/*
 * jQuery creditcard2 extension for the jQuery Validation plugin (http://plugins.jquery.com/project/validate).
 * Ported from http://www.braemoor.co.uk/software/creditcard.shtml by John Gardner, with some enhancements.
 *
 * Author: Jack Killpatrick
 * Copyright (c) 2008 iHwy, Inc.
 *
 * Version 1.0.0 (11/17/2008)
 * Tested with jquery 1.2.6, but will probably work with earlier versions.
 *
 * History:
 * 1.0.0 - released 2008-11-17
 * 
 * Modified to infer the credit card type based on the prefixes, instead of requiring 'cardType' argument.
 *
 * Visit http://www.ihwy.com/labs/jquery-validate-credit-card-extension.aspx for usage information
 *
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
*/
 
jQuery.validator.addMethod("creditcard2", function(value) {
	var cards = new Array();
	cards [0] = {cardName: "Visa", lengths: "13,16", prefixes: "4", checkdigit: true};
	cards [1] = {cardName: "MasterCard", lengths: "16", prefixes: "51,52,53,54,55", checkdigit: true};
	cards [2] = {cardName: "DinersClub", lengths: "14,16", prefixes: "300,301,302,303,304,305,36,38,55", checkdigit: true};
	cards [3] = {cardName: "CarteBlanche", lengths: "14", prefixes: "300,301,302,303,304,305,36,38", checkdigit: true};
	cards [4] = {cardName: "AmEx", lengths: "15", prefixes: "34,37", checkdigit: true};
	cards [5] = {cardName: "Discover", lengths: "16", prefixes: "6011,650", checkdigit: true};
	cards [6] = {cardName: "JCB", lengths: "15,16", prefixes: "3,1800,2131", checkdigit: true};
	cards [7] = {cardName: "enRoute", lengths: "15", prefixes: "2014,2149", checkdigit: true};
	cards [8] = {cardName: "Solo", lengths: "16,18,19", prefixes: "6334, 6767", checkdigit: true};
	cards [9] = {cardName: "Switch", lengths: "16,18,19", prefixes: "4903,4905,4911,4936,564182,633110,6333,6759", checkdigit: true};
	cards [10] = {cardName: "Maestro", lengths: "16,18", prefixes: "5020,6", checkdigit: true};
	cards [11] = {cardName: "VisaElectron", lengths: "16", prefixes: "417500,4917,4913", checkdigit: true};
	
	value = value.replace (/[\s-]/g, ""); // remove spaces and dashes
	if (value.length == 0) { return false; } // no length
	
	var cardNo = value;
	cardNo = cardNo.replace(/\D/g, ""); // strip down to digits
	
	var cardType = -1;
	var prefixValid = false;  
	for (cardType=0; cardType<cards.length; cardType++) {
		var prefix = cards[cardType].prefixes.split(",");
		for (i=0; i<prefix.length; i++) {
			var exp = new RegExp ("^" + prefix[i]);
			if (exp.test (cardNo)) {
				prefixValid = true;
				break;
			}
		}
		if (prefixValid) {
		    break;
		}
	}
	if (!prefixValid) { return false; } // invalid prefix

	//$('#cardType').html(cards[cardType].cardName);
	
	var cardexp = /^[0-9]{13,19}$/;
	if (!cardexp.exec(cardNo)) { return false; } // has chars or wrong length
	
	
	if (cards[cardType].checkdigit){
		var checksum = 0;
		var mychar = "";
		var j = 1;

		var calc;
		for (i = cardNo.length - 1; i >= 0; i--) {
			calc = Number(cardNo.charAt(i)) * j;
			if (calc > 9) {
				checksum = checksum + 1;
				calc = calc - 10;
			}
			checksum = checksum + calc;
			if (j ==1) {j = 2} else {j = 1};
		} 

		if (checksum % 10 != 0) { return false; } // not mod10
	}  

	var lengthValid = false;
	var lengths = new Array ();
	lengths = cards[cardType].lengths.split(",");
	for (j=0; j<lengths.length; j++) {
		if (cardNo.length == lengths[j]) lengthValid = true;
	}
	if (!lengthValid) { return false; } // wrong length
	
	return true;
}, jQuery.validator.messages.creditcard);