/* eslint-env node, es2020 */
'use strict';

const express = require('express');
const client = require('prom-client');

const app = express();
app.use(express.json());

// ---------------------------------------------------------------------------
// Prometheus metrics
// ---------------------------------------------------------------------------
const register = new client.Registry();
client.collectDefaultMetrics({ register });

// ---------------------------------------------------------------------------
// In-memory store
// ---------------------------------------------------------------------------
let nextId = 1;
const store = new Map();

// ---------------------------------------------------------------------------
// Health
// ---------------------------------------------------------------------------
app.get('/health', (_req, res) => res.json({ status: 'UP' }));

// ---------------------------------------------------------------------------
// Metrics
// ---------------------------------------------------------------------------
app.get('/metrics', async (_req, res) => {
  res.set('Content-Type', register.contentType);
  res.end(await register.metrics());
});

// ---------------------------------------------------------------------------
// Items CRUD
// ---------------------------------------------------------------------------
app.get('/api/items', (_req, res) => {
  res.json([...store.values()]);
});

app.post('/api/items', (req, res) => {
  const { name = 'unnamed', description = '' } = req.body ?? {};
  const item = { id: nextId++, name, description };
  store.set(item.id, item);
  res.status(201).json(item);
});

app.get('/api/items/:id', (req, res) => {
  const item = store.get(Number(req.params.id));
  if (!item) return res.status(404).json({ error: 'Not found' });
  res.json(item);
});

app.put('/api/items/:id', (req, res) => {
  const id = Number(req.params.id);
  const existing = store.get(id);
  if (!existing) return res.status(404).json({ error: 'Not found' });
  const updated = { ...existing, ...req.body, id };
  store.set(id, updated);
  res.json(updated);
});

app.delete('/api/items/:id', (req, res) => {
  const id = Number(req.params.id);
  store.delete(id);
  res.json({ deleted: id });
});

// ---------------------------------------------------------------------------
// Start
// ---------------------------------------------------------------------------
const PORT = Number(process.env.PORT ?? 3000);
app.listen(PORT, () => {
  console.log('test-micro-alex-stable-1 listening on :' + PORT);
});

module.exports = app; // for testing