//<!-- Original:  Simon Tneoh (tneohcb@pc.jaring.my) -->

//<!-- This script and many more are available free online at -->
//<!-- The JavaScript Source!! http://javascript.internet.com -->

//debugWin = window.open("","debugWin","height=500,width=400,top=5,left=5,resizable=yes,scrollbars=yes");
function println(str) {
  if(debugWin)
    debugWin.document.writeln(str+"<br>");
}


var Cards = new makeArray(8);
Cards[0] = new CardType("M", "51,52,53,54,55", "16");
var M = Cards[0];
Cards[1] = new CardType("V", "4", "13,16");
var V = Cards[1];
Cards[2] = new CardType("A", "34,37", "15");
var A = Cards[2];
Cards[3] = new CardType("D", "6011", "16");
var D = Cards[3];
Cards[4] = new CardType("DC", "30,36,38", "14");
var DC = Cards[4];
Cards[5] = new CardType("enRouteCard", "2014,2149", "15");
var enRouteCard = Cards[5];
Cards[6] = new CardType("JCBCard", "3088,3096,3112,3158,3337,3528", "16");
var JCBCard = Cards[6];
var LuhnCheckSum = Cards[7] = new CardType();

/*************************************************************************\
CheckCardNumber(form)
function called when users click the "check" button.
\*************************************************************************/
function CheckCardNumber(form) {
  if (!validatePayment(form)) {
    return false;
  }

  tmpyear = form.cc_ex_year.options[form.cc_ex_year.selectedIndex].value;
  tmpmonth = form.cc_ex_month.options[form.cc_ex_month.selectedIndex].value;

  if (!(new CardType()).isExpiryDate(tmpyear, tmpmonth)) {
    alert("This card has already expired.");
    return false;
  }
//  card = form.cc_type.options[form.cc_type.selectedIndex].value;
  card = "";
  for(i=0; i<form.cc_type.length; i++) {
    if(form.cc_type[i].checked) {
      card = form.cc_type[i].value;
      break;
    }
  }
  var retval = eval(card + ".checkCardNumber(\"" + form.cc_number.value +
  "\", " + tmpyear + ", " + tmpmonth + ");");
  cardname = "";
  if (!retval) {
    // The cardnumber has the valid luhn checksum, but we want to know which
    // cardtype it belongs to.
    for (var n = 0; n < Cards.size; n++) {
      if (Cards[n].checkCardNumber(form.cc_number.value, tmpyear, tmpmonth)) {
        cardname = Cards[n].getCardType();
        break;
      }
    }
    if (cardname.length > 0) {
      alert("This is not a valid " + card + " number.");
    }
    else { 
      alert("This card number is not valid.");
    } 
    return false;
  }
  return true;
}

/*************************************************************************\
Object CardType([String cardtype, String rules, String len, int year, 
                                        int month])
cardtype    : type of card, eg: MasterCard, Visa, etc.
rules       : rules of the cardnumber, eg: "4", "6011", "34,37".
len         : valid length of cardnumber, eg: "16,19", "13,16".
year        : year of expiry date.
month       : month of expiry date.
eg:
var VisaCard = new CardType("Visa", "4", "16");
var AmExCard = new CardType("AmEx", "34,37", "15");
\*************************************************************************/
function CardType() {
  var n;
  var argv = CardType.arguments;
  var argc = CardType.arguments.length;

  this.objname = "object CardType";

  var tmpcardtype = (argc > 0) ? argv[0] : "CardObject";
  var tmprules = (argc > 1) ? argv[1] : "0,1,2,3,4,5,6,7,8,9";
  var tmplen = (argc > 2) ? argv[2] : "13,14,15,16,19";

  this.setCardNumber = setCardNumber;  // set CardNumber method.
  this.setCardType = setCardType;  // setCardType method.
  this.setLen = setLen;  // setLen method.
  this.setRules = setRules;  // setRules method.
  this.setExpiryDate = setExpiryDate;  // setExpiryDate method.

