// =========== global functions =========================

// Marks the form as invalid and adds an errormessage
function error(message){
	valid = false;
	error_text += "* " + message + "\r\n";
}

// Gets a question name from a given ID
function getName(id){
	var label = document.getElementById(id + '_label');
	var children = label.childNodes;
	for (var i = 0; i < children.length ; i++){
		if(children[i].nodeType == 3){
			return children[i].nodeValue;
		}
	}
}

function markAsBad(id){
	var elem = document.getElementById(id);
	if(elem){
		elem.oldClassName = elem.className;
		elem.className = 'badinput';
	}
	
	var elem = document.getElementById(id+'_label');
	if(elem){
		elem.oldClassName = elem.className;
		elem.className = 'badinput';
	}
}

function unmarkAll(){
	unmark('input');
	unmark('select');
	unmark('textarea');
	unmark('p')
	unmark('label');
}

function unmark(tagname){
	var elems = document.getElementsByTagName(tagname);
	for(var i = 0; i < elems.length; i++){
		var elem = elems[i];
		if(elem.className == 'badinput'){
			elem.className = elem.oldClassName;
			elem.oldClassName = '';
		}
	}
}

// ========= specific functions ==============

// Validate against the bounds-option
function validate_bounds(id, lowerBound, upperBound){
	var value = parseInt(document.getElementById(id).value, 10);
	if(isNaN(value)){
		return;
	}
	if(value < lowerBound || value > upperBound){
		var name = getName(id);
		error("Answer to '" + name + "' out of bounds (must be between " + lowerBound + " and " + upperBound + ")");
		markAsBad(id);
	}
}

// Validate against maxlength-option
function validate_maxlength(id, maxlength){
	var length = document.getElementById(id).value.length;
	if(length > maxlength){
		var name = getName(id);
		error("Answer to '" + name + "' is too long (maximum " + maxlength + " characters)");
		markAsBad(id);
	}
}


function validate_text(id){
	// Empty
}


function validate_email(id){
	var value = document.getElementById(id).value;
	if(value.length > 0){
		var regex = /^[A-Za-z0-9_-]+(\.[A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\.[A-Za-z0-9-]+)*\.[A-Za-z0-9]{2,4}$/;
		if(!regex.test(value)){
			var name = getName(id);
			error("Answer to '" + name + "' is not a valid e-mail address");
			markAsBad(id);
		}
	}
}

function validate_file(id){
	// Empty
}

function validate_date(id){
	var value = document.getElementById(id).value;
	if(value.length > 0){
		if(!validDate(value)){
			var name = getName(id);
			error("Answer to '" + name + "' is not a valid date (please format the date as dd-mm-yyyy)");
			markAsBad(id);
		}
	}
}

function validate_number(id){
	var value = document.getElementById(id).value;
	if(value.length > 0){
		if(isNaN(parseInt(value))){
			var name = getName(id);
			error("Answer to '" + name + "' is not a valid nubmer");
			markAsBad(id);
		}
	}
}


function validate_choice(id){
	// only possible validation is to check 'other' specification field
	var elem = document.getElementById(id);
	var otherOption = document.getElementById(id + '_optionother');
	var name = getName(id);

	if(elem){
		if(otherOption && otherOption.selected && document.getElementById(id + '_other').value == ''){
			error("Please clarify your answer 'other' to '" + name + "'");
			markAsBad(id);
		}
	}else{
		if(otherOption && otherOption.checked && document.getElementById(id + '_other').value == ''){
			error("Please clarify your answer 'other' to '" + name + "'");	
			markAsBad(id);
		}
	}
}

function validate_required(id, type){
	var elem = document.getElementById(id);
	var name = getName(id);

	switch(type){
		case 'choice':
			if(elem){
				if(elem.selectedIndex == -1){
					error("Question '" + name + "' was not answered");
					markAsBad(id);
				}
			}else{
				var optionName = 'q[' + id.substr(1) + '][options][]';
				var optionElems = document.getElementsByName(optionName);
				found = false;

				for(var i = 0; i < optionElems.length; i++){
					if(optionElems[i].checked){ found = true; }
				}

				if(!found){
					error("Question '" + name + "' was not answered");
					markAsBad(id);
				}
			}
			break;
		case 'email':
		case 'text':
		case 'file':
		case 'date':
		case 'number':
		case 'default':
			if(elem.value == ''){
				error("Question '" + name + "' was not answered");
				markAsBad(id);
			}
			break;
	}
}