/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Calendar views code
 *
 * The Initial Developer of the Original Code is
 *   the Mozilla Calendar Squad
 * Portions created by the Initial Developer are Copyright (C) 2006
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Vladimir Vukicevic <vladimir.vukicevic@oracle.com>
 *   Joey Minta <jminta@gmail.com>
 *   Michael Buettner <michael.buettner@sun.com>
 *   gekacheka@yahoo.com
 *   Matthew Willis <lilmatt@mozilla.com>
 *   Philipp Kewisch <mozilla@kewis.ch>
 *   Martin Schroeder <mschroeder@mozilla.x-home.org>
 *   Berend Cornelius <berend.cornelius@sun.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

Components.utils.import("resource://calendar/modules/calUtils.jsm");
Components.utils.import("resource://calendar/modules/calAlarmUtils.jsm");

/**
 * Controller for the views
 * @see calIcalendarViewController
 */
var calendarViewController = {
    QueryInterface: function(aIID) {
        if (!aIID.equals(Components.interfaces.calICalendarViewController) &&
            !aIID.equals(Components.interfaces.nsISupports)) {
            throw Components.results.NS_ERROR_NO_INTERFACE;
        }

        return this;
    },

    /**
     * Creates a new event
     * @see calICalendarViewController
     */
    createNewEvent: function (aCalendar, aStartTime, aEndTime, aForceAllday) {
        aCalendar = aCalendar || getSelectedCalendar();

        // if we're given both times, skip the dialog
        if (aStartTime && aEndTime && !aStartTime.isDate && !aEndTime.isDate) {
            let item = cal.createEvent();
            item.startDate = aStartTime;
            item.endDate = aEndTime;
            item.title = calGetString("calendar", "newEvent");
            item.calendar = aCalendar;
            cal.alarms.setDefaultValues(item);
            doTransaction('add', item, aCalendar, null, null);
        } else {
            createEventWithDialog(aCalendar, aStartTime, null, null, null, aForceAllday);
        }
    },

    pendingJobs: [],

    /**
     * In order to initiate a modification for the occurrence passed as argument
     * we create an object that records the necessary details and store it in an
     * internal array ('pendingJobs'). this way we're in a position to terminate
     * any pending modification if need should be.
     *
     * @param aOccurrence       The occurrence to create the pending
     *                            modification for.
     */
    createPendingModification: function (aOccurrence) {
        // finalize a (possibly) pending modification. this will notify
        // an open dialog to save any outstanding modifications.
        aOccurrence = this.finalizePendingModification(aOccurrence);

        // XXX TODO logic to ask for which occurrence to modify is currently in
        // modifyEventWithDialog, since the type of transactions done depend on
        // this. This in turn makes the aOccurrence here be potentially wrong, I
        // haven't seen it used anywhere though.
        var pendingModification = {
            controller: this,
            item: aOccurrence,
            finalize: null,
            dispose: function() {
                var array = this.controller.pendingJobs;
                for (var i=0; i<array.length; i++) {
                    if (array[i] == this) {
                        array.splice(i,1);
                        break;
                    }
                }
            }
        }

        this.pendingJobs.push(pendingModification);

        modifyEventWithDialog(aOccurrence, pendingModification, true);
    },

    /**
     * Iterate the list of pending modifications and see if the occurrence
     * passed as argument is currently about to be modified (event dialog is
     * open with the item in question). If this should be the case we call
     * finalize() in order to bring the dialog down and avoid dataloss.
     *
     * @param aOccurrence       The occurrence to finalize the modification for.
     */
    finalizePendingModification: function (aOccurrence) {

      for each (var job in this.pendingJobs) {
          var item = job.item;
          var parent = item.parent;
          if ((item.hashId == aOccurrence.hashId) ||
              (item.parentItem.hashId == aOccurrence.hashId) ||
              (item.hashId == aOccurrence.parentItem.hashId)) {
              // terminate() will most probably create a modified item instance.
              aOccurrence = job.finalize();
              break;
        }
      }

      return aOccurrence;
    },

    /**
     * Modifies the given occurrence
     * @see calICalendarViewController
     */
    modifyOccurrence: function (aOccurrence, aNewStartTime, aNewEndTime, aNewTitle) {

        aOccurrence = this.finalizePendingModification(aOccurrence);

