/**
 * @class Ext.util.Format
 * Reusable data formatting functions
 * @singleton
 */
Ext.util.Format = {
    defaultDateFormat: 'm/d/Y',
    escapeRe: /('|\\)/g,
    trimRe: /^[\x09\x0a\x0b\x0c\x0d\x20\xa0\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000]+|[\x09\x0a\x0b\x0c\x0d\x20\xa0\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000]+$/g,
    formatRe: /\{(\d+)\}/g,
    escapeRegexRe: /([-.*+?^${}()|[\]\/\\])/g,
    
    
/**
     * Truncate a string and add an ellipsis ('...') to the end if it exceeds the specified length
     * @param {String} value The string to truncate
     * @param {Number} length The maximum length to allow before truncating
     * @param {Boolean} word True to try to find a common word break
     * @return {String} The converted text
     */
    ellipsis: function(value, len, word) {
        if (value && value.length > len) {
            if (word) {
                var vs = value.substr(0, len - 2),
                index = Math.max(vs.lastIndexOf(' '), vs.lastIndexOf('.'), vs.lastIndexOf('!'), vs.lastIndexOf('?'));
                if (index != -1 && index >= (len - 15)) {
                    return vs.substr(0, index) + "...";
                }
            } 
            return value.substr(0, len - 3) + "...";
        }
        return value;
    },

    
/**
     * Escapes the passed string for use in a regular expression
     * @param {String} str
     * @return {String}
     */
    escapeRegex : function(s) {
        return s.replace(Ext.util.Format.escapeRegexRe, "\\$1");
    },

    
/**
     * Escapes the passed string for ' and \
     * @param {String} string The string to escape
     * @return {String} The escaped string
     * @static
     */
    escape : function(string) {
        return string.replace(Ext.util.Format.escapeRe, "\\$1");
    },

    
/**
     * Utility function that allows you to easily switch a string between two alternating values.  The passed value
     * is compared to the current string, and if they are equal, the other value that was passed in is returned.  If
     * they are already different, the first value passed in is returned.  Note that this method returns the new value
     * but does not change the current string.
     * 

    // alternate sort directions
    sort = Ext.util.Format.toggle(sort, 'ASC', 'DESC');

    // instead of conditional logic:
    sort = (sort == 'ASC' ? 'DESC' : 'ASC');
       
     * @param {String} string The current string
     * @param {String} value The value to compare to the current string
     * @param {String} other The new value to use if the string already equals the first value passed in
     * @return {String} The new value
     */
    toggle : function(string, value, other) {
        return string == value ? other : value;
    },

    
/**
     * Trims whitespace from either end of a string, leaving spaces within the string intact.  Example:
     * 

    var s = '  foo bar  ';
    alert('-' + s + '-');         //alerts "- foo bar -"
    alert('-' + Ext.util.Format.trim(s) + '-');  //alerts "-foo bar-"
       
     * @param {String} string The string to escape
     * @return {String} The trimmed string
     */
    trim : function(string) {
        return string.replace(Ext.util.Format.trimRe, "");
    },

    
/**
     * Pads the left side of a string with a specified character.  This is especially useful
     * for normalizing number and date strings.  Example usage:
     *
     * 

var s = Ext.util.Format.leftPad('123', 5, '0');
// s now contains the string: '00123'
       
     * @param {String} string The original string
     * @param {Number} size The total length of the output string
     * @param {String} char (optional) The character with which to pad the original string (defaults to empty string " ")
     * @return {String} The padded string
     * @static
     */
    leftPad : function (val, size, ch) {
        var result = String(val);
        ch = ch || " ";
        while (result.length < size) {
            result = ch + result;
        }
        return result;
    },

    
/**
     * Allows you to define a tokenized string and pass an arbitrary number of arguments to replace the tokens.  Each
     * token must be unique, and must increment in the format {0}, {1}, etc.  Example usage:
     * 

var cls = 'my-class', text = 'Some text';
var s = Ext.util.Format.format('<div class="{0}">{1}</div>', cls, text);
// s now contains the string: '<div class="my-class">Some text</div>'
       
     * @param {String} string The tokenized string to be formatted
     * @param {String} value1 The value to replace token {0}
     * @param {String} value2 Etc...
     * @return {String} The formatted string
     * @static
     */
    format : function (format) {
        var args = Ext.toArray(arguments, 1);
        return format.replace(Ext.util.Format.formatRe, function(m, i) {
            return args[i];
        });
    },

    
/**
     * Convert certain characters (&, <, >, and ') to their HTML character equivalents for literal display in web pages.
     * @param {String} value The string to encode
     * @return {String} The encoded text
     */
    htmlEncode: function(value) {
        return ! value ? value: String(value).replace(/&/g, "&").replace(/>/g, ">").replace(//**
     * Convert certain characters (&, <, >, and ') from their HTML character equivalents.
     * @param {String} value The string to decode
     * @return {String} The decoded text
     */
    htmlDecode: function(value) {
        return ! value ? value: String(value).replace(/>/g, ">").replace(/</g, "<").replace(/"/g, '"').replace(/&/g, "&");
    },

    
/**
     * Parse a value into a formatted date using the specified format pattern.
     * @param {String/Date} value The value to format (Strings must conform to the format expected by the javascript 
     * Date object's parse() method)
     * @param {String} format (optional) Any valid date format string (defaults to 'm/d/Y')
     * @return {String} The formatted date string
     */
    date: function(v, format) {
        if (!v) {
            return "";
        }
        if (!Ext.isDate(v)) {
            v = new Date(Date.parse(v));
        }
        return v.dateFormat(format || Ext.util.Format.defaultDateFormat);
    }
};