/*! 
 * a-tools 1.5.2
 * 
 * Copyright (c) 2009 Andrey Kramarev(andrey.kramarev[at]ampparit.com), Ampparit Inc. (www.ampparit.com)
 * Licensed under the MIT license.
 * http://www.ampparit.fi/a-tools/license.txt
 *
 * Basic usage:
 
    <textarea></textarea>
    <input type="text" />

    // Get current selection
    var sel = $("textarea").getSelection()
    
    // Replace current selection
    $("input").replaceSelection("foo");

    // Count characters
    alert($("textarea").countCharacters());

    // Set max length without callback function
    $("textarea").setMaxLength(7);

    // Set max length with callback function which will be called when limit is exceeded
    $("textarea").setMaxLength(10, function() {
        alert("hello")
    });

    // Removing limit:
    $("textarea").setMaxLength(-1);
    
    // Insert text at current caret position
    $("#textarea").insertAtCaretPos("hello");
    
    // Set caret position (1 = beginning, -1 = end)
    $("#textArea").setCaretPos(10);
    
    // Set Selection
    $("#textArea").setSelection(10,15);

 */
var caretPositionAmp = new Array();
function init() {
    if(navigator.appName == "Microsoft Internet Explorer") {
        obj = document.getElementsByTagName('TEXTAREA');
        var input;
        var i = 0;
        for (var i = 0; i < obj.length; i++) {
            input = obj[i];
            caretPositionAmp[i] = input.value.length;
            input.onmouseup = function() { // for IE because it loses caret position when focus changed
                input = document.activeElement;
                for (var i = 0; i < obj.length; i++) {
                    if (obj[i] == input) {
                        break;
                    }
                }
                input.focus();
                var s = document.selection.createRange();
                var re = input.createTextRange();
                var rc = re.duplicate();
                re.moveToBookmark(s.getBookmark());
                rc.setEndPoint("EndToStart", re);
                caretPositionAmp[i] = rc.text.length;
            }
            input.onkeyup = function() {
                input = document.activeElement;
                for (var i = 0; i < obj.length; i++) {
                    if (obj[i] == input) {
                        break;
                    }
                }
                input.focus();
                var s = document.selection.createRange();
                var re = input.createTextRange();
                var rc = re.duplicate();
                re.moveToBookmark(s.getBookmark());
                rc.setEndPoint("EndToStart", re);
                caretPositionAmp[i] = rc.text.length;
            }
        }
    }
}

window.onload = init;

jQuery.fn.extend({
    getSelection: function() {  // function for getting selection, and position of the selected text
        var input = this.jquery ? this[0] : this;
        var start;
        var end;
        var part;
        var number = 0;
        input.onmousedown = function() { // for IE 
            if (document.selection && typeof(input.selectionStart) != "number") {
                document.selection.empty();
            } else {
                window.getSelection().removeAllRanges();
            }
        }
        if (document.selection) {
            // part for IE and Opera
            var s = document.selection.createRange();
            var minus = 0;
            var position = 0;
            var minusEnd = 0;
            var re;
            var rc;
            var obj = document.getElementsByTagName('TEXTAREA');
            var pos = 0;
            for (pos; pos < obj.length; pos++) {
                if (obj[pos] == input) {
                    break;
                }
            }
            if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
            }
            if (s.text) {
                part = s.text;
                // OPERA support
                if (typeof(input.selectionStart) == "number") {
                    start = input.selectionStart;
                    end = input.selectionEnd;
                    // return null if the selected text not from the needed area
                    if (start == end) {
                        return { start: start, end: end, text: s.text, length: end - start };
                    }
                } else {
                    // IE support
                    re = input.createTextRange();
                    rc = re.duplicate();
                    firstRe = re.text;
                    re.moveToBookmark(s.getBookmark());
                    secondRe = re.text;
                    rc.setEndPoint("EndToStart", re);
                    // return null if the selectyed text not from the needed area
                    if (firstRe == secondRe && firstRe != s.text || rc.text.length > firstRe.length) {
                        return { start: caretPositionAmp[pos], end: caretPositionAmp[pos], text: "", length: 0 };
                    }
                    start = rc.text.length; 
                    end = rc.text.length + s.text.length;
                }
                // remove all EOL to have the same start and end positons as in MOZILLA
                if (number > 0) {
                    for (var i = 0; i <= number; i++) {
                        var w = input.value.indexOf("\n", position);
                        if (w != -1 && w < start) {
                            position = w + 1;
                            minus++;
                            minusEnd = minus;
                        } else if (w != -1 && w >= start && w <= end) {
                            if (w == start + 1) {
                                minus--;
                                minusEnd--;
                                position = w + 1;
                                continue;
                            }
                            position = w + 1;
                            minusEnd++;
                        } else {
                            i = number;
                        }
                    }
                }
                if (s.text.indexOf("\n", 0) == 1) {
                    minusEnd = minusEnd + 2;
                }
                start = start - minus;
                end = end - minusEnd;
                
