const http = require('http');
const fs = require('fs');
const path = require('path');
const url = require('url');

const PORT = process.env.PORT || 3000;

function serveStatic(filePath, res) {
  if (!fs.existsSync(filePath) || !fs.statSync(filePath).isFile()) {
    res.writeHead(404, {'Content-Type':'text/plain'});
    return res.end('Not found');
  }
  const ext = path.extname(filePath).toLowerCase();
  const map = {'.html':'text/html', '.css':'text/css', '.js':'application/javascript'};
  res.writeHead(200, {'Content-Type': (map[ext]||'text/plain') + '; charset=utf-8'});
  res.end(fs.readFileSync(filePath));
}

async function fetchAlemTest() {
  // Expected env vars from Alem integration
  const base = process.env.ALEM_BASE_URL;
  const key = process.env.ALEM_API_KEY;
  const tmpl = process.env.ALEM_TEMPLATE_ID;
  if (!base || !key || !tmpl) return {error:'Alem not configured'};
  // Create session
  const sessResp = await fetch(`${base}/api/v1/open-api/conversation`, {
    method:'POST',
    headers:{'Content-Type':'application/json','Authorization':'Bearer '+key},
    body:JSON.stringify({template_id:tmpl,title:'SafetyTest',user_id:'vibe42_user'})
  });
  if (!sessResp.ok) return {error:'Alem session error'};
  const sessBody = await sessResp.json();
  const sid = sessBody && sessBody.data && sessBody.data.session_id;
  if (!sid) return {error:'No session_id'};
  // Ask prompt
  const askResp = await fetch(`${base}/api/v1/open-api/conversation/${sid}/send`, {
    method:'POST',
    headers:{'Content-Type':'application/json','Authorization':'Bearer '+key},
    body:JSON.stringify({content:'Сгенерируй тест из 10 вопросов по технике безопасности монтеров в Казахстане. Верни JSON массив вопросов с вариантами и правильным индексом.',user_id:'vibe42_user',model_api_key:key})
  });
  if (!askResp.ok) return {error:'Alem ask error'};
  const raw = await askResp.text();
  let answer = null;
  for (const line of raw.split('\n')) {
    const s = line.trim();
    if (!s.startsWith('data:')) continue;
    const payload = s.slice(5).trim();
    if (!payload || payload === '[DONE]') continue;
    try { const ev = JSON.parse(payload); if (ev && ev.detail && ev.detail.full_content) answer = ev.detail.full_content; } catch(e) {}
  }
  if (!answer) return {error:'No answer'};
  // Expect answer to be JSON
  try { return JSON.parse(answer); } catch(e) { return {error:'Parse error',raw:answer}; }
}

http.createServer(async (req, res) => {
  const parsed = url.parse(req.url, true);
  if (parsed.pathname === '/api/generate') {
    const data = await fetchAlemTest();
    res.writeHead(200, {'Content-Type':'application/json'});
    return res.end(JSON.stringify(data));
  }
  // static files
  let file = parsed.pathname === '/' ? '/index.html' : parsed.pathname;
  serveStatic(path.join(__dirname, file), res);
}).listen(PORT, () => console.log('Server listening on '+PORT));