/**
* remy sharp / http://remysharp.com
* http://remysharp.com/2007/05/18/add-twitter-to-your-blog-step-by-step/
*
* @params
*   cssIdOfContainer: e.g. twitters
*   options:
*       {
*           id: {String} username,
*           count: {Int} 1-20, defaults to 1 - max limit 20
*           prefix: {String} '%name% said', defaults to blank
*           clearContents: {Boolean} true, removes contents of element specified in cssIdOfContainer, defaults to true
*           ignoreReplies: {Boolean}, skips over tweets starting with '@', defaults to false
*           template: {String} HTML template to use for LI element (see URL above for examples), defaults to predefined template
*           enableLinks: {Boolean} linkifies text, defaults to true,
*           timeout: {Int} How long before triggering onTimeout, defaults to 10 seconds if onTimeout is set
*           onTimeoutCancel: {Boolean} Completely cancel twitter call if timedout, defaults to false
*           onTimeout: {Function} Function to run when the timeout occurs. Function is bound to element specified with
*              cssIdOfContainer (i.e. 'this' keyword)
*
*      CURRENTLY DISABLED DUE TO CHANGE IN TWITTER API:
*           withFriends: {Boolean} includes friend's status
*
*       }
*
* @license MIT (MIT-LICENSE.txt)
* @version 1.11 - Added timeout functionality, and removed withFriends while Twitter works out API changes
* @date $Date: 2008-10-16 18:49:40 +0100 (Thu, 16 Oct 2008) $
*/

// to protect variables from resetting if included more than once
if (typeof renderTwitters != 'function') (function () {
	/** Private variables */
	var browser = (function() {
		var b = navigator.userAgent.toLowerCase();

		// Figure out what browser is being used
		return {
			safari: /webkit/.test(b),
			opera: /opera/.test(b),
			msie: /msie/.test(b) && !(/opera/).test(b),
			mozilla: /mozilla/.test(b) && !(/(compatible|webkit)/).test(b)
		};
	})();

	var guid = 0;
	var readyList = [];
	var isReady = false;

	/** Global functions */

	// to create a public function within our private scope, we attach the
	// the function to the window object
	window.renderTwitters = function (obj, options) {
		// private shortcuts
		function node(e) {
			return document.createElement(e);
		}

		function text(t) {
			return document.createTextNode(t);
		}

		var target = document.getElementById(options.twitterTarget);
		var data = null;
		var ul = node('ul'), li, statusSpan, timeSpan, i, max = obj.length > options.count ? options.count : obj.length;

		for (i = 0; i < max && obj[i]; i++) {
			data = getTwitterData(obj[i]);

			if (options.ignoreReplies && obj[i].text.substr(0, 1) == '@') {
				max++;
				continue; // skip
			}

			li = node('li');

			if (options.template) {
				li.innerHTML = options.template.replace(/%([a-z_\-\.]*)%/ig, function (m, l) {
					var r = data[l] + "" || "";
					if (l == 'text' && options.enableLinks) r = linkify(r);
					return r;
				});
			} else {
				statusSpan = node('span');
				statusSpan.className = 'twitterstatus';
				timeSpan = node('span');
				timeSpan.className = 'twittertime';
				statusSpan.innerHTML = obj[i].text; // forces the entities to be converted correctly

				if (options.enableLinks == true) {
					statusSpan.innerHTML = linkify(statusSpan.innerHTML);
				}

				timeSpan.innerHTML = relative_time(obj[i].created_at);

				if (options.prefix) {
					var s = node('span');
					s.className = 'twitterPrefix';
					s.innerHTML = options.prefix.replace(/%(.*?)%/g, function (m, l) {
						return obj[i].user[l];
					});
					li.appendChild(s);
					li.appendChild(text(' ')); // spacer :-(
				}

				li.appendChild(statusSpan);
				li.appendChild(text(' '));
				li.appendChild(timeSpan);
			}

			ul.appendChild(li);
		}

		if (options.clearContents) {
			while (target.firstChild) {
				target.removeChild(target.firstChild);
			}
		}

		target.appendChild(ul);
	};

	window.getTwitters = function (target, id, count, options) {
		guid++;


		if (typeof id == 'object') {
			options = id;
			id = options.id;
			count = options.count;
		}

		// defaulting options
		if (!count) count = 1;

		if (options) {
			options.count = count;
		} else {
			options = {};
		}

		if (!options.timeout && typeof options.onTimeout == 'function') {
			options.timeout = 10;
		}

		if (typeof options.clearContents == 'undefined') {
			options.clearContents = true;
		}

		// Hack to disable withFriends, twitter changed their API so this requires auth
		// http://getsatisfaction.com/twitter/topics/friends_timeline_api_call_suddenly_requires_auth
		if (options.withFriends) options.withFriends = false;

