<template>
  <el-input
    v-model="filterText"
    class="w-60 mb-2"
    placeholder="Filter keyword"
  />

  <el-tree
    ref="treeRef"
    style="max-width: 600px"
    class="filter-tree"
    :data="data"
    :props="defaultProps"
    default-expand-all
    :filter-node-method="filterNode"
  />
</template>

<script lang="ts" setup>
import { ref, watch } from 'vue'

import type { FilterNodeMethodFunction, TreeInstance } from 'element-plus'

interface Tree {
  [key: string]: any
}

const filterText = ref('')
const treeRef = ref<TreeInstance>()

const defaultProps = {
  children: 'children',
  label: 'label',
}

watch(filterText, (val) => {
  treeRef.value!.filter(val)
})

const filterNode: FilterNodeMethodFunction = (value: string, data: Tree) => {
  if (!value) return true
  return data.label.includes(value)
}

const data: Tree[] = [
  {
    id: 1,
    label: 'Level one 1',
    children: [
      {
        id: 4,
        label: 'Level two 1-1',
        children: [
          {
            id: 9,
            label: 'Level three 1-1-1',
          },
          {
            id: 10,
            label: 'Level three 1-1-2',
          },
        ],
      },
    ],
  },
  {
    id: 2,
    label: 'Level one 2',
    children: [
      {
        id: 5,
        label: 'Level two 2-1',
      },
      {
        id: 6,
        label: 'Level two 2-2',
      },
    ],
  },
  {
    id: 3,
    label: 'Level one 3',
    children: [
      {
        id: 7,
        label: 'Level two 3-1',
      },
      {
        id: 8,
        label: 'Level two 3-2',
      },
    ],
  },
]
</script>
