(function () {
    var apps = {};
    var themesLoaded = {};
    var widgetsets = {};


    var log;
    if (typeof console === "undefined" || !window.location.search.match(/[&?]debug(&|$)/)) {
        //If no console.log present, just use a no-op
        log = function () {
        };
    } else if (typeof console.log === "function") {
        //If it's a function, use it with apply
        log = function () {
            console.log.apply(console, arguments);
        };
    } else {
        //In IE, its a native function for which apply is not defined, but it works without a proper 'this' reference
        log = console.log;
    }

    var loadTheme = function (url, version) {
        if (!themesLoaded[url]) {
            log("loadTheme", url, version);

            var href = url + '/styles.css';
            if (version) {
                href += '?v=' + version;
            }

            var stylesheet = document.createElement('link');
            stylesheet.setAttribute('rel', 'stylesheet');
            stylesheet.setAttribute('type', 'text/css');
            stylesheet.setAttribute('href', href);
            document.getElementsByTagName('head')[0].appendChild(stylesheet);
            themesLoaded[url] = true;
        }
    };

    var getCookie = function (cname) {
        var b = document.cookie.match('(^|;)\\s*' + cname + '\\s*=\\s*([^;]+)');
        return b ? b.pop() : '';
    };

    var isWidgetsetLoaded = function (widgetset) {
        var className = widgetset.replace(/\./g, "_");
        return (typeof window[className]) != "undefined";
    };

    var loadWidgetset = function (url, widgetset, ready) {
        if (widgetsets[widgetset]) {
            return;
        }
        log("load widgetset", url, widgetset);
        setTimeout(function () {
            if (!isWidgetsetLoaded(widgetset)) {
                if (ready) {
                    alert("Failed to load the widgetset: " + url);
                } else {
                    if (window.confirm("Failed to load the widgetset. If using CDN for the widgetset, it is possible that compiling it takes up to a few minutes. Would you like to try again?")) {
                        window[widgetset] = undefined;
                        window.location.reload(false);
                    } else {
                        alert("Failed to load the widgetset: " + url);
                    }
                }
            }
        }, 15000);

        var scriptTag = document.createElement('script');
        scriptTag.setAttribute('type', 'text/javascript');
        scriptTag.setAttribute('src', url);
        document.getElementsByTagName('head')[0].appendChild(scriptTag);

        widgetsets[widgetset] = {
            pendingApps: []
        };
    };

    var isInitializedInDom = function (appId) {
        var appDiv = document.getElementById(appId);
        if (!appDiv) {
            return false;
        }
        for (var i = 0; i < appDiv.childElementCount; i++) {
            var className = appDiv.childNodes[i].className;
            // If the app div contains a child with the class
            // "v-app-loading" we have only received the HTML
            // but not yet started the widget set
            // (UIConnector removes the v-app-loading div).
            if (className && className.indexOf("v-app-loading") != -1) {
                return false;
            }
        }
        return true;
    };

    window.vaadin = window.vaadin || {
        initApplication: function (appId, config) {
            var testbenchId = appId.replace(/-\d+$/, '');

            if (apps[appId]) {
                if (window.vaadin && window.vaadin.clients && window.vaadin.clients[testbenchId] && window.vaadin.clients[testbenchId].initializing) {
                    throw "Application " + appId + " is already being initialized";
                }
                if (isInitializedInDom(appId)) {
                    throw "Application " + appId + " already initialized";
                }
            }

            log("init application", appId, config);

            window.vaadin.clients[testbenchId] = {
                isActive: function () {
                    return true;
                },
                initializing: true
            };

            var getConfig = function (name) {
                var value = config[name];
                return value;
            };

            var fetchRootConfig = function (callback) {
                log('Fetching root config');
                var url = getConfig('browserDetailsUrl');
                if (!url) {
                    // No special url defined, use the same URL that loaded this page (without the fragment)
                    url = window.location.href.replace(/#.*/, '');
                }
                // Timestamp to avoid caching
                url += ((/\?/).test(url) ? "&" : "?") + "v-" + (new Date()).getTime();

                var params = "v-browserDetails=1";
                var rootId = getConfig("v-rootId");
                if (rootId !== undefined) {
                    params += "&v-rootId=" + rootId;
                }