        // if modifying this item directly (e.g. just dragged to new time),
        // then do so; otherwise pop up the dialog
        if (aNewStartTime || aNewEndTime || aNewTitle) {
            var instance = aOccurrence.clone();

            if (aNewTitle) {
                instance.title = aNewTitle;
            }

            // When we made the executive decision (in bug 352862) that
            // dragging an occurrence of a recurring event would _only_ act
            // upon _that_ occurrence, we removed a bunch of code from this
            // function. If we ever revert that decision, check CVS history
            // here to get that code back.

            if (aNewStartTime || aNewEndTime) {
                // Yay for variable names that make this next line look silly
                if (isEvent(instance)) {
                    if (aNewStartTime && instance.startDate) {
                        instance.startDate = aNewStartTime;
                    }
                    if (aNewEndTime && instance.endDate) {
                        instance.endDate = aNewEndTime;
                    }
                } else {
                    if (aNewStartTime && instance.entryDate) {
                        instance.entryDate = aNewStartTime;
                    }
                    if (aNewEndTime && instance.dueDate) {
                        instance.dueDate = aNewEndTime;
                    }
                }
            }

            doTransaction('modify', instance, instance.calendar, aOccurrence, null);
        } else {
            this.createPendingModification(aOccurrence);
        }
    },

    /**
     * Deletes the given occurrences
     * @see calICalendarViewController
     */
    deleteOccurrences: function (aCount,
                                 aOccurrences,
                                 aUseParentItems,
                                 aDoNotConfirm) {
        startBatchTransaction();
        var recurringItems = {};

        function getSavedItem(aItemToDelete) {
            // Get the parent item, saving it in our recurringItems object for
            // later use.
            var hashVal = aItemToDelete.parentItem.hashId;
            if (!recurringItems[hashVal]) {
                recurringItems[hashVal] = {
                    oldItem: aItemToDelete.parentItem,
                    newItem: aItemToDelete.parentItem.clone()
                };
            }
            return recurringItems[hashVal];
        }

        // Make sure we are modifying a copy of aOccurrences, otherwise we will
        // run into race conditions when the view's doDeleteItem removes the
        // array elements while we are iterating through them. While we are at
        // it, filter out any items that have readonly calendars, so that
        // checking for one total item below also works out if all but one item
        // are readonly.
        var occurrences = aOccurrences.filter(function(item) { return isCalendarWritable(item.calendar); });

        for each (var itemToDelete in occurrences) {
            if (aUseParentItems) {
                // Usually happens when ctrl-click is used. In that case we
                // don't need to ask the user if he wants to delete an
                // occurrence or not.
                itemToDelete = itemToDelete.parentItem;
            } else if (!aDoNotConfirm && occurrences.length == 1) {
                // Only give the user the selection if only one occurrence is
                // selected. Otherwise he will get a dialog for each occurrence
                // he deletes.
                var [itemToDelete, hasFutureItem, response] = promptOccurrenceModification(itemToDelete, false, "delete");
                if (!response) {
                    // The user canceled the dialog, bail out
                    break;
                }
            }

            // Now some dirty work: Make sure more than one occurrence can be
            // deleted by saving the recurring items and removing occurrences as
            // they come in. If this is not an occurrence, we can go ahead and
            // delete the whole item.
            itemToDelete = this.finalizePendingModification(itemToDelete);
            if (itemToDelete.parentItem.hashId != itemToDelete.hashId) {
                var savedItem = getSavedItem(itemToDelete);
                savedItem.newItem.recurrenceInfo
                         .removeOccurrenceAt(itemToDelete.recurrenceId);
                // Dont start the transaction yet. Do so later, in case the
                // parent item gets modified more than once.
            } else {
                doTransaction('delete', itemToDelete, itemToDelete.calendar, null, null);
            }
        }

