<?PHP  // -*- php -*-

// Creates the data array for the GeneratePSR function
function GeneratePSRData($filename, $doCache = true)
{
    if (! file_exists($filename)) {
	return array("File does not exist.");
    }

    $cacheDir = getenv('MEDIABASE') . 'software/dnd_helper/cache/';
    $cacheName = basename($filename);
    $cacheName = preg_replace('/\..*/', '.inc', $cacheName);
    
    if (file_exists($cacheDir . $cacheName) && 
	filemtime($cacheDir . $cacheName) >= filemtime($filename)) {
	include($cacheDir . $cacheName);
	return $Data;
    }

    $f = file_get_contents($filename);
    $Data = array();
    $key = false;
    
    $f = str_replace("\r\n", "\n", $f);
    $f = str_replace("\r", "\n", $f);
    $f = split("\n", $f);
    
    while (count($f))
    {
	$line = trim(GetLinePSR($f));
	if (substr($line, 0, 1) == '*')
	{
	    $key = trim(substr($line, 1));
	    if (isset($Data[$key]))
	      return array("Key $KEY is defined twice.  PSR file is incorrect.");
	    $Data[$key] = array();
	}
	elseif ($line != '')
	{
	    $line = str_replace("\\n", "\n", $line);
	    if ($key === false)
	      return array("Problem loading data.  PSR file is incorrect.");
	    $Chance = 1;
	    if (preg_match("/^([0-9]+):(.*)\$/m", $line, $hits))
	    {
		$Chance = $hits[1];
		$line = $hits[2];
	    }
	    $Data[$key][] = array($Chance, $line);
	}
    }
   
    if ($doCache) { 
        $cache = "<?PHP\n";
        $cache .= "// Automatically generated by psr.inc\n";
        $cache .= '$Data = ' . var_export($Data, true) . ";\n";
        $fp = fopen($cacheDir . $cacheName, 'w');
        if ($fp) {
	    fputs($fp, $cache);
	    fclose($fp);
        }
    }

    return $Data;
}

// $count is the number of entries you would like to see generated.
// $DumpData, if set, it returns the $Data array.  Useful for generating
// new databases.
//
// Returns an array of messages (or an array containing a single error).
// If you are planning on using the output on a web page, you should
// wrap output in nl2br(htmlspecialchars($entry))
function GeneratePSR($Data, $count)
{
    // Reformat the percentages
    $Totals = array();
    foreach ($Data as $key => $rules)
    {
	$Total = 0;
	foreach ($rules as $index => $data)
	{
	    $Total += $data[0];
	    $Data[$key][$index][0] = $Total;
	}
	$Totals[$key] = $Total;
    }
    
    // Generate the message
    $Results = array();
    $StartRule = array_keys($Data);
    $StartRule = $StartRule[0];
    while ($count --)
    {
	$R = GenerateRulePSR($Data, $Totals, $StartRule);
	$Results[] = $R;
    }
    
    return $Results;
}


function GetLinePSR(&$data)
{
    $line = trim(array_shift($data));
    
    // Ignore comments
    while (substr($line, 0, 1) == '#')
    {
	if (count($data))
	  $line = trim(array_shift($data));
	else
	  $line = '';
    }
    while (substr($line, -1) == '\\')
    {
	if (count($data))
	{
	    $line2 = trim(array_shift($data));
	    while ($line2[0] == '#')
	    {
		if (count($data))
		  $line2 = trim(array_shift($data));
		else
		  $line2 = '';
	    }
	}
	else
	  $line2 = '';
	$line = substr($line, 0, strlen($line) - 1) . $line2;
   }
   
   return $line;
}


function GenerateRulePSR(&$Data, &$Totals, $Key)
{
    // Pick a random rule
    $Text = PickRandomPSR($Totals[$Key], $Data[$Key]);

    $bits = preg_split('/\\[([\\^]?[^\\]]*)\\]/', $Text, -1, 
		       PREG_SPLIT_DELIM_CAPTURE);
    $out = array_shift($bits);
    while (count($bits))
    {
	$Rule = array_shift($bits);
	
	$MakeUpper = false;
	if (substr($Rule, 0, 1) == '^')
	{
	    $MakeUpper = true;
	    $Rule = substr($Rule, 1);
	}
	
	if ($Rule == '[' || $Rule == ']' || $Rule == '*' || $Rule == '#')
	{
	    $out .= $Rule;
	}
	elseif (! isset($Data[$Rule]))
	{
	    $out .= "[Rule \"$Rule\" not found.]";
	}
	else
	{
	    $out2 = GenerateRulePSR($Data, $Totals, $Rule);
	    if ($MakeUpper)
	      $out2 = ucfirst($out2);
	    $out .= $out2;
	}
	
	$out .= array_shift($bits);
    }
    
    return $out;
}

function PickRandomPSR($total, $arr)
{
   // $arr is an array of ($num, $val)
   // $total is the biggest ($num)
   // Pick a number from 1 to $total
   $num = rand(1, $total);
   // Now find where it is in the array
   $i = count($arr) / 2;
   settype($i, 'integer');
   $j = $i / 2;
   settype($j, 'integer');
   while ($j > 2)
   {
      if ($arr[$i][0] > $num)
      {
         $i -= $j;
      }
      else
      {
         $i += $j;
      }
      $j = $j / 2;
      settype($j, 'integer');
   }
   while ($arr[$i][0] < $num && isset($arr[$i + 1]))
   {
      $i ++;
   }
   while (isset($arr[$i - 1]) && $arr[$i - 1][0] >= $num)
      $i --;
    
   return $arr[$i][1];
}