init: 微信支付 Native 页面 (Express + JSON 存储)

routes/index.js

@@ -0,0 +1,9 @@
+const express = require('express');
+const router = express.Router();
+const config = require('../config');
+
+router.get('/', (req, res) => {
+  res.render('index', { products: config.products });
+});
+
+module.exports = router;

routes/pay.js

@@ -0,0 +1,136 @@
+const express = require('express');
+const router = express.Router();
+const crypto = require('crypto');
+const axios = require('axios');
+const xml2js = require('xml2js');
+const { v4: uuidv4 } = require('uuid');
+const QRCode = require('qrcode');
+const config = require('../config');
+const storage = require('../utils/storage');
+
+function buildSign(params, key) {
+  const str = Object.keys(params)
+    .filter(k => params[k] !== '' && k !== 'sign')
+    .sort()
+    .map(k => `${k}=${params[k]}`)
+    .join('&') + `&key=${key}`;
+  return crypto.createHash('md5').update(str, 'utf-8').digest('hex').toUpperCase();
+}
+
+function buildXml(obj) {
+  let xml = '<xml>';
+  for (const [k, v] of Object.entries(obj)) {
+    xml += `<${k}>${v}</${k}>`;
+  }
+  xml += '</xml>';
+  return xml;
+}
+
+// Step 1: Create order page - show QR code
+router.get('/create/:productId', async (req, res) => {
+  const product = config.products.find(p => p.id === parseInt(req.params.productId));
+  if (!product) return res.status(404).send('商品不存在');
+
+  const orderId = uuidv4().replace(/-/g, '').substring(0, 28);
+  const order = {
+    orderId,
+    productId: product.id,
+    productName: product.name,
+    totalFee: product.price,
+    status: 'CREATING',
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString(),
+  };
+  storage.saveOrder(order);
+
+  try {
+    const nonceStr = uuidv4().replace(/-/g, '').substring(0, 16);
+    const unifiedParams = {
+      appid: config.wechat.appid,
+      mch_id: config.wechat.mchid,
+      nonce_str: nonceStr,
+      body: product.name,
+      out_trade_no: orderId,
+      total_fee: product.price,
+      spbill_create_ip: req.ip || '127.0.0.1',
+      notify_url: config.wechat.notifyUrl,
+      trade_type: 'NATIVE',
+    };
+    unifiedParams.sign = buildSign(unifiedParams, config.wechat.key);
+
+    const xml = buildXml(unifiedParams);
+    const resp = await axios.post(
+      `${config.wechat.apiBase}/pay/unifiedorder`,
+      xml,
+      { headers: { 'Content-Type': 'text/xml' } }
+    );
+
+    const parsed = await xml2js.parseStringPromise(resp.data, { explicitArray: false });
+    const result = parsed.xml;
+
+    if (result.return_code !== 'SUCCESS' || result.result_code !== 'SUCCESS') {
+      order.status = 'FAILED';
+      storage.saveOrder(order);
+      return res.render('pay', { error: `下单失败: ${result.err_code_des || result.return_msg}` });
+    }
+
+    order.codeUrl = result.code_url;
+    order.status = 'PENDING';
+    storage.saveOrder(order);
+
+    const qrDataUrl = await QRCode.toDataURL(result.code_url, { width: 300, margin: 2 });
+    res.render('pay', { order, qrDataUrl, error: null });
+  } catch (err) {
+    order.status = 'FAILED';
+    storage.saveOrder(order);
+    res.render('pay', { error: `系统错误: ${err.message}` });
+  }
+});
+
+// Step 2: Poll payment status
+router.get('/status/:orderId', (req, res) => {
+  const order = storage.findOrder(req.params.orderId);
+  if (!order) return res.json({ status: 'NOT_FOUND' });
+  res.json({ status: order.status, orderId: order.orderId });
+});
+
+// Step 3: WeChat payment notification callback
+router.post('/notify', async (req, res) => {
+  if (!req.body) {
+    return res.send(buildXml({ return_code: 'FAIL', return_msg: '空请求体' }));
+  }
+
+  try {
+    const parsed = await xml2js.parseStringPromise(req.body, { explicitArray: false });
+    const data = parsed.xml;
+
+    const expectedSign = buildSign(data, config.wechat.key);
+    if (data.sign !== expectedSign) {
+      return res.send(buildXml({ return_code: 'FAIL', return_msg: '签名失败' }));
+    }
+
+    if (data.return_code === 'SUCCESS' && data.result_code === 'SUCCESS') {
+      storage.updateOrderStatus(data.out_trade_no, 'SUCCESS', data.transaction_id);
+      return res.send(buildXml({ return_code: 'SUCCESS', return_msg: 'OK' }));
+    }
+
+    res.send(buildXml({ return_code: 'FAIL', return_msg: data.err_code_des || '支付失败' }));
+  } catch (err) {
+    res.send(buildXml({ return_code: 'FAIL', return_msg: '解析失败' }));
+  }
+});
+
+// Step 4: Order list
+router.get('/orders', (req, res) => {
+  const orders = storage.readOrders().sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
+  res.render('orders', { orders });
+});
+
+// Success page
+router.get('/success/:orderId', (req, res) => {
+  const order = storage.findOrder(req.params.orderId);
+  if (!order) return res.status(404).send('订单不存在');
+  res.render('success', { order });
+});
+
+module.exports = router;