        // Now handle recurring events. This makes sure that all occurrences
        // that have been passed are deleted.
        for each (var ritem in recurringItems) {
            doTransaction('modify',
                          ritem.newItem,
                          ritem.newItem.calendar,
                          ritem.oldItem,
                          null);
        }
        endBatchTransaction();
    }
};

/**
 * This function provides a neutral way to switch between views.
 * XXX Kind of confusing. This function calls the app specific function, which
 * again calls the common switchToView function. They should be consolidated in
 * a different bug.
 *
 * @param type      The type of view to show
 * @param event     (optional) A DOM event that caused the view to show.
 */
function showCalendarView(type, event) {
    if (isSunbird()) {
        sbSwitchToView(type, event);
    } else if (document.getElementById('switch2calendar').getAttribute('checked')) {
        ltnShowCalendarView(type, event);
    }
    onCalendarViewResize(event);
}

/**
 * This function acts like showCalendarView, but does not bring the view to the front
 * if the application is showing other elements (i.e Lightning).
 *
 * @see showCalendarView
 * @param type          The type of view to select.
 */
function selectCalendarView(type) {
    if (isSunbird()) {
        sbSwitchToView(type);
    } else {
        ltnSelectCalendarView(type);
    }
}

/**
 * This function does the common steps to switch between views. Should be called
 * from app-specific view switching functions
 *
 * @param aViewType     The type of view to select.
 */
function switchToView(aViewType) {
    var viewDeck = getViewDeck();
    var selectedDay;
    var currentSelection = [];

    // Set up the view commands
    var views = viewDeck.childNodes;
    for (var i = 0; i < views.length; i++) {
        var view = views[i];
        var commandId = "calendar_" + view.id + "_command";
        var command = document.getElementById(commandId);
        if (view.id == aViewType + "-view") {
            command.setAttribute("checked", "true");
        } else {
            command.removeAttribute("checked");
        }
    }

    /**
     * Sets up a node to use view specific attributes. If there is no view
     * specific attribute, then <attr>-all is used instead.
     *
     * @param id        The id of the node to set up.
     * @param attr      The view specific attribute to modify.
     */
    function setupViewNode(id, attr) {
        let node = document.getElementById(id);
        if (node.hasAttribute(attr + "-" + aViewType)) {
            node.setAttribute(attr, node.getAttribute(attr + "-" + aViewType));
        } else {
            node.setAttribute(attr, node.getAttribute(attr + "-all"));
        }
    }

    // Set up the labels for the context menu
    ["calendar-view-context-menu-next",
     "calendar-view-context-menu-previous",
     "calendar-go-menu-next",
     "calendar-go-menu-previous"].forEach(function(x) setupViewNode(x, "label"));

    ["calendar-go-menu-next",
     "calendar-go-menu-previous"].forEach(function(x) setupViewNode(x, "accesskey"));

    // Set up the labels for the view navigation
    ["previous-view-button",
     "today-view-button",
     "next-view-button"].forEach(function(x) setupViewNode(x, "tooltiptext"));
    
    try {
        selectedDay = viewDeck.selectedPanel.selectedDay;
        currentSelection = viewDeck.selectedPanel.getSelectedItems({});
    } catch (ex) {
        // This dies if no view has even been chosen this session, but that's
        // ok because we'll just use now() below.
    }

    if (!selectedDay) {
        selectedDay = now();
    }

    // Anyone wanting to plug in a view needs to follow this naming scheme
    let view = document.getElementById(aViewType + "-view");
    viewDeck.selectedPanel = view;

    // Select the corresponding tab
    let viewTabs = document.getElementById("view-tabs");
    viewTabs.selectedIndex = getViewDeck().selectedIndex;

    let compositeCal = getCompositeCalendar();
    if (view.displayCalendar != compositeCal) {
        view.displayCalendar = compositeCal;
        view.timezone = calendarDefaultTimezone();
        view.controller = calendarViewController;
    }

    view.goToDay(selectedDay);
    view.setSelectedItems(currentSelection.length, currentSelection);
}

