Synnefo

// Copyright 2011 GRNET S.A. All rights reserved.

// 

// Redistribution and use in source and binary forms, with or

// without modification, are permitted provided that the following

// conditions are met:

// 

//   1. Redistributions of source code must retain the above

//      copyright notice, this list of conditions and the following

//      disclaimer.

// 

//   2. Redistributions in binary form must reproduce the above

//      copyright notice, this list of conditions and the following

//      disclaimer in the documentation and/or other materials

//      provided with the distribution.

// 

// THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

// POSSIBILITY OF SUCH DAMAGE.

// 

// The views and conclusions contained in the software and

// documentation are those of the authors and should not be

// interpreted as representing official policies, either expressed

// or implied, of GRNET S.A.

// 

;(function(root){

    // root

    var root = root;

    // setup namepsaces

    var snf = root.synnefo = root.synnefo || {};

    var models = snf.models = snf.models || {}

    var storage = snf.storage = snf.storage || {};

    var ui = snf.ui = snf.ui || {};

    var views = snf.views = snf.views || {}

    // shortcuts

    var bb = root.Backbone;

    var util = snf.util;

    // generic details overlay view.

    views.DetailsView = views.Overlay.extend({

        view_id: "details_view",

        content_selector: "#details-overlay",

        css_class: 'overlay-api-info overlay-info',

        overlay_id: "overlay-details",

        subtitle: "",

        title: "Details",

        show: function(title, msg, content) {

            this.title = title;

            this.msg = msg;

            this.content = content;

            views.DetailsView.__super__.show.apply(this);

        },

        beforeOpen: function() {

            this.set_title(this.title);

            if (!this.msg) { 

                this.$(".description.intro").hide() 

            } else {

                this.$(".description.intro").html(this.msg).show();

            }

            if (!this.content) { 

                this.$(".description.subinfo").hide() 

            } else {

                this.$(".description.subinfo").html(this.content).show(); 

            };

        }

    });

    views.SuspendedVMView = views.FeedbackView.extend({

        view_id: "suspended_info_view",

        css_class: 'overlay-api-info overlay-error non-critical',

        overlay_id: "overlay-api-info",

        subtitle: "",

        title: "VM Suspended",

        beforeOpen: function() {

            views.SuspendedVMView.__super__.beforeOpen.apply(this);

            $(this.$(".description p")[0]).html($("#suspended-vm-overlay .description").html())

        },

        show: function(vm, data, collect_data, extra_data, cb) {

            this.vm = vm;

            data = "Suspended VM Details";

            data += "\n====================";

            data += "\nID: " + vm.id;

            data += "\nName: " + vm.get('name');

            data += "\nPublic IP: " + vm.get_public_nic().get('ipv4');

            data += "\n\n";

            views.SuspendedVMView.__super__.show.call(this, data, collect_data, extra_data, cb);

        }

    });

    views.ApiInfoView = views.Overlay.extend({

        view_id: "api_info_view",

        content_selector: "#api-info-overlay",

        css_class: 'overlay-api-info overlay-info',

        overlay_id: "overlay-api-info",

        subtitle: "",

        title: "API Access",

        beforeOpen: function() {

            var cont = this.$(".copy-content p");

            var token = snf.user.token;

            cont.html("");

            cont.text(token);

            this.cont = cont;

            this.token = token;

            try { delete this.clip; } catch (err) {};

        },

        onOpen: function() {

            views.ApiInfoView.__super__.onOpen(this, arguments);

            this.clip = new snf.util.ClipHelper(this.cont.parent(), this.token);

        },

        onClose: function() {

            var cont = this.$(".copy-content p");

            var token = snf.user.token;

            cont.html("");

        }

    });

    // TODO: implement me

    views.NoticeView = views.Overlay.extend({});

    views.MultipleActionsView = views.View.extend({

        view_id: "multiple_actions",

        _actions: {},

        el: '#multiple_actions_container',

        initialize: function() {

            this.actions = {};

            this.ns_config = {};

            views.MultipleActionsView.__super__.initialize.call(this);

            this.ns_tpl = this.$(".confirm_multiple_actions-template").clone()

            this.init_handlers();

            this.update_layout();

