import { Router, type Request, type Response } from 'express';
import { pipeline } from 'node:stream/promises';
import { getAllNotes, streamAllNotes } from '../db/notes.dao.js';
import { clusterNotes } from '../services/clustering.service.js';
import { jsonArray } from '../lib/streams.js';

const router = Router();

router.get('/', async (_req: Request, res: Response) => {
  try {
    const rows = await streamAllNotes();
    res.type('application/json');
    await pipeline(rows, jsonArray(), res);
  } catch (err) {
    console.error(`Error loading notes: ${err}`);
    if (res.headersSent) {
      res.destroy(err as Error);
      return;
    }
    res.status(500).json({ error: 'Failed to load notes' });
  }
});

router.post('/cluster', async (_req: Request, res: Response) => {
  const controller = new AbortController();
  res.on('close', () => {
    if (!res.writableEnded) controller.abort();
  });

  try {
    const notes = await getAllNotes();
    const result = await clusterNotes(notes, { signal: controller.signal });
    res.json(result);
  } catch (err) {
    if (controller.signal.aborted) return;
    console.error(`Clustering failed: ${err}`);
    res.status(500).json({ error: 'Clustering failed' });
  }
});

export default router;