<template>
  <div>
    <aflogo
      :objCurrentBarInfo="objCurrentBarInfo"/>
    <div class="goods">
      <div
        ref="menuWrapper"
        class="menu-wrapper">
        <ul>
          <li
            v-for="(item, index) in goods"
            :key="index"
            ref="menuList"
            :class="{'current':currentIndex === index}"
            class="menu-item"
            @click="selectMenu(index, $event)">
          <span class="text border-1px">
            <span
              v-show="false"
              class="icon"></span>
            {{ item.category_name }}
          </span>
          </li>
        </ul>
      </div>
      <div
        ref="foodsWrapper"
        class="foods-wrapper">
        <ul>
          <li
            v-for="(item, index) in goods"
            :key="index"
            ref="foodList"
            class="food-list">
            <h1 class="title">{{ item.category_name }}</h1>
            <ul>
              <li
                v-for="(food, idx) in item.products"
                :key="idx"
                class="food-item border-1px"
                @click="selectFood(food, $event)">
                <div class="icon">
                  <img
                    :src="food.product_img_url"
                    alt=""
                    height="88"
                    width="88">
                </div>
                <div class="content">
                  <div>
                    <h2 class="name">{{ food.product_name }}</h2>
                    <p v-if="false" class="desc">{{ food.product_sale_num }}人推荐</p>
                  </div>
                  <div class="price">
                    <span class="now">￥{{ food.product_price | fen2Yuan }}</span>
                  </div>
                  <!--第一个版本暂时不用-->
                  <div
                    v-if="false"
                    class="cartcontrol-wrapper">
                    <cartcontrol
                      :food="food"
                      @add="addFood"/>
                  </div>
                  <van-button
                    v-if="food.is_sell_out === 0"
                    class="btn-show-sku"
                    type="danger">选规格
                  </van-button>
                  <!--售罄图标-->
                  <img
                    v-if="food.is_sell_out === 1"
                    alt=""
                    class="sell-out"
                    src="./image/ic_sold_out@2x.png">
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <shopcart
        ref="shopcart"
        @handleJumpPay="handleJumpPay"/>
    </div>
    <food
      ref="food"
      :food="selectedFood"
      @add="addFood"
      @initCartList="initCartList"></food>
    <editTableNum ref="editTableNum"/>
  </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'
import editTableNum from '../editTableNum/index'
import { apiProductList, apiProductDetail } from './api'
import { mapGetters } from 'vuex'
import { Toast, Button } from 'vant'

// todo 登录成功不会掉接口
export default {
  data () {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectedFood: {}
    }
  },
  computed: {
    ...mapGetters({
      objCurrentBarInfo: 'common/objCurrentBarInfo'
    }),
    currentIndex () {
      for (let i = 0; i < this.listHeight.length; i++) {
        const height1 = this.listHeight[i]
        const height2 = this.listHeight[i + 1]
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          this._followScroll(i)
          return i
        }
      }
      return 0
    }
  },
  watch: {
    'objCurrentBarInfo.id': {
      immediate: true,
      handler: function () {
        this.fetchProductList()
      }
    }
  },
  async activated () {},
  methods: {
    selectMenu (index, event) {
      if (!event._constructed) {
        return
      }
      const foodList = this.$refs.foodList
      const el = foodList[index]
      // offsetY的值改为3，是因为px转rem有误差，iOS12.4.1点击左侧导航时，当前点击的菜单无法被选中，类似一个修正值
      this.foodsScroll.scrollToElement(el, 300, true, 3)
    },
    async selectFood (food, event) {
      // better-scroll 默认会阻止浏览器的原生 click 事件。当设置为 true，better-scroll 会派发一个 click 事件，我们会给派发的 event 参数加一个私有属性 _constructed，值为 true
      // 这里暂时用不到
      // if (!event._constructed) {
      //   return
      // }
      try {
        const { data, status, msg } = await apiProductDetail(food.id)
        if (status) {
          this.selectedFood = {
            ...data,
            product_num: 1 // 默认购买数量1
          }
        } else {
          Toast(msg)
        }
        this.$refs.food.show()
      } catch (err) {}
    },
    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 () {
      const foodList = this.$refs.foodList
      let height = 0
      this.listHeight.push(height)
      for (let i = 0; i < foodList.length; i++) {
        const item = foodList[i]
        height += item.clientHeight
        this.listHeight.push(height)
      }
    },
    _followScroll (index) {
      const menuList = this.$refs.menuList
      const el = menuList[index]
      this.meunScroll.scrollToElement(el, 300, 0, -100)
    },
    handleJumpPay () {
      this.$refs.editTableNum.init()
    },
    // 获取商品列表
    async fetchProductList () {
      const { id } = this.objCurrentBarInfo
      if (!id) {
        return
      }
      try {
        const { data, status, msg } = await apiProductList(id)
        if (status) {
          if (Array.isArray(data) && data.length) {
            this.goods = data
            setTimeout(() => {
              this._initScroll()
              this._calculateHeight()
            }, 500)
          }
        } else {
          Toast(msg)
        }
      } catch (err) {}
    },
    // 单个商品从商详添加到购物车手，购物车更新数据
    initCartList () {
      this.$refs.shopcart.init()
    }
  },
  components: {
    aflogo,
    shopcart,
    cartcontrol,
    food,
    editTableNum,
    'van-button': Button
  }
}
</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;
    overflow: hidden;

    img {
      border-radius: 8px;
    }
  }

  .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: 14px;
      font-family: PingFangSC-Medium, PingFang SC;
      font-weight: 600;
      color: #D32323;
      line-height: 22px;
    }

    .cartcontrol-wrapper {
      position: absolute;
      right: 0;
      bottom: 1px;
    }

    .btn-show-sku {
      position: absolute;
      right: 0;
      bottom: 7px;
      width: 55px;
      height: 24px;
      padding: 0;
      border: none;
      background: #D32323;
      border-radius: 12px;

      ::v-deep .van-button__text {
        font-size: 12px;
        color: #FFFFFF;
        line-height: 24px;
      }
    }

    .sell-out {
      position: absolute;
      right: 0;
      bottom: 9px;
      display: block;
      width: 46px;
      height: 32px;
    }
  }
}
</style>