            // for heavy resize/scroll window events

            // do it `like a boss` 

            this.fix_position = _.throttle(this.fix_position, 100);

            this.update_layout = _.throttle(this.update_layout, 100);

            this.show_limit = 1;

            this.init_ns("vms", {

                msg_tpl:"Your actions will affect 1 machine",

                msg_tpl_plural:"Your actions will affect {0} machines",

                actions_msg: {confirm: "Confirm all", cancel: "Cancel all"},

                limit: 1,

                cancel_all: function() { snf.storage.vms.reset_pending_actions(); },

                do_all: function() { snf.storage.vms.do_all_pending_actions(); }

            });

            this.init_ns("nets", {

                msg_tpl:"Your actions will affect 1 private network",

                msg_tpl_plural:"Your actions will affect {0} private networks",

                actions_msg: {confirm: "Confirm all", cancel: "Cancel all"},

                limit: 1,

                cancel_all: function() { snf.storage.networks.reset_pending_actions(); },

                do_all: function() { snf.storage.networks.do_all_pending_actions(); }

            });

            this.init_ns("reboots", {

                msg_tpl:"1 machine needs to be rebooted for changes to apply.",

                msg_tpl_plural:"{0} machines needs to be rebooted for changes to apply.",

                actions_msg: {confirm: "Reboot all", cancel: "Cancel all"},

                limit: 0,

                cancel_all: function() { snf.storage.vms.reset_reboot_required(); },

                do_all: function() { snf.storage.vms.do_all_reboots(); }

            });

        },

        init_ns: function(ns, params) {

            this.actions[ns] = {};

            var nsconf = this.ns_config[ns] = params || {};

            nsconf.cont = $(this.$("#conirm_multiple_cont_template").clone());

            nsconf.cont.attr("id", "confirm_multiple_cont_" + ns);

            $(this.el).find(".ns-confirms-cont").append(nsconf.cont).addClass(ns);

            $(this.el).find(".ns-confirms-cont").append(nsconf.cont).addClass("confirm-ns");

            nsconf.cont.find(".msg button.yes").text(

                nsconf.actions_msg.confirm).click(_.bind(this.do_all, this, ns));

            nsconf.cont.find(".msg button.no").text(

                nsconf.actions_msg.cancel).click(_.bind(this.cancel_all, this, ns));

        },

        do_all: function(ns) {

            this.ns_config[ns].do_all();

        },

        cancel_all: function(ns) {

            this.ns_config[ns].cancel_all();

        },

        init_handlers: function() {

            var self = this;

            $(window).resize(_.bind(function(){

                this.fix_position();

            }, this));

            $(window).scroll(_.bind(function(){

                this.fix_position();

            }, this));

            storage.vms.bind("change:pending_action", _.bind(this.handle_action_add, this, "vms"));

            storage.vms.bind("change:reboot_required", _.bind(this.handle_action_add, this, "reboots"));

            storage.networks.bind("change:actions", _.bind(this.handle_action_add, this, "nets"));

        },

        handle_action_add: function(type, model, action) {

            var actions = this.actions[type];

            // TODO: remove type specific addition code in its own namespace

            if (type == "nets") {

                if (!action || action.is_empty()) {

                    delete actions[model.id];

                } else {

                    actions[model.id] = {model: model, actions: action.actions};

                }

            }

            if (type == "vms") {

                _.each(actions, function(action) {

                    if (action.model.id == model.id) {

                        delete actions[action]

                    }

                });

                var actobject = {};

                actobject[action] = [[]];

                actions[model.id] = {model: model, actions: actobject};

                if (typeof action == "undefined") {

                    delete actions[model.id]

                }

            }

            if (type == "reboots") {

                _.each(actions, function(action) {

                    if (action.model.id == model.id) {

                        delete actions[action]

                    }

                });

                var actobject = {};

                actobject['reboot'] = [[]];

                actions[model.id] = {model: model, actions: actobject};

                if (!action) {

                    delete actions[model.id]

                }

            }

            this.update_layout();

        },

        update_actions_content: function(ns) {

            var conf = this.ns_config[ns];

            conf.cont.find(".details").empty();

            conf.cont.find(".msg p").text("");

            var count = 0;

            var actionscount = 0;

            _.each(this.actions[ns], function(actions, model_id) {

                count++;

                _.each(actions.actions, function(params, act_name){

                    if (params && params.length) {

                        actionscount += params.length;

