/**
 * @file
 * A Backbone view for the toolbar element. Listens to mouse & touch.
 */

(function ($, Drupal, drupalSettings, Backbone) {
  Drupal.toolbar.ToolbarVisualView = Backbone.View.extend(/** @lends Drupal.toolbar.ToolbarVisualView# */{

    /**
     * Event map for the `ToolbarVisualView`.
     *
     * @return {object}
     *   A map of events.
     */
    events() {
      // Prevents delay and simulated mouse events.
      const touchEndToClick = function (event) {
        event.preventDefault();
        event.target.click();
      };

      return {
        'click .toolbar-bar .toolbar-tab .trigger': 'onTabClick',
        'click .toolbar-toggle-orientation button': 'onOrientationToggleClick',
        'touchend .toolbar-bar .toolbar-tab .trigger': touchEndToClick,
        'touchend .toolbar-toggle-orientation button': touchEndToClick,
      };
    },

    /**
     * Backbone view for the toolbar element. Listens to mouse & touch.
     *
     * @constructs
     *
     * @augments Backbone.View
     *
     * @param {object} options
     *   Options for the view object.
     * @param {object} options.strings
     *   Various strings to use in the view.
     */
    initialize(options) {
      this.strings = options.strings;

      this.listenTo(this.model, 'change:activeTab change:orientation change:isOriented change:isTrayToggleVisible', this.render);
      this.listenTo(this.model, 'change:mqMatches', this.onMediaQueryChange);
      this.listenTo(this.model, 'change:offsets', this.adjustPlacement);
      this.listenTo(this.model, 'change:activeTab change:orientation change:isOriented', this.updateToolbarHeight);

      // Add the tray orientation toggles.
      this.$el
        .find('.toolbar-tray .toolbar-lining')
        .append(Drupal.theme('toolbarOrientationToggle'));

      // Trigger an activeTab change so that listening scripts can respond on
      // page load. This will call render.
      this.model.trigger('change:activeTab');
    },

    /**
     * Update the toolbar element height.
     *
     * @constructs
     *
     * @augments Backbone.View
     */
    updateToolbarHeight() {
      const toolbarTabOuterHeight = $('#toolbar-bar').find('.toolbar-tab').outerHeight() || 0;
      const toolbarTrayHorizontalOuterHeight = $('.is-active.toolbar-tray-horizontal').outerHeight() || 0;
      this.model.set('height', toolbarTabOuterHeight + toolbarTrayHorizontalOuterHeight);

      $('body').css({
        'padding-top': this.model.get('height'),
      });

      this.triggerDisplace();
    },

    // Trigger a recalculation of viewport displacing elements. Use setTimeout
    // to ensure this recalculation happens after changes to visual elements
    // have processed.
    triggerDisplace() {
      _.defer(() => {
        Drupal.displace(true);
      });
    },

    /**
     * @inheritdoc
     *
     * @return {Drupal.toolbar.ToolbarVisualView}
     *   The `ToolbarVisualView` instance.
     */
    render() {
      this.updateTabs();
      this.updateTrayOrientation();
      this.updateBarAttributes();

      $('body').removeClass('toolbar-loading');

      // Load the subtrees if the orientation of the toolbar is changed to
      // vertical. This condition responds to the case that the toolbar switches
      // from horizontal to vertical orientation. The toolbar starts in a
      // vertical orientation by default and then switches to horizontal during
      // initialization if the media query conditions are met. Simply checking
      // that the orientation is vertical here would result in the subtrees
      // always being loaded, even when the toolbar initialization ultimately
      // results in a horizontal orientation.
      //
      // @see Drupal.behaviors.toolbar.attach() where admin menu subtrees
      // loading is invoked during initialization after media query conditions
      // have been processed.
      if (this.model.changed.orientation === 'vertical' || this.model.changed.activeTab) {
        this.loadSubtrees();
      }

      return this;
    },

    /**
     * Responds to a toolbar tab click.
     *
     * @param {jQuery.Event} event
     *   The event triggered.
     */
    onTabClick(event) {
      // If this tab has a tray associated with it, it is considered an
      // activatable tab.
      if (event.target.hasAttribute('data-toolbar-tray')) {
        const activeTab = this.model.get('activeTab');
        const clickedTab = event.target;

