/**
 * 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 OR
 *           search: {String} URL-encoded search-string
 *           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)
 *           textFilter: {RegEx} regex to match text in tweet that should be removed (e.g. a hashtag) 
 *           linkTarget: {String} if you don't want to open links in the same window 
 *           tweetFilter: {String} ids of specific tweets you don't want to see (e.g. deleted tweets that still show up via search)
 *              comma separated
 *           showTweetsMatching: {RegEx} show only tweets matching RegEx
 *
 *      CURRENTLY DISABLED DUE TO CHANGE IN TWITTER API:
 *           withFriends: {Boolean} includes friend's status
 *
 *       }
 *
 * @license MIT (MIT-LICENSE.txt)
 * @version 1.12.2 - Fixed Safari 4 returning blank by using simple cache busting
 * @date $Date: 2009-03-09 09:46:25 +0000 (Mon, 09 Mar 2009) $
 */

// 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);
        }

        if (options.search) obj = obj.results;

        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], (options.search ? "search" : "timeline"));

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

            if (options.tweetFilter)
            {
                // we could split the string and write a array.contains-method, but I just don't feel like it :)
                var pattern = '(^|,)\\s*' + obj[i].id + '\\s*(,|$)';
                var re = new RegExp(pattern);
                if (re.test(options.tweetFilter))
                {
                    max++;
                    continue; // skip
                }
            }

            if (options.showTweetsMatching)
            {
                if (!options.showTweetsMatching.test(obj[i].text))
                {
                    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, options.linkTarget);
                    if (options.textFilter) r = r.replace(options.textFilter, '')
                    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, (options.search ? "search" : "timeline"));

                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 = '';
                if (options.search)
                {
                    url = 'http://search.twitter.com/search.json?q=' + options.search + '&callback=twitterCallback' + guid + '&count=20&cb=' + Math.random();
                }
                else
                {
                    url = 'http://www.twitter.com/statuses/' + (options.withFriends ? 'friends_timeline' : 'user_timeline') + '/' + id + '.json?callback=twitterCallback' + guid + '&count=20&cb=' + Math.random();
                }

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

        data.time = relative_time(orig.created_at, time_format);

        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, time_format)
    {
        var values = time_value.split(" "),
            parsed_date = Date.parse((time_format == 'search' ? values[2] + " " + values[1] + ", " + values[3] + " " + values[4] :
                values[1] + " " + values[2] + ", " + values[5] + " " + values[3])),
            date = new Date(parsed_date),
            relative_to = (arguments.length > 2) ? arguments[2] : new Date(),
            delta = parseInt((relative_to.getTime() - parsed_date) / 1000),
            r = '';

        function formatTime(date)
        {
            var hour = date.getHours(),
                min = date.getMinutes() + "",
                ampm = 'AM';

            if (hour == 0)
            {
                hour = 12;
            } else if (hour > 12)
            {
                hour -= 12;
                ampm = 'PM';
            }

            if (min.length == 1)
            {
                min = '0' + min;
            }

            return hour + ':' + min + ' ' + ampm;
        }

        function formatDate(date)
        {
            var ds = date.toDateString().split(/ /),
                mon = ds[2],
                day = ds[1],
                dayi = parseInt(day),
                year = date.getFullYear(),
                thisyear = (new Date()).getFullYear(),
                th = 'th';

            // anti-'th' - but don't do the 11th, 12th or 13th
            if ((dayi % 10) == 1 && day.substr(0, 1) != '1')
            {
                th = 'st';
            } else if ((dayi % 10) == 2 && day.substr(0, 1) != '1')
            {
                th = 'nd';
            } else if ((dayi % 10) == 3 && day.substr(0, 1) != '1')
            {
                th = 'rd';
            }

            if (day.substr(0, 1) == '0')
            {
                day = day.substr(1);
            }

            return mon + ' ' + day + th + (thisyear != year ? ', ' + year : '');
        }

        delta = delta + (relative_to.getTimezoneOffset() * 60);

        if (delta < 5)
        {
            r = 'less than 5 seconds ago';
        } else if (delta < 30)
        {
            r = 'half a minute ago';
        } else if (delta < 60)
        {
            r = 'less than a minute ago';
        } else if (delta < 120)
        {
            r = '1 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 1 hour ago';
        } else if (delta < (24 * 60 * 60))
        {
            r = 'about ' + (parseInt(delta / 3600)).toString() + ' hours ago';
        } else
        {
            if (delta < (48 * 60 * 60))
            {
                r = formatTime(date) + ' yesterday';
            } else
            {
                r = formatTime(date) + ' ' + formatDate(date);
                // r = (parseInt(delta / 86400)).toString() + ' days ago';
            }
        }

        return r;
    }

    function linkify(s, target)
    {
        var entities = {
            '"': '&quot;',
            '&': '&amp;',
            '<': '&lt;',
            '>': '&gt;'
        };

        return s.replace(/[A-Za-z]+:\/\/[A-Za-z0-9-_]+\.[A-Za-z0-9-_:%&\?\/.=]+/g, function(m)
        {
            return (target ? '<a target="' + target + '" href="' + m + '">' + m + '</a>' : m.link(m));
        }).replace(/(^|[^\w])(@[\d\w\-]+)/g, function(d, m1, m2)
        {
            return m1 + '@<a href="http://twitter.com/' + m2.substr(1) + '">' + m2.substr(1) + '</a>';
        }).replace(/"&<>/, function(m)
        {
            return entities[m];
        });
    }
})();