                    } else {

                        actionscount++;

                    }

                })

                this.total_confirm_actions++;

            });

            var limit = conf.limit;

            if (ui.main.current_view.view_id == "vm_list") {

                limit = 0;

            }

            if (actionscount > limit) {

                conf.cont.show();

                this.confirm_ns_open++;

            } else {

                conf.cont.hide();

            }

            var msg = count > 1 ? conf.msg_tpl_plural : conf.msg_tpl;

            conf.cont.find(".msg p").text(msg.format(count));

            return conf.cont;

        },

        fix_position: function() {

            $('.confirm_multiple').removeClass('fixed');

            if (($(this.el).offset().top +$(this.el).height())> ($(window).scrollTop() + $(window).height())) {

                $('.confirm_multiple').addClass('fixed');

            }

        },

        update_layout: function() {

            this.confirm_ns_open = 0;

            this.total_confirm_actions = 0;

            $(this.el).show();

            $(this.el).find("#conirm_multiple_cont_template").hide();

            $(this.el).find(".confirm-ns").show();

            _.each(this.ns_config, _.bind(function(params, key) {

                this.update_actions_content(key);

            }, this));

            if (this.confirm_ns_open > 0) {

                $(this.el).show();

                this.$(".confirm-all-cont").hide();

                this.$(".ns-confirms-cont").show();

            } else {

                $(this.el).hide();

                this.$(".confirm-all-cont").hide();

                this.$(".ns-confirms-cont").hide();

            }

            $(window).trigger("resize");

        }

    })

    // menu wrapper view

    views.SelectView = views.View.extend({

        initialize: function(view, router) {

            this.parent = view;

            this.router = router;

            this.pane_view_selector = $(".css-tabs");

            this.machine_view_selector = $("#view-select");

            this.el = $(".css-tabs");

            this.title = $(".tab-name");

            this.set_handlers();

            this.update_layout();

            views.SelectView.__super__.initialize.apply(this, arguments);

        },

        clear_active: function() {

            this.pane_view_selector.find("a").removeClass("active");

            this.machine_view_selector.find("a").removeClass("activelink");

        },

        // intercept menu links

        set_handlers: function() {

            var self = this;

            this.pane_view_selector.find("a").hover(function(){

                // FIXME: title from href ? omg

                self.title.text($(this).attr("href"));

            }, function(){

                self.title.text(self.parent.get_title());

            });

            this.pane_view_selector.find("a#machines_view_link").click(_.bind(function(ev){

                ev.preventDefault();

                this.router.vms_index();

            }, this))

            this.pane_view_selector.find("a#networks_view_link").click(_.bind(function(ev){

                ev.preventDefault();

                this.router.networks_view();

            }, this))

            this.pane_view_selector.find("a#disks_view_link").click(_.bind(function(ev){

                ev.preventDefault();

                this.router.disks_view();

            }, this))

            this.machine_view_selector.find("a#machines_view_icon_link").click(_.bind(function(ev){

                ev.preventDefault();

                var d = $.now();

                this.router.vms_icon_view();

            }, this))

            this.machine_view_selector.find("a#machines_view_list_link").click(_.bind(function(ev){

                ev.preventDefault();

                this.router.vms_list_view();

            }, this))

            this.machine_view_selector.find("a#machines_view_single_link").click(_.bind(function(ev){

                ev.preventDefault();

                this.router.vms_single_view();

            }, this))

        },

        update_layout: function() {

            this.clear_active();

            var pane_index = this.parent.pane_ids[this.parent.current_view_id];

            $(this.pane_view_selector.find("a")).removeClass("active");

            $(this.pane_view_selector.find("a").get(pane_index)).addClass("active");

            if (this.parent.current_view && this.parent.current_view.vms_view) {

                if (storage.vms.length > 0) {

                    this.machine_view_selector.show();

                    var machine_index = this.parent.views_ids[this.parent.current_view_id];

                    $(this.machine_view_selector.find("a").get(machine_index)).addClass("activelink");

                } else {

                    this.machine_view_selector.hide();

                }

            } else {

                this.machine_view_selector.hide();

            }

        }

    });

    views.MainView = views.View.extend({

        el: 'body',

        view_id: 'main',

        // FIXME: titles belong to SelectView

        views_titles: {

            'icon': 'machines', 'single': 'machines', 

            'list': 'machines', 'networks': 'networks',

            'disks': 'disks'

