<template>
  <scroll-view
    scroll-x="true"
    scroll-with-animation
    :scroll-left="scrollLeft"
    ref="tabsscroll"
    class="colpu__tabs-header"
    :style="{
      backgroundColor: backgroundColor,
    }"
  >
    <view class="colpu__tabs-header-scroll" :style="styles">
      <template v-for="(item, idx) in dataList" :key="idx">
        <view
          class="colpu__tabs-header-item"
          :class="{ active: selectIndex === idx }"
          @tap="selectHanddle(idx)"
        >
          {{ item[keyName] }}
        </view>
      </template>
    </view>
    <view
      v-if="showHover"
      class="colpu__tabs-header-hover"
      :style="{
        left: hoverDetail.left + 'px',
        width: hoverDetail.width + 'px',
        borderRadius: borderRadius,
        bottom: bottom + 'px',
      }"
    ></view>
  </scroll-view>
</template>

<script setup>
/**
 * tab最大支持10个，首scroll-view限制，会导致计算错误
 */
import { getCurrentInstance, onMounted, ref, watch } from "vue";
const scrollLeft = ref(0);
const hoverDetail = ref({ left: 0, width: 0 });
const tabListDetail = ref([]);
const selectIndex = ref(0);
const tabsDetail = ref({ left: 0, width: 0 });
const props = defineProps({
  dataList: {
    type: Array,
    default: () => [],
  },
  index: { type: Number, default: 0 },
  bottom: {
    type: Number,
    default: 0,
  },
  styles: {
    type: [Object, String],
    default: () => ({}),
  },
  borderHeight: {
    type: Number,
    default: 2,
  },
  borderRadius: {
    type: String,
    default: "3px",
  },
  backgroundColor: {
    type: String,
    default: "none",
  },
  keyName: {
    type: String,
    default: "name",
  },
  showHover: {
    type: Boolean,
    default: true,
  },
});

const emits = defineEmits({
  select: null,
});

const getSelectQuery = () => {
  const query = uni.createSelectorQuery().in(getCurrentInstance());
  const pr = [];
  pr.push(
    new Promise((res) => {
      query
        .selectAll(".colpu__tabs-header-item")
        .boundingClientRect((data) => {
          tabListDetail.value = data;
          res(data);
        })
        .exec();
    })
  );
  pr.push(
    new Promise((res) => {
      query
        .selectAll(".colpu__tabs-header")
        .boundingClientRect((value) => {
          tabsDetail.value = value[0];
          res(value[0]);
        })
        .exec();
    })
  );
  return Promise.all(pr);
};

onMounted(async () => {
  await getSelectQuery();
  selectHanddle(props.index, false);
});

const selectHanddle = (index, isEmit = true) => {
  const halfWidth = tabsDetail.value.width / 2;
  selectIndex.value = index;
  const data = tabListDetail.value[index] || {};
  let { left = 0, width = 0 } = data;
  if (halfWidth > left) {
    scrollLeft.value = 0;
  } else {
    scrollLeft.value = left - halfWidth + width / 2;
  }
  hoverDetail.value.left = left;
  hoverDetail.value.width = width - 10;
  isEmit && emits("select", { index, data: props.dataList[index] });
};

defineExpose({
  switchTab: (index) => {
    selectHanddle(index);
  },
});

watch(
  () => props.dataList,
  (value, ov) => {
    selectIndex.value = props.index;
    if (props.index !== 0) {
      selectHanddle(props.index, false);
    }
  }
);
</script>
<style lang="scss">
$color-primary: #001d4f;
$color-tips: #999;
.colpu__tabs-header {
  position: relative;
  flex: 1;
  $h: 48rpx;
  &-scroll {
    display: flex;
    align-items: center;
    flex-wrap: nowrap;
    align-content: stretch;
    justify-content: space-around;
    height: $h;
    .active {
      color: $color-primary;
      font-weight: 800;
    }
  }
  &-hover {
    $hoverH: 4rpx;
    position: absolute;
    width: 0;
    height: $hoverH;
    top: $h - $hoverH;
    border-radius: $hoverH;
    background-color: $color-primary;
    bottom: 0;
    transition: all 0.3s ease;
  }
  &-item {
    position: relative;
    margin: 0 10px;
    flex-shrink: 0;
    display: flex;
    justify-content: space-between;
    font-size: 28rpx;
    color: $color-tips;
  }
}
</style>