<template>
  <div v-loading="loading">
    <div class="mask" v-show="isShowSelect"></div>
    <el-popover placement="bottom-start" :width="popoverWidth" trigger="manual" v-model="isShowSelect"
                @hide="popoverHide" v-click-outside="outsideClick">
      <el-input
        size="mini"
        prefix-icon="el-icon-search"
        v-model="filterText">
      </el-input>
      <el-tree class="common-tree" :width="width" ref="tree" :data="treeData" :props="obj"
               :show-checkbox="multiple"
               :node-key="obj.id"
               :check-strictly="checkStrictly"
               :expand-on-click-node="multiple&&expandClickNode"
               :check-on-click-node="checkClickNode"
               :highlight-current="true"
               @check="clickDeal"
               :default-checked-keys="checkedId"
               :filter-node-method="filterNode"
               @node-click="nodeClick"/>
      <el-select slot="reference" ref="select" :size="size"
                 v-model="returnDataKeys"
                 :multiple="multiple"
                 :clearable="clearable"
                 :collapse-tags="collapseTags"
                 :disabled="disabled"
                 @click.native="selectClick"
                 @remove-tag="removeTag"
                 @clear="clean"
                 :placeholder="placeholder"
                 class="ms-tree-select">
        <el-option v-for="item in options" :key="item.value" :label="item.label" :value="item.value"></el-option>
      </el-select>
      <el-row>
        <el-button v-if="multiple" class="ok" @click="isShowSelect=false" size="mini" type="text">
          {{ $t('commons.confirm') }}
        </el-button>
      </el-row>
    </el-popover>
  </div>
</template>

<script>

export default {
  name: 'SelectTree',
  props: {
    // 树结构数据
    data: {
      type: Array,
      default() {
        return [];
      }
    },
    obj: {
      type: Object,
      required: false,
      default: () => {
        return {
          id: 'id',// ID
          label: 'name',// 显示名称
          children: 'children', //子级字段名
          path: 'path',//路径
          content: 'content',//描述
          pid: 'pid',//父id
          disabled: this.isDisabled
        }
      }
    },
    disabled: {
      type: Boolean,
      default: false,
    },
    // 配置是否可多选
    multiple: {
      type: Boolean,
      default() {
        return false;
      }
    },
    // 配置是否可清空选择
    clearable: {
      type: Boolean,
      default() {
        return false;
      }
    },
    // 配置多选时是否将选中值按文字的形式展示
    collapseTags: {
      type: Boolean,
      default() {
        return false;
      }
    },
    // 显示复选框情况下，是否严格遵循父子不互相关联
    checkStrictly: {
      type: Boolean,
      default() {
        return false;
      }
    },
    //多选是设置点击节点是否可以选中
    checkClickNode: {
      type: Boolean,
      default() {
        return false;
      }
    },
    //多选时：点击节点展开还是点三角标
    expandClickNode: {
      type: Boolean,
      default() {
        return false;
      }
    },
    // 默认选中的节点key
    defaultKey: {
      type: [Number, String, Array, Object],
      default() {
        return [];
      }
    },
    size: {
      type: String,
      default() {
        return 'small';
      }
    },
    width: {
      type: String,
      default() {
        return '100%';
      }
    },
    height: {
      type: String,
      default() {
        return '300px';
      }
    },
    placeholder: {
      type: String,
      default() {
        return this.$t('el.select.placeholder');
      }
    }
  },
  //上面是父组件可传入参数
  data() {
    return {
      popoverWidth: "0px",//下拉框大小
      isShowSelect: false, // 是否显示树状选择器
      options: [],//select option选项
      returnDatas: [],//返回给父组件数组对象
      returnDataKeys: [],//返回父组件数组主键值
      filterText: "",
      loading: false,
      checkedId: [],
      selectNodeIds: []
    };
  },
  computed: {
    treeData() { // 若非树状结构，则转化为树状结构数据
      return JSON.stringify(this.data).indexOf(this.obj.children) !== -1 ? this.data : this.switchTree();
    },
  },
  mounted() {
    this.init();
  },
  methods: {
    updated() {
      // 给多选树设置默认值
      this.$refs.tree.setCheckedKeys(this.checkedId)
    },
    clickDeal(currentObj, treeStatus) {
      // 用于：父子节点严格互不关联时，父节点勾选变化时通知子节点同步变化，实现单向关联。
      let selected = treeStatus.checkedKeys.indexOf(currentObj.id) // -1未选中
      // 选中
      if (selected !== -1) {
        // 子节点只要被选中父节点就被选中
        // this.selectedParent(currentObj)
        // 统一处理子节点为相同的勾选状态
        this.uniteChildSame(currentObj, true)
      } else {
        // 未选中 处理子节点全部未选中
        if (currentObj.children && currentObj.children.length !== 0) {
          this.uniteChildSame(currentObj, false)
        }
      }
      this.nodeClick(currentObj, treeStatus)
    },
    // 统一处理子节点为相同的勾选状态
    uniteChildSame(treeList, isSelected) {
      this.$refs.tree.setChecked(treeList.id, isSelected)
      if (treeList.children) {
        for (let i = 0; i < treeList.children.length; i++) {
          this.uniteChildSame(treeList.children[i], isSelected)
        }
      }
    },
    // 统一处理父节点为选中
    selectedParent(currentObj) {
      let currentNode = this.$refs.tree.getNode(currentObj)
      if (currentNode.parent.key !== undefined) {
        this.$refs.tree.setChecked(currentNode.parent, true)
        this.selectedParent(currentNode.parent)
      }
    },
    outsideClick(e) {
      e.stopPropagation();
      this.isShowSelect = false;
    },
    init() {
      if (this.defaultKey != undefined && this.defaultKey.length > 0) {
        if (this.multiple) {
          // 多选
          if (Object.prototype.toString.call(this.defaultKey).indexOf("Array") != -1) {
            if (Object.prototype.toString.call(this.defaultKey[0]).indexOf("Object") != -1) {//对象
              this.setDatas(this.defaultKey);
            } else if (Object.prototype.toString.call(this.defaultKey[0]).indexOf("Number") != -1
              || Object.prototype.toString.call(this.defaultKey[0]).indexOf("String") != -1) {
              this.setKeys(this.defaultKey);
            } else {
              return;
            }
          } else {
            return;
          }

