/**
 * Mixin for views
 */
'use strict'

import React, {PropTypes as types} from 'react'

/** @lends ApViewMixin */
const ApViewMixin = {

  // --------------------
  // Custom
  // --------------------
  $apViewMixed: true,

  /**
   * Pop this view from the current stack only if this view is the top.
   */
  popThisViewFromCurrentStack () {
    const s = this
    let { props } = s
    let topView = props.viewTop()
    let isTop = topView.id === props.viewId
    if (!isTop) {
      console.warn('The top view of current stack is not this view.')
      return
    }
    return s.popViewFromCurrentStack()
  },

  /**
   * Pop a view from the current stack.
   */
  popViewFromCurrentStack () {
    const s = this
    return s._popView()
  },

  /**
   * Push a view to the current stack.
   * @param {object} view - View component class.
   * @param {object} params - View params.
   * @param {string} way - View push way.
   */
  pushViewToCurrentStack (view, params, way) {
    const s = this
    return s._pushView(view, params, way)
  },

  // --------------------
  // Specs
  // --------------------

  propTypes: {
    viewId: types.string.isRequired,
    viewWay: types.string.isRequired,
    viewPush: types.func.isRequired,
    viewPop: types.func.isRequired,
    viewTop: types.func.isRequired,
    onViewPop: types.func,
    onViewPush: types.func
  },

  getDefaultProps () {
    let noop = (values) => values
    return {
      viewId: null,
      viewWay: null,
      viewPush: null,
      viewPop: null,
      viewTop: null,
      onViewPop: noop,
      onViewPush: noop
    }
  },

  // --------------------
  // Private
  // --------------------

  _pushView (view, params, way) {
    const s = this
    let { props } = s
    return props.viewPush(view, params, way).then(props.onViewPush)
  },

  _popView() {
    const s = this
    let { props } = s
    return props.viewPop().then(props.onViewPop)
  }

}

export default Object.freeze(ApViewMixin)