import * as XLSX from 'xlsx';

export const domToExcel = (dom, name="data") => {
        const worksheet = XLSX.utils.table_to_sheet(dom);
        const workbook = XLSX.utils.book_new();
        XLSX.utils.book_append_sheet(workbook, worksheet);
        XLSX.writeFile(workbook, `${name}.xlsx`);
}
/**
 * eg: .columns = [
 *    { header: 'Id', key: 'id', wpx: 10 },
 *    { header: 'Name', key: 'name', wch: 32 },
 *    { header: 'D.O.B.', key: 'dob', width: 10, hidden: true }
 * ]
 * data: [{id: 1, name: 'John Doe', dob: new Date(1970,1,1)}]
 * @param columns 定义列属性数组
 * @param data  数据
 * @param name  文件名
 */
export const dataToExcel = (columns = [], data = [], name = 'data') => {
  const headers = columns.map((item) => item.header);
  const dataList = data.map((item) => {
    let obj = {};
    columns.forEach(col => {
      obj[col.header] = getNestedValue(item, col.key) ?? '';
    });
    return obj;
  });
  const workbook = XLSX.utils.book_new();
  // workbook.SheetNames.push(name);
  const worksheet = XLSX.utils.json_to_sheet(dataList, {
    header: headers,
  });
  // 自动计算列宽
  worksheet['!cols'] = calculateColumnWidths(columns, dataList);
  // const otherConfigs = columns.map(({ key, header, ...item }) => item);
  // worksheet['!cols'] = otherConfigs;
  XLSX.utils.book_append_sheet(workbook, worksheet);
  XLSX.writeFile(workbook, `${name}.xlsx`);
  // workbook.Sheets[name] = worksheet;
  // // 生成Blob数据
  // const excelData = XLSX.write(workbook, { type: 'array', bookType: 'xlsx' });
  // const blobData = new Blob([excelData], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
  // // 创建Blob URL
  // const blobUrl = URL.createObjectURL(blobData);
  // // 创建一个隐藏的<a>标签并设置href属性为Blob URL
  // const link = document.createElement('a');
  // link.href = blobUrl;
  // link.target = '_blank';
  // link.download = `${name}.xlsx`;
  // // 触发点击操作，开始下载文件
  // link.click();
  // // 释放Blob URL
  // URL.revokeObjectURL(blobUrl);
};

const getNestedValue = (obj, path, defaultValue = '') => {
  if (!obj || !path) return defaultValue;
  
  const keys = path.split('.');
  let result = obj;
  
  for (const key of keys) {
    if (result === null || result === undefined) {
      return defaultValue;
    }
    result = result[key];
  }
  
  return result !== undefined ? result : defaultValue;
};
const calculateColumnWidths = (columns, dataList) => {
  // 确保 dataList 有数据
  if (!dataList || dataList.length === 0) {
    return columns.map(col => ({ wch: 15 })); // 返回默认宽度
  }
  
  return columns.map(col => {
    // 固定宽度优先
    if (col.wpx) return { wpx: col.wpx };
    if (col.wch) return { wch: col.wch };
    if (col.width) return { wch: col.width };
    
    const header = col.header || '';
    let maxWidth = header.length;
    
    // 遍历数据计算最大宽度
    for (let i = 0; i < Math.min(dataList.length, 100); i++) {
      const item = dataList[i];
      // 确保使用正确的键名
      const value = item[header] !== undefined ? String(item[header]) : '';
      if (value.length > maxWidth) {
        maxWidth = value.length;
      }
    }
    
    return { wch: Math.min(Math.max(maxWidth + 2, 8), 50) };
  });
};