        },

        // indexes registry

        views_indexes: {0: 'icon', 2:'single', 1: 'list', 3:'networks'},

        views_pane_indexes: {0:'single', 1:'networks', 2:'disks'},

        // views classes registry

        views_classes: {'icon': views.IconView, 'single': views.SingleView, 

            'list': views.ListView, 'networks': views.NetworksView, 'disks': views.DisksView},

        // view ids

        views_ids: {'icon':0, 'single':2, 'list':1, 'networks':3, 'disks':4},

        // on which pane id each view exists

        // machine views (icon,single,list) are all on first pane

        pane_ids: {'icon':0, 'single':0, 'list':0, 'networks':1, 'disks':2},

        initialize: function(show_view) {

            if (!show_view) { show_view = 'icon' };

            this.router = snf.router;

            this.empty_hidden = true;

            // fallback to browser error reporting (true for debug)

            this.skip_errors = true

            // reset views

            this.views = {};

            this.el = $("#app");

            // reset main view status

            this._loaded = false;

            this.status = "Initializing...";

            // initialize handlers

            this.init_handlers();

            // identify initial view from user cookies

            // this view will be visible after loading of

            // main view

            this.initial_view = this.session_view();

            views.MainView.__super__.initialize.call(this);

            $(window).focus(_.bind(this.handle_window_focus, this, "focus"));

            $(window).blur(_.bind(this.handle_window_focus, this, "out"));

            this.focused = true;

        },

        handle_window_focus: function(focus) {

            if (!snf.config.delay_on_blur) { return };

            if (focus === "focus") {

                this.focused = true;

                this.set_interval_timeouts();

            } else {

                this.focused = false;

                this.set_interval_timeouts();

            }

        },

        set_interval_timeouts: function(time) {

            _.each([this._networks, this._vms], _.bind(function(fetcher){

                if (!fetcher) { return };

                if (this.focused) {

                    fetcher.interval = fetcher.normal_interval;

                    fetcher.stop(false).start(true);

                } else {

                    fetcher.interval = fetcher.maximum_interval;

                    fetcher.stop(false).start(false);

                }

            }, this));

        },

        vms_handlers_registered: false,

        // register event handlers

        // 

        // vms storage events to identify if vms list 

        // is empty and display empty view if user viewing

        // a machine view

        //

        // api/ui error event handlers

        init_handlers: function() {

            // vm handlers

            storage.vms.bind("remove", _.bind(this.check_empty, this));

            storage.vms.bind("add", _.bind(this.check_empty, this));

            storage.vms.bind("change:status", _.bind(this.check_empty, this));

            storage.vms.bind("reset", _.bind(this.check_empty, this));

        },

        handle_api_error_state: function(state) {

            if (snf.api.error_state === snf.api.STATES.ERROR) {

                this.stop_intervals();

            } else {

                if (this.intervals_stopped) {

                    this.update_intervals();

                }

            }

        },

        handle_api_error: function(args) {

            if (arguments.length == 1) { arguments = _.toArray(arguments[0])};

            if (!_.last(arguments).display) {

                return;

            }

            this.error_state = true;

            var xhr = arguments[0];

            var args = util.parse_api_error.apply(util, arguments);

            // force logout if UNAUTHORIZED request arrives

            if (args.code == 401) { snf.auth_client.redirect_to_login(); return };

            var error_entry = [args.ns, args.code, args.message, args.type, args.details, args];

            this.error_view.show_error.apply(this.error_view, error_entry);

        },

        handle_ui_error: function(data) {

            var msg = data.msg, code = data.code, err_obj = data.error;

            error = msg + "<br /><br />" + snf.util.stacktrace().replace("at", "<br /><br />at");

            params = { title: "UI error", extra_details: data.extra };

            params.allow_close = data.extra.allow_close === undefined ? true : data.extra.allow_close;

            this.error_view.show_error("UI", -1, msg, "JS Exception", error, params);

        },

        init_overlays: function() {

            this.create_vm_view = new views.CreateVMView();

            this.api_info_view = new views.ApiInfoView();

            this.details_view = new views.DetailsView();

            this.suspended_view = new views.SuspendedVMView();

            //this.notice_view = new views.NoticeView();

