// fuesse.sexy — "Wanted!" (Fuss-Fahndung)
// Schlanker Express-Server: liefert das Frontend + die Bildchen aus, stellt die Liste
// der verfuegbaren Fuesse/Deko bereit und verwaltet eine persistente Rangliste.

import express from 'express';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { existsSync, readdirSync, readFileSync, writeFileSync, mkdirSync } from 'node:fs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const ROOT = join(__dirname, '..');
const PUBLIC_DIR = join(ROOT, 'public');
const LIBRARY_DIR = join(ROOT, 'library');
const DATA_DIR = join(ROOT, 'data');
const LEADERBOARD_FILE = join(DATA_DIR, 'leaderboard.json');

const PORT = process.env.PORT || 3000;
const IMAGE_EXT = ['.svg', '.png', '.webp', '.jpg', '.jpeg', '.gif'];

// ---- Bildchen aus der Library einlesen ----
function isImage(f) {
  return IMAGE_EXT.some((ext) => f.toLowerCase().endsWith(ext));
}
function prettyName(file) {
  return file
    .replace(/\.[^.]+$/, '')
    .replace(/[-_]+/g, ' ')
    .replace(/\b\w/g, (c) => c.toUpperCase());
}
function listImages(dir, urlPrefix) {
  if (!existsSync(dir)) return [];
  return readdirSync(dir)
    .filter(isImage)
    .sort()
    .map((f) => ({ id: f.replace(/\.[^.]+$/, ''), name: prettyName(f), url: `${urlPrefix}/${f}` }));
}

const feet = listImages(join(LIBRARY_DIR, 'feet'), '/library/feet');
const props = listImages(join(LIBRARY_DIR, 'props'), '/library/props');

if (feet.length < 2) {
  console.warn(`[server] Achtung: nur ${feet.length} Fuss/Fuesse in library/feet — brauche mind. 2.`);
} else {
  console.log(`[server] ${feet.length} Fuesse, ${props.length} Deko-Bildchen geladen.`);
}

// ---- Rangliste (persistente JSON-Datei) ----
function readLeaderboard() {
  try {
    if (!existsSync(LEADERBOARD_FILE)) return [];
    const data = JSON.parse(readFileSync(LEADERBOARD_FILE, 'utf8'));
    return Array.isArray(data) ? data : [];
  } catch (err) {
    console.warn('[server] Rangliste unlesbar:', err.message);
    return [];
  }
}
function writeLeaderboard(list) {
  if (!existsSync(DATA_DIR)) mkdirSync(DATA_DIR, { recursive: true });
  writeFileSync(LEADERBOARD_FILE, JSON.stringify(list, null, 2));
}
function topN(list, n) {
  return [...list].sort((a, b) => b.score - a.score).slice(0, n);
}

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

// Statisches Frontend + Bildchen (no-cache -> nie veraltetes JS nach Update)
app.use(express.static(PUBLIC_DIR, { setHeaders: (res) => res.setHeader('Cache-Control', 'no-cache') }));
app.use('/library', express.static(LIBRARY_DIR));

// Verfuegbare Bildchen
app.get('/api/feet', (req, res) => {
  res.json({ feet, props });
});

// Rangliste: Top 10
app.get('/api/leaderboard', (req, res) => {
  res.json(topN(readLeaderboard(), 10));
});

// Score eintragen -> aktualisierte Top 10 zurueck
app.post('/api/score', (req, res) => {
  let { name, score } = req.body || {};
  score = Number(score);
  if (!Number.isFinite(score) || score < 0) {
    return res.status(400).json({ error: 'Ungueltiger Score.' });
  }
  name = String(name || 'Anonym').trim().slice(0, 20) || 'Anonym';
  score = Math.min(Math.floor(score), 100000); // grobe Plausibilitaet

  const list = readLeaderboard();
  list.push({ name, score, at: new Date().toISOString() });
  const trimmed = topN(list, 100); // Datei klein halten
  writeLeaderboard(trimmed);
  res.json(topN(trimmed, 10));
});

app.listen(PORT, () => {
  console.log(`[server] fuesse.sexy (Wanted!) laeuft auf http://localhost:${PORT}`);
});