  this.setCardType(tmpcardtype);
  this.setLen(tmplen);
  this.setRules(tmprules);
  if (argc > 4)
    this.setExpiryDate(argv[3], argv[4]);

  this.checkCardNumber = checkCardNumber;  // checkCardNumber method.
  this.getExpiryDate = getExpiryDate;  // getExpiryDate method.
  this.getCardType = getCardType;  // getCardType method.
  this.isCardNumber = isCardNumber;  // isCardNumber method.
  this.isExpiryDate = isExpiryDate;  // isExpiryDate method.
  this.luhnCheck = luhnCheck;// luhnCheck method.
  return this;
}

/*************************************************************************\
boolean checkCardNumber([String cardnumber, int year, int month])
return true if cardnumber pass the luhncheck and the expiry date is
valid, else return false.
\*************************************************************************/
function checkCardNumber() {
  var argv = checkCardNumber.arguments;
  var argc = checkCardNumber.arguments.length;
  var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
  var year = (argc > 1) ? argv[1] : this.year;
  var month = (argc > 2) ? argv[2] : this.month;

  this.setCardNumber(cardnumber);
  this.setExpiryDate(year, month);

  if (!this.isCardNumber())
    return false;
  if (!this.isExpiryDate())
    return false;

  return true;
}
/*************************************************************************\
String getCardType()
return the cardtype.
\*************************************************************************/
function getCardType() {
  return this.cardtype;
}
/*************************************************************************\
String getExpiryDate()
return the expiry date.
\*************************************************************************/
function getExpiryDate() {
  return this.month + "/" + this.year;
}
/*************************************************************************\
boolean isCardNumber([String cardnumber])
return true if cardnumber pass the luhncheck and the rules, else return
false.
\*************************************************************************/
function isCardNumber() {
  var argv = isCardNumber.arguments;
  var argc = isCardNumber.arguments.length;
  var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
  if (!this.luhnCheck())
    return false;

  for (var n = 0; n < this.len.size; n++) {
    if (cardnumber.toString().length == this.len[n]) {
      for (var m = 0; m < this.rules.size; m++) {
        var headdigit = cardnumber.substring(0, this.rules[m].toString().length);
        if (headdigit == this.rules[m])
          return true;
      }
      return false;
    }
  }
  return false;
}

/*************************************************************************\
boolean isExpiryDate([int year, int month])
return true if the date is a valid expiry date,
else return false.
\*************************************************************************/
function isExpiryDate() {
  var argv = isExpiryDate.arguments;
  var argc = isExpiryDate.arguments.length;

  year = argc > 0 ? argv[0] : this.year;
  month = argc > 1 ? argv[1] : this.month;

  if (!isNum(year+""))
    return false;
  if (!isNum(month+""))
    return false;
  today = new Date();
  expiry = new Date(year, month);
  if (today.getTime() > expiry.getTime())
    return false;
  else
    return true;
}

/*************************************************************************\
boolean isNum(String argvalue)
return true if argvalue contains only numeric characters,
else return false.
\*************************************************************************/
function isNum(argvalue) {
  argvalue = argvalue.toString();

  if (argvalue.length == 0)
    return false;

  for (var n = 0; n < argvalue.length; n++)
    if (argvalue.substring(n, n+1) < "0" || argvalue.substring(n, n+1) > "9")
      return false;

  return true;
}

/*************************************************************************\
boolean luhnCheck([String CardNumber])
return true if CardNumber pass the luhn check else return false.
Reference: http://www.ling.nwu.edu/~sburke/pub/luhn_lib.pl
\*************************************************************************/
function luhnCheck() {
  var argv = luhnCheck.arguments;
  var argc = luhnCheck.arguments.length;

  var CardNumber = argc > 0 ? argv[0] : this.cardnumber;

  if (! isNum(CardNumber)) {
    return false;
  }

  var no_digit = CardNumber.length;
  var oddoeven = no_digit & 1;
  var sum = 0;

  for (var count = 0; count < no_digit; count++) {
    var digit = parseInt(CardNumber.charAt(count));
    if (!((count & 1) ^ oddoeven)) {
      digit *= 2;
      if (digit > 9)
        digit -= 9;
    }
    sum += digit;
  }
  if (sum % 10 == 0)
    return true;
  else
    return false;
}

