import Ember from 'ember';
import computed from 'ember-new-computed';

/**
  Action context event object for an nf-scroll-area scroll event.
  @namespace utils.nf
  @class scroll-area-action-context
*/
export default Ember.Object.extend({
  /**
    The scroll top in pixels.
    @property scrollTop
    @type Number
    @default 0
  */
  scrollTop: 0,

  /**
    The scroll height of the element.
    @property scrollHeight
    @type number
    @default 0
  */
  scrollHeight: 0,

  /**
    The outer height of the element
    @property outerHeight
    @type Number
    @default 0
  */
  outerHeight: 0,

  /**
    The scroll left in pixels.
    @property scrollLeft
    @type Number
    @default 0
  */
  scrollLeft: 0,

  /**
    The scroll width of the element.
    @property scrollWidth
    @type number
    @default 0
  */
  scrollWidth: 0,

  /**
    The outer width of the element
    @property outerWidth
    @type Number
    @default 0
  */
  outerWidth: 0,

  /**
    The calculated maximum value for scrollTop in pixels.
    @property scrollTopMax
    @type Number
    @readonly
  */
  scrollTopMax: computed('outerHeight', 'scrollHeight', {
    get() {
      return this.get('scrollHeight') - this.get('outerHeight');
    }
  }),

  /**
    The calculated percentage, in decimals, of content scrolled.
    @property scrollTopPercentage
    @type Number
    @readonly
  */
  scrollTopPercentage: computed('scrollTop', 'scrollTopMax', {
    get() {
      return this.get('scrollTop') / this.get('scrollTopMax');
    }
  }),
  
  /**
    The calculated maximum value for scrollTop in pixels.
    @property scrollLeftMax
    @type Number
    @readonly
  */
  scrollLeftMax: computed('outerWidth', 'scrollWidth', {
    get() {
      return this.get('scrollWidth') - this.get('outerWidth');
    }
  }),

  /**
    The calculated percentage, in decimals, of content scrolled.
    @property scrollLeftPercentage
    @type Number
    @readonly
  */
  scrollLeftPercentage: computed('scrollLeft', 'scrollLeftMax', {
    get() {
      return this.get('scrollLeft') / this.get('scrollLeftMax');
    }
  }),

  /**
    The component that fired the event
    @property source
    @type Ember.Component
    @default null
  */
  source: null,

  /**
    The optional data to send with the action
    @property data
    @default null
  */
  data: null,

  /**
    The original scroll event object
    @property originalEvent
    @type Event
    @default null
  */
  originalEvent: null,
});