<?php
/*=======================================================================
 *
 * mc_math.php
 *
 * Autor: Marc Vollmann
 *
 =======================================================================*/


include_once ("../include/mcglobal.inc.php");
include_once ("../include/html.inc.php");


// Check HTTP-Parameters
getSecHttpVars("1",array("f_act", "credit_amount", "rate_percent", "duration", "decimals"));



// Formats the output of a number
function formatNumber ($value, $decimals = 2) {
	return number_format(round($value, $decimals), $decimals, ",", ".");
}


// Berechnet die (jährliche) Annuität bei einer Kreditsumme
// $credit_amount : credit amount (Kreditbetrag)
// $rate_percent  : rate_percent (Zinssatz)
// $duration      : duration (Laufzeit)
function mc_math_annuity ($credit_amount, $rate_percent, $duration, $decimals = 2) {
	$q = 1 + ($rate_percent / 100);
	$a = $credit_amount * ($rate_percent / 100) * pow($q, $duration) / (pow($q, $duration) - 1);
	return $a;
}

$pageTitel = "ANNUITÄTENBERECHNUNG";

$credit_amount = str_replace(",", ".", $credit_amount);
$rate_percent = str_replace(",", ".", $rate_percent);
$duration = str_replace(",", ".", $duration);
if ($decimals == "") : $decimals = 2; endif;

$result = "";
$resultPerMonth = "";
$errOut = "";
if (is_numeric($credit_amount) && is_numeric($rate_percent) && is_numeric($duration)) :
   if ($f_act == "mc_math_annuity") :
      $result = mc_math_annuity($credit_amount, $rate_percent, $duration, $decimals);
      $resultPerMonth = $result / 12;
      $result = formatNumber ($result, $decimals);
      $resultPerMonth = formatNumber ($resultPerMonth, $decimals);
   endif;   
else :
   if ($credit_amount != "" || $rate_percent != "" || $duration != "") :
      $errOut = "Bitte nur Zahlen eingeben!";
   endif;
endif;


/*
1. Zinssatz 3%   =>     i = 0,03    und    q = 1,03
2. Laufzeit 10 Jahre     => n = 10
3. Restschuld 125.000,- €  (Anfangsbasis)

Jährliche Annuität für vollständige Tilgung nach 10 Jahren: 14.653,- € (pro Jahr)

Monatlich also ca. 1221,- € 

echo mc_math_annuity(125000, 3, 10, 2);
*/
?>


<html>

<head>
<title><?php echo $pageTitel ?></title>

<link rel="stylesheet" type="text/css" href="../css/phoenix.css">
<style type="text/css">
  <?php include_once ("../css/navigation.css.php"); ?>
</style>

<script src="../include/checkFormTags.js" type="text/javascript"></script>

<script type="text/javascript">
<!--

function finishPage(f_act) {
  document.forms[0].f_act.value = f_act;
  document.forms[0].submit();  
};

-->
</script>
</head>

<body onLoad="">

<div class="maincontent" name="maincontent" id="maincontent">

<form action="../tools/mc_math.php" method="post">
  <input type="hidden" name="f_act" value="">

  <div class="f12bp1_blue">
  	<br>
    <?php echo $pageTitel ?>
    <br><br>
  </div>

  <div>
  	<table>
  		<tr>
  			<td>Kreditsumme:</td><td>&nbsp;&nbsp;&nbsp;</td><td><input class="f8np1" type="text" name="credit_amount" value="<?php echo $credit_amount ?>" maxlength="10"  size="10"></td>
  		</tr>
  		<tr>
  			<td>Zinssatz:</td><td>&nbsp;&nbsp;&nbsp;</td><td><input class="f8np1" type="text" name="rate_percent" value="<?php echo $rate_percent ?>" maxlength="5"  size="5"></td>
  		</tr>
  		<tr>
  			<td>Laufzeit:</td><td>&nbsp;&nbsp;&nbsp;</td><td><select name="duration"><?php echo addOptionsFromRange("1","30",$duration,"YES") ?></select></td>
  		</tr>
  		<tr>
  			<td>Dezimalstellen:</td><td>&nbsp;&nbsp;&nbsp;</td><td><select name="decimals"><?php echo addOptionsFromRange("0","4",$decimals,"") ?></select></td>
  		</tr>
    </table>
    <br><br>
  </div>
  <?php echo defineButtonType08(getLngt("Berechnen"), "action_compute", "finishPage('mc_math_annuity');", "90", "left", "3"); ?>

  <?php if ($result != "") : ?>
    <div class="f10bp1">
  	  <br><br><br><br>
  	  Über die Laufzeit von <?php echo $duration ?> Jahren wären jährlich <span class="f10bp1_blue"><?php echo $result ?> €</span> zu entrichten. (Mtl.: <span class="f10bp1_blue"><?php echo $resultPerMonth ?> €</span>)
    </div>
  <?php endif; ?>

  <?php if ($errOut != "") : ?>
    <div class="f10bp1">
  	  <br><br><br><br>
      <?php echo $errOut ?>
    </div>
  <?php endif; ?>

</form>
</div>
</body>

</html>


      