                return { start: start, end: end, text: s.text, length: end - start };
            }
            input.focus ();
            if (typeof(input.selectionStart) == "number") {
                start = input.selectionStart;
            } else {
                s = document.selection.createRange();
                re = input.createTextRange();
                rc = re.duplicate();
                re.moveToBookmark(s.getBookmark());
                rc.setEndPoint("EndToStart", re);
                start = rc.text.length;
            }
            if (number > 0) {
                for (var i = 0; i <= number; i++) {
                    var w = input.value.indexOf("\n", position);
                    if (w != -1 && w < start) {
                        position = w + 1;
                        minus++;
                    } else {
                        i = number;
                    }
                }
            }
            start = start - minus;
            if (start == 0 && typeof(input.selectionStart) != "number") {
                start = caretPositionAmp[pos];
                end = caretPositionAmp[pos];
            }
            return { start: start, end: start, text: s.text, length: 0 };
        } else if (typeof(input.selectionStart) == "number" ) {
            start = input.selectionStart;
            end = input.selectionEnd;
            part = input.value.substring(input.selectionStart, input.selectionEnd);
            return { start: start, end: end, text: part, length: end - start };
        } else { return { start: undefined, end: undefined, text: undefined, length: undefined }; }
    },

    // function for the replacement of the selected text
    replaceSelection: function(inputStr) {
        var input = this.jquery ? this[0] : this; 
        //part for IE and Opera
        var start;
        var end;
        var position = 0;
        var rc;
        var re;
        var number = 0;
        var minus = 0;
        var mozScrollFix = ( input.scrollTop == undefined ) ? 0 : input.scrollTop;
        var obj = document.getElementsByTagName('TEXTAREA');
        var pos = 0;
        for (pos; pos < obj.length; pos++) {
            if (obj[pos] == input) {
                break;
            }
        }
        if (document.selection && typeof(input.selectionStart) != "number") {
            var s = document.selection.createRange();
            
            // IE support
            if (typeof(input.selectionStart) != "number") { // return null if the selected text not from the needed area
                var firstRe;
                var secondRe;
                re = input.createTextRange();
                rc = re.duplicate();
                firstRe = re.text;
                re.moveToBookmark(s.getBookmark());
                secondRe = re.text;
                try {
                    rc.setEndPoint("EndToStart", re);
                }
                catch(err) {
                    return this;
                }
                if (firstRe == secondRe && firstRe != s.text || rc.text.length > firstRe.length) {
                    return this;
                }
            }
            if (s.text) {
                part = s.text;
                if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
                }
                // IE support
                start = rc.text.length; 
                // remove all EOL to have the same start and end positons as in MOZILLA
                if (number > 0) {
                    for (var i = 0; i <= number; i++) {
                        var w = input.value.indexOf("\n", position);
                        if (w != -1 && w < start) {
                            position = w + 1;
                            minus++;
                            
