<template>
  <el-select
    ref="test"
    :size="size"
    :disabled="isBindPlan"
    :value="valueTitle"
    :clearable="clearable"
    @clear="clearHandle"
    :placeholder="placeholder"
  >
    <el-option :value="valueTitle" :label="valueTitle" class="options">
      <slot :pHandleNodeClick="handleNodeClick">
        <el-tree
          id="tree-option"
          ref="selectTree"
          :key="treeKey"
          :accordion="accordion"
          :data="options"
          :props="props"
          :node-key="props.value"
          :default-expand-all="true"
          :default-expanded-keys="defaultExpandedKey"
          @node-click="handleNodeClick"
        >
        </el-tree>
      </slot>
    </el-option>
  </el-select>
</template>

<script>
export default {
  props: {
    // 配置项
    props: {
      type: Object,
      default () {
        return {
          value: 'value', // ID字段名
          label: 'label', // 显示名称
          children: 'children' // 子级字段名
        }
      }
    },
    // 选项列表数据(树形结构的对象数组)
    options: { type: Array, default: () => [] },
    // 初始值
    value: { type: [String, Number], default: null },
    // 可清空选项
    clearable: { type: Boolean, default: false },
    // 自动收起
    accordion: { type: Boolean, default: false },
    // // 可清空选项
    // disabled: { type: Boolean, default: false },
    // 多选
    multiple: { type: Boolean, default: false },
    //

    placeholder: {
      type: String,
      default: '请选择'
    },
    size: {
      type: String,
      default: 'mini'
    },
    dialogType: {
      type: String,
      default: ''
    },
    tableIndex: { type: Number, default: null },
    initStr: {
      type: String,
      default: ''
    },
    isBindPlan: {
      type: Boolean,
      default: function () {
        return false
      }
    },
  },
  data () {
    return {
      valueId: null,
      treeKey: true,
      valueTitle: '',
      defaultExpandedKey: []
    }
  },
  watch: {
    // 这个需要用深度监听，不然回显有时会失效
    value: {
      handler (val) {
        this.valueId = this.value
        this.initHandle()
      },
      deep: true,
      immediate: true
    },
    options:{
      handler (val) {
        this.initHandle()
      },
      deep: true,
      immediate: true
    },
    initStr: {
      handler (newVal, oldVal) {
        if (this.initStr) {
          // console.log(newVal);
          this.valueTitle = newVal
        }
      },
      immediate: true
    }
  },
  // mounted() {
  //   this.valueId = this.value; // 初始值
  //   setTimeout(() => {
  //     this.initHandle();
  //   },300)
  // },
  methods: {
    // 初始化值
    async initHandle () {
      if (this.valueId) {
        this.$nextTick(async () => {
          const tempValue = await this.$refs.selectTree.getNode(this.valueId)
          setTimeout(() => {
            if (tempValue) {
              this.valueTitle = tempValue.data[this.props.label] // 初始化显示
              this.$refs.selectTree.setCurrentKey(this.valueId) // 设置默认选中
              this.defaultExpandedKey = [this.valueId] // 设置默认展开
            }
          }, 300)
        })
      } else {
        this.valueTitle = ''
      }
      this.initScroll()
    },
    // 初始化滚动条
    initScroll () {
      this.$nextTick(() => {
        let scrollWrap = document.querySelectorAll(
          '.el-scrollbar .el-select-dropdown__wrap'
        )[0]
        let scrollBar = document.querySelectorAll(
          '.el-scrollbar .el-scrollbar__bar'
        )
        scrollWrap.style.cssText =
          'margin: 0px; max-height: none; overflow: hidden;'
        scrollBar.forEach(ele => (ele.style.width = 0))
      })
    },
    // 切换选项
    handleNodeClick (node) {
      // 多选
      if (this.multiple) {
        this.valueTitle += `${node[this.props.label]} , `
        this.valueId = node[this.props.value]
        this.$emit('getValue', node)
        this.defaultExpandedKey = []
        return
      }
      this.valueTitle = node[this.props.label]
      this.valueId = node[this.props.value]
      this.$emit('getValue', node)
      this.defaultExpandedKey = []
      this.$refs.test.handleClose()
    },
    // 清除选中
    clearHandle () {
      this.valueTitle = ''
      this.valueId = null
      this.defaultExpandedKey = []
      // this.clearSelected()
      this.treeKey = !this.treeKey
      this.$emit('getValue', null)
    },
    // 清空选中样式
    clearSelected () {
      let allNode = document.querySelectorAll('#tree-option .el-tree-node')
      allNode.forEach(element => element.classList.remove('is-current'))
    }
  }
}
</script>
<style scoped>
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item {
  height: auto;
  max-height: 274px;
  padding: 0;
  overflow: hidden;
  overflow-y: auto;
}
.el-select-dropdown__item.selected {
  font-weight: normal;
}
ul li >>> .el-tree .el-tree-node__content {
  height: auto;
  padding: 0 20px;
}
.el-tree-node__label {
  font-weight: normal;
}
.el-tree >>> .is-current .el-tree-node__label {
  color: #157a2c;
  font-weight: 700;
}
.el-tree >>> .is-current .el-tree-node__children .el-tree-node__label {
  color: #606266;
  font-weight: normal;
}
</style>
