// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

(function() {
  /** Amount that each level of bookmarks is indented by (px). */
  var BOOKMARK_INDENT = 20;

  Polymer({
    is: 'viewer-bookmark',

    properties: {
      /**
       * A bookmark object, each containing a:
       * - title
       * - page (optional)
       * - children (an array of bookmarks)
       */
      bookmark: {
        type: Object,
        observer: 'bookmarkChanged_'
      },

      depth: {
        type: Number,
        observer: 'depthChanged'
      },

      childDepth: Number,

      childrenShown: {
        type: Boolean,
        reflectToAttribute: true,
        value: false
      },

      keyEventTarget: {
        type: Object,
        value: function() {
          return this.$.item;
        }
      }
    },

    behaviors: [
      Polymer.IronA11yKeysBehavior
    ],

    keyBindings: {
      'enter': 'onEnter_',
      'space': 'onSpace_'
    },

    bookmarkChanged_: function() {
      this.$.expand.style.visibility =
          this.bookmark.children.length > 0 ? 'visible' : 'hidden';
    },

    depthChanged: function() {
      this.childDepth = this.depth + 1;
      this.$.item.style.webkitPaddingStart =
          (this.depth * BOOKMARK_INDENT) + 'px';
    },

    onClick: function() {
      if (this.bookmark.hasOwnProperty('page'))
        this.fire('change-page', {page: this.bookmark.page});
      else if (this.bookmark.hasOwnProperty('uri'))
        this.fire('navigate', {uri: this.bookmark.uri, newtab: true});
    },

    onEnter_: function(e) {
      // Don't allow events which have propagated up from the expand button to
      // trigger a click.
      if (e.detail.keyboardEvent.target != this.$.expand)
        this.onClick();
    },

    onSpace_: function(e) {
      // paper-icon-button stops propagation of space events, so there's no need
      // to check the event source here.
      this.onClick();
      // Prevent default space scroll behavior.
      e.detail.keyboardEvent.preventDefault();
    },

    toggleChildren: function(e) {
      this.childrenShown = !this.childrenShown;
      e.stopPropagation();  // Prevent the above onClick handler from firing.
    }
  });
})();