/*
 * Copyright (c) 2007-2008 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: 1.1.3
 * Release: 2008-04-16
 */ 
(function($) {

    //Helper Function for Caret positioning
    $.fn.caret=function(begin,end){ 
        if(this.length==0) return;
        if (typeof begin == 'number') {
            end = (typeof end == 'number')?end:begin;  
            return this.each(function(){
                if(this.setSelectionRange){
                    this.focus();
                    this.setSelectionRange(begin,end);
                }else if (this.createTextRange){
                    var range = this.createTextRange();
                    range.collapse(true);
                    range.moveEnd('character', end);
                    range.moveStart('character', begin);
                    range.select();
                }
            });
        } else {
            if (this[0].setSelectionRange){
                begin = this[0].selectionStart;
                end = this[0].selectionEnd;
            }else if (document.selection && document.selection.createRange){
                var range = document.selection.createRange();           
                begin = 0 - range.duplicate().moveStart('character', -100000);
                end = begin + range.text.length;
            }
            return {begin:begin,end:end};
        }       
    };

    //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;
        }
    };
    
    $.fn.unmask=function(){
        return this.trigger("unmask");
    };
    
    //Main Method
    $.fn.mask = function(mask,settings) {   
        settings = $.extend({
            placeholder: "_",           
            completed: null
        }, settings);       
        
        //Build Regex for format validation
        var re = new RegExp("^"+    
        $.map( mask.split(""), function(c,i){                 
          return charMap[c]||((/[A-Za-z0-9]/.test(c)?"":"\\")+c);
        }).join('')+                
        "$");       

        return this.each(function(){        
            var input=$(this);
            var buffer=new Array(mask.length);
            var locked=new Array(mask.length);
            var valid=false;   
            var ignore=false;           //Variable for ignoring control keys
            var firstNonMaskPos=null; 
            
            //Build buffer layout from mask & determine the first non masked character          
            $.each( mask.split(""), function(i,c){              
                locked[i]=(charMap[c]==null);               
                buffer[i]=locked[i]?c:settings.placeholder;                                 
                if(!locked[i] && firstNonMaskPos==null)
                    firstNonMaskPos=i;
            });     
            
            function focusEvent(){                  
                checkVal();
                writeBuffer();
                setTimeout(function(){
                    $(input[0]).caret(valid?mask.length:firstNonMaskPos);                   
                },0);
            };
            
            function keydownEvent(e){               
                var pos=$(this).caret();
                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.                               
                                s=writeBuffer();
                                input.val(s.substring(0,pos.begin)+" "+s.substring(pos.begin));
                                $(this).caret(pos.begin+1);                             
                            }else{
                                writeBuffer();
                                $(this).caret(Math.max(firstNonMaskPos,pos.begin));                             
                            }                                   
                            return false;                               
                        }
                    }                       
                }else if(k==46){//delete
                    clearBuffer(pos.begin,pos.begin+1);
                    writeBuffer();
                    $(this).caret(Math.max(firstNonMaskPos,pos.begin));                 
                    return false;
                }else if (k==27){//escape
                    clearBuffer(0,mask.length);
                    writeBuffer();
                    $(this).caret(firstNonMaskPos);                 
                    return false;
                }                                   
            };
            
            function keypressEvent(e){                  
                if(ignore){
                    ignore=false;
                    //Fixes Mac FF bug on backspace
                    return (e.keyCode == 8)? false: null;
                }
                e=e||window.event;
                var k=e.charCode||e.keyCode||e.which;                       
                var pos=$(this).caret();
                                
                if(e.ctrlKey || e.altKey){//Ignore
                    return true;
                }else if ((k>=41 && k<=122) ||k==32 || k>186){//typeable characters
                    var p=seekNext(pos.begin-1);                    
                    if(p<mask.length){
                        if(new RegExp(charMap[mask.charAt(p)]).test(String.fromCharCode(k))){
                            buffer[p]=String.fromCharCode(k);                                   
                            writeBuffer();
                            var next=seekNext(p);
                            $(this).caret(next);
                            if(settings.completed && next == mask.length)
                                settings.completed.call(input);
                        }               
                    }
                }               
                return false;               
            };
            
            function clearBuffer(start,end){
                for(var i=start;i<end&&i<mask.length;i++){
                    if(!locked[i])
                        buffer[i]=settings.placeholder;
                }               
            };
            
            function writeBuffer(){             
                return input.val(buffer.join('')).val();                
            };
            
            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]){
                        buffer[i]=settings.placeholder;
                        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);
                    valid=false;
                }else
                    valid=true;
            };
            
            function seekNext(pos){             
                while(++pos<mask.length){                   
                    if(!locked[pos])
                        return pos;
                }
                return mask.length;
            };
            
            input.one("unmask",function(){
                input.unbind("focus",focusEvent);
                input.unbind("blur",checkVal);
                input.unbind("keydown",keydownEvent);
                input.unbind("keypress",keypressEvent);
                if ($.browser.msie) 
                    this.onpaste= null;                     
                else if ($.browser.mozilla)
                    this.removeEventListener('input',checkVal,false);
            });
            input.bind("focus",focusEvent);
            input.bind("blur",checkVal);
            input.bind("keydown",keydownEvent);
            input.bind("keypress",keypressEvent);
            //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);
                
            checkVal();//Perform initial check for existing values
        });
    };
})(jQuery);