// formLib.js
// Common functions used with forms
// Copied from book "CGI Programming with PERL"

// We use this as a hash to track those elements validated on a per-element
// basis that has formatting problems
validate = new Object();

// Takes a value, checks if it's an integer, and returns true or false
/* This comparison of value to its parsed value will not work when the <script> 
* tag has LANGUAGE="JavaScript1.2", because of how equality is defined in that version of JavaScript.
* It works fine when LANGUAGE="JavaScript"
*/
function isInteger ( value ) { 
    return ( value == parseInt(value) );
}

function isFloat ( value ) { 
    return ( value == parseFloat(value) );
}

//Verifies that the value is a valid Gene Ontology attribute....
function checkGOattr (element) {
    // Regexp is (GO:)?[0-9]+
    var GOterm = /^(GO:[0-9]+|[0-9]+)$/; //regexp with optional 'GO:' followed by only digits
    if (element.value.search(GOterm)==-1) { // match failed
	alert("A GO term can take one of two forms:\n"
	      + "'GO:012678' or '012678'\n"
	      + "You entered '" + element.value + "'.\n"
	      + "Please correct it, and submit again.");
	validate[element.name] = false; 
	attr = document.getElementById("attribute");
	//    alert("attrID = " + attr)
	element.focus();
	return false;
    }
    else {return true;}
}

//Verifies that the value is a valid Gene Ontology attribute....
function checkGOattr (element) {
    // Regexp is (GO:)?[0-9]+
    var GOterm = /^(GO:[0-9]+|[0-9]+)$/; //regexp with optional 'GO:' followed by only digits
    if (element.value.search(GOterm)==-1) { // match failed
	alert("A GO term can take one of two forms:\n"
	      + "'GO:012678' or '012678'\n"
	      + "You entered '" + element.value + "'.\n"
	      + "Please correct it, and submit again.");
	validate[element.name] = false; 
	attr = document.getElementById("attribute");
	//    alert("attrID = " + attr)
	element.focus();
	return false;
    }
    else {return true;}
}

//Verifies that the value is a valid MGI name
function checkMGI (element) {
    // Regexp is (GO:)?[0-9]+
    var GOterm = /^(MGI:[0-9]+|[0-9]+)$/; //regexp with optional 'GO:' followed by only digits
    if (element.value.search(GOterm)==-1) { // match failed
	alert("An MGI number can take one of two forms:\n"
	      + "'MGI:012678' or '012678'\n"
	      + "You entered '" + element.value + "'.\n"
	      + "Please correct it, and submit again.");
	validate[element.name] = false; 
	element.focus();
	return false;
    }
    else {return true;}
}


// Take a value and a range, checks if the value is in the range, and 
// returns true or false
function inRange (value, low, high ) {
    return ( !( value < low ) && value <= high );
}

// Checks values against formats such as '####' or '###-##-###'
function checkFormat (value, format) {
    var formatOkay = true;
    if (value.length != format.length ) {
	return false;
    }
    for (var i = 0; i < format.length; i++) {
	if ( format.charAt(i) == '#' && ! isInteger (value.charAt(i)) ) {
	    return false;
	}
	else if ( format.charAt(i) != '#' &&
		  format.charAt(i) != value.charAt(i) ) {
	    return false;
	}
    } 
    return true;
}

// Takes a form and an array of element names
// Verifies that each has a value
function requireValues (form, requiredValues) {
    for (var i = 0; i < requiredValues.length; i++ ) {
	element = requiredText[i];
	if (form[element].value == "" ) {
	    alert("Please enter a value for " + element + "." );
	    return false;
	}
    }
    return true;
}

// Takes a form and an array of element names; verifies that each has an 
// option selected (other than the first; assumes that the first option in
// each select menu contains instructions)
function requireSelects ( form, requiredSelect ) {
    for (var i = 0; i < requiredSelect.length; i++ ) {
	element = requiredSelect[i];
	if (form[element].selectedIndex <= 0) {
	    alert ("Please select a value for" + element + "." );
	    return false;
	}
    }
    return true;
}

// Takes a form and an array of element names; verifies that each has a 
// value checked
function requireRadios (form, requiredRadio) {
    for (var i= 0; i < requiredRadio.length; i++ ){
	element = requiredRadio[i];
	isChecked = false;
	for ( j = 0; j < form[element].length; j++ ) { 
	    if ( form[element][j].checked ) {
		isChecked = true;
	    }
	}
	if ( ! isChecked ) {
	    alert( "Please choose a " + form[element][0].name + ".");
	    return false;
	}
    }
    return true;
}

// Verify there are no uncorrected formatting problems with elements
// validated on a per-element basis
function checkProblems () {
    for ( element in validate ) {
	if (! validate[element] ) {
	    alert ("Please correct the format of " + element + ".");
	    return false;
	}
    }
    return true;
}

//Verifies that the value of the provided element has ##### format
function checkZip (element ) {
    if (! checkFormat( element.value, "#####" ) ) {
	alert ("Please enter a five-digit zip code." );
	element.focus();
	validate[element.name] = false;
    }
    else {
	validate[element.name] = true;
    }
    return validate[element.name];
}

// Verifies that the value of the provided element has ###-###-#### format
function checkPhone (element) {
    if (! checkFormat( element.value, "###-###-####" ) ) {
	alert ("Please enter " + element.name + " in 800-555-1212 format." );
	element.focus();
	validate[element.name] = false;
    }
    else {
	validate[element.name] = true;
    }
    return validate[element.name];
}

// Verifies that the value of the provided element has ###-##-#### format
function checkSSN (element) {
    if (! checkFormat( element.value, "###-##-###" ) ) {
	alert( "Please enter your Social Security Number in " + "123-45-6789 format." );
	element.focus();
	validate[element.name] = false;
    }
    else { 
	validatae[element.name] = true;
    }
    return validate[element.name];
}

// Verifies that the value of the provided element is an integer between 1 and 150
function checkAge (element)  {
    if (! isInteger( element.value ) 
	|| ! inRange(element.value, 1, 150) ) {
	alert ("Please enter a number between 1 and 150 for age.");
	element.focus();
	validate[element.name] = false;
    }
    else { 
	validate[element.name] = true;
    }
    return validate[element.name];
}



// Verifies that the value of the provided element is an integer
function checkInteger (element)  {
//	alert("Checking " + element.name)
    if (! isInteger(element.value) ) {
	alert(element.name + " must be a whole number (integer).\nPlease go back and change it.");
	element.focus();
	element.select();
	validate[element.name] = false;
    }
    else { 
	validate[element.name] = true;
    }
    return validate[element.name];
}

function checkFloat (element)  {
//	alert("Checking " + element.name)
    if (! isFloat(element.value) ) {
	alert(element.name + " must be a number.\nPlease go back and change it.");
	element.focus();
	element.select();
	validate[element.name] = false;
    }
    else { 
	validate[element.name] = true;
    }
    return validate[element.name];
}