        },

        show_loading_view: function() {

            $("#container #content").hide();

            $("#loading-view").show();

        },

        hide_loading_view: function() {

            $("#container #content").show();

            $("#loading-view").hide();

            $(".css-panes").show();

        },

        items_to_load: 4,

        completed_items: 0,

        check_status: function(loaded) {

            this.completed_items++;

            // images, flavors loaded

            if (this.completed_items == 2) {

                this.load_nets_and_vms();

            }

            if (this.completed_items == this.items_to_load) {

                this.update_status("Rendering layout...");

                var self = this;

                window.setTimeout(function(){

                    self.after_load();

                }, 10)

            }

        },

        load_nets_and_vms: function() {

            var self = this;

            this.update_status("Loading vms...");

            storage.vms.fetch({refresh:true, update:false, success: function(){

                self.update_status("VMS Loaded.");

                self.check_status();

            }});

            this.update_status("Loading networks...");

            storage.networks.fetch({refresh:true, update:false, success: function(){

                self.update_status("Networks loaded.");

                self.check_status();

            }});

        },  

        init_intervals: function() {

            var fetcher_params = [snf.config.update_interval, 

                                  snf.config.update_interval_increase || 500,

                                  snf.config.fast_interval || snf.config.update_interval/2, 

                                  snf.config.update_interval_increase_after_calls || 4,

                                  snf.config.update_interval_max || 20000,

                                  true, 

                                  {is_recurrent: true}]

            this._networks = storage.networks.get_fetcher.apply(storage.networks, _.clone(fetcher_params));

            this._vms = storage.vms.get_fetcher.apply(storage.vms, _.clone(fetcher_params));

        },

        stop_intervals: function() {

            if (this._networks) { this._networks.stop(); }

            if (this._vms) { this._vms.stop(); }

            this.intervals_stopped = true;

        },

        update_intervals: function() {

            if (this._networks) {

                this._networks.stop();

                this._networks.start();

            } else {

                this.init_intervals();

            }

            if (this._vms) {

                this._vms.stop();

                this._vms.start();

            } else {

                this.init_intervals();

            }

            this.intervals_stopped = false;

        },

        after_load: function() {

            var self = this;

            this.update_status("Setting vms update interval...");

            this.init_intervals();

            this.update_intervals();

            this.update_status("Showing initial view...");

            // bypass update_hidden_views in initial view

            // rendering to force all views to get render

            // on their creation

            var uhv = snf.config.update_hidden_views;

            snf.config.update_hidden_views = true;

            this.initialize_views();

            snf.config.update_hidden_views = uhv;

            window.setTimeout(function() {

                self.update_status("Initializing overlays...");

                self.load_initialize_overlays();

            }, 20);

        },

        load_initialize_overlays: function() {

            this.init_overlays();

            // display initial view

            this.loaded = true;

            // application start point

            this.check_empty();

            this.show_initial_view();

        },

        load: function() {

            if (synnefo.config.use_glance) {

                synnefo.glance.register();

            }

            this.error_view = new views.ErrorView();

            // api request error handling

            synnefo.api.bind("error", _.bind(this.handle_api_error, this));

            synnefo.api.bind("change:error_state", _.bind(this.handle_api_error_state, this));

            synnefo.ui.bind("error", _.bind(this.handle_ui_error, this));

            this.feedback_view = new views.FeedbackView();

            this.public_keys_view = new views.PublicKeysOverlay();

            if (synnefo.config.use_glance) {

                this.custom_images_view = new views.CustomImagesOverlay();

            }

            var self = this;

            // initialize overlay views

            // display loading message

            this.show_loading_view();

            // sync load initial data

            this.update_status("Loading images...");

            storage.images.fetch({refresh:true, update:false, success: function(){

                self.check_status()

            }});

            this.update_status("Loading flavors...");

            storage.flavors.fetch({refresh:true, update:false, success:function(){

                self.check_status()

            }});

        },

        update_status: function(msg) {

            //this.log.debug(msg)

            this.status = msg;

            $("#loading-view .info").removeClass("hidden")

            $("#loading-view .info").text(this.status);