        } else {
          // 单选
          if (Object.prototype.toString.call(this.defaultKey).indexOf("Number") != -1
            || Object.prototype.toString.call(this.defaultKey).indexOf("String") != -1
            || Object.prototype.toString.call(this.defaultKey).indexOf("Object") != -1) {
            this.setKey(this.defaultKey);
          } else {
            return;
          }
        }
      } else {
        this.returnDataKeys = this.defaultKey;
        this.setKey(this.defaultKey);
      }
    },
    //下拉框select点击[入口]
    selectClick() {
      if (this.disabled) {
        return;
      }
      this.$nextTick(function () {//设置下拉框自适应宽度
        this.popoverWidth = this.$refs.select.$el.clientWidth - 26;
      })
      //显示下拉框
      return this.isShowSelect = !this.isShowSelect
    },
    //单选: 树点击方法
    nodeClick(data, node) {
      if (!this.multiple) {//单选
        this.isShowSelect = false;
        this.setKey(node.key);
      } else {//多选
        let checkedKeys = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
        let t = [];
        this.options = checkedKeys.map((item) => {//设置option选项
          let node = this.$refs.tree.getNode(item); // 所有被选中的节点对应的node
          t.push(node.data);
          return {label: node.label, value: node.key};
        });
        this.returnDataKeys = this.options.map((item) => {
          return item.value;
        });
        this.returnDatas = t;
      }

