import JSZip from 'jszip';

// 通用表格导出：CSV（带 BOM，Excel 直接打开中文不乱码）与 XLSX（基于 jszip 生成最小 OOXML 工作簿）。
// columns 复用 antd Table 列定义（title/dataIndex），可选 exportValue(value, row) 提供导出值格式化（与 antd render 的 value 语义一致）。

export const escapeXmlText = (value) => String(value)
  .replace(/&/g, '&')
  .replace(/</g, '&lt;')
  .replace(/>/g, '&gt;')
  .replace(/"/g, '&quot;')
  .replace(/'/g, '&apos;');

export const spreadsheetColumnName = (index) => {
  let name = '';
  let value = index + 1;
  while (value > 0) {
    const remainder = (value - 1) % 26;
    name = String.fromCharCode(65 + remainder) + name;
    value = Math.floor((value - 1) / 26);
  }
  return name;
};

const resolveCell = (column, row) => {
  const value = row?.[column?.dataIndex];
  return typeof column?.exportValue === 'function' ? column.exportValue(value, row) : value;
};

export const resolveExportRows = (columns, rows) => (
  (rows || []).map((row) => columns.map((column) => resolveCell(column, row)))
);

const saveBlob = (blob, fileName) => {
  const url = URL.createObjectURL(blob);
  const link = document.createElement('a');
  link.href = url;
  link.download = fileName;
  document.body.appendChild(link);
  link.click();
  link.remove();
  URL.revokeObjectURL(url);
};

// 服务端直接返回文件的场景（/export 接口，responseType: 'blob'）在这里统一落盘
export const downloadBlobAsFile = (blob, fileName) => saveBlob(blob, fileName);

// 导出接口出错时，错误响应体同样是 Blob（内含 JSON），这里统一解出可读文案
export const readBlobErrorMessage = async (error, fallback = '导出失败') => {
  const data = error?.response?.data;
  if (typeof Blob !== 'undefined' && data instanceof Blob) {
    try {
      const text = await data.text();
      try {
        const parsed = JSON.parse(text);
        return parsed?.error || parsed?.message || fallback;
      } catch {
        return text.slice(0, 300) || fallback;
      }
    } catch {
      return fallback;
    }
  }
  return error?.response?.data?.error || error?.message || fallback;
};

const quoteCsvCell = (value) => {
  const text = value === null || value === undefined ? '' : String(value);
  return /[",\r\n]/.test(text) ? `"${text.replace(/"/g, '""')}"` : text;
};

export const buildCsvContent = (columns, rows) => {
  const header = columns.map((column) => quoteCsvCell(column?.title ?? '')).join(',');
  const body = resolveExportRows(columns, rows)
    .map((cells) => cells.map((cell) => quoteCsvCell(cell)).join(','))
    .join('\r\n');
  return body ? `${header}\r\n${body}` : header;
};

export const exportTableToCsv = (fileName, columns, rows) => {
  const content = buildCsvContent(columns, rows);
  saveBlob(new Blob([`\ufeff${content}`], { type: 'text/csv;charset=utf-8;' }), `${fileName}.csv`);
};

const CONTENT_TYPES_XML = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
  + '<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">'
  + '<Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>'
  + '<Default Extension="xml" ContentType="application/xml"/>'
  + '<Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/>'
  + '<Override PartName="/xl/worksheets/sheet1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/>'
  + '</Types>';

const ROOT_RELS_XML = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
  + '<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">'
  + '<Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/>'
  + '</Relationships>';

const WORKBOOK_RELS_XML = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
  + '<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">'
  + '<Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet1.xml"/>'
  + '</Relationships>';

const workbookXml = (sheetName) => '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
  + '<workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" '
  + 'xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">'
  + `<sheets><sheet name="${escapeXmlText(sheetName)}" sheetId="1" r:id="rId1"/></sheets>`
  + '</workbook>';

const cellXml = (value, rowIndex, columnIndex) => {
  const ref = `${spreadsheetColumnName(columnIndex)}${rowIndex + 1}`;
  if (value === null || value === undefined || value === '') {
    return `<c r="${ref}"/>`;
  }
  if (typeof value === 'number' && Number.isFinite(value)) {
    return `<c r="${ref}"><v>${value}</v></c>`;
  }
  return `<c r="${ref}" t="inlineStr"><is><t xml:space="preserve">${escapeXmlText(value)}</t></is></c>`;
};

export const buildWorksheetXml = (columns, rows) => {
  const lines = [columns.map((column, columnIndex) => cellXml(column?.title ?? '', 0, columnIndex)).join('')];
  resolveExportRows(columns, rows).forEach((cells, rowIndex) => {
    lines.push(cells.map((cell, columnIndex) => cellXml(cell, rowIndex + 1, columnIndex)).join(''));
  });
  return '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
    + '<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">'
    + `<sheetData>${lines.map((row) => `<row>${row}</row>`).join('')}</sheetData>`
    + '</worksheet>';
};

export const exportTableToXlsx = async (fileName, columns, rows, sheetName = '数据') => {
  const zip = new JSZip();
  zip.file('[Content_Types].xml', CONTENT_TYPES_XML);
  zip.file('_rels/.rels', ROOT_RELS_XML);
  zip.file('xl/workbook.xml', workbookXml(sheetName));
  zip.file('xl/_rels/workbook.xml.rels', WORKBOOK_RELS_XML);
  zip.file('xl/worksheets/sheet1.xml', buildWorksheetXml(columns, rows));

  const blob = await zip.generateAsync({ type: 'blob', compression: 'DEFLATE' });
  saveBlob(blob, `${fileName}.xlsx`);
};

export const exportTableFile = async (format, fileName, columns, rows, sheetName) => {
  if (format === 'xlsx') {
    await exportTableToXlsx(fileName, columns, rows, sheetName);
    return;
  }
  exportTableToCsv(fileName, columns, rows);
};