        },

        initialize_views: function() {

            this.select_view = new views.SelectView(this, this.router);

            this.empty_view = new views.EmptyView();

            this.metadata_view = new views.MetadataView();

            this.multiple_actions_view = new views.MultipleActionsView();

            this.add_view("icon");

            this.add_view("list");

            this.add_view("single");

            this.add_view("networks");

            this.add_view("disks");

            this.init_menu();

        },

        init_menu: function() {

            $(".usermenu .feedback").click(_.bind(function(e){

                e.preventDefault();

                this.feedback_view.show();

            }, this));

            $(".usermenu .public_keys").click(_.bind(function(e){

                e.preventDefault();

                this.public_keys_view.show();

            }, this));

            if (snf.glance) {

                $(".usermenu .custom_images").click(_.bind(function(e){

                    e.preventDefault();

                    this.custom_images_view.show();

                }, this));

            } else {

                $(".usermenu .custom_images").hide();

            }

        },

        load_user_quotas: function() {

          var main_view = this;

          snf.api.sync('read', undefined, {

            url: synnefo.config.quota_url, 

            success: function(d) {

              snf.user.quotas = {};

              snf.user.quotas['vms'] = d.vms_quota;

              snf.user.quotas['networks'] = d.networks_quota;

              main_view.init_quotas_handlers(['vms','networks']);

            }

          });

        },

        check_quotas: function(type) {

          var storage = synnefo.storage[type];

          var consumed = storage.length;

          if (type == "networks") {

            consumed = storage.filter(function(net){

              return !net.is_public() && !net.is_deleted();

            }).length;

          }

          if (snf.user.quotas && consumed >= snf.user.quotas[type]) {

            storage.trigger("quota_reached");

          } else {

            storage.trigger("quota_free");

          }

        },

        init_quotas_handlers: function(types) {

          var self = this;

          _.each(types, function(type) {

            var storage = synnefo.storage[type];

            if (!storage) { return };

            var check_quotas = function() {

              self.check_quotas(type);

            }

            storage.bind("add", check_quotas);

            storage.bind("remove", check_quotas);

            check_quotas();

          })

        },

        // initial view based on user cookie

        show_initial_view: function() {

          this.set_vm_view_handlers();

          this.load_user_quotas();

          this.hide_loading_view();

          bb.history.start();

          this.trigger("ready");

        },

        show_vm_details: function(vm) {

            if (vm) {

              this.router.vm_details_view(vm.id);

            }

        },

        set_vm_view_handlers: function() {

            var self = this;

            $("#createcontainer #create").click(function(e){

                e.preventDefault();

                if ($(this).hasClass("disabled")) { return }

                self.router.vm_create_view();

            });

            synnefo.storage.vms.bind("quota_reached", function(){

              $("#createcontainer #create").addClass("disabled");

              $("#createcontainer #create").attr("title", "Machines limit reached");

            });

            synnefo.storage.vms.bind("quota_free", function(){

              $("#createcontainer #create").removeClass("disabled");

              $("#createcontainer #create").attr("title", "");

            });

            this.check_quotas('vms');

        },

        check_empty: function() {

            if (!this.loaded) { return }

            if (storage.vms.length == 0) {

                this.show_view("machines");

                this.router.show_welcome();

                this.empty_hidden = false;

            } else {

                this.hide_empty();

            }

        },

        show_empty: function() {

            if (!this.empty_hidden) { return };

            $("#machines-pane-top").addClass("empty");

            this.$(".panes").hide();

            this.$("#machines-pane").show();

            this.hide_views([]);

            this.empty_hidden = false;

            this.empty_view.show();

            this.select_view.update_layout();

            this.empty_hidden = false;

        },

        hide_empty: function() {

            if (this.empty_hidden) { return };

            $("#machines-pane-top").removeClass("empty");

            this.empty_view.hide(true);

            this.router.vms_index();

            this.empty_hidden = true;

            this.select_view.update_layout();

        },

        get_title: function(view_id) {

            var view_id = view_id || this.current_view_id;

            return this.views_titles[view_id];

        },

        // return class object for the given view or false if

        // the view is not registered

        get_class_for_view: function (view_id) {

            if (!this.views_classes[view_id]) {

                return false;

            }

            return this.views_classes[view_id];

        },

        view: function(view_id) {

            return this.views[view_id];

        },

        add_view: function(view_id) {

            if (!this.views[view_id]) {

                var cls = this.get_class_for_view(view_id);

                if (this.skip_errors) {

                    this.views[view_id] = new cls();