/**
 * Returns the calendar view deck XUL element.
 *
 * @return      The view-deck element.
 */
function getViewDeck() {
    return document.getElementById("view-deck");
}

/**
 * Returns the currently selected calendar view.
 *
 * @return      The selected calendar view
 */
function currentView() {
    return getViewDeck().selectedPanel;
}

/**
 * Returns the selected day in the current view.
 *
 * @return      The selected day
 */
function getSelectedDay() {
    return currentView().selectedDay;
}

var gMidnightTimer;

/**
 * Creates a timer that will fire after midnight.  Pass in a function as
 * aRefreshCallback that should be called at that time.
 *
 * XXX This function is not very usable, since there is only one midnight timer.
 * Better would be a function that uses the observer service to notify at
 * midnight.
 *
 * @param aRefreshCallback      A callback to be called at midnight.
 */
function scheduleMidnightUpdate(aRefreshCallback) {
    var jsNow = new Date();
    var tomorrow = new Date(jsNow.getFullYear(), jsNow.getMonth(), jsNow.getDate() + 1);
    var msUntilTomorrow = tomorrow.getTime() - jsNow.getTime();

    // Is an nsITimer/callback extreme overkill here? Yes, but it's necessary to
    // workaround bug 291386.  If we don't, we stand a decent chance of getting
    // stuck in an infinite loop.
    var udCallback = {
        notify: function(timer) {
            aRefreshCallback();
        }
    };

    if (!gMidnightTimer) {
        // Observer for wake after sleep/hibernate/standby to create new timers and refresh UI
        var wakeObserver = {
           observe: function(aSubject, aTopic, aData) {
               if (aTopic == "wake_notification") {
                   // postpone refresh for another couple of seconds to get netwerk ready:
                   if (this.mTimer) {
                       this.mTimer.cancel();
                   } else {
                       this.mTimer = Components.classes["@mozilla.org/timer;1"]
                                               .createInstance(Components.interfaces.nsITimer);
                   }
                   this.mTimer.initWithCallback(udCallback, 10 * 1000,
                                                Components.interfaces.nsITimer.TYPE_ONE_SHOT);
               }
           }
        };

        // Add observer
        var observerService = Components.classes["@mozilla.org/observer-service;1"]
                                        .getService(Components.interfaces.nsIObserverService);
        observerService.addObserver(wakeObserver, "wake_notification", false);

        // Remove observer on unload
        window.addEventListener("unload",
                                function() {
                                    observerService.removeObserver(wakeObserver, "wake_notification");
                                }, false);
        gMidnightTimer = Components.classes["@mozilla.org/timer;1"]
                                   .createInstance(Components.interfaces.nsITimer);
    } else {
        gMidnightTimer.cancel();
    }
    gMidnightTimer.initWithCallback(udCallback, msUntilTomorrow, gMidnightTimer.TYPE_ONE_SHOT);
}

/**
 * Retuns a cached copy of the view stylesheet.
 *
 * @return      The view stylesheet object.
 */
function getViewStyleSheet() {
  if (!getViewStyleSheet.sheet) {
      const cssUri = "chrome://calendar/content/calendar-view-bindings.css";
      for each (let sheet in document.styleSheets) {
          if (sheet.href == cssUri) {
              getViewStyleSheet.sheet = sheet;
              break;
          }
      }
  }
  return getViewStyleSheet.sheet;
}

/**
 * Updates the view stylesheet to contain rules that give all boxes with class
 * .calendar-color-box and an attribute calendar-id="<id of the calendar>" the
 * background color of the specified calendar.
 *
 * @param aCalendar     The calendar to update the stylesheet for.
 */
function updateStyleSheetForViews(aCalendar) {
    if (!updateStyleSheetForViews.ruleCache) {
        updateStyleSheetForViews.ruleCache = {};
    }
    let ruleCache = updateStyleSheetForViews.ruleCache;

    if (!(aCalendar.id in ruleCache)) {
        // We haven't create a rule for this calendar yet, do so now.
        let sheet = getViewStyleSheet();
        let ruleString = '.calendar-color-box[calendar-id="' + aCalendar.id + '"] {} ';
        let ruleIndex = sheet.insertRule(ruleString, sheet.cssRules.length);

        ruleCache[aCalendar.id] = sheet.cssRules[ruleIndex];
    }

    let color = aCalendar.getProperty("color") || "#A8C2E1";
    ruleCache[aCalendar.id].style.backgroundColor = color;
    ruleCache[aCalendar.id].style.color = cal.getContrastingTextColor(color);
}

