// ========================================================================
// SproutCore
// copyright 2006-2007 Sprout Systems, Inc.
// ========================================================================

require('validators/validator') ;

// Force to be a valid credit card number.
SC.Validator.CreditCard = SC.Validator.extend({
  
  // expects a string of 16 digits. split into groups of 4
  fieldValueForObject: function(object, form, field) {
    if (typeof(object) == "string" && object.length == 16) {
      object = [object.slice(0,4),object.slice(4,8),object.slice(8,12),object.slice(12,16)].join(' ') ;
    }
    return object ;
  },
  
  // remove all whitespace to make a single number.
  objectForFieldValue: function(value, form, field) {
    return value.replace(/^\s+|\s+$/g,'') ;
  },
  
  validate: function(form, field) { 
    return this.checkNumber(field.get('fieldValue')) ; 
  },
  
  validateError: function(form, field) {
    var label = field.get('errorLabel') || 'Field' ;
    return $error("Invalid.CreditCard(%@)".loc(label), label);
  },
  
  // Borrowed from: David Leppek :: https://www.azcode.com/Mod10
  checkNumber: function(ccNumb) {
    var valid = "0123456789"  // Valid digits in a credit card number
    var len = ccNumb.length;  // The length of the submitted cc number
    var iCCN = parseInt(ccNumb);  // integer of ccNumb
    var sCCN = ccNumb.toString();  // string of ccNumb
    sCCN = sCCN.replace (/^\s+|\s+$/g,'');  // strip spaces
    var iTotal = 0;  // integer total set at zero
    var bNum = true;  // by default assume it is a number
    var bResult = false;  // by default assume it is NOT a valid cc
    var temp;  // temp variable for parsing string
    var calc;  // used for calculation of each digit

    // Determine if the ccNumb is in fact all numbers
    for (var j=0; j<len; j++) {
      temp = "" + sCCN.substring(j, j+1);
      if (valid.indexOf(temp) == "-1"){bNum = false;}
    }

    // if it is NOT a number, you can either alert to the fact, 
    // or just pass a failure
    if(!bNum) bResult = false;

    // Determine if it is the proper length 
    if((len == 0)&&(bResult)){  // nothing, field is blank AND passed above # check
      bResult = false;
    } else{  // ccNumb is a number and the proper length - let's see if it is a valid card number
      if(len >= 15){  // 15 or 16 for Amex or V/MC
        for(var i=len;i>0;i--){  // LOOP throught the digits of the card
          calc = parseInt(iCCN) % 10;  // right most digit
          calc = parseInt(calc);  // assure it is an integer
          iTotal += calc;  // running total of the card number as we loop - Do Nothing to first digit
          i--;  // decrement the count - move to the next digit in the card
          iCCN = iCCN / 10;                               // subtracts right most digit from ccNumb
          calc = parseInt(iCCN) % 10 ;    // NEXT right most digit
          calc = calc *2;                                 // multiply the digit by two
          // Instead of some screwy method of converting 16 to a string and then parsing 1 and 6 and then adding them to make 7,
          // I use a simple switch statement to change the value of calc2 to 7 if 16 is the multiple.
          switch(calc){
            case 10: calc = 1; break;       //5*2=10 & 1+0 = 1
            case 12: calc = 3; break;       //6*2=12 & 1+2 = 3
            case 14: calc = 5; break;       //7*2=14 & 1+4 = 5
            case 16: calc = 7; break;       //8*2=16 & 1+6 = 7
            case 18: calc = 9; break;       //9*2=18 & 1+8 = 9
            default: calc = calc;           //4*2= 8 &   8 = 8  -same for all lower numbers
          }                                               
        iCCN = iCCN / 10;  // subtracts right most digit from ccNum
        iTotal += calc;  // running total of the card number as we loop
      }  // END OF LOOP
      if ((iTotal%10)==0){  // check to see if the sum Mod 10 is zero
        bResult = true;  // This IS (or could be) a valid credit card number.
      } else {
        bResult = false;  // This could NOT be a valid credit card number
        }
      }
    }
    return bResult; // Return the results
  }
    
}) ;