                    $(this.views[view_id]).bind("resize", _.bind(function() {

                        window.positionFooter();

                        this.multiple_actions_view.fix_position();

                    }, this));

                } else {

                    // catch ui errors

                    try {

                        this.views[view_id] = new cls();

                        $(this.views[view_id]).bind("resize", _.bind(function() {

                            window.positionFooter();

                            this.multiple_actions_view.fix_position();

                        }, this));

                    } catch (err) {snf.ui.trigger_error(-1, "Cannot add view", err)}

                }

            } else {

            }

            if (this.views[view_id].vms_view) {

                this.views[view_id].metadata_view = this.metadata_view;

            }

            return this.views[view_id];

        },

        hide_views: function(skip) {

            _.each(this.views, function(view) {

                if (skip.indexOf(view) === -1) {

                    $(view.el).hide();

                }

            }, this)

        },

        get: function(view_id) {

            return this.views[view_id];

        },

        session_view: function() {

            if (this.pane_view_from_session() > 0) {

                return this.views_pane_indexes[this.pane_view_from_session()];

            } else {

                return this.views_indexes[this.machine_view_from_session()];

            }

        },

        pane_view_from_session: function() {

            return $.cookie("pane_view") || 0;

        },

        machine_view_from_session: function() {

            return $.cookie("machine_view") || 0;

        },

        update_session: function() {

            $.cookie("pane_view", this.pane_ids[this.current_view_id]);

            if (this.current_view.vms_view) {

                $.cookie("machine_view", this.views_ids[this.current_view_id]);

            }

        },

        identify_view: function(view_id) {

            // machines view_id is an alias to

            // one of the 3 machines view

            // identify which one (if no cookie set defaults to icon)

            if (view_id == "machines") {

                var index = this.machine_view_from_session();

                view_id = this.views_indexes[index];

            }

            return view_id;

        },

        // switch to current view pane

        // if differs from the visible one

        show_view_pane: function() {

            if (this.current_view.pane != this.current_pane) {

                $(this.current_view.pane).show();

                $(this.current_pane).hide();

                this.current_pane = this.current_view.pane;

            }

        },

        show_view: function(view_id) {

            //var d = new Date;

            var ret = this._show_view(view_id);

            //console.log((new Date)-d)

            return ret;

        },

        _show_view: function(view_id) {

                // same view, visible

                // get out of here asap

                if (this.current_view && 

                    this.current_view.id == view_id && 

                    this.current_view.visible()) {

                    return;

                }

                // choose proper view_id

                view_id = this.identify_view(view_id);

                // add/create view and update current view

                var view = this.add_view(view_id);

                // set current view

                this.current_view = view;

                this.current_view_id = view_id;

                // hide all other views

                this.hide_views([this.current_view]);

                // FIXME: depricated

                $(".large-spinner").remove();

                storage.vms.reset_pending_actions();

                storage.networks.reset_pending_actions();

                storage.vms.stop_stats_update();

                // show current view

                this.show_view_pane();

                view.show();

                // update menus

                if (this.select_view) {

                    this.select_view.update_layout();

                }

                this.current_view.__update_layout();

                // update cookies

                this.update_session();

                // machines view subnav

                if (this.current_view.vms_view) {

                    $("#machines-pane").show();

                } else {

                    $("#machines-pane").hide();

                }

                // fix footer position

                // TODO: move footer handlers in

                // main view (from home.html)

                if (window.positionFooter) {

                    window.positionFooter();

                }

                // trigger view change event

                this.trigger("view:change", this.current_view.view_id);

                this.select_view.title.text(this.get_title());

                $(window).trigger("view:change");

                return view;

        },

        reset_vm_actions: function() {

        },

        // identify current view

        // based on views element visibility

        current_view_id: function() {

            var found = false;

            _.each(this.views, function(key, value) {

                if (value.visible()) {

                    found = value;

                }

            })

            return found;

        }

    });

    snf.ui.main = new views.MainView();

    snf.ui.init = function() {

        if (snf.config.handle_window_exceptions) {

            window.onerror = function(msg, file, line) {

                snf.ui.trigger_error("CRITICAL", msg, {}, { file:file + ":" + line, allow_close: false });

            };

        }

        snf.ui.main.load();

    }

})(this);