/**
 * Category preferences observer. Used to update the stylesheets for category
 * colors.
 *
 * Note we need to keep the categoryPrefBranch variable outside of
 * initCategories since branch observers only live as long as the branch object
 * is alive, and out of categoryManagement to avoid cyclic references.
 */
var categoryPrefBranch;
var categoryManagement = {
    QueryInterface: function cM_QueryInterface(aIID) {
        return cal.doQueryInterface(this,
                                    categoryPrefObserver.prototype,
                                    aIID,
                                    [Components.interfaces.nsIObserver]);
    },

    initCategories: function cM_initCategories() {
      let prefService = Components.classes["@mozilla.org/preferences-service;1"]
                                  .getService(Components.interfaces.nsIPrefService);
      categoryPrefBranch = prefService.getBranch("calendar.category.color.")
                                      .QueryInterface(Components.interfaces.nsIPrefBranch2);
      let categories = categoryPrefBranch.getChildList("", {});

      // Fix illegally formatted category prefs.
      for (let i in categories) {
          let category = categories[i];
          if (category.search(/[^_0-9a-z-]/) != -1) {
              let categoryFix = formatStringForCSSRule(category);
              if (!categoryPrefBranch.prefHasUserValue(categoryFix)) {
                  let color = categoryPrefBranch.getCharPref(category);
                  categoryPrefBranch.setCharPref(categoryFix, color);
                  categoryPrefBranch.clearUserPref(category); // not usable
                  categories[i] = categoryFix;  // replace illegal name
              } else {
                  categories.splice(i, 1); // remove illegal name
              }
          }
      }

      // Add color information to the stylesheets.
      categories.forEach(categoryManagement.updateStyleSheetForCategory,
                         categoryManagement);
      categoryPrefBranch.addObserver("", categoryManagement, false);
    },

    cleanupCategories: function cM_cleanupCategories() {
      let prefService = Components.classes["@mozilla.org/preferences-service;1"]
                                  .getService(Components.interfaces.nsIPrefService);
      categoryPrefBranch = prefService.getBranch("calendar.category.color.")
                                      .QueryInterface(Components.interfaces.nsIPrefBranch2);
      categoryPrefBranch.removeObserver("", categoryManagement);
    },

    observe: function cM_observe(aSubject, aTopic, aPrefName) {
        this.updateStyleSheetForCategory(aPrefName);
        // TODO Currently, the only way to find out if categories are removed is
        // to initially grab the calendar.categories.names preference and then
        // observe changes to it. it would be better if we had hooks for this,
        // so we could delete the rule from our style cache and also remove its
        // color preference.
    },

    categoryStyleCache: {},

    updateStyleSheetForCategory: function cM_updateStyleSheetForCategory(aCatName) {
        if (!(aCatName in this.categoryStyleCache)) {
            // We haven't created a rule for this category yet, do so now.
            let sheet = getViewStyleSheet();
            let ruleString = '.category-color-box[categories~="' + aCatName + '"] {} ';
            let ruleIndex = sheet.insertRule(ruleString, sheet.cssRules.length);

            this.categoryStyleCache[aCatName] = sheet.cssRules[ruleIndex];
        }

        let color = cal.getPrefSafe("calendar.category.color." + aCatName) || "";
        this.categoryStyleCache[aCatName].style.backgroundColor = color;
    }
};

