#!/usr/bin/env node
/**
 * T18 调试期局域网模型服务器（零依赖，Node 18+）。
 *
 * 用法：node scripts/serve-models.mjs [端口=8080]
 * 手机与电脑连同一 Wi-Fi，App 内模型地址填 http://<电脑局域网IP>:<端口>
 *
 * 服务内容：models/ 目录下的 manifest.json 与模型文件。
 * 调试阶段一次性整包下载即可；断点续传（Range）留待商用阶段接 CDN 时再做。
 */
import { createServer } from 'node:http';
import { createReadStream, existsSync, statSync } from 'node:fs';
import { networkInterfaces } from 'node:os';
import { extname, join, normalize } from 'node:path';
import { fileURLToPath } from 'node:url';

const root = normalize(join(fileURLToPath(import.meta.url), '..', '..', 'models'));
const port = Number(process.argv[2] ?? 8080);

const MIME = {
  '.json': 'application/json; charset=utf-8',
  '.txt': 'text/plain; charset=utf-8',
  '.mnn': 'application/octet-stream',
  '.weight': 'application/octet-stream',
};

const server = createServer((req, res) => {
  const urlPath = decodeURIComponent((req.url ?? '/').split('?')[0]);
  // 防目录穿越：规范化后必须仍落在 root 内
  const filePath = normalize(join(root, urlPath));
  if (!filePath.startsWith(root) || !existsSync(filePath) || !statSync(filePath).isFile()) {
    res.writeHead(404).end('not found');
    return;
  }
  res.writeHead(200, {
    'Content-Type': MIME[extname(filePath)] ?? 'application/octet-stream',
    'Content-Length': statSync(filePath).size,
  });
  createReadStream(filePath).pipe(res);
});

server.listen(port, '0.0.0.0', () => {
  console.log(`serving ${root}`);
  for (const [name, addrs] of Object.entries(networkInterfaces())) {
    for (const a of addrs ?? []) {
      if (a.family === 'IPv4' && !a.internal) {
        console.log(`  http://${a.address}:${port}/  (${name})`);
      }
    }
  }
});