                // Tell the UI what theme it is configured to use
                var theme = getConfig('theme');
                if (theme !== undefined) {
                    params += '&theme=' + encodeURIComponent(theme);
                }

                params += "&v-appId=" + appId;

                var extraParams = getConfig('extraParams')
                if (extraParams !== undefined) {
                    params += extraParams;
                }

                params += '&' + vaadin.getBrowserDetailsParameters(appId, getConfig('sendUrlsAsParameters'));

                var r;
                try {
                    r = new XMLHttpRequest();
                } catch (e) {
                    r = new ActiveXObject("MSXML2.XMLHTTP.3.0");
                }
                r.open('POST', url, true);
                r.onreadystatechange = function (aEvt) {
                    if (r.readyState == 4) {
                        // Save responseStatus so as Offline Applications know what happened
                        // when loading root configuration from server, and depending on the
                        // error status display an error message or the offline UI.
                        config.rootResponseStatus = r.status;
                        config.rootResponseText = r.responseText;

                        var text = r.responseText;
                        if (r.status == 200) {
                            log("Got root config response", text);
                            var updatedConfig = JSON.parse(text);

                            // Copy new properties to the config object
                            for (var property in updatedConfig) {
                                if (updatedConfig.hasOwnProperty(property)) {
                                    config[property] = updatedConfig[property];
                                }
                            }

                            // Try bootstrapping again, this time without fetching missing info
                            bootstrapApp(false);
                        } else {
                            log('Error', r.statusText, text);

                            //Let TB waitForVaadin work again
                            delete window.vaadin.clients[testbenchId];

                            // Show the error in the app's div
                            var appDiv = document.getElementById(appId);
                            appDiv.innerHTML = text;
                            appDiv.style['overflow'] = 'auto';
                        }

                        // Run the fetchRootConfig callback if present.
                        callback && callback(r);
                    }
                };
                // send parameters as POST data
                r.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

                var xsrfToken = getCookie("XSRF-TOKEN");
                if (xsrfToken && xsrfToken.length > 0) {
                    r.setRequestHeader("X-XSRF-TOKEN", xsrfToken);
                }

                r.send(params);

                log('sending request to ', url);
            };

            //Export public data
            var app = {
                getConfig: getConfig,
                // Used when the app was started in offline, so as it is possible
                // to defer root configuration loading until network is available.
                fetchRootConfig: fetchRootConfig
            };
            apps[appId] = app;

            if (!window.name) {
                window.name = appId + '-' + Math.random();
            }

            var bootstrapApp = function (mayDefer) {
                var vaadinDir = getConfig('vaadinDir');

                var versionInfo = getConfig('versionInfo');

                var themeUri = vaadinDir + 'themes/' + getConfig('theme');
                loadTheme(themeUri, versionInfo && versionInfo['vaadinVersion']);

                var widgetset = getConfig('widgetset');
                var widgetsetUrl = getConfig('widgetsetUrl');
                if (!widgetsetUrl) {
                    widgetsetUrl = vaadinDir + 'widgetsets/' + widgetset + "/" + widgetset + ".nocache.js?" + new Date().getTime();
                }
                var widgetsetReady = getConfig('widgetsetReady');
                loadWidgetset(widgetsetUrl, widgetset, widgetsetReady);

                if (getConfig('uidl') === undefined) {
                    if (mayDefer) {
                        fetchRootConfig();
                    } else {
                        throw "May not defer bootstrap any more";
                    }
                } else {
                    if (widgetsets[widgetset].callback) {
                        log("Starting from bootstrap", appId);
                        widgetsets[widgetset].callback(appId);
                    } else {
                        log("Setting pending startup", appId);
                        widgetsets[widgetset].pendingApps.push(appId);
                    }
                }
            };
            bootstrapApp(true);