        // Set the event target as the active item if it is not already.
        this.model.set('activeTab', (!activeTab || clickedTab !== activeTab) ? clickedTab : null);

        event.preventDefault();
        event.stopPropagation();
      }
    },

    /**
     * Toggles the orientation of a toolbar tray.
     *
     * @param {jQuery.Event} event
     *   The event triggered.
     */
    onOrientationToggleClick(event) {
      const orientation = this.model.get('orientation');
      // Determine the toggle-to orientation.
      const antiOrientation = (orientation === 'vertical') ? 'horizontal' : 'vertical';
      const locked = antiOrientation === 'vertical';
      // Remember the locked state.
      if (locked) {
        localStorage.setItem('Drupal.toolbar.trayVerticalLocked', 'true');
      }
      else {
        localStorage.removeItem('Drupal.toolbar.trayVerticalLocked');
      }
      // Update the model.
      this.model.set({
        locked,
        orientation: antiOrientation,
      }, {
        validate: true,
        override: true,
      });

      event.preventDefault();
      event.stopPropagation();
    },

    /**
     * Updates the display of the tabs: toggles a tab and the associated tray.
     */
    updateTabs() {
      const $tab = $(this.model.get('activeTab'));
      // Deactivate the previous tab.
      $(this.model.previous('activeTab'))
        .removeClass('is-active')
        .prop('aria-pressed', false);
      // Deactivate the previous tray.
      $(this.model.previous('activeTray'))
        .removeClass('is-active');

      // Activate the selected tab.
      if ($tab.length > 0) {
        $tab
          .addClass('is-active')
          // Mark the tab as pressed.
          .prop('aria-pressed', true);
        const name = $tab.attr('data-toolbar-tray');
        // Store the active tab name or remove the setting.
        const id = $tab.get(0).id;
        if (id) {
          localStorage.setItem('Drupal.toolbar.activeTabID', JSON.stringify(id));
        }
        // Activate the associated tray.
        const $tray = this.$el.find(`[data-toolbar-tray="${name}"].toolbar-tray`);
        if ($tray.length) {
          $tray.addClass('is-active');
          this.model.set('activeTray', $tray.get(0));
        }
        else {
          // There is no active tray.
          this.model.set('activeTray', null);
        }
      }
      else {
        // There is no active tray.
        this.model.set('activeTray', null);
        localStorage.removeItem('Drupal.toolbar.activeTabID');
      }
    },

    /**
     * Update the attributes of the toolbar bar element.
     */
    updateBarAttributes() {
      const isOriented = this.model.get('isOriented');
      if (isOriented) {
        this.$el.find('.toolbar-bar').attr('data-offset-top', '');
      }
      else {
        this.$el.find('.toolbar-bar').removeAttr('data-offset-top');
      }
      // Toggle between a basic vertical view and a more sophisticated
      // horizontal and vertical display of the toolbar bar and trays.
      this.$el.toggleClass('toolbar-oriented', isOriented);
    },

    /**
     * Updates the orientation of the active tray if necessary.
     */
    updateTrayOrientation() {
      const orientation = this.model.get('orientation');

      // The antiOrientation is used to render the view of action buttons like
      // the tray orientation toggle.
      const antiOrientation = (orientation === 'vertical') ? 'horizontal' : 'vertical';

      // Toggle toolbar's parent classes before other toolbar classes to avoid
      // potential flicker and re-rendering.
      $('body')
        .toggleClass('toolbar-vertical', (orientation === 'vertical'))
        .toggleClass('toolbar-horizontal', (orientation === 'horizontal'));

      const removeClass = (antiOrientation === 'horizontal') ? 'toolbar-tray-horizontal' : 'toolbar-tray-vertical';
      const $trays = this.$el.find('.toolbar-tray')
        .removeClass(removeClass)
        .addClass(`toolbar-tray-${orientation}`);