                        } else {
                            i = number;
                        }
                    }
                }
                s.text = inputStr;
                caretPositionAmp[pos] = rc.text.length + inputStr.length;
                re.move("character", caretPositionAmp[pos]);
                document.selection.empty();
                input.blur();
            }
            return this;
        } else if (typeof(input.selectionStart) == "number" && // MOZILLA support
                input.selectionStart != input.selectionEnd) {
            
            start = input.selectionStart;
            end = input.selectionEnd;
            input.value = input.value.substr(0, start) + inputStr + input.value.substr(end);
            position = start + inputStr.length;
            input.setSelectionRange(position, position); 
            input.scrollTop = mozScrollFix;
            return this;
        }
        return this;
    },

    //Set Selection in text
    setSelection: function(startPosition, endPosition) {
        startPosition = parseInt(startPosition);
        endPosition = parseInt(endPosition);
        
        var input = this.jquery ? this[0] : this; 
        input.focus ();
        if (typeof(input.selectionStart) != "number") {
            re = input.createTextRange();
            if (re.text.length < endPosition) {
                endPosition = re.text.length+1;
            }
        }
        if (endPosition < startPosition) {
            return this;
        }
        if (document.selection) { 
            var number = 0;
            var plus = 0;
            var position = 0;
            var plusEnd = 0;
            if (typeof(input.selectionStart) != "number") { // IE
                re.collapse(true); 
                re.moveEnd('character', endPosition); 
                re.moveStart('character', startPosition); 
                re.select(); 
                return this;
            } else if (typeof(input.selectionStart) == "number") {      // Opera
                if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
                }
                if (number > 0) {
                    for (var i = 0; i <= number; i++) {
                        var w = input.value.indexOf("\n", position);
                        if (w != -1 && w < startPosition) {
                            position = w + 1;
                            plus++;
                            plusEnd = plus;
                        } else if (w != -1 && w >= startPosition && w <= endPosition) {
                            if (w == startPosition + 1) {
                                plus--;
                                plusEnd--;
                                position = w + 1;
                                continue;
                            }
                            position = w + 1;
                            plusEnd++;
                        } else {
                            i = number;
                        }
                    }
                }
                startPosition = startPosition + plus;
                endPosition = endPosition + plusEnd;
                input.selectionStart = startPosition; 
                input.selectionEnd = endPosition;
                input.focus ();
                return this;
            } else {
                input.focus ();
                return this;
            }
        }
        else if (input.selectionStart || input.selectionStart == 0) {   // MOZILLA support
            input.focus ();
            window.getSelection().removeAllRanges();
            input.selectionStart = startPosition; 
            input.selectionEnd = endPosition; 
            input.focus ();
            return this;
        } 
    },

    // insert text at current caret position
    insertAtCaretPos: function(inputStr) {
        var input = this.jquery ? this[0] : this; 
        var start;
        var end;
        var position;
        var s;
        var re;
        var rc;
        var point;
        var minus = 0;
        var number = 0;
        var mozScrollFix = ( input.scrollTop == undefined ) ? 0 : input.scrollTop; 
        var obj = document.getElementsByTagName('TEXTAREA');
        var pos = 0;
        for (pos; pos < obj.length; pos++) {
            if (obj[pos] == input) {
                break;
            }
        }
        input.focus();
        if (document.selection && typeof(input.selectionStart) != "number") {
            if (input.value.match(/\n/g) != null) {
                number = input.value.match(/\n/g).length;// number of EOL simbols
            }
            point = parseInt(caretPositionAmp[pos]);
            if (number > 0) {
                for (var i = 0; i <= number; i++) {
                    var w = input.value.indexOf("\n", position);
                    if (w != -1 && w <= point) {
                        position = w + 1;
                        point = point - 1;
                        minus++;
                    } 
                }
            }
        }
        caretPositionAmp[pos] = parseInt(caretPositionAmp[pos]);

        // IE
        input.onkeyup = function() { // for IE because it loses caret position when focus changed
            if (document.selection && typeof(input.selectionStart) != "number") {
                input.focus();
                s = document.selection.createRange();
                re = input.createTextRange();
                rc = re.duplicate();
                re.moveToBookmark(s.getBookmark());
                rc.setEndPoint("EndToStart", re);
                caretPositionAmp[pos] = rc.text.length;
            }
            
