const express = require('express');
const multer = require('multer');
const {
  getProductCodeMeta,
  getProductCodeSequence,
  listProductCodes,
  buildProductCodeBatchImportTemplateBuffer,
  buildProductCodeExportBuffer,
  createProductCodes,
  createProductCodeBatch,
  importProductCodeBatchWorkbook,
} = require('../services/productCodeBoard');

const router = express.Router();
const productCodeBatchImportUpload = multer({
  storage: multer.memoryStorage(),
  limits: {
    fileSize: 10 * 1024 * 1024,
  },
  fileFilter: (_req, file, callback) => {
    const lowerName = String(file.originalname || '').toLowerCase();
    if (lowerName.endsWith('.xlsx') || lowerName.endsWith('.xls')) {
      callback(null, true);
      return;
    }
    callback(new Error('仅支持上传 Excel 文件（.xlsx / .xls）'));
  },
});

function sendError(res, error, fallbackMessage) {
  const status = error.status || error.statusCode || 500;
  res.status(status).json({
    success: false,
    error: error.message || fallbackMessage,
  });
}

router.get('/meta', async (_req, res) => {
  try {
    const data = await getProductCodeMeta();
    res.json({
      success: true,
      data,
    });
  } catch (error) {
    sendError(res, error, '获取编码规则失败');
  }
});

router.get('/sequence', async (req, res) => {
  try {
    const data = await getProductCodeSequence({
      operationCenter: req.query.operationCenter,
      categoryName: req.query.categoryName,
    });
    res.json({ success: true, data });
  } catch (error) {
    sendError(res, error, '获取编码序号失败');
  }
});

router.get('/items', async (req, res) => {
  try {
    const data = await listProductCodes({
      page: req.query.page,
      pageSize: req.query.pageSize,
      keyword: req.query.keyword,
      operationCenter: req.query.operationCenter,
      categoryName: req.query.categoryName,
      productStatus: req.query.productStatus,
      createdByNames: req.query.createdByNames,
      createdAtStart: req.query.createdAtStart,
      createdAtEnd: req.query.createdAtEnd,
    });
    res.json({ success: true, data });
  } catch (error) {
    sendError(res, error, '获取商品编码看板失败');
  }
});

router.get('/items/export', async (req, res) => {
  try {
    const { buffer, totalRows } = await buildProductCodeExportBuffer({
      keyword: req.query.keyword,
      operationCenter: req.query.operationCenter,
      categoryName: req.query.categoryName,
      productStatus: req.query.productStatus,
      createdByNames: req.query.createdByNames,
      createdAtStart: req.query.createdAtStart,
      createdAtEnd: req.query.createdAtEnd,
    });
    const fileName = encodeURIComponent('测款数据导出.xlsx');
    res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
    res.setHeader('Content-Disposition', `attachment; filename*=UTF-8''${fileName}`);
    res.setHeader('X-Export-Count', String(totalRows));
    res.send(buffer);
  } catch (error) {
    sendError(res, error, '导出测款数据失败');
  }
});

router.get('/batch-template', (_req, res) => {
  try {
    const buffer = buildProductCodeBatchImportTemplateBuffer();
    const fileName = encodeURIComponent('测款批量新增模板.xlsx');
    res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
    res.setHeader('Content-Disposition', `attachment; filename*=UTF-8''${fileName}`);
    res.send(buffer);
  } catch (error) {
    sendError(res, error, '下载批量导入模板失败');
  }
});

router.post('/items', async (req, res) => {
  try {
    const data = await createProductCodes(req.body, req.user || {});
    res.json({ success: true, data });
  } catch (error) {
    sendError(res, error, '新增商品编码失败');
  }
});

router.post('/items/batch', async (req, res) => {
  try {
    const data = await createProductCodeBatch(req.body, req.user || {});
    res.json({ success: true, data });
  } catch (error) {
    sendError(res, error, '批量新增商品编码失败');
  }
});

router.post('/items/batch-import', (req, res, next) => {
  productCodeBatchImportUpload.single('file')(req, res, (error) => {
    if (error) {
      return res.status(400).json({ success: false, error: error.message || '上传文件失败' });
    }
    return next();
  });
}, async (req, res) => {
  try {
    if (!req.file?.buffer) {
      return res.status(400).json({ success: false, error: '请上传批量新增 Excel 文件' });
    }

    const data = await importProductCodeBatchWorkbook(req.file.buffer, {
      operationCenter: req.body.operationCenter,
      categoryName: req.body.categoryName,
    }, req.user || {});
    res.json({
      success: true,
      message: `已导入 ${data.productCount || data.importedProductCount || 0} 个商品、${data.skuCount || data.importedSkuCount || 0} 个规格`,
      data,
    });
  } catch (error) {
    sendError(res, error, '批量导入商品失败');
  }
});

module.exports = router;