      this.selectNodeIds = [];
      if (data) {
        this.getChildNodeId(data, this.selectNodeIds);
      }
    },
    getChildNodeId(rootNode, nodeIds) {
      //递归获取所有子节点ID
      nodeIds.push(rootNode.id);
      if (rootNode.children) {
        for (let i = 0; i < rootNode.children.length; i++) {
          this.getChildNodeId(rootNode.children[i], nodeIds);
        }
      }
    },
    //单选:清空选中
    clean() {
      this.$refs.tree.setCurrentKey(null);//清除树选中key
      this.returnDatas = null;
      this.returnDataKeys = '';
      this.selectNodeIds = [];
      this.popoverHide();
      this.$emit('clean');
    },
    //单选:设置、初始化值 key
    setKey(thisKey) {
      this.$refs.tree.setCurrentKey(thisKey);
      let node = this.$refs.tree.getNode(thisKey);
      if (node && node.data) {
        this.setData(node.data);
      }
      this.popoverHide();
    },
    //单选：设置、初始化对象
    setData(data) {
      this.options = [];
      this.options.push({label: data[this.obj.label], value: data[this.obj.id]});
      this.returnDatas = data;
      this.returnDataKeys = data[this.obj.id]
      this.selectNodeIds = [];
      this.getChildNodeId(data, this.selectNodeIds);
    },
    //多选:设置、初始化值 keys
    setKeys(thisKeys) {
      this.$refs.tree.setCheckedKeys(thisKeys);
      this.returnDataKeys = thisKeys;
      let t = [];
      this.options = [];
      thisKeys.map((item) => {//设置option选项
        let node = this.$refs.tree.getNode(item); // 所有被选中的节点对应的node
        if (node) {
          t.push(node.data);
          this.options.push({label: node.label, value: node.key});
          return {label: node.label, value: node.key};
        }
      });
      this.returnDatas = t;
      this.popoverHide()
    },
    //多选:设置、初始化对象
    setDatas(data) {
      this.$refs.tree.setCheckedNodes(data);
      this.returnDatas = data;
      let t = [];
      data.map((item) => {//设置option选项
        t.push(item[this.obj.id]);
      });
      this.returnDataKeys = t;
      this.popoverHide()
    },
    // 多选,删除任一select选项的回调
    removeTag(val) {
      this.$refs.tree.setChecked(val, false);//设置为未选中
      let node = this.$refs.tree.getNode(val);//获取节点
      if (!this.checkStrictly && node.childNodes.length > 0) {
        this.treeToList(node).map(item => {
          if (item.childNodes.length <= 0) {
            this.$refs.tree.setChecked(item, false);
          }
        });
      }
      this.nodeClick();
      this.popoverHide();

    },
    //下拉框关闭执行
    popoverHide() {
      this.$emit('setSelectNodeIds', this.selectNodeIds);
      this.$emit('getValue', this.returnDataKeys, this.returnDatas ? this.returnDatas : {});
    },
    // 多选，清空所有勾选
    clearSelectedNodes() {
      let checkedKeys = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
      for (let i = 0; i < checkedKeys.length; i++) {
        this.$refs.tree.setChecked(checkedKeys[i], false);
      }
    },

    //树形转为集合
    treeToList(tree) {
      let queen = [];
      let out = [];
      queen = queen.concat(tree);
      while (queen.length) {
        let first = queen.shift();
        if (first.childNodes) {
          queen = queen.concat(first.childNodes);
        }
        out.push(first);
      }
      return out;
    },
    switchTree() {
      return this.buildTree(this.data, this.defaultValue);
    },
    // 将一维的扁平数组转换为多层级对象
    buildTree(data, id) {
      const fa = (id) => {
        const temp = [];
        for (let i = 0; i < data.length; i++) {
          const n = data[i];
          if (n[this.obj.pid] === id) {
            if (this.obj.children) {
              n[this.obj.children] = fa(n[this.obj.id]);
            }
            temp.push(n);
          }
        }
        return temp;
      };
      return fa(id);
    },
    filterNode(value, data) {
      if (!value) return true;
      if (data.label) {
        return data.label.toLowerCase().indexOf(value.toLowerCase()) !== -1;
      }
      return false;
    },
    reload() {
      this.loading = true
      this.$nextTick(() => {
        this.loading = false
      });
    },
  },

  watch: {
    // eslint-disable-next-line no-unused-vars
    isShowSelect(val) {
      // 隐藏select自带的下拉框
      this.$refs.select.blur();
    },
    treeData: {//监听tree数据
      handler: function () {
        this.$nextTick(() => {
          this.init();
        })
      },
      deep: true
    },
    defaultKey: {
      handler: function () {
        this.init();
        if (this.data && this.data.length > 0) {
          if (this.defaultKey instanceof Array) {
            this.$refs.tree.setCheckedKeys(this.defaultKey);
          }
        }
      },
      deep: true
    },
    data: {
      handler: function () {
        if (this.defaultKey && this.defaultKey.length > 0 && this.defaultKey instanceof Array) {
          if (this.defaultKey instanceof Array) {
            this.$refs.tree.setCheckedKeys(this.defaultKey);
          }
        }
      },
      deep: true
    },
    filterText(val) {
      this.$nextTick(() => {
        this.$refs.tree.filter(val);
      });
    },
    filter(val) {
      this.$nextTick(() => {
        this.$refs.tree.filter(val);
      });
    },
  }
};
</script>

<style scoped>
.mask {
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  opacity: 0;
  z-index: 11;
}

.common-tree {
  overflow: auto;
  min-height: 200px;
  max-height: 400px;
}

.ms-tree-select {
  width: 100%;
  z-index: 111;
}

:deep(.el-tree-node__children ) {
  overflow: inherit;
}

.ok {
  float: right;
}

.el-row {
  padding-top: 0px !important;
}

</style>
