// this function helps us to check if a string starts with a specified substring or not
if(!String.prototype.startsWith){
    String.prototype.startsWith = function (str) {
        return !this.indexOf(str);
    }
}
//abtValidator literal
var abtValidator = {
	init: function (settings) {
		this.settings = settings;
		this.form = document.getElementById(this.settings["formId"]);
		formInputs = this.form.getElementsByTagName('*');
			
		// change color of inputs on focus
		for(i=0;i<formInputs.length;i++)
		{
			formInputs[i].onfocus = function () {
				this.style.background = "#FFFFFF";
			}
		};		
		var error = abtValidator.validate();
		if(error == "" || error == null){
			return true;
		} else {
			abtValidator.printError(error);
			return false;
		}
	},
	validate: function () {
		error = '';
		this.form = document.getElementById(this.settings["formId"]);
		formInputs = this.form.getElementsByTagName('*');
		error = abtValidatorInternal(formInputs);
		return error;
	},
	printError: function (error) {
		alert(error);
		return false;
	}
};
// returns true if the string is not empty
function isRequired(str){
	if(str == null || str.length == 0){
		return true;
	}
	else{
		return false;
	}
	//return (str == null) || (str.length == 0);
}
// returns true if the string is a valid email
function isEmail(str){
	if(isRequired(str)) return false;
	var re = /^[^\s()<>@,;:\/]+@\w[\w\.-]+\.[a-z]{2,}$/i
	return re.test(str);
}
// returns true if the string only contains characters 0-9 and is not null
function isNumeric(str){
	if(isRequired(str)) return false;
	var re = /[\D]/g
	if (re.test(str)) return false;
	return true;
}
// returns true if the string only contains characters A-Z or a-z
function isAlpha(str){
	if(isRequired(str)) return false;
	var re = /[a-zA-Z]/
	if (re.test(str)) return true;
	return false;
}
// returns true if the string only contains characters 0-9 A-Z or a-z
function isAlphaNum(str){
	if(isRequired(str)) return false;
	var re = /[0-9a-zA-Z]/
	if (re.test(str)) return true;
	return false;
}
// returns true if the string only contains characters OTHER THAN 0-9 A-Z or a-z
function isSymbol(str){
	if(isRequired(str)) return false;
	var re = /[^0-9a-zA-Z]/
	if (re.test(str)) return true;
	return false;
}
// checks if the string is of a specified minimum length or not
function minLength(str,len){
	if(isRequired(str)) return false;
	if(str.length < len){
            return false;
        }
        else{
            return true;
        }
}
// checks if the string is within a specified maximum length or not
function maxLength(str,len){
	if(isRequired(str)) return false;
	if(str.length > len){
            return false;
        }
        else{
            return true;
        }
}
// checks if the string is exactly equal to the specified length or not
function exactLength(str,len){
	if(isRequired(str)) return false;
	if(str.length == len){
            return true;
        }
        else{
            return false;
        }
}
//confirm password validation
function confirmPassword(name){
	var elements = document.getElementsByName(name);
	//assuming that there will be only 2 fields with this name
	
	if(elements[0].value == elements[1].value){
		return true;
	}
	else{
		return false;
	}
	
}
//checkbox or radio required validation
function isRequiredCheckBox(name){
	var flag = false;
	var elements = document.getElementsByName(name);	
	size = elements.length;
	count = 0;
	
	for(var i=0;i <size;i++){
		if(elements[i].checked){
			flag = true;
			break;
		}
		else{
			continue;
		}
	}
	return flag;
}

function abtValidatorInternal(formInputs){
		// change color of inputs on focus
	for(i=0;i<formInputs.length;i++){
		classes = formInputs[i].className;
		if(classes == "" || classes== null){
			valid = true;
		}
		var parts = classes.split(" ");
		for(var cCount=0; cCount< parts.length; cCount++){
			if(parts[cCount] == "isRequired"){
				
				
				if(formInputs[i].type == 'checkbox' || formInputs[i].type == 'radio'){
					valid = isRequiredCheckBox(formInputs[i].name);
					if(formInputs[i].title != null && formInputs[i].title != "")
					{
						errorMsg = formInputs[i].title;
					}
					else{
						errorMsg = "Please select "+formInputs[i].name;	
					}
				
				}
				else{
				
					var valu = (formInputs[i].value);
					valid = !isRequired(valu);
					if(formInputs[i].title != null && formInputs[i].title != "")
					{
						errorMsg = formInputs[i].title;
					}
					else{				
						errorMsg = "Please don't leave this field blank";
					}
				}
			}
			else if(parts[cCount] == "isEmail"){
				var valu = (formInputs[i].value);
				valid = isEmail(valu);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "Please enter a valid email id";
				}
			}
			else if(parts[cCount] == "isNumeric"){
				valid = isNumeric(formInputs[i].value);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "Please enter a valid number.";
				}
			}
			else if(parts[cCount] == "isAlpha"){
				valid = isAlpha(formInputs[i].value);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "This field can only contain alphabets and numbers.";
				}
			}
			else if(parts[cCount] == "isAlphaNum" ){
				valid = isAlphaNum(formInputs[i].value);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "This field can only contain alphabets and numbers.";
				}
			}
			else if(parts[cCount] == "isSymbol"){
				valid = isSymbol(formInputs[i].value);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "This field cannot contain alphabets and numbers.";
				}
			}
			else if(parts[cCount].startsWith("minLength")){
				innerParts = parts[cCount].split("_");
				valid = minLength(formInputs[i].value,innerParts[1]);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "Minimum "+innerParts[1]+" characters required";
				}
            }
			else if(parts[cCount].startsWith("maxLength")){
				innerParts = parts[cCount].split("_");
				valid = maxLength(formInputs[i].value,innerParts[1]);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "More than "+innerParts[1]+" characters not allowed";
				}
			}
			else if(parts[cCount].startsWith("exactLength")){
				innerParts = parts[cCount].split("_");
				valid = exactLength(formInputs[i].value,innerParts[1]);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "This field should have exactly "+innerParts[1]+" characters";
				}
			}
			else if(parts[cCount] == "confirmPassword"){
				valid = confirmPassword(formInputs[i].name);
				if(formInputs[i].title != null && formInputs[i].title != "")
				{
					errorMsg = formInputs[i].title;
				}
				else{				
					errorMsg = "Please make sure password and confirm password are same";
				}
			}
			else{
				valid = true;
			}
			if(!valid) {
				formInputs[i].style.background = "#FFFF99";
				formInputs[i].style.border = "1px solid #CF3339";
				return errorMsg;
			}
		}
    };
}