/*
 * jQuery Textarea Characters Counter Plugin v 2.0
 * Examples and documentation at: http://roy-jin.appspot.com/jsp/textareaCounter.jsp
 * Copyright (c) 2010 Roy Jin
 * Version: 2.0 (11-JUN-2010)
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 * Requires: jQuery v1.4.2 or later
 */
(function($){  
    $.fn.textareaCount = function(options, fn) {   
        var defaults = {  
            maxCharacterSize: -1,
            truncate: true,
            countCR: false,  
            originalStyle: 'originalTextareaInfo',
            warningStyle: 'warningTextareaInfo',  
            warningNumber: 20,
            displayFormat: '#input characters | #words words'
        };  
        var options = $.extend(defaults, options);

        /* Wrapping all passed elements */
        return this.each(function() {
            var container = $(this);
            
            $("<div class='charleft'>&nbsp;</div>").insertAfter(container);
            
            //create charleft css
            var charLeftCss = {
                'width' : container.width()
            };
            
            var charLeftInfo = getNextCharLeftInformation(container);
            charLeftInfo.addClass(options.originalStyle);
            charLeftInfo.css(charLeftCss);
            
            var numInput = 0;
            var maxCharacters = options.maxCharacterSize;
            var numLeft = 0;
            var numWords = 0;
            var isFull = false;
            var isNotFull = true;

            container.bind('keyup', function(event){limitTextAreaByCharacterCount();})
                     .bind('mouseover', function(event){setTimeout(function(){limitTextAreaByCharacterCount();}, 10);})
                     .bind('paste', function(event){setTimeout(function(){limitTextAreaByCharacterCount();}, 10);});
            
            
            function limitTextAreaByCharacterCount(){
                charLeftInfo.html(countByCharacters());
                //function call back
                if(typeof fn != 'undefined'){
                    fn.call(this, getInfo());
                }
                return true;
            }
            
            function countByCharacters(){
                var content = container.val();
                var contentLength = content.length;
                
                //Start Cut
                if(options.maxCharacterSize > 0){
                    //If copied content is already more than maxCharacterSize, chop it to maxCharacterSize.
                    if(options.truncate && contentLength >= options.maxCharacterSize) {
                        content = content.substring(0, options.maxCharacterSize);               
                    }
                    
                    var newlineCount = getNewlineCount(content);
                    
                    // newlineCount new line character. For windows, it occupies 2 characters
                    var systemmaxCharacterSize = options.maxCharacterSize - newlineCount;
                    if (!isWin()){
                         systemmaxCharacterSize = options.maxCharacterSize
                    }
                    if(options.truncate && contentLength > systemmaxCharacterSize){
                        //avoid scroll bar moving
                        var originalScrollTopPosition = this.scrollTop;
                        container.val(content.substring(0, systemmaxCharacterSize));
                        this.scrollTop = originalScrollTopPosition;
                    }
                    charLeftInfo.removeClass(options.warningStyle);
                    if(systemmaxCharacterSize - contentLength <= options.warningNumber){
                        charLeftInfo.addClass(options.warningStyle);
                        if(!isFull) {
                            container.trigger('isFull');
                            isFull = true;
                            isNotFull = false;
                        }
                    } else {
                        if(!isNotFull) {
                            container.trigger('isNotFull');
                            isNotFull = true;
                            isFull = false;
                        }
                    }
                    
                    numInput = container.val().length + newlineCount;
                    if(!isWin()){
                        numInput = container.val().length;
                    }
                
                    numWords = countWord(getCleanedWordString(container.val()));
                    
                    numLeft = maxCharacters - numInput;
                } else {
                    //normal count, no cut
                    var newlineCount = getNewlineCount(content);
                    numInput = container.val().length + newlineCount;
                    if(!isWin()){
                        numInput = container.val().length;
                    }
                    numWords = countWord(getCleanedWordString(container.val()));
                }
                
                return formatDisplayInfo();
            }
            
            function formatDisplayInfo(){
                var format = options.displayFormat;
                format = format.replace('#input', numInput);
                format = format.replace('#words', numWords);
                //When maxCharacters <= 0, #max, #left cannot be substituted.
                if(maxCharacters > 0){
                    format = format.replace('#max', maxCharacters);
                    format = format.replace('#left', numLeft);
                }
                return format;
            }
            
            function getInfo(){
                var info = {
                    input: numInput,
                    max: maxCharacters,
                    left: numLeft,
                    words: numWords
                };
                return info;
            }
            
            function getNextCharLeftInformation(container){
                    return container.next('.charleft');
            }
            
            function isWin(){
                var strOS = navigator.appVersion;
                if (strOS.toLowerCase().indexOf('win') != -1){
                    return true;
                }
                return false;
            }
            
            function getNewlineCount(content){
                var newlineCount = 0;
                if (options.countCR) {
                    for(var i=0; i<content.length;i++){
                        if(content.charAt(i) == '\n'){
                            newlineCount++;
                        }
                    }
                }
                return newlineCount;
            }
            
            function getCleanedWordString(content){
                var fullStr = content + " ";
                var initial_whitespace_rExp = /^[^A-Za-z0-9]+/gi;
                var left_trimmedStr = fullStr.replace(initial_whitespace_rExp, "");
                var non_alphanumerics_rExp = rExp = /[^A-Za-z0-9]+/gi;
                var cleanedStr = left_trimmedStr.replace(non_alphanumerics_rExp, " ");
                var splitString = cleanedStr.split(" ");
                return splitString;
            }
            
            function countWord(cleanedWordString){
                var word_count = cleanedWordString.length-1;
                return word_count;
            }
        });
    };  
})(jQuery);