		// need to make these global since we can't pass in to the twitter callback
		options['twitterTarget'] = target;

		// default enable links
		if (typeof options.enableLinks == 'undefined') options.enableLinks = true;

		// this looks scary, but it actually allows us to have more than one twitter
		// status on the page, which in the case of my example blog - I do!
		window['twitterCallback' + guid] = function (obj) {
			if (options.timeout) {
				clearTimeout(window['twittertimeout' + guid]);
			}
			renderTwitters(obj, options);
		};

		// check out the mad currying!
		ready((function(options, guid) {
			return function () {
				// if the element isn't on the DOM, don't bother
				if (!document.getElementById(options.twitterTarget)) {
					return;
				}

				var url = 'http://www.twitter.com/statuses/' + (options.withFriends ? 'friends_timeline' : 'user_timeline') + '/' + id + '.json?callback=twitterCallback' + guid + '&count=20';

				if (options.timeout) {
					window['twittertimeout' + guid] = setTimeout(function () {
						// cancel callback
						if (options.onTimeoutCancel) window['twitterCallback' + guid] = function () {};
						options.onTimeout.call(document.getElementById(options.twitterTarget));
					}, options.timeout * 1000);
				}

				var script = document.createElement('script');
				script.setAttribute('src', url);
				document.getElementsByTagName('head')[0].appendChild(script);
			};
		})(options, guid));
	};

	// GO!
	DOMReady();


	/** Private functions */

	function getTwitterData(orig) {
		var data = orig, i;
		for (i in orig.user) {
			data['user_' + i] = orig.user[i];
		}

		data.time = relative_time(orig.created_at);

		return data;
	}

	function ready(callback) {
		if (!isReady) {
			readyList.push(callback);
		} else {
			callback.call();
		}
	}

	function fireReady() {
		isReady = true;
		var fn;
		while (fn = readyList.shift()) {
			fn.call();
		}
	}

	// ready and browser adapted from John Resig's jQuery library (http://jquery.com)
	function DOMReady() {
		if ( browser.mozilla || browser.opera ) {
			document.addEventListener( "DOMContentLoaded", fireReady, false );
		} else if ( browser.msie ) {
			// If IE is used, use the excellent hack by Matthias Miller
			// http://www.outofhanwell.com/blog/index.php?title=the_window_onload_problem_revisited

			// Only works if you document.write() it
			document.write("<scr" + "ipt id=__ie_init defer=true src=//:><\/script>");

			// Use the defer script hack
			var script = document.getElementById("__ie_init");

			// script does not exist if jQuery is loaded dynamically
			if (script) {
				script.onreadystatechange = function() {
					if ( this.readyState != "complete" ) return;
					this.parentNode.removeChild( this );
					fireReady.call();
				};
			}

			// Clear from memory
			script = null;

			// If Safari  is used
		} else if ( browser.safari ) {
			// Continually check to see if the document.readyState is valid
			var safariTimer = setInterval(function () {
				// loaded and complete are both valid states
				if ( document.readyState == "loaded" ||
				document.readyState == "complete" ) {

					// If either one are found, remove the timer
					clearInterval( safariTimer );
					safariTimer = null;
					// and execute any waiting functions
					fireReady.call();
				}
			}, 10);
		}
	}

	function relative_time(time_value) {
		var values = time_value.split(" ");
		time_value = values[1] + " " + values[2] + ", " + values[5] + " " + values[3];
		var parsed_date = Date.parse(time_value);
		var relative_to = (arguments.length > 1) ? arguments[1] : new Date();
		var delta = parseInt((relative_to.getTime() - parsed_date) / 1000);
		delta = delta + (relative_to.getTimezoneOffset() * 60);

		var r = '';
		if (delta < 60) {
			r = 'less than a minute ago';
		} else if(delta < 120) {
			r = 'about a minute ago';
		} else if(delta < (45*60)) {
			r = (parseInt(delta / 60)).toString() + ' minutes ago';
		} else if(delta < (2*90*60)) { // 2* because sometimes read 1 hours ago
			r = 'about an hour ago';
		} else if(delta < (24*60*60)) {
			r = 'about ' + (parseInt(delta / 3600)).toString() + ' hours ago';
		} else if(delta < (48*60*60)) {
			r = '1 day ago';
		} else {
			r = (parseInt(delta / 86400)).toString() + ' days ago';
		}

		return r;
	}

	function linkify(s) {
		return s.replace(/[A-Za-z]+:\/\/[A-Za-z0-9-_]+\.[A-Za-z0-9-_:%&\?\/.=]+/g, function(m) {
			return m.link(m);
		}).replace(/@[\S]+/g, function(m) {
			return '<a target="_blank" href="http://www.twitter.com/' + m.substr(1) + '">' + m + '</a>';
		});
	}
})();