        }

        input.onmouseup = function() { // for IE because it loses caret position when focus changed
            if (document.selection && typeof(input.selectionStart) != "number") {
                input.focus();
                s = document.selection.createRange();
                re = input.createTextRange();
                rc = re.duplicate();
                re.moveToBookmark(s.getBookmark());
                rc.setEndPoint("EndToStart", re);
                caretPositionAmp[pos] = rc.text.length;
            }
        }

        if (document.selection && typeof(input.selectionStart) != "number") {
            s = document.selection.createRange();
            if (s.text.length != 0) {
                return this;
            }
            re = input.createTextRange();
            textLength = re.text.length;
            rc = re.duplicate();
            re.moveToBookmark(s.getBookmark());
            rc.setEndPoint("EndToStart", re);
            start = rc.text.length; 
            if (caretPositionAmp[pos] > 0 && start ==0) {
                minus = caretPositionAmp[pos] - minus;
                re.move("character", minus);
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] += inputStr.length;
            } else if (!(caretPositionAmp[pos] >= 0) && textLength ==0) {
                s = document.selection.createRange();
                caretPositionAmp[pos] = inputStr.length + textLength;
            } else if (!(caretPositionAmp[pos] >= 0) && start ==0) {
                re.move("character", textLength);
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] = inputStr.length + textLength;
            } else if (!(caretPositionAmp[pos] >= 0) && start > 0) { 
                re.move("character", 0);
                document.selection.empty();
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] = start + inputStr.length;
            } else if (caretPositionAmp[pos] >= 0 && caretPositionAmp[pos] == textLength) { 
                if (textLength != 0) {
                    re.move("character", textLength);
                    re.select();
                } else {
                    re.move("character", 0);
                }
                s = document.selection.createRange();
                caretPositionAmp[pos] = inputStr.length + textLength;
            } else if (caretPositionAmp[pos] >= 0 && start != 0 && caretPositionAmp[pos] >= start) { 
                minus = caretPositionAmp[pos] - start;
                re.move("character", minus);
                document.selection.empty();
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] = caretPositionAmp[pos] + inputStr.length; 
            } else if (caretPositionAmp[pos] >= 0 && start != 0 && caretPositionAmp[pos] < start) { 
                re.move("character", 0);
                document.selection.empty();
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] = caretPositionAmp[pos] + inputStr.length; 
            } else { 
                document.selection.empty();
                re.select();
                s = document.selection.createRange();
                caretPositionAmp[pos] = caretPositionAmp[pos] + inputStr.length; 
            } 
            s.text = inputStr; 
            input.focus();

            return this;
        } else if (typeof(input.selectionStart) == "number" && // MOZILLA support
                input.selectionStart == input.selectionEnd) {
            position = input.selectionStart + inputStr.length;
            start = input.selectionStart;
            end = input.selectionEnd;
            input.value = input.value.substr(0, start) + inputStr + input.value.substr(end);
            input.setSelectionRange(position, position); 
            input.scrollTop = mozScrollFix; 
            return this;
        }
        return this;
    },

