// Node 脚本：生成携带 storeId 的小程序码（永久码）
// 使用方法：在命令行设置环境变量并运行
//   Windows PowerShell：
//     $env:WX_APPID="<你的AppID>"; $env:WX_SECRET="<你的AppSecret>"; node server/generate-minicode.js
//   或在同一命令行：
//     node server/generate-minicode.js
// 将在 server/output/ 目录下生成 PNG 文件

const https = require('https');
const fs = require('fs');
const path = require('path');

const APPID = process.env.WX_APPID || 'wxbb048b80cd2a14b9';
const SECRET = process.env.WX_SECRET; // 必须提供 AppSecret

const STORE_ID = 'ARhMGM5Y1W';
const PAGE = 'nova-pbf/pages/index/index';

function httpGetJson(url) {
  return new Promise((resolve, reject) => {
    https
      .get(url, (res) => {
        let data = '';
        res.on('data', (chunk) => (data += chunk));
        res.on('end', () => {
          try {
            const json = JSON.parse(data);
            resolve(json);
          } catch (e) {
            reject(e);
          }
        });
      })
      .on('error', reject);
  });
}

function httpPostBuffer(url, bodyObj) {
  const body = JSON.stringify(bodyObj);
  return new Promise((resolve, reject) => {
    const req = https.request(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Content-Length': Buffer.byteLength(body),
      },
    });
    const chunks = [];
    req.on('response', (res) => {
      res.on('data', (chunk) => chunks.push(chunk));
      res.on('end', () => resolve(Buffer.concat(chunks)));
    });
    req.on('error', reject);
    req.write(body);
    req.end();
  });
}

async function main() {
  if (!SECRET) {
    console.error('❌ 未提供 WX_SECRET（AppSecret）。请设置环境变量后重试。');
    process.exit(1);
  }

  console.log('🔑 获取 access_token...');
  const tokenResp = await httpGetJson(
    `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${APPID}&secret=${SECRET}`
  );
  if (!tokenResp.access_token) {
    console.error('❌ 获取 access_token 失败:', tokenResp);
    process.exit(1);
  }
  const accessToken = tokenResp.access_token;
  console.log('✅ access_token 获取成功');

  console.log('🖨️ 生成携带参数的小程序码...');
  const apiUrl = `https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=${accessToken}`;
  const payload = {
    scene: `storeId=${STORE_ID}`,
    page: PAGE,
    check_path: false, // 允许未发布页面，仅用于测试/体验
    is_hyaline: true,
    width: 430,
  };
  const buf = await httpPostBuffer(apiUrl, payload);

  // 微信接口在错误时也可能返回 JSON 文本，需要粗略判断
  const isJson = buf.slice(0, 1).toString() === '{';
  if (isJson) {
    try {
      const err = JSON.parse(buf.toString('utf8'));
      console.error('❌ 生成小程序码失败:', err);
      process.exit(1);
    } catch (_) {
      // ignore
    }
  }

  const outDir = path.join(__dirname, 'output');
  if (!fs.existsSync(outDir)) {
    fs.mkdirSync(outDir, { recursive: true });
  }
  const outPath = path.join(outDir, `minicode_store_${STORE_ID}.png`);
  fs.writeFileSync(outPath, buf);
  console.log(`✅ 已生成：${outPath}`);
  console.log('📌 扫码后将进入页面并携带参数：storeId=', STORE_ID);
}

main().catch((e) => {
  console.error('程序异常:', e);
  process.exit(1);
});