      // Update the tray orientation toggle button.
      const iconClass = `toolbar-icon-toggle-${orientation}`;
      const iconAntiClass = `toolbar-icon-toggle-${antiOrientation}`;
      const $orientationToggle = this.$el.find('.toolbar-toggle-orientation')
        .toggle(this.model.get('isTrayToggleVisible'));
      $orientationToggle.find('button')
        .val(antiOrientation)
        .attr('title', this.strings[antiOrientation])
        .text(this.strings[antiOrientation])
        .removeClass(iconClass)
        .addClass(iconAntiClass);

      // Update data offset attributes for the trays.
      const dir = document.documentElement.dir;
      const edge = (dir === 'rtl') ? 'right' : 'left';
      // Remove data-offset attributes from the trays so they can be refreshed.
      $trays.removeAttr('data-offset-left data-offset-right data-offset-top');
      // If an active vertical tray exists, mark it as an offset element.
      $trays.filter('.toolbar-tray-vertical.is-active').attr(`data-offset-${edge}`, '');
      // If an active horizontal tray exists, mark it as an offset element.
      $trays.filter('.toolbar-tray-horizontal.is-active').attr('data-offset-top', '');
    },

    /**
     * Sets the tops of the trays so that they align with the bottom of the bar.
     */
    adjustPlacement() {
      const $trays = this.$el.find('.toolbar-tray');
      if (!this.model.get('isOriented')) {
        $trays.removeClass('toolbar-tray-horizontal').addClass('toolbar-tray-vertical');
      }
    },

    /**
     * Calls the endpoint URI that builds an AJAX command with the rendered
     * subtrees.
     *
     * The rendered admin menu subtrees HTML is cached on the client in
     * localStorage until the cache of the admin menu subtrees on the server-
     * side is invalidated. The subtreesHash is stored in localStorage as well
     * and compared to the subtreesHash in drupalSettings to determine when the
     * admin menu subtrees cache has been invalidated.
     */
    loadSubtrees() {
      const $activeTab = $(this.model.get('activeTab'));
      const orientation = this.model.get('orientation');
      // Only load and render the admin menu subtrees if:
      //   (1) They have not been loaded yet.
      //   (2) The active tab is the administration menu tab, indicated by the
      //       presence of the data-drupal-subtrees attribute.
      //   (3) The orientation of the tray is vertical.
      if (!this.model.get('areSubtreesLoaded') && typeof $activeTab.data('drupal-subtrees') !== 'undefined' && orientation === 'vertical') {
        const subtreesHash = drupalSettings.toolbar.subtreesHash;
        const theme = drupalSettings.ajaxPageState.theme;
        const endpoint = Drupal.url(`toolbar/subtrees/${subtreesHash}`);
        const cachedSubtreesHash = localStorage.getItem(`Drupal.toolbar.subtreesHash.${theme}`);
        const cachedSubtrees = JSON.parse(localStorage.getItem(`Drupal.toolbar.subtrees.${theme}`));
        const isVertical = this.model.get('orientation') === 'vertical';
        // If we have the subtrees in localStorage and the subtree hash has not
        // changed, then use the cached data.
        if (isVertical && subtreesHash === cachedSubtreesHash && cachedSubtrees) {
          Drupal.toolbar.setSubtrees.resolve(cachedSubtrees);
        }
        // Only make the call to get the subtrees if the orientation of the
        // toolbar is vertical.
        else if (isVertical) {
          // Remove the cached menu information.
          localStorage.removeItem(`Drupal.toolbar.subtreesHash.${theme}`);
          localStorage.removeItem(`Drupal.toolbar.subtrees.${theme}`);
          // The AJAX response's command will trigger the resolve method of the
          // Drupal.toolbar.setSubtrees Promise.
          Drupal.ajax({ url: endpoint }).execute();
          // Cache the hash for the subtrees locally.
          localStorage.setItem(`Drupal.toolbar.subtreesHash.${theme}`, subtreesHash);
        }
      }
    },
  });
}(jQuery, Drupal, drupalSettings, Backbone));