/*************************************************************************\
ArrayObject makeArray(int size)
return the array object in the size specified.
\*************************************************************************/
function makeArray(size) {
  this.size = size;
  return this;
}

/*************************************************************************\
CardType setCardNumber(cardnumber)
return the CardType object.
\*************************************************************************/
function setCardNumber(cardnumber) {
  this.cardnumber = cardnumber;
  return this;
}

/*************************************************************************\
CardType setCardType(cardtype)
return the CardType object.
\*************************************************************************/
function setCardType(cardtype) {
  this.cardtype = cardtype;
  return this;
}

/*************************************************************************\
CardType setExpiryDate(year, month)
return the CardType object.
\*************************************************************************/
function setExpiryDate(year, month) {
  this.year = year;
  this.month = month;
  return this;
}

/*************************************************************************\
CardType setLen(len)
return the CardType object.
\*************************************************************************/
function setLen(len) {
  // Create the len array.
  if (len.length == 0 || len == null)
    len = "13,14,15,16,19";

  var tmplen = len;
  n = 1;
  while (tmplen.indexOf(",") != -1) {
    tmplen = tmplen.substring(tmplen.indexOf(",") + 1, tmplen.length);
    n++;
  }
  this.len = new makeArray(n);
  n = 0;
  while (len.indexOf(",") != -1) {
    var tmpstr = len.substring(0, len.indexOf(","));
    this.len[n] = tmpstr;
    len = len.substring(len.indexOf(",") + 1, len.length);
    n++;
  }
  this.len[n] = len;
  return this;
}

/*************************************************************************\
CardType setRules()
return the CardType object.
\*************************************************************************/
function setRules(rules) {
  // Create the rules array.
  if (rules.length == 0 || rules == null)
    rules = "0,1,2,3,4,5,6,7,8,9";
    
  var tmprules = rules;
  n = 1;
  while (tmprules.indexOf(",") != -1) {
    tmprules = tmprules.substring(tmprules.indexOf(",") + 1, tmprules.length);
    n++;
  }
  this.rules = new makeArray(n);
  n = 0;
  while (rules.indexOf(",") != -1) {
    var tmpstr = rules.substring(0, rules.indexOf(","));
    this.rules[n] = tmpstr;
    rules = rules.substring(rules.indexOf(",") + 1, rules.length);
    n++;
  }
  this.rules[n] = rules;
  return this;
}

/*************************************************************************\
Validate Form Values
\*************************************************************************/
function validatePayment(d_form) {
  err = false;
  msg = "";
  if (d_form.cc_type.value == "" || d_form.cc_type.value == "null") {
    msg += "     -  Select your credit card type.\n";
    err = true;
  }
  if (d_form.cc_number && (""+parseInt(d_form.cc_number.value)) == "NaN") {
    msg += "     -  Enter your credit card number.\n";
    err = true;
  } else if (d_form.cc_number.value.indexOf(" ") != -1) {
    msg += "     -  Remove blank spaces from\n       your credit card number.\n";
    err = true;
  } else if (d_form.cc_number.value.indexOf("-") != -1) {
    msg += "     -  Remove dashes from\n       your credit card number.\n";
    err = true;
  }
  if (d_form.cc_ex_month.value == "") {
    msg += "     -  Select your expiration month.\n";
    err = true;
  }
  if (d_form.cc_ex_year.value == "") {
    msg += "     -  Select your expiration year.\n";
    err = true;
  }
  if (err == true) {
    alert("Please make the following changes:\n\n" + msg);
    return false;
  }
  return true;
}