/**
 * A localization support library for JavaScript applications.
 *
 * Provides implementations of useful functions from other programming
 * languages:
 *   - sprintf() - String formatting utility
 *   - gettext() and _() - GNU gettext-like localization of strings
 *
 * @package    Spenlen
 * @subpackage l10n
 * @copyright  Copyright 2009 Spenlen Media, Inc. (http://spenlen.com)
 * @version    $Id$
 */


/**** sprintf() ****/

if (typeof sprintf === 'undefined') {
    /**
     * JavaScript printf/sprintf functions.
     *
     * This code is unrestricted: you are free to use it however you like.
     *
     * The functions should work as expected, performing left or right alignment,
     * truncating strings, outputting numbers with a required precision etc.
     *
     * For complex cases, these functions follow the Perl implementations of
     * (s)printf, allowing arguments to be passed out-of-order, and to set the
     * precision or length of the output based on arguments instead of fixed
     * numbers.
     *
     * See http://perldoc.perl.org/functions/sprintf.html for more information.
     *
     * Implemented:
     * - zero and space-padding
     * - right and left-alignment,
     * - base X prefix (binary, octal and hex)
     * - positive number prefix
     * - (minimum) width
     * - precision / truncation / maximum width
     * - out of order arguments
     *
     * Not implemented (yet):
     * - vector flag
     * - size (bytes, words, long-words etc.)
     *
     * Will not implement:
     * - %n or %p (no pass-by-reference in JavaScript)
     *
     * @version 2007.04.27
     * @author Ash Searle
     * http://hexmen.com/js/sprintf.js
     */
    function sprintf ()
    {
        function pad(str, len, chr, leftJustify)
        {
        	var padding = (str.length >= len) ? '' : Array(1 + len - str.length >>> 0).join(chr);
        	return leftJustify ? str + padding : padding + str;
        }

        function justify(value, prefix, leftJustify, minWidth, zeroPad)
        {
        	var diff = minWidth - value.length;
        	if (diff > 0) {
        	    if (leftJustify || !zeroPad) {
        		value = pad(value, minWidth, ' ', leftJustify);
        	    } else {
        		value = value.slice(0, prefix.length) + pad('', diff, '0', true) + value.slice(prefix.length);
        	    }
        	}
        	return value;
        }

        function formatBaseX(value, base, prefix, leftJustify, minWidth, precision, zeroPad)
        {
        	// Note: casts negative numbers to positive ones
        	var number = value >>> 0;
        	prefix = prefix && number && {'2': '0b', '8': '0', '16': '0x'}[base] || '';
        	value = prefix + pad(number.toString(base), precision || 0, '0', false);
        	return justify(value, prefix, leftJustify, minWidth, zeroPad);
        }

        function formatString(value, leftJustify, minWidth, precision, zeroPad)
        {
        	if (precision != null) {
        	    value = value.slice(0, precision);
        	}
        	return justify(value, '', leftJustify, minWidth, zeroPad);
        }

        var a = arguments, i = 0, format = a[i++];
        return format.replace(/%%|%(\d+\$)?([-+#0 ]*)(\*\d+\$|\*|\d+)?(\.(\*\d+\$|\*|\d+))?([scboxXuidfegEG])/g,
                              function(substring, valueIndex, flags, minWidth, unused, precision, type) {
    	    if (substring == '%%') {
    	        return '%';
    	    }

    	    // parse flags
    	    var leftJustify = false, positivePrefix = '', zeroPad = false, prefixBaseX = false;
    	    for (var j = 0; flags && j < flags.length; j++) {
    	        switch (flags.charAt(j)) {
            		case ' ': positivePrefix = ' ';  break;
            		case '+': positivePrefix = '+';  break;
            		case '-': leftJustify    = true; break;
            		case '0': zeroPad        = true; break;
            		case '#': prefixBaseX    = true; break;
        	    }
    	    }

    	    // parameters may be null, undefined, empty-string or real valued
    	    // we want to ignore null, undefined and empty-string values

    	    if (! minWidth) {
        		minWidth = 0;
    	    } else if (minWidth == '*') {
        		minWidth = +a[i++];
    	    } else if (minWidth.charAt(0) == '*') {
        		minWidth = +a[minWidth.slice(1, -1)];
    	    } else {
        		minWidth = +minWidth;
    	    }

    	    // Note: undocumented perl feature:
    	    if (minWidth < 0) {
        		minWidth = -minWidth;
        		leftJustify = true;
    	    }

    	    if (!isFinite(minWidth)) {
        		throw new Error('sprintf: (minimum-)width must be finite');
    	    }

    	    if (! precision) {
        		precision = 'fFeE'.indexOf(type) > -1 ? 6 : (type == 'd') ? 0 : void(0);
    	    } else if (precision == '*') {
        		precision = +a[i++];
    	    } else if (precision.charAt(0) == '*') {
        		precision = +a[precision.slice(1, -1)];
    	    } else {
        		precision = +precision;
    	    }

    	    // grab value using valueIndex if required?
    	    var value = valueIndex ? a[valueIndex.slice(0, -1)] : a[i++];

    	    switch (type) {
        		case 's': return formatString(String(value), leftJustify, minWidth, precision, zeroPad);
        		case 'c': return formatString(String.fromCharCode(+value), leftJustify, minWidth, precision, zeroPad);
        		case 'b': return formatBaseX(value, 2, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
        		case 'o': return formatBaseX(value, 8, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
        		case 'x': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
        		case 'X': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad).toUpperCase();
        		case 'u': return formatBaseX(value, 10, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
        		case 'i':
        		case 'd':
                    {
                        var number = parseInt(+value);
                        var prefix = number < 0 ? '-' : positivePrefix;
                        value = prefix + pad(String(Math.abs(number)), precision, '0', false);
                        return justify(value, prefix, leftJustify, minWidth, zeroPad);
                    }
        		case 'e':
        		case 'E':
        		case 'f':
        		case 'F':
        		case 'g':
        		case 'G':
                    {
                        var number = +value;
                        var prefix = number < 0 ? '-' : positivePrefix;
                        var method = ['toExponential', 'toFixed', 'toPrecision']['efg'.indexOf(type.toLowerCase())];
                        var textTransform = ['toString', 'toUpperCase']['eEfFgG'.indexOf(type) % 2];
                        value = prefix + Math.abs(number)[method](precision);
                        return justify(value, prefix, leftJustify, minWidth, zeroPad)[textTransform]();
                    }
        		default: return substring;
    	    }
	    });
    }

}


/**
 * Returns the string, translated according to the user's current locale, as
 * returned by navigator.language (or navigator.userLanguage).
 *
 * @todo Write this code
 *
 * @param  String string
 * @return String
 */
function gettext (string) {
    return string;
}

/**
 * gettext() shorthand function. Makes for smaller code: _('some string')
 *
 * @param  String string
 * @return String
 */
function _ (string) {
    return gettext(string);
}