            if (getConfig("debug")) {
                // TODO debug state is now global for the entire page, but should somehow only be set for the current application
                window.vaadin.debug = true;
            }

            return app;
        },
        clients: {},
        getAppIds: function () {
            var ids = [];
            for (var id in apps) {
                if (apps.hasOwnProperty(id)) {
                    ids.push(id);
                }
            }
            return ids;
        },
        getApp: function (appId) {
            return apps[appId];
        },
        loadTheme: loadTheme,
        registerWidgetset: function (widgetset, callback) {
            log("Widgetset registered", widgetset);
            var ws = widgetsets[widgetset];
            if (ws && ws.pendingApps) {
                ws.callback = callback;
                for (var i = 0; i < ws.pendingApps.length; i++) {
                    var appId = ws.pendingApps[i];
                    log("Starting from register widgetset", appId);
                    callback(appId);
                }
                ws.pendingApps = null;
            }
        },
        getBrowserDetailsParameters: function (parentElementId, sendUrlsAsParameters) {
            // Screen height and width
            var params = 'v-sh=' + window.screen.height;
            params += '&v-sw=' + window.screen.width;

            // Window height and width
            var cw = 0;
            var ch = 0;
            if (typeof(window.innerWidth) == 'number') {
                // Modern browsers
                cw = window.innerWidth;
                ch = window.innerHeight;
            } else {
                // IE 8
                cw = document.documentElement.clientWidth;
                ch = document.documentElement.clientHeight;
            }
            params += '&v-cw=' + cw + '&v-ch=' + ch;


            var d = new Date();

            params += '&v-curdate=' + d.getTime();

            var tzo1 = d.getTimezoneOffset(); // current offset
            var dstDiff = 0;
            var rtzo = tzo1;

            for (var m = 12; m > 0; m--) {
                d.setUTCMonth(m);
                var tzo2 = d.getTimezoneOffset();
                if (tzo1 != tzo2) {
                    dstDiff = (tzo1 > tzo2 ? tzo1 - tzo2 : tzo2 - tzo1); // offset w/o DST
                    rtzo = (tzo1 > tzo2 ? tzo1 : tzo2); // offset w/o DST
                    break;
                }
            }

            // Time zone offset
            params += '&v-tzo=' + tzo1;

            // DST difference
            params += '&v-dstd=' + dstDiff;

            // Raw time zone offset
            params += '&v-rtzo=' + rtzo;

            // DST in effect?
            params += '&v-dston=' + (tzo1 != rtzo);

            // Time zone id (if available)
            try {
                params += '&v-tzid=' + encodeURIComponent(Intl.DateTimeFormat().resolvedOptions().timeZone);
            } catch (err) {

            }

            var pe = document.getElementById(parentElementId);
            if (pe) {
                params += '&v-vw=' + pe.offsetWidth;
                params += '&v-vh=' + pe.offsetHeight;
            }

            // Location
            if (sendUrlsAsParameters !== false) {
                params += '&v-loc=' + encodeURIComponent(location.href);
            }

            // Window name
            if (window.name) {
                params += '&v-wn=' + encodeURIComponent(window.name);
            }

            // This parameter is used in multiplatform-runtime as a key for
            // storing the MPR UI content in the session
            if (window.mprUiId) {
                params += '&v-mui=' + encodeURIComponent(window.mprUiId);
            }

            // Detect touch device support
            var supportsTouch = false;
            try {
                document.createEvent("TouchEvent");
                supportsTouch = true;
            } catch (e) {
                // Chrome and IE10 touch detection
                supportsTouch = 'ontouchstart' in window
                    || navigator.msMaxTouchPoints;
            }

            if (supportsTouch) {
                params += "&v-td=1";
            }

            return params;
        }
    };

    log('Vaadin bootstrap loaded');
})();