/*
 * Copyright (c) 2007 Josh Bush (digitalbush.com)
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:

 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE. 
 */
 
/*
 * Version: RC3
 * Release: 2007-07-01
 */ 

(function($) {
        //Helper Functions for Caret positioning
        getCaretPosition=function(ctl){
                var res = {begin: 0, end: 0 };
                if (ctl.setSelectionRange){
                        res.begin = ctl.selectionStart;
                        res.end = ctl.selectionEnd;
                }else if (document.selection && document.selection.createRange){
                        var range = document.selection.createRange();                   
                        res.begin = 0 - range.duplicate().moveStart('character', -100000);
                        res.end = res.begin + range.text.length;
                }
                return res;
        }

        setCaretPosition=function(ctl, pos){
                if(ctl.setSelectionRange){
                        ctl.focus();
                        ctl.setSelectionRange(pos,pos);
                }else if (ctl.createTextRange){
                        var range = ctl.createTextRange();
                        range.collapse(true);
                        range.moveEnd('character', pos);
                        range.moveStart('character', pos);
                        range.select();
                }
        }
        
        //Predefined character definitions
        var charMap={
                '9':"[0-9]",
                'a':"[A-Za-z]",
                '*':"[A-Za-z0-9]"
        };
        
        //Helper method to inject character definitions
        $.mask={
                addPlaceholder : function(c,r){
                        charMap[c]=r;
                }
        };
        
        //Main Method
        $.fn.mask = function(mask,settings) {   
                settings = $.extend({
                        placeholder: "_",
                        completed: null
                }, settings);
                        
                //Build Regex for format validation
                var reString="^";       
                for(var i=0;i<mask.length;i++)
                        reString+=(charMap[mask.charAt(i)] || ("\\"+mask.charAt(i)));                                   
                reString+="$";
                var re = new RegExp(reString);

                return this.each(function(){            
                        var input=$(this);
                        var buffer=new Array(mask.length);
                        var locked=new Array(mask.length);              

                        //Build buffer layout from mask
                        for(var i=0;i<mask.length;i++){
                                locked[i]=charMap[mask.charAt(i)]==null;
                                buffer[i]=locked[i]?mask.charAt(i):settings.placeholder;                                        
                        }
                        
                        /*Event Bindings*/
                        input.focus(function(){                                 
                                checkVal();
                                writeBuffer();
                                setCaretPosition(this,0);               
                        });

                        input.blur(checkVal);
                        
                        //Paste events for IE and Mozilla thanks to Kristinn Sigmundsson
                        if ($.browser.msie) 
                                this.onpaste= function(){setTimeout(checkVal,0);};                     
                        else if ($.browser.mozilla)
                                this.addEventListener('input',checkVal,false);
                        
                        var ignore=false;  //Variable for ignoring control keys
                        
                        input.keydown(function(e){
                                var pos=getCaretPosition(this);                                                                                                 
                                var k = e.keyCode;
                                ignore=(k < 16 || (k > 16 && k < 32 ) || (k > 32 && k < 41));
                                
                                //delete selection before proceeding
                                if((pos.begin-pos.end)!=0 && (!ignore || k==8 || k==46)){
                                        clearBuffer(pos.begin,pos.end);
                                }       
                                //backspace and delete get special treatment
                                if(k==8){//backspace                                    
                                        while(pos.begin-->=0){
                                                if(!locked[pos.begin]){                                                         
                                                        buffer[pos.begin]=settings.placeholder;
                                                        if($.browser.opera){
                                                                //Opera won't let you cancel the backspace, so we'll let it backspace over a dummy character.                                                           
                                                                writeBuffer(pos.begin);
                                                                setCaretPosition(this,pos.begin+1);
                                                        }else{
                                                                writeBuffer();
                                                                setCaretPosition(this,pos.begin);
                                                        }                                                                       
                                                        return false;                                                           
                                                }
                                        }                                               
                                }else if(k==46){//delete
                                        clearBuffer(pos.begin,pos.begin+1);
                                        writeBuffer();
                                        setCaretPosition(this,pos.begin);
                                        return false;
                                }else if (k==27){
                                        clearBuffer(0,mask.length);
                                        writeBuffer();
                                        setCaretPosition(this,0);
                                        return false;
                                }
                                                                        
                        });

                        input.keypress(function(e){                                     
                                if(ignore){
                                        ignore=false;
                                        return;
                                }
                                e=e||window.event;
                                var k=e.charCode||e.keyCode||e.which;

                                var pos=getCaretPosition(this);                                 
                                var caretPos=pos.begin; 
                                
                                if(e.ctrlKey || e.altKey){//Ignore
                                        return true;
                                }else if ((k>=41 && k<=122) ||k==32 || k>186){//typeable characters
                                        while(pos.begin<mask.length){   
                                                var reString=charMap[mask.charAt(pos.begin)];
                                                var match;
                                                if(reString){
                                                        var reChar=new RegExp(reString);
                                                        match=String.fromCharCode(k).match(reChar);
                                                }else{//we're on a mask char, go forward and try again
                                                        pos.begin+=1;
                                                        pos.end=pos.begin;
                                                        caretPos+=1;
                                                        continue;
                                                }

                                                if(match)
                                                        buffer[pos.begin]=String.fromCharCode(k);
                                                else
                                                        return false;//reject char

                                                while(++caretPos<mask.length){//seek forward to next typable position
                                                        if(!locked[caretPos])                                                   
                                                                break;                                                  
                                                }
                                                break;
                                        }
                                }else
                                        return false;                                                           

                                writeBuffer();
                                if(settings.completed && caretPos>=buffer.length)
                                        settings.completed.call(input);
                                else
                                        setCaretPosition(this,caretPos);
                                
                                return false;                           
                        });

                        /*Helper Methods*/
                        function clearBuffer(start,end){
                                for(var i=start;i<end;i++){
                                        if(!locked[i])
                                                buffer[i]=settings.placeholder;
                                }                               
                        }
                        
                        function writeBuffer(pos){
                                var s="";
                                for(var i=0;i<mask.length;i++){
                                        s+=buffer[i];
                                        if(i==pos)
                                                s+=settings.placeholder;
                                }
                                input.val(s);
                                return s;
                        }
                        
                        function checkVal(){    
                                //try to place charcters where they belong
                                var test=input.val();
                                var pos=0;
                                for(var i=0;i<mask.length;i++){
                                        if(!locked[i]){
                                                while(pos++<test.length){
                                                        //Regex Test each char here.
                                                        var reChar=new RegExp(charMap[mask.charAt(i)]);
                                                        if(test.charAt(pos-1).match(reChar)){
                                                                buffer[i]=test.charAt(pos-1);
                                                                break;
                                                        }                                                                       
                                                }
                                        }
                                }
                                var s=writeBuffer();
                                if(!s.match(re)){                                                       
                                        input.val("");  
                                        clearBuffer(0,mask.length);
                                }                                       
                        }                               
                });
        };
})(jQuery);