'use strict';

const express = require('express');
const multer = require('multer');
const {
  buildExportColumns,
  getReturnStockWarningExportRows,
  getReturnStockWarningList,
  resolveWarehouse,
  resolveWarehouseKey,
} = require('../services/returnStockWarningService');
const {
  clearStockWarningImport,
  importStockWarning,
} = require('../services/returnStockWarningImport');
const { sendWorkbookDownload } = require('../services/exportWorkbook');

const router = express.Router();
const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 20 * 1024 * 1024 },
});

const resolveScope = (value) => (['imported', 'replica'].includes(String(value)) ? String(value) : 'all');

/**
 * GET /api/return-stock-warning/list —— 退货库存预警列表（客退数据监控，按仓库出数）
 * warehouse: 仓库标识 henlin2 / subei / suining / shandong / henan（缺省 = 横林二仓）
 */
router.get('/list', async (req, res, next) => {
  try {
    const payload = await getReturnStockWarningList({
      warehouse: req.query.warehouse,
      page: req.query.page,
      pageSize: req.query.pageSize,
      keyword: req.query.keyword,
      supplier: req.query.supplier,
      sortBy: req.query.sortBy,
      sortOrder: req.query.sortOrder,
      qtyBasis: req.query.qtyBasis,
      createdAtBasis: req.query.createdAtBasis,
      scope: resolveScope(req.query.scope),
      focusDays: req.query.focusDays,
      alertDays: req.query.alertDays,
      warningLevel: req.query.warningLevel,
      priceFocusMin: req.query.priceFocusMin,
      priceHighMin: req.query.priceHighMin,
      priceLevel: req.query.priceLevel,
      returnLimitDays: req.query.returnLimitDays,
      refresh: req.query.refresh,
    });
    res.json({ success: true, data: payload });
  } catch (error) {
    next(error);
  }
});

/** GET /api/return-stock-warning/export —— 服务端全量导出（xlsx / csv） */
router.get('/export', async (req, res, next) => {
  try {
    const format = String(req.query.format || 'xlsx').toLowerCase() === 'csv' ? 'csv' : 'xlsx';
    const keyword = String(req.query.keyword || '').trim();
    const warehouse = resolveWarehouse(req.query.warehouse);
    const rows = await getReturnStockWarningExportRows({
      warehouse: req.query.warehouse,
      keyword,
      supplier: req.query.supplier,
      qtyBasis: req.query.qtyBasis,
      createdAtBasis: req.query.createdAtBasis,
      scope: resolveScope(req.query.scope),
      focusDays: req.query.focusDays,
      alertDays: req.query.alertDays,
      warningLevel: req.query.warningLevel,
      priceFocusMin: req.query.priceFocusMin,
      priceHighMin: req.query.priceHighMin,
      priceLevel: req.query.priceLevel,
      returnLimitDays: req.query.returnLimitDays,
      refresh: req.query.refresh,
    });

    const exportColumns = buildExportColumns(warehouse);
    sendWorkbookDownload(res, {
      fileName: `${warehouse.shortName}客退数据监控_${keyword || '全部'}`,
      format,
      sheets: [{
        name: `${warehouse.shortName}客退数据监控`,
        header: exportColumns.map((column) => column.title),
        rows: rows.map((row) => exportColumns.map((column) => row[column.key])),
      }],
    });
  } catch (error) {
    next(error);
  }
});

/** POST /api/return-stock-warning/import —— 导入聚水潭「箱及仓位库存」导出文件 */
router.post('/import', upload.single('file'), async (req, res, next) => {
  try {
    if (!req.file || !req.file.buffer) {
      res.status(400).json({ success: false, message: '请选择要导入的文件（xlsx / xls / csv）' });
      return;
    }
    // multer 按 latin1 解析 multipart 文件名，中文会变成乱码，这里转回 UTF-8
    const rawName = req.file.originalname || '';
    const fileName = /[\u00c0-\u00ff]/.test(rawName)
      ? Buffer.from(rawName, 'latin1').toString('utf8')
      : rawName;

    const result = await importStockWarning({
      buffer: req.file.buffer,
      fileName,
      importedBy: req.user?.username || req.user?.name || null,
      // 导入落在哪个仓库下：优先取表单字段，其次 query，最后回落默认仓
      warehouseKey: resolveWarehouseKey(req.body?.warehouse || req.query.warehouse),
    });
    res.json({ success: true, data: result });
  } catch (error) {
    next(error);
  }
});

/** DELETE /api/return-stock-warning/import —— 清除当前仓库的导入，回到系统推算口径 */
router.delete('/import', async (req, res, next) => {
  try {
    const result = await clearStockWarningImport(resolveWarehouseKey(req.query.warehouse));
    res.json({ success: true, data: result });
  } catch (error) {
    next(error);
  }
});

module.exports = router;