// 开发桥接服务：以 HTTP 形式暴露与 Tauri IPC 相同的命令契约
// 浏览器预览模式使用；打包为桌面应用后由 Rust 后端接管同一契约
import http from 'node:http';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { handleCommand, DATA_DIR } from './db.mjs';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const DIST = path.join(__dirname, '..', 'dist');
const PORT = Number(process.env.FP_PORT || process.env.PORT || 8787);

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

const server = http.createServer(async (req, res) => {
  const url = new URL(req.url, 'http://localhost');

  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
  res.setHeader('Access-Control-Allow-Methods', 'POST, GET, OPTIONS');
  if (req.method === 'OPTIONS') { res.writeHead(204); res.end(); return; }

  if (req.method === 'POST' && url.pathname.startsWith('/api/')) {
    const cmd = url.pathname.slice(5);
    let body = '';
    let size = 0;
    req.on('data', chunk => {
      size += chunk.length;
      if (size > 160 * 1024 * 1024) { req.destroy(); } // 与 sync-server 对齐
      else body += chunk;
    });
    req.on('end', () => {
      let payload = {};
      try { payload = body ? JSON.parse(body) : {}; } catch {}
      try {
        const data = handleCommand(cmd, payload);
        res.writeHead(200, { 'Content-Type': 'application/json; charset=utf-8' });
        res.end(JSON.stringify({ ok: true, data }));
      } catch (e) {
        res.writeHead(200, { 'Content-Type': 'application/json; charset=utf-8' });
        res.end(JSON.stringify({ ok: false, error: e.message || String(e) }));
      }
    });
    return;
  }

  // 静态托管 dist（若已构建），便于纯浏览器验收
  if (req.method === 'GET' && fs.existsSync(DIST)) {
    let p = url.pathname === '/' ? '/index.html' : url.pathname;
    const abs = path.join(DIST, p);
    if (fs.existsSync(abs) && fs.statSync(abs).isFile()) {
      res.writeHead(200, { 'Content-Type': MIME[path.extname(abs)] ?? 'application/octet-stream' });
      res.end(fs.readFileSync(abs));
      return;
    }
    const indexHtml = path.join(DIST, 'index.html');
    if (fs.existsSync(indexHtml)) {
      res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
      res.end(fs.readFileSync(indexHtml));
      return;
    }
  }

  res.writeHead(404, { 'Content-Type': 'application/json; charset=utf-8' });
  res.end(JSON.stringify({ ok: false, error: 'not found' }));
});

server.listen(PORT, '127.0.0.1', () => {
  console.log('[footprints-bridge] listening on http://127.0.0.1:' + PORT);
  console.log('[footprints-bridge] data dir:', DATA_DIR);
});