// I Do Foundation basic validation library
// Largely based on this:
// http://developer.netscape.com/docs/examples/javascript/formval/overview.html

// VARIABLE DECLARATIONS

var digits = "0123456789";

var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz";

var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

var postalLetters = "ABCEGHJKLMNPRSTVWXYZ";

// whitespace characters
var whitespace = " \t\n\r";

// decimal point character differs by language and culture
var decimalPointDelimiter = "."

// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";

// characters which are allowed in US phone numbers
var validUSPhoneChars = digits + phoneNumberDelimiters;

// U.S. phone numbers have 10 digits.
// They are formatted as 123 456 7890 or (123) 456-7890.
var digitsInUSPhoneNumber = 10;

// non-digit characters which are allowed in ZIP Codes
var ZIPCodeDelimiters = "-";

// our preferred delimiter for reformatting ZIP Codes
var ZIPCodeDelimiter = "-"

// characters which are allowed in Social Security Numbers
var validZIPCodeChars = digits + ZIPCodeDelimiters

// U.S. ZIP codes have 5 or 9 digits.
// They are formatted as 12345 or 12345-6789.
var digitsInZIPCode1 = 5
var digitsInZIPCode2 = 9

var defaultEmptyOK = true;

// Valid U.S. and Canadian Postal Codes for states, territories, armed forces, etc.
// See http://www.usps.gov/ncsc/lookups/abbr_state.txt.

var USStateCodeDelimiter = "|";
var USStateCodes = "AL|AK|AS|AZ|AR|CA|CO|CT|DE|DC|FM|FL|GA|GU|HI|ID|IL|IN|IA|KS|KY|LA|ME|MH|MD|MA|MI|MN|MS|MO|MT|NE|NV|NH|NJ|NM|NY|NC|ND|MP|OH|OK|OR|PW|PA|PR|RI|SC|SD|TN|TX|UT|VT|VI|VA|WA|WV|WI|WY|AA|AE|AP|AB|BC|MB|NB|NL|NT|NS|NU|ON|PE|QC|SK|YT"

// Check whether string s is empty.

function isEmpty(s)
{   return ((s == null) || (s.length == 0));
}



// Returns true if string s is empty or 
// whitespace characters only.

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}



// Removes all characters which appear in string bag from string s.

function stripCharsInBag (s, bag)

{   var i;
    var returnString = "";

    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }

    return returnString;
}



// Removes all characters which do NOT appear in string bag 
// from string s.

function stripCharsNotInBag (s, bag)

{   var i;
    var returnString = "";

    // Search through string's characters one by one.
    // If character is in bag, append to returnString.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) != -1) returnString += c;
    }

    return returnString;
}



// Removes all whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.

function stripWhitespace (s)

{   return stripCharsInBag (s, whitespace)
}

// Removes initial (leading) whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.

function stripInitialWhitespace (s)

{   var i = 0;

    while ((i < s.length) && charInString (s.charAt(i), whitespace))
       i++;
    
    return s.substring (i, s.length);
}

// Returns true if character c is an English letter 
// (A .. Z, a..z).
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.

function isLetter (c)
{   return ( ((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")) )
}

// Returns true if character c is a Canadian postal code letter
function isPostalLetter (c)
{   return (postalLetters.indexOf(c.toUpperCase()) != -1)
}


// Returns true if character c is a digit 
// (0 .. 9).

function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}



// Returns true if character c is a letter or digit.

function isLetterOrDigit (c)
{   return (isLetter(c) || isDigit(c))
}

function isInteger (s)

{   var i;

    if (isEmpty(s)) return defaultEmptyOK;

    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);

        if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}

function isFloat (s)

{   var i;
    var seenDecimalPoint = false;

    if (isEmpty(s)) return defaultEmptyOK;

    if (s == decimalPointDelimiter) return false;

    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);

        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}

function isAlphabetic (s)

{   var i;

    if (isEmpty(s)) return defaultEmptyOK;

    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is letter.
        var c = s.charAt(i);

        if (!isLetter(c))
        return false;
    }

    // All characters are letters.
    return true;
}

function isAlphanumeric (s) {
    var i;

    if (isEmpty(s)) return defaultEmptyOK;

    // Search through string's characters one by one
    // until we find a non-alphanumeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number or letter.
        var c = s.charAt(i);

        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }

    // All characters are numbers or letters.
    return true;
}

function isUSPhoneNumber (s) {
    if (isEmpty(s)) return defaultEmptyOK;
    s = stripCharsInBag(s, phoneNumberDelimiters);
    return (isInteger(s) && s.length == digitsInUSPhoneNumber)
}

function isZIPCode (s) {
    if (isEmpty(s)) return defaultEmptyOK;
    if (isInteger(s) &&
        ((s.length == digitsInZIPCode1) ||
         (s.length == digitsInZIPCode2))) {
        return true;
    }
    if ((s.length == 10) && (s.indexOf('-') == 5)) {
        s = stripCharsInBag(s, "-");
        if (isInteger(s)) {
            return true;
        }
    }
    return false;
}

function isPostalCode (s) {
    var i;

    if (isEmpty(s)) return defaultEmptyOK;

    // Search through string's characters one by one
    // until we find an invalid character.
    // When we do, return false; if we don't, return true.

    if ((s.length == 7) && (s.indexOf(' ') == 3)) {
        s = stripCharsInBag(s, " ");
	for (i = 0; i < s.length; i++)
	{   
	    var c = s.charAt(i);
	    if (i % 2 == 0) {
		if (!isPostalLetter(c))
		    return false;
	    }
	    else {
		if (!isDigit(c))
		    return false;
	    }
	}

	// All characters are valid.
	return true;
    }
    return false;
}

function isStateCode(s)
{   if (isEmpty(s)) return defaultEmptyOK;
    if (s.length != 2) { return false; }
    return ( (USStateCodes.indexOf(s.toUpperCase()) != -1) &&
             (s.indexOf(USStateCodeDelimiter) == -1) )
}

function isEmail (s)
{   if (isEmpty(s)) return defaultEmptyOK;
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}

function passwordsMatch (first, second) {
    if (first == second) {
        return true;
    }
    return false;
}