/**
 * textSelect is a jQuery Plug-in enables easy manipulation of text using the browsers native text selection.
 * 
 * It was created to bridge the gap between the DOM Range and Selection objects that are missing in Internet Explorer up until version 9.
 */
(function ($) {

    var internal = {
        clear : function () {
            if (window.getSelection) { // all browsers, except IE before version 9
                var selection = window.getSelection();
                selection.removeAllRanges();
            } else if (document.selection.createRange) { // Internet Explorer
                document.selection.empty();
            }
        },
        getTextNode : function (element) {
            var domObj = $(element).first().get(0);

            if (window.getSelection && domObj.childNodes) {
                var nodes = domObj.childNodes;
                for ( var i = 0; i < nodes.length; i++) {
                    var node = nodes[i];
                    if (node.nodeType === 3) {
                        return node;
                    }
                }
            } else if (document.selection) {
                return domObj;
            }
            return false;
        },
        getElement: function (element){
            return $(element).first().get(0);
        }
    };

    var methods = {
        getRange : function () {

            var rangeRtn = {
                start : 0,
                startElement : null,
                end : 0,
                endElement : null
            };

            if (window.getSelection) {
                // All browsers, except IE before version 9
                var selection = window.getSelection();
                var rangeObj = selection.getRangeAt(0);

                rangeRtn.start = rangeObj.startOffset;
                rangeRtn.startElement = rangeObj.startContainer;
                rangeRtn.end = rangeObj.endOffset;
                rangeRtn.endElement = rangeObj.endContainer;

            } else if (document.selection) {
                // Internet Explorer before version 9
                var rangeRtnObj = document.selection.createRange();
                var startRange = rangeRtnObj.duplicate();
                var endRange = rangeRtnObj.duplicate();

                startRange.collapse(true); // Make the rangeRtn point to just the beginning
                endRange.collapse(false);// Make the rangeRtn point to just the end

                rangeRtn.startElement = startRange.parentElement(); // There is the element where the selection starts
                rangeRtn.endElement = endRange.parentElement(); // There is the element where the selection ends

                // Create a rangeRtn encapsulating the element where the start point sits
                var startElPos = rangeRtnObj.duplicate();
                startElPos.moveToElementText(startRange.parentElement());
                // Set the end point so that the rangeRtn starts from the first element and ends where it the selection starts
                startElPos.setEndPoint('EndToStart', startRange);

                // Get the offset from the first element
                rangeRtn.start = startElPos.text.length;

                // Create a rangeRtn encapsulating the element where the end point sits
                var endElPos = rangeRtnObj.duplicate();
                endElPos.moveToElementText(endRange.parentElement());
                // Set the end point so that the rangeRtn starts from the last element and ends where it the selection ends
                endElPos.setEndPoint('EndToStart', endRange);

                // Get the offset from the end element
                rangeRtn.end = endElPos.text.length;
            }

            return rangeRtn;

        },
        setRange : function (range) {

            internal.clear();

            if (typeof range !== 'object') {
                return;
            }

            var startNode = false;
            var endNode = false;



            if (window.getSelection) { // all browsers, except IE before version 9

                var selection = window.getSelection();
                var rangeObj = document.createRange();
                
                if (range.startElement !== undefined) {
                    startNode = internal.getTextNode(range.startElement);
                }

                if (range.endElement !== undefined) {
                    endNode = internal.getTextNode(range.endElement);
                }

                if (range.start !== undefined && startNode) {

                    rangeObj.setStart(startNode, range.start);
                }

                if (range.end !== undefined && endNode) {
                    rangeObj.setEnd(endNode, range.end);
                }

                selection.addRange(rangeObj);

            } else if (document.selection) { // Internet Explorer

                var rangeObj = document.body.createTextRange();
                
                if (range.startElement !== undefined) {
                    startNode = internal.getElement(range.startElement);
                }

                if (range.endElement !== undefined) {
                    endNode = internal.getElement(range.endElement);
                }


                if (range.start && startNode) {
                    var startRange = rangeObj.duplicate();
                    startRange.moveToElementText(startNode);
                    startRange.move('character', range.start);

                    rangeObj.setEndPoint('StartToStart', startRange);
                }

                if (range.end && endNode) {
                    var endRange = rangeObj.duplicate();
                    endRange.moveToElementText(endNode);
                    endRange.move('character', range.end);

                    rangeObj.setEndPoint('EndToEnd', endRange);
                }
                
                rangeObj.select();
            }
            return this;
        },
        select : function () {

            internal.clear(); // required for IE9 it won't select the whole element otherwise

            for ( var i = 0; i < this.length; i++) {
                var element = this[i];

                if (window.getSelection) {
                    // All browsers, except IE before version 9
                    var selection = window.getSelection();
                    var textNode = element.firstChild; // get the text node

                    if (textNode && textNode.data.length > 1) {
                        var rangeObj = document.createRange();
                        rangeObj.selectNode(element);
                        selection.addRange(rangeObj);
                    }
                } else {
                    // Internet Explorer before version 9
                    var rangeObj = document.body.createTextRange();
                    rangeObj.moveToElementText(element);
                    rangeObj.select();
                }
            }
            return this;
        },
        clear : function () {
            internal.clear();
            return this;
        },
        remove : function () {

            if (window.getSelection) { // all browsers, except IE before version 9
                var selection = window.getSelection();
                try {
                    selection.deleteFromDocument();
                } catch (e) {
                    // TODO: When select is empty or it fails to delete
                }
                /*
                 * The deleteFromDocument does not work in Opera. Work around this bug.
                 */
                if (!selection.isCollapsed) {
                    var selRange = selection.getRangeAt(0);
                    selRange.deleteContents();
                }

                /*
                 * The deleteFromDocument works in IE, but a part of the new content becomes selected prevent the selection
                 */
                if (selection.anchorNode) {
                    selection.collapse(selection.anchorNode, selection.anchorOffset);
                }
            } else if (document.selection) { // Internet Explorer
                document.selection.clear();

            }
            return this;
        },
        toString : function () {
            if (window.getSelection) { // all browsers, except IE before version 9
                var selRange = window.getSelection();
                return selRange.toString();
            } else if (document.selection) { // Internet Explorer
                var textRange = document.selection.createRange();
                return textRange.text;
            }

        }
    };

    $.textSelect = $.fn.textSelect = function (method) {
        // Method calling logic
        if (methods[method]) {
            return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
        } else {
            return methods['toString'].apply(this, Array.prototype.slice.call(arguments, 1));
        }
    };

})(jQuery);