/**
 * OPC 培训站 · 独立启动服务
 * -------------------------------------------------------------
 * 用途：把构建产物 dist/ 静态托管 + 挂载模拟认证 API，一条命令跑起来。
 * 启动：npm run build && node server/start.mjs
 * 默认端口 8091（避开 PineAgentsServer 的 8090）。
 * 迁移：后期接真实后端后，本文件可替换为生产服务器/网关。
 */
import http from 'node:http';
import { createReadStream, existsSync, statSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import path from 'node:path';
import { mockApi } from './mock-api.mjs';

const PORT = process.env.PORT || 8091;
const DIST = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '../dist');

const MIME = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.png': 'image/png',
  '.webp': 'image/webp',
  '.json': 'application/json; charset=utf-8',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.ico': 'image/x-icon'
};

function serveStatic(req, res) {
  let p = (req.url || '/').split('?')[0];
  if (p === '/' || p === '') p = '/index.html';
  // 防路径穿越
  const file = path.normalize(path.join(DIST, p));
  if (!file.startsWith(DIST)) return notFound(res);
  if (!existsSync(file) || statSync(file).isDirectory()) {
    // SPA 回退：非文件请求一律给 index.html（仅当请求的不是带扩展名的资源）
    if (!path.extname(file)) return sendFile(res, path.join(DIST, 'index.html'));
    return notFound(res);
  }
  sendFile(res, file);
}

function sendFile(res, file) {
  const ext = path.extname(file).toLowerCase();
  res.setHeader('Content-Type', MIME[ext] || 'application/octet-stream');
  res.setHeader('Cache-Control', ext === '.html' ? 'no-cache' : 'public, max-age=31536000, immutable');
  createReadStream(file).pipe(res);
}

function notFound(res) {
  res.statusCode = 404;
  res.setHeader('Content-Type', 'text/plain; charset=utf-8');
  res.end('Not Found');
}

const server = http.createServer((req, res) => {
  mockApi(req, res, () => serveStatic(req, res));
});

server.listen(PORT, () => {
  console.log(`▶ OPC 培训站已启动: http://localhost:${PORT}`);
  console.log(`  静态资源: ${DIST}`);
  console.log(`  模拟登录: POST /api/auth/login  (pine / 123456)`);
});