'use strict';
// Serveur de sync communautaire Farm Tracker.
// Stocke les stats de chaque joueur (identifié par UUID) et renvoie l'agrégat.
// Lance avec : node server.js   (ou PORT=3742 node server.js)
// Aucune dépendance externe.

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

const DATA_FILE = path.join(__dirname, 'sync-data.json');
const PORT = Number(process.env.PORT) || 3742;
const MAX_BODY = 10 * 1024 * 1024; // 10 Mo max par requête

function loadData() {
  try { return JSON.parse(fs.readFileSync(DATA_FILE, 'utf8')); }
  catch { return { clients: {} }; }
}

function saveData(data) {
  const tmp = DATA_FILE + '.tmp';
  fs.writeFileSync(tmp, JSON.stringify(data));
  fs.renameSync(tmp, DATA_FILE);
}

function mergeInto(target, source) {
  for (const [mob, mobData] of Object.entries(source.mobs || {})) {
    if (!mob) continue;
    if (!target.mobs[mob]) target.mobs[mob] = { kills: 0, items: {} };
    const t = target.mobs[mob];
    t.kills += Number(mobData.kills) || 0;
    for (const [key, item] of Object.entries(mobData.items || {})) {
      if (!t.items[key]) t.items[key] = { rawName: '', name: '', occurrences: 0, totalQty: 0 };
      t.items[key].occurrences += Number(item.occurrences) || 0;
      t.items[key].totalQty += Number(item.totalQty) || 0;
      if (item.rawName) t.items[key].rawName = item.rawName;
      if (item.name) t.items[key].name = item.name;
    }
  }
}

// Recompute l'agrégat à partir des contributions individuelles de chaque client.
// Chaque client est compté exactement une fois (la dernière soumission).
function computeAggregate(clients) {
  const agg = { type: 'farm-tracker-dropstats', version: 1, updatedAt: new Date().toISOString(), mobs: {} };
  for (const stats of Object.values(clients)) mergeInto(agg, stats);
  return agg;
}

http.createServer((req, res) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'POST, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

  if (req.method === 'OPTIONS') { res.writeHead(204); res.end(); return; }

  if (req.method === 'GET' && req.url === '/stats') {
    const data = loadData();
    const aggregate = computeAggregate(data.clients);
    const clientCount = Object.keys(data.clients).length;
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ ok: true, dropStats: aggregate, clientCount }));
    return;
  }

  if (req.method !== 'POST' || req.url !== '/sync') {
    res.writeHead(404); res.end('Not found'); return;
  }

  let body = '';
  req.on('data', chunk => {
    body += chunk;
    if (body.length > MAX_BODY) req.destroy();
  });
  req.on('end', () => {
    try {
      const { clientId, dropStats } = JSON.parse(body);
      if (!clientId || typeof clientId !== 'string' || clientId.length > 64)
        throw new Error('clientId invalide');
      if (!dropStats || dropStats.type !== 'farm-tracker-dropstats')
        throw new Error('Format dropStats invalide');

      const data = loadData();
      data.clients[clientId] = dropStats;
      const aggregate = computeAggregate(data.clients);
      saveData(data);

      const clientCount = Object.keys(data.clients).length;
      console.log(`[${new Date().toISOString()}] sync client=${clientId.slice(0, 8)}… clients=${clientCount}`);

      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ ok: true, dropStats: aggregate, clientCount }));
    } catch (e) {
      res.writeHead(400, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ ok: false, error: e.message }));
    }
  });
  req.on('error', () => {});
}).listen(PORT, '0.0.0.0', () => {
  console.log(`Farm Tracker sync server — port ${PORT} — data: ${DATA_FILE}`);
});