    // Set caret position
    setCaretPos: function(inputStr) {
        var input = this.jquery ? this[0] : this; 
        var s;
        var re;
        var position;
        var number = 0;
        var minus = 0;
        var w;
        var obj = document.getElementsByTagName('TEXTAREA');
        var pos = 0;
        for (pos; pos < obj.length; pos++) {
            if (obj[pos] == input) {
                break;
            }
        }
        input.focus();
        if (parseInt(inputStr) == 0) {
            return this;
        }
        //if (document.selection && typeof(input.selectionStart) == "number") {
        if (parseInt(inputStr) > 0) {
            inputStr = parseInt(inputStr) - 1;
            if (document.selection && typeof(input.selectionStart) == "number" && input.selectionStart == input.selectionEnd) {
                if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
                }
                if (number > 0) {
                    for (var i = 0; i <= number; i++) {
                        w = input.value.indexOf("\n", position);
                        if (w != -1 && w <= inputStr) {
                            position = w + 1;
                            inputStr = parseInt(inputStr) + 1;
                        } 
                    }
                }
            }
        } 
        else if (parseInt(inputStr) < 0) {
            inputStr = parseInt(inputStr) + 1;
            if (document.selection && typeof(input.selectionStart) != "number") {
                inputStr = input.value.length + parseInt(inputStr);
                if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
                }
                if (number > 0) {
                    for (var i = 0; i <= number; i++) {
                        w = input.value.indexOf("\n", position);
                        if (w != -1 && w <= inputStr) {
                            position = w + 1;
                            inputStr = parseInt(inputStr) - 1;
                            minus += 1;
                        } 
                    }
                    inputStr = inputStr + minus - number;
                }
            } else if (document.selection && typeof(input.selectionStart) == "number") {
                inputStr = input.value.length + parseInt(inputStr);
                if (input.value.match(/\n/g) != null) {
                    number = input.value.match(/\n/g).length;// number of EOL simbols
                }
                if (number > 0) {
                    inputStr = parseInt(inputStr) - number;
                    for (var i = 0; i <= number; i++) {
                        w = input.value.indexOf("\n", position);
                        if (w != -1 && w <= (inputStr)) {
                            position = w + 1;
                            inputStr = parseInt(inputStr) + 1;
                            minus += 1;
                        } 
                    }
                }
            } else { inputStr = input.value.length + parseInt(inputStr); }
        } else { return this; }
        // IE
        if (document.selection && typeof(input.selectionStart) != "number") {
            s = document.selection.createRange();
            if (s.text != 0) {
                return this;
            }
            re = input.createTextRange();
            re.collapse(true);
            re.moveEnd('character', inputStr);
            re.moveStart('character', inputStr);
            re.select();
            caretPositionAmp[pos] = inputStr;
            return this;
        } else if (typeof(input.selectionStart) == "number" && // MOZILLA support
                input.selectionStart == input.selectionEnd) {
            input.setSelectionRange(inputStr, inputStr); 
            return this;
        }
        return this;
    },

    countCharacters: function(str) {
        var input = this.jquery ? this[0] : this;
        if (input.value.match(/\r/g) != null) {
            return input.value.length - input.value.match(/\r/g).length;
        }
        return input.value.length;
    },

    setMaxLength: function(max, f) {
        this.each(function() {
            var input = this.jquery ? this[0] : this;
            var type = input.type;
            var isSelected;    
            var maxCharacters;
            // remove limit if input is a negative number
            if (parseInt(max) < 0) {
                max=100000000;
            }
            if (type == "text") {
                input.maxLength = max;
            }
            if (type == "textarea" || type == "text") {
                input.onkeypress = function(e) {
                    var spacesR = input.value.match(/\r/g);
                    maxCharacters = max;
                    if (spacesR != null) {
                        maxCharacters = parseInt(maxCharacters) + spacesR.length;
                    }
                    // get event
                    var key = e || event;
                    var keyCode = key.keyCode;
                    // check if any part of text is selected
                    if (document.selection) {
                        isSelected = document.selection.createRange().text.length > 0;
                    } else {
                        isSelected = input.selectionStart != input.selectionEnd;
                    }
                    if (input.value.length >= maxCharacters && (keyCode > 47 || keyCode == 32 ||
                            keyCode == 0 || keyCode == 13) && !key.ctrlKey && !key.altKey && !isSelected) {
                        input.value = input.value.substring(0,maxCharacters);
                        if (typeof(f) == "function") { f() } //callback function
                        return false;
                    }
                }
                input.onkeyup = function() { 
                    var spacesR = input.value.match(/\r/g);
                    var plus = 0;
                    var position = 0;
                    maxCharacters = max;
                    if (spacesR != null) {
                        for (var i = 0; i <= spacesR.length; i++) {
                            if (input.value.indexOf("\n", position) <= parseInt(max)) {
                                plus++;
                                position = input.value.indexOf("\n", position) + 1;
                            }
                        }
                        maxCharacters = parseInt(max) + plus;
                    } 
                    if (input.value.length > maxCharacters) {  
                        input.value = input.value.substring(0, maxCharacters); 
                        if (typeof(f) == "function") { f() }
                        return this;
                    }
                }
            } else { return this; }
        })
        return this;
    }
});