/**
 * Developed Pau Sanchez for http://www.codigomanso.com
 * Adapted from PHP code found in http://www.tufuncion.com/pagerank-php
 *
 * As long as you keep above notice you can do whatever you want with this code
 */

/** string to number */
function StrToNum(str, check, magic)
{
  int32Unit = 4294967296; // 2^32

  for (i = 0; i < str.length; i++)
  {
    check *= magic;
    if (check >= int32Unit)
    {
      check = (check - int32Unit * parseInt (check / int32Unit));
      check = (check < -2147483648) ? (check + int32Unit) : check;
    }
    check += str.charCodeAt(i);
  }

  return check;
}

/** 
 * You should be wondering why am I using this function instead of '|' operator...  so do I,
 * but otherwise this won't work on some webpages
 */
function bitwise_or (op1, op2)
{
  op1 = op1.toString(16);
  op2 = op2.toString(16);

  res = '';
  for (i1 = op1.length - 1, i2 = op2.length-1; i1 >= 0 || i2 >= 0; i1--,i2--) {
    var o1 = 0, o2 = 0;
    if (i1 >= 0) o1 = op1.charAt(i1);
    if (i2 >= 0) o2 = op2.charAt(i2);
    res = (parseInt(o1, 16) | parseInt (o2, 16)).toString(16) + res;
  }

  return parseInt (res, 16);
}

/** Generate a hash for a url */
function HashURL(str)
{
  check1 = StrToNum (str, 0x1505, 0x21);
  check2 = StrToNum (str, 0, 0x1003F);

  check1 >>= 2;
  check1 = ((check1 >> 4) & 0x3FFFFC0 ) | (check1 & 0x3F);
  check1 = ((check1 >> 4) & 0x3FFC00 ) | (check1 & 0x3FF);
  check1 = ((check1 >> 4) & 0x3C000 ) | (check1 & 0x3FFF);

  // if javascript were perfect, and unsigned numbers were returned on bitwise-like operations then this would be the code
  //  t1 = ((((check1 & 0x3C0) << 4) | (check1 & 0x3C)) <<2 ) | (check2 & 0xF0F );
  //  t2 = ((((check1 & 0xFFFFC000) << 4) | (check1 & 0x3C00)) << 0xA) | (check2 & 0xF0F0000);

  // Nothing personal, but I trust 'bitwise_or' more than '|' for unsigned operations
  t1 = bitwise_or (bitwise_or((check1 & 0x3C0) << 4, (check1 & 0x3C)) << 2, check2 & 0xF0F);

  // due to some issues with javascript sign handling
  t2_1 = parseInt ((((((check1 & 0xFFFFC000) << 4) | (check1 & 0x3C00)) ) * 4).toString (16) + '00', 16);
  t2_2 = (check2 & 0xF0F0000);
  t2   = bitwise_or (t2_1, t2_2);
  // This also works:  t2 = parseInt (((t2_1 >>> 16) | (t2_2 >>> 16)).toString(16) + '0000', 16);

  return bitwise_or (t1, t2);
}

/* generate a checksum for the hash string */
function CheckHash (hashnum)
{
  checkByte = 0;
  flag      = 0;

  hashstr = ""+hashnum; // tostring

  for (i = hashstr.length - 1; i >= 0; i--)
  {
    re = parseInt (hashstr.charAt (i));
    if (1 === (flag % 2))
    {
      re += re;
      re = parseInt(re / 10) + (re % 10);
    }
    checkByte += re;
    flag ++;
  }

  checkByte %= 10;
  if (0 != checkByte)
  {
    checkByte = 10 - checkByte;
    if (1 === (flag % 2) )
    {
      if (1 === (checkByte % 2))
      {
        checkByte += 9;
      }
      checkByte >>= 1;
    }
  }

  return '7' + checkByte + hashstr;
}

function getPageRank (url)
{

  if ($('#PRForm').length == 0) {  
    var frameName = 'jpost_iframe_' + (new Date()).getTime();
    $('#PageRank').html ('<iframe scrolling="no" id="marco" name="' + frameName + '"></iframe>');
    $('<form id="PRForm" action="http://toolbarqueries.google.com/search" method="GET" target="' + frameName + '"></form>').appendTo('body');
    $('<input type="hidden" name="client" value="navclient-auto"/>').appendTo ('#PRForm');
    $('<input type="hidden" name="features" value="Rank"/>').appendTo ('#PRForm');
    $('<input type="hidden" name="ch" value="' + CheckHash(HashURL(url)) + '"/>').appendTo ('#PRForm');
    $('<input type="hidden" name="q" value="info:' + url + '"/>').appendTo ('#PRForm');
    $('<input type="hidden" name="num" value="100"/>').appendTo ('#PRForm');
    $('<input type="hidden" name="filter" value="0"/>').appendTo ('#PRForm');
  }
  else {
    $('#PRForm input[name=ch]').val (CheckHash(HashURL(url)));
    $('#PRForm input[name=q]').val  ("info:" + url);
  }
  $('#PRForm').submit();
}