/**
 * Handler function to set the selected day in the minimonth to the currently
 * selected day in the current view.
 *
 * @param event     The "dayselect" event emitted from the views.
 *
 */
function observeViewDaySelect(event) {
    var date = event.detail;
    var jsDate = new Date(date.year, date.month, date.day);

    // for the month and multiweek view find the main month,
    // which is the month with the most visible days in the view;
    // note, that the main date is the first day of the main month
    var jsMainDate;
    if (!event.originalTarget.supportsDisjointDates) {
        var mainDate = null;
        var maxVisibleDays = 0;
        var startDay = currentView().startDay;
        var endDay = currentView().endDay;
        var firstMonth = startDay.startOfMonth;
        var lastMonth = endDay.startOfMonth;
        for (var month = firstMonth.clone(); month.compare(lastMonth) <= 0; month.month += 1) {
            var visibleDays = 0;
            if (month.compare(firstMonth) == 0) {
                visibleDays = startDay.endOfMonth.day - startDay.day + 1;
            } else if (month.compare(lastMonth) == 0) {
                visibleDays = endDay.day;
            } else {
                visibleDays = month.endOfMonth.day;
            }
            if (visibleDays > maxVisibleDays) {
                mainDate = month.clone();
                maxVisibleDays = visibleDays;
            }
        }
        jsMainDate = new Date(mainDate.year, mainDate.month, mainDate.day);
    }

    getMinimonth().selectDate(jsDate, jsMainDate);
    currentView().focus();
}

/**
 * Provides a neutral way to get the minimonth, regardless of whether we're in
 * Sunbird or Lightning.
 *
 * @return          The XUL minimonth element.
 */
function getMinimonth() {
    return document.getElementById("calMinimonth");
}

/**
 * Update the view orientation based on the checked state of the command
 */
function toggleOrientation() {
    var cmd = document.getElementById("calendar_toggle_orientation_command");
    var newValue = (cmd.getAttribute("checked") == "true" ? "false" : "true");
    cmd.setAttribute("checked", newValue);

    var deck = getViewDeck();
    for each (var view in deck.childNodes) {
        view.rotated = (newValue == "true");
    }

    // orientation refreshes automatically
}

/**
 * Toggle the workdays only checkbox and refresh the current view
 *
 * XXX We shouldn't need to refresh the view just to toggle the workdays. This
 * should happen automatically.
 */
function toggleWorkdaysOnly() {
    var cmd = document.getElementById("calendar_toggle_workdays_only_command");
    var newValue = (cmd.getAttribute("checked") == "true" ? "false" : "true");
    cmd.setAttribute("checked", newValue);

    var deck = getViewDeck();
    for each (var view in deck.childNodes) {
        view.workdaysOnly = (newValue == "true");
    }

    // Refresh the current view
    currentView().goToDay(currentView().selectedDay);
}

/**
 * Toggle the tasks in view checkbox and refresh the current view
 */
function toggleTasksInView() {
    var cmd = document.getElementById("calendar_toggle_tasks_in_view_command");
    var newValue = (cmd.getAttribute("checked") == "true" ? "false" : "true");
    cmd.setAttribute("checked", newValue);

    var deck = getViewDeck();
    for each (var view in deck.childNodes) {
        view.tasksInView = (newValue == "true");
    }

    // Refresh the current view
    currentView().goToDay(currentView().selectedDay);
}

/**
 * Toggle the show completed in view checkbox and refresh the current view
 */
function toggleShowCompletedInView() {
    var cmd = document.getElementById("calendar_toggle_show_completed_in_view_command");
    var newValue = (cmd.getAttribute("checked") == "true" ? "false" : "true");
    cmd.setAttribute("checked", newValue);

    var deck = getViewDeck();
    for each (var view in deck.childNodes) {
        view.showCompleted = (newValue == "true");
    }

    // Refresh the current view
    currentView().goToDay(currentView().selectedDay);
}

/**
 * Provides a neutral way to go to the current day in the views and minimonth.
 *
 * @param aDate     The date to go.
 */
function goToDate(aDate) {
    getMinimonth().value = aDate.jsDate;
    currentView().goToDay(aDate);
}

