67          $strings = [];
  68          foreach ($this->getBranches() as $branch)
  69          {
  70              if (!($branch->$childType instanceof DOMText))
  71              {
  72                  return [];
  73              }
  74              $strings[] = $branch->$childType->textContent;
  75          }
  76  
  77          return $strings;
  78      }
  79  
  80      /**
  81      * {@inheritdoc}
  82      */
  83  	protected function optimizeChoose()
  84      {
  85          if (!$this->hasOtherwise())
  86          {
  87              return;
  88          }
  89  
  90          $this->optimizeLeadingText();
  91          $this->optimizeTrailingText();
  92      }
  93  
  94      /**
  95      * Move common leading text outside of current choose
  96      *
  97      * @return void
  98      */
  99  	protected function optimizeLeadingText()
 100      {
 101          $strings = $this->getTextContent('firstChild');
 102          if (empty($strings))
 103          {
 104              return;
 105          }
 106  
 107          $len = $this->getPrefixLength($strings);
 108          if ($len)
 109          {
 110              $this->adjustTextNodes('firstChild', $len);
 111              $this->choose->parentNode->insertBefore(
 112                  $this->createText(substr($strings[0], 0, $len)),
 113                  $this->choose
 114              );
 115          }
 116      }
 117  
 118      /**
 119      * Move common trailing text outside of current choose
 120      *
 121      * @return void
 122      */
 123  	protected function optimizeTrailingText()
 124      {
 125          $strings = $this->getTextContent('lastChild');
 126          if (empty($strings))
 127          {
 128              return;
 129          }
 130  
 131          // Flip the strings before computing the prefix length to get the suffix length
 132          $len = $this->getPrefixLength(array_map('strrev', $strings));
 133          if ($len)
 134          {
 135              $this->adjustTextNodes('lastChild', 0, -$len);
 136              $this->choose->parentNode->insertBefore(
 137                  $this->createText(substr($strings[0], -$len)),
 138                  $this->choose->nextSibling
 139              );
 140          }
 141      }
 142  }