// ==UserScript==
// @include http://*.spreadsheets.google.com/*
// @include https://*.spreadsheets.google.com/*
// @include http://spreadsheets.google.com/*
// @include https://spreadsheets.google.com/*
// ==/UserScript==
(function(){
	if(navigator.userAgent.indexOf('Opera') != -1)
	{
		alert('Google Spreadsheets is blocking Opera. \nDo the following to fix it:\n\n' +
		      '1. Right click the page and choose Edit Site Preferences\n' +
		      '2. Choose the Network tab\n' +
		      '3. From Browser identification, choose Mask as Firefox\n' +
		      '4. Reload the page');
		return;
	}

	//Attempt to repair Spreadsheets' browser detection
	window.opera.addEventListener('AfterScript',function(ev){
		if(!ev.element.src || 
			ev.element.src.indexOf('trix_core.js') == -1)
		{
			return;
		}

		var func = getBrokenFunction(ev.element.text);
		if(func == null)
			return;

		window.opera.defineMagicFunction(func, function(){
			return true;
		});
	}, false);

	//Fix buggy cell editor style
	window.addEventListener('DOMContentLoaded', function(ev){
		var style = document.createElement('style');
		style.setAttribute('type', 'text/css');
		
		var css = '.editBoxWrapper { overflow: hidden !important; }';

		style.innerHTML = css;
		document.getElementsByTagName('head')[0].appendChild(style);
	}, false);

	/**
	 * Attempts to locate the broken function in the spreadsheets
	 * code that's breaking Opera support
	 * @param string code
	 * @return string|null function name or null on failure
	 */
	function getBrokenFunction(code)
	{
	
		var rex = new RegExp(
			'_getInstanceOfApp\([^)]+\)[^{]*\{' + //Match start of function
			'[^}]+' +     //Match function contents
			'\}',         //Match function end
			'm');
		var match = rex.exec(code);

		if(!match)
			return null;

		var funcStr = match[0];
		rex = /if\(([^(]+)/im; //Match if clause and a function name inside it

		match = rex.exec(funcStr);
		if(!match[1])
			return null;

		return match[1];
	}
})();