/*!
 * Copyright Andrée Hansson, 2009
 * Licensed under the MIT license
 * http://www.opensource.org/licenses/mit-license.php
 *
 * Contact: E-mail:  peolanha _AT gmail _DOT com
 *          Twitter: peolanha
 *          Website: http://andreehansson.se/
 */
 
 (function ($) {
	var
		// Will contain the last events' string and element, used for comparison
		selObj = { str : "", el : undefined },

		// Cache selection range methods
		docSel = document.selection,
		winSel = window.getSelection && window.getSelection(),

		// Events to be bound for our handler
		bindEvents = ['mouseup', 'keyup'],

		// Helper to grab currently selected text
		getSelected = function (evt) {

			// If the called event originates from a inputbox/form element (in FF), use that
			// to get the selected text (FF doesn't trigger getSelection() on input
			// elements natively)
			var el = $(evt.originalEvent.target).is(':input') ?
				evt.originalEvent.target :
				undefined;
			
			//var str = el && +el.selectionEnd ? $(el).val().substring(el.selectionStart, el.selectionEnd) : (winSel || docSel.createRange().text || "").toString();
			
			if (el && +el.selectionEnd) {
				var str = $(el).val().substring(el.selectionStart, el.selectionEnd);
				var p1 = (el.selectionStart > 10) ? el.selectionStart-10 : 0;
				var p2 = (el.selectionEnd + 10 < el.length) ? el.selectionStart+10 : el.length;
				if (str!='') str = $(el).val().substring(p1, el.selectionStart)+'['+str+']'+$(el).val().substring(el.selectionEnd,p2);
			} else if (docSel) {
				var str = docSel.createRange().text.toString();
				range = docSel.createRange();
				if (range.text!='') {
					range.moveEnd('word',2);
					range.moveStart('word',-2);
					str = range.text.replace(str,'['+str+']');
				} else str = '';	
			} else {
				selection=winSel;
				if (selection && selection.getRangeAt) {
					range=selection.getRangeAt(0);
					prev=window.opera ? selection.getRangeAt(0) : document.createRange()
					prev.setStartBefore(range.startContainer)
					prev.setEnd(range.startContainer,range.startOffset);
					prev=prev.toString();
					if (prev.length>20) prev=prev.substring(Math.max(prev.length-20,0),prev.length).replace(/^\S{1,10}\s+/,"");
				
					next=window.opera?selection.getRangeAt(0) : document.createRange();
					next.setStart(range.endContainer,range.endOffset);
					next.setEndAfter(range.endContainer);
					next=next.toString();
					if (next.length>40) next=next.toString().substring(0,20).replace(/\s+\S{1,10}$/,"");
				} else if(window.document.selection.createRange){
					selection=window.document.selection.createRange();
					selection.expand("word");
					prev=window.document.selection.createRange();
					prev.moveStart("character",-20);
					prev.setEndPoint("EndToStart",selection);
					prev.expand("word");
					prev=prev.text;
					next=window.document.selection.createRange();
					next.moveEnd("character",20);
					next.setEndPoint("StartToEnd",selection);
					next.expand("word");
					next=next.text;
					selection=selection.text
				}
				if (selection!='') str = prev+'['+selection+']'+next; else str='';
			}
			return str;
		}

		// Helper to grab which common ancestor the text has
		getOrigin = function (input) {
			return docSel && docSel.createRange().parentElement()
				|| input
				|| winSel && winSel.getRangeAt(0).commonAncestorContainer
				|| document.body;
		},

		// Create our custom event namespace
		$me = $.event.special.textselect = {

			// Do stuff when it is bound
			setup: function () {
				var that = this;
	
				// Hook mouseup to fire our custom event
				$(bindEvents).each(function (i, o) {
					$(that).bind(o, $me.handler);
				});
			},
	
			// Do stuff when it is unbound
			teardown: function () {
				var that = this;
	
				$(bindEvents).each(function (i, o) {
					$(that).unbind(o, $me.handler);
				});
			},
	
			// Do stuff when the event is triggered
			handler: function (evt) {
	
				// Since we're not letting jQuery handle this object (due to our return
				// parameters, we "fix" the event object to be cross-browser compliant
				// manually
				evt = $.event.fix(evt);
	
				// Grab currently selected text and its common ancestor element
				var
					curText = getSelected(evt),
					conElement = $(evt.originalEvent.target).is(':input') ?
						getOrigin(evt.originalEvent.target) :
						getOrigin();

				if (conElement.nodeType === 3) conElement = conElement.parentNode;

				// If it differs from the old selected text, trigger event
				if (selObj.str !== curText || selObj.el !== conElement) {
	
					// Set currently selected text (and element) to the actual currently
					// selected text and element
					selObj = { str : curText, el : conElement };
	
					// Change event type to our custom event
					evt.type = 'textselect';
	
					// Fire the simulated event
					$.event.trigger(evt, [selObj.str, selObj.el]);
				}
			}
		};
})(jQuery);