/**
 * Returns the calendar view that was selected before restart, or the current
 * calendar view if it has already been set in this session
 *
 * @return          The last calendar view.
 */
function getLastCalendarView() {
    var deck = getViewDeck();
    if (deck.selectedIndex > -1) {
        var viewNode = deck.childNodes[deck.selectedIndex];
        return viewNode.id.replace(/-view/, "");
    }

    // No deck item was selected beforehand, default to week view.
    return "week";
}

/**
 * Deletes items currently selected in the view and clears selection.
 */
function deleteSelectedEvents() {
    var selectedItems = currentView().getSelectedItems({});
    calendarViewController.deleteOccurrences(selectedItems.length,
                                             selectedItems,
                                             false,
                                             false);
    // clear selection
    currentView().setSelectedItems(0, [], true);
}

/**
 * Edit the items currently selected in the view with the event dialog.
 */
function editSelectedEvents() {
    var selectedItems = currentView().getSelectedItems({});
    if (selectedItems && selectedItems.length >= 1) {
        modifyEventWithDialog(selectedItems[0], null, true);
    }
}

/**
 * Select all events from all calendars. Use with care.
 */
function selectAllEvents() {
    var items = [];
    var listener = {
        onOperationComplete: function selectAll_ooc(aCalendar, aStatus,
                                                    aOperationType, aId,
                                                    aDetail) {
            currentView().setSelectedItems(items.length, items, false);
        },
        onGetResult: function selectAll_ogr(aCalendar, aStatus, aItemType,
                                            aDetail, aCount, aItems) {
            for each (var item in aItems) {
                items.push(item);
            }
        }
    };

    var composite = getCompositeCalendar();
    var filter = composite.ITEM_FILTER_CLASS_OCCURRENCES;

    if (currentView().tasksInView) {
        filter |= composite.ITEM_FILTER_TYPE_ALL;
    } else {
        filter |= composite.ITEM_FILTER_TYPE_EVENT;
    }
    if (currentView().showCompleted) {
        filter |= composite.ITEM_FILTER_COMPLETED_ALL;
    } else {
        filter |= composite.ITEM_FILTER_COMPLETED_NO;
    }

    // Need to move one day out to get all events
    var end = currentView().endDay.clone();
    end.day += 1;

    composite.getItems(filter, 0, currentView().startDay, end, listener);
}

let cal = cal || {};
cal.navigationBar = {
    setDateRange: function setDateRange(aStartDate, aEndDate) {
        let docTitle = "";
        if (aStartDate) {
            let intervalLabel = document.getElementById("intervalDescription");
            let firstWeekNo = getWeekInfoService().getWeekTitle(aStartDate);
            let secondWeekNo = firstWeekNo;
            let weekLabel = document.getElementById("calendarWeek");
            if (aStartDate.nativeTime == aEndDate.nativeTime) {
                intervalLabel.value = getDateFormatter().formatDate(aStartDate);
            } else {
                intervalLabel.value = currentView().getRangeDescription();
                secondWeekNo = getWeekInfoService().getWeekTitle(aEndDate);
            }
            if (secondWeekNo == firstWeekNo) {
                weekLabel.value = calGetString("calendar", "singleShortCalendarWeek", [firstWeekNo]);
                weekLabel.tooltipText = calGetString("calendar", "singleLongCalendarWeek", [firstWeekNo]);
            } else {
                weekLabel.value = calGetString("calendar", "severalShortCalendarWeeks", [firstWeekNo, secondWeekNo]);
                weekLabel.tooltipText = calGetString("calendar", "severalLongCalendarWeeks", [firstWeekNo, secondWeekNo]);
            }
            docTitle = intervalLabel.value;
        }
        if (document.getElementById("modeBroadcaster").getAttribute("mode") == "calendar") {
            document.title = (docTitle ? docTitle + " - " : "") +
                calGetString("brand", "brandShortName", null, "branding");
        }
        let viewTabs = document.getElementById("view-tabs");
        viewTabs.selectedIndex = getViewDeck().selectedIndex;
    }
};
