$(function(){

	//set global variables and cache DOM elements for reuse later
	var form = $('#contact-form').find('form'),
		formElements = form.find('input[type!="submit"],textarea'),
		formSubmitButton = form.find('[type="submit"]'),
		errorNotice = $('#errors'),
		successNotice = $('#success'),
		loading = $('#loading'),
		errorMessages = {
			required: ' is a required field',
			email: 'You have not entered a valid email address for the field: ',
			minlength: ' must be greater than '
		}
	
	//feature detection + polyfills
	formElements.each(function(){

		//if HTML5 input placeholder attribute is not supported
		if(!Modernizr.input.placeholder){
			var placeholderText = this.getAttribute('placeholder');
			if(placeholderText){
				$(this)
					.addClass('placeholder-text')
					.val(placeholderText)
					.bind('focus',function(){
						if(this.value == placeholderText){
							$(this)
								.val('')
								.removeClass('placeholder-text');
						}
					})
					.bind('blur',function(){
						if(this.value == ''){
							$(this)
								.val(placeholderText)
								.addClass('placeholder-text');
						}
					});
			}
		}
		
		//if HTML5 input autofocus attribute is not supported
		if(!Modernizr.input.autofocus){
			if(this.getAttribute('autofocus')) this.focus();
		}
		
	});
	
	//to ensure compatibility with HTML5 forms, we have to validate the form on submit button click event rather than form submit event. 
	//An invalid html5 form element will not trigger a form submit.
	formSubmitButton.bind('click',function(){
		var formok = true,
			errors = [];
			
		formElements.each(function(){
			var name = this.name,
				nameUC = name.ucfirst(),
				value = this.value,
				placeholderText = this.getAttribute('placeholder'),
				type = this.getAttribute('type'), //get type old school way
				isRequired = this.getAttribute('required'),
				minLength = this.getAttribute('data-minlength');
			
			//if HTML5 formfields are supported			
			if( (this.validity) && !this.validity.valid ){
				formok = false;
				
				console.log(this.validity);
				
				//if there is a value missing
				if(this.validity.valueMissing){
					errors.push(nameUC + errorMessages.required);	
				}
				//if this is an email input and it is not valid
				else if(this.validity.typeMismatch && type == 'email'){
					errors.push(errorMessages.email + nameUC);
				}
				
				this.focus(); //safari does not focus element an invalid element
				return false;
			}
			
			//if this is a required element
			if(isRequired){	
				//if HTML5 input required attribute is not supported
				if(!Modernizr.input.required){
					if(value == placeholderText){
						this.focus();
						formok = false;
						errors.push(nameUC + errorMessages.required);
						return false;
					}
				}
			}

			//if HTML5 input email input is not supported
			if(type == 'email'){ 	
				if(!Modernizr.inputtypes.email){ 
					var emailRegEx = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/; 
				 	if( !emailRegEx.test(value) ){	
						this.focus();
						formok = false;
						errors.push(errorMessages.email + nameUC);
						return false;
					}
				}
			}
			
			//check minimum lengths
			if(minLength){
				if( value.length < parseInt(minLength) ){
					this.focus();
					formok = false;
					errors.push(nameUC + errorMessages.minlength + minLength + ' charcters');
					return false;
				}
			}
		});
		
		//if form is not valid
		if(!formok){
			
			//animate required field notice
			$('#req-field-desc')
				.stop()
				.animate({
					marginLeft: '+=' + 5
				},150,function(){
					$(this).animate({
						marginLeft: '-=' + 5
					},150);
				});
			
			//show error message 
			showNotice('error',errors);
			
		}
		//if form is valid
		else {
			loading.show();
			$.ajax({
				url: form.attr('action'),
				type: form.attr('method'),
				data: form.serialize(),
				success: function(){
					showNotice('success');
					form.get(0).reset();
					loading.hide();
				}
			});
		}
		
		return false; //this stops submission off the form and also stops browsers showing default error messages
		
	});

	//other misc functions
	function showNotice(type,data)
	{
		if(type == 'error'){
			successNotice.hide();
			errorNotice.find("li[id!='info']").remove();
			for(x in data){
				errorNotice.append('<li>'+data[x]+'</li>');	
			}
			errorNotice.show();
		}
		else {
			errorNotice.hide();
			successNotice.show();	
		}
	}
	
	String.prototype.ucfirst = function() {
		return this.charAt(0).toUpperCase() + this.slice(1);
	}
	
});