<template>
  <div>
    <aflogo/>
    <div class="goods">
      <div class="menu-wrapper" ref="menuWrapper">
        <ul>
          <li v-for="(item,index) in goods" class="menu-item" :class="{'current':currentIndex===index}"
              @click="selectMenu(index,$event)" ref="menuList">
          <span class="text border-1px">
            <span v-show="false" class="icon"></span>{{item.name}}
          </span>
          </li>
        </ul>
      </div>
      <div class="foods-wrapper" ref="foodsWrapper">
        <ul>
          <li v-for="item in goods" class="food-list" ref="foodList">
            <h1 class="title">{{item.name}}</h1>
            <ul>
              <li @click="selectFood(food,$event)" v-for="food in item.foods" class="food-item border-1px">
                <div class="icon">
                  <img width="88" height="88" :src="food.icon" alt="">
                </div>
                <div class="content">
                  <div>
                    <h2 class="name">{{food.name}}</h2>
                    <p class="desc">{{food.description}}</p>
                  </div>
                  <div class="price">
                    <span class="now">￥{{food.price}}</span>
                  </div>
                  <div class="cartcontrol-wrapper">
                    <cartcontrol @add="addFood" :food="food"></cartcontrol>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <shopcart ref="shopcart" :selectFoods="selectFoods" :deliveryPrice="seller.deliveryPrice"
                :minPrice="seller.minPrice"></shopcart>
    </div>
    <food @add="addFood" :food="selectedFood" ref="food"></food>
  </div>
</template>

<script type="text/ecmascript-6">
import BScroll from 'better-scroll'
import aflogo from '../aflogo/index'
import shopcart from '../shopcart/shopcart'
import cartcontrol from '../cartcontrol/cartcontrol'
import food from '../food/food'

const mockDataJson = require('../../../mock/data.json')

export default {
  data () {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectedFood: {},
      seller: {}
    }
  },
  computed: {
    currentIndex () {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i]
        let height2 = this.listHeight[i + 1]
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          this._followScroll(i)
          return i
        }
      }
      return 0
    },
    selectFoods () {
      let foods = []
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food)
          }
        })
      })
      return foods
    }
  },
  async activated () {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee']
    this.seller = mockDataJson.seller
    this.goods = mockDataJson.goods
    setTimeout(() => {
      this._initScroll()
      this._calculateHeight()
    }, 1000)
  },
  methods: {
    selectMenu (index, event) {
      if (!event._constructed) {
        return
      }
      let foodList = this.$refs.foodList
      let el = foodList[index]
      this.foodsScroll.scrollToElement(el, 300)
    },
    selectFood (food, event) {
      if (!event._constructed) {
        return
      }
      this.selectedFood = food
      this.$refs.food.show()
    },
    addFood (target) {
      this._drop(target)
    },
    _drop (target) {
      // 体验优化,异步执行下落动画
      this.$nextTick(() => {
        this.$refs.shopcart.drop(target)
      })
    },
    _initScroll () {
      this.meunScroll = new BScroll(this.$refs.menuWrapper, {
        click: true
      })

      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        click: true,
        probeType: 3
      })

      this.foodsScroll.on('scroll', (pos) => {
        // 判断滑动方向，避免下拉时分类高亮错误（如第一分类商品数量为1时，下拉使得第二分类高亮）
        if (pos.y <= 0) {
          this.scrollY = Math.abs(Math.round(pos.y))
        }
      })
    },
    _calculateHeight () {
      let foodList = this.$refs.foodList
      let height = 0
      this.listHeight.push(height)
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i]
        height += item.clientHeight
        this.listHeight.push(height)
      }
    },
    _followScroll (index) {
      let menuList = this.$refs.menuList
      let el = menuList[index]
      this.meunScroll.scrollToElement(el, 300, 0, -100)
    }
  },
  components: {
    aflogo,
    shopcart,
    cartcontrol,
    food
  }
}
</script>

<style lang="scss" scoped>
.goods {
  display: flex;
  position: absolute;
  top: 107px;
  bottom: 68px;
  width: 100%;
  overflow: hidden;
  background: #fff;

  .menu-wrapper {
    flex: 0 0 100px;
    width: 100px;
    background: #FAF4F4;

    .menu-item {
      display: table;
      height: 60px;
      width: 100%;
      padding: 0 12px;

      &.current {
        position: relative;
        z-index: 10;
        margin-top: -1px;
        background: #fff;
        font-weight: 700;

        &:before {
          content: '';
          position: absolute;
          left: 0;
          top: 0;
          display: block;
          height: 100%;
          border-left: 3px solid #D32323;
        }
      }

      .text {
        display: table-cell;
        width: 100%;
        vertical-align: middle;
        font-size: 14px;
        color: #736F6F;
        line-height: 20px;
      }
    }
  }
}

.foods-wrapper {
  flex: 1;

  .title {
    padding: 10px 0 20px 19px;
    height: 42px;
    font-size: 14px;
    font-family: PingFangSC-Medium, PingFang SC;
    font-weight: 500;
    color: #736F6F;
    line-height: 20px;
    background: #F2F2F2;
  }

  .food-item {
    display: flex;
    margin: 8px 18px 0 16px;
    padding-bottom: 8px;
    @include border-1px(#F2F2F2);
  }

  &:last-child {
    @include border-none();
    margin-bottom: 0;
  }

  .icon {
    flex: 0 0 88px;
    margin-right: 8px;
    border-radius: 8px;
    overflow: hidden;
  }

  .content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;

    .name {
      display: -webkit-box;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 1;
      overflow: hidden;
      margin: 4px 0;
      font-size: 16px;
      font-family: PingFangSC-Medium, PingFang SC;
      font-weight: 500;
      color: #1F1E1E;
      line-height: 22px;
      word-break: break-all;
    }

    .desc {
      display: -webkit-box;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 2;
      overflow: hidden;
      font-size: 12px;
      color: #736F6F;
      line-height: 17px;
      word-break: break-all;
    }

    .price {
      display: flex;
      flex-direction: column;
    }

    .now {
      font-size: 16px;
      font-family: PingFangSC-Medium, PingFang SC;
      font-weight: 600;
      color: #D32323;
      line-height: 22px;
    }

    .cartcontrol-wrapper {
      position: absolute;
      right: 0;
      bottom: 1px;
    }
  }
}
</style>
