<template>
  <el-dialog
    :close-on-click-modal="false"
    v-el-drag-dialog
    class="dialog"
    title="自定义列选择"
    width="326px"
    destroy-on-close
    :visible.sync="visible"
    @closed="close"
  >
    <el-table
      stripe
      ref="dragTable"
      size="mini"
      :data="tableData"
      row-key="itemKey"
      @selection-change="handleSelectionChange"
    >
      <el-table-column
        type="index"
        width="30"
        align="center"
        class-name="table-index"
      />
      <el-table-column
        type="selection"
        width="36"
        align="center"
        class-name="table-selection"
      />
      <el-table-column prop="label" label="列名" />
      <el-table-column
        label="移动"
        width="110"
        align="center"
        class-name="table-arrow"
      >
        <template slot-scope="{ row }">
          <i @click="up(row)"><svg-icon icon-class="up" /></i>
          <i @click="down(row)"><svg-icon icon-class="down" /></i>
        </template>
      </el-table-column>
    </el-table>
    <div class="check">
      <el-checkbox v-model="wrap">列宽自动换行</el-checkbox>
      <div v-if="showPageSizeSet">
        <span>每页默认</span>
        <el-select v-model="pageSize" size="mini" style="width: 70px">
          <el-option
            v-for="item in options"
            :key="item"
            :label="item"
            :value="item"
          />
        </el-select>
        <span>条记录</span>
      </div>
    </div>
    <span slot="footer" class="dialog-footer">
      <el-button size="mini" @click="reset">重 置</el-button>
      <el-button type="primary" size="mini" @click="save">保 存</el-button>
    </span>
  </el-dialog>
</template>

<script>
import Sortable from "sortablejs";

export default {
  props: ["showPageSizeSet"],
  data() {
    return {
      visible: false,
      tableData: null,
      multipleSelection: [],
      options: [10, 20, 30, 40, 50, 100],
      wrap: false,
      pageSize: undefined,
    };
  },
  methods: {
    open(column, wrap, pageSize) {
      return new Promise((resolve) => {
        this.resolve = resolve;
        if (!column || column.length === 0) {
          resolve([]);
          return;
        }
        this.wrap = wrap;
        this.pageSize = pageSize;
        const _column = [...column];
        const typeCols = []; // 不需要排序的列
        const tableData = [];
        _column.forEach((item, index) => {
          if (item.type || item.fixed || !item.label) {
            typeCols.push({ index, item });
          } else {
            tableData.push(item);
          }
        });
        this.typeCols = typeCols;
        this.tableData = tableData;
        this.visible = true;
        this.$nextTick(() => {
          this.setSort();
          this.tableData.forEach((item) => {
            this.$refs.dragTable.toggleRowSelection(item, item.show);
          });
        });
      });
    },
    setSort() {
      const el = this.$refs.dragTable.$el.querySelectorAll(
        ".el-table__body-wrapper > table > tbody"
      )[0];
      this.sortable = Sortable.create(el, {
        ghostClass: "lb-custom-colnum-ghost", // Class name for the drop placeholder,
        setData: function (dataTransfer) {
          // to avoid Firefox bug
          // Detail see : https://github.com/RubaXa/Sortable/issues/1012
          dataTransfer.setData("Text", "");
        },
        onEnd: (evt) => {
          const targetRow = this.tableData.splice(evt.oldIndex, 1)[0];
          this.tableData.splice(evt.newIndex, 0, targetRow);
        },
      });
    },
    up(row) {
      const oldIndex = this.tableData.findIndex(
        (item) => item.itemKey === row.itemKey
      );
      if (oldIndex === 0) return;
      const newIndex = oldIndex - 1;
      const targetRow = this.tableData.splice(oldIndex, 1)[0];
      this.tableData.splice(newIndex, 0, targetRow);
    },
    down(row) {
      const oldIndex = this.tableData.findIndex(
        (item) => item.itemKey === row.itemKey
      );
      if (oldIndex === this.tableData.length - 1) return;
      const newIndex = oldIndex + 1;
      const targetRow = this.tableData.splice(oldIndex, 1)[0];
      this.tableData.splice(newIndex, 0, targetRow);
    },
    save() {
      const _column = this.tableData.map((item) => {
        if (this.multipleSelection.some((it) => it.itemKey === item.itemKey)) {
          return { ...item, show: true };
        } else {
          return { ...item, show: false };
        }
      });
      this.typeCols.forEach((item) => {
        _column.splice(item.index, 0, item.item);
      });
      this.resolve &&
        this.resolve({
          column: _column,
          wrap: this.wrap,
          pageSize: this.pageSize,
        });
      this.visible = false;
    },
    reset() {
      this.visible = false;
      this.$emit("reset");
    },
    close() {
      this.tableData = [];
      this.multipleSelection = [];
    },
    handleSelectionChange(val) {
      this.multipleSelection = val;
    },
  },
};
</script>
<style>
.lb-custom-colnum-ghost {
  color: #fff !important;
  background: #42b983 !important;
  opacity: 0.8;
}
</style>
<style lang="scss" scoped>
.dialog {
  & ::v-deep .table-index .cell {
    padding-right: 0;
    padding-left: 0;
  }
  & ::v-deep .table-selection .cell {
    padding-left: 0;
  }
  & ::v-deep td.table-arrow .cell {
    display: flex;
    align-items: center;
    justify-content: space-around;
    padding: 0 20px;
    color: #999;
    cursor: pointer;
    i {
      display: inline-block;
      width: 30px;
      height: 32px;
      line-height: 32px;
      text-align: center;
      vertical-align: middle;
      cursor: pointer;
    }
  }
  & ::v-deep .el-table tr td {
    cursor: move;
  }
  & ::v-deep .el-dialog__body {
    padding: 0 !important;
  }
  & ::v-deep .el-table {
    border: none !important;
  }
}
.el-icon-rank,
.el-icon-top,
.el-icon-bottom {
  font-size: 17px;
  font-weight: bold;
  cursor: pointer;
}
.el-icon-bottom {
  margin-left: 20px;
}
.footer-right {
  float: left;
  margin-top: 13px;
}
.check {
  display: flex;
  align-items: center;
  justify-content: space-around;
  height: 40px;
}
</style>
