// ---------------------------------------------------------------
// Dino Isle Online — main server: static files + websocket + game loop
// Run: node server.js   (PORT env optional, default 8090)
// ---------------------------------------------------------------
'use strict';
const http = require('http');
const fs = require('fs');
const path = require('path');

const { Game, TICK_MS } = require('./sim');
const wsattach = require('./ws').attach;

const PORT = parseInt(process.env.PORT || '8095', 10);
const PUBLIC_DIR = path.join(__dirname, 'public');
const CHEATS = process.env.DEBUG_CHEATS === '1';

const MIME = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.json': 'application/json',
  '.png': 'image/png',
  '.svg': 'image/svg+xml',
  '.ico': 'image/x-icon',
  '.woff2': 'font/woff2',
};

const server = http.createServer((req, res) => {
  let urlPath = decodeURIComponent((req.url || '/').split('?')[0]);
  if (urlPath === '/') urlPath = '/index.html';
  const filePath = path.normalize(path.join(PUBLIC_DIR, urlPath));
  if (!filePath.startsWith(PUBLIC_DIR)) { res.writeHead(403); res.end('Forbidden'); return; }
  fs.readFile(filePath, (err, data) => {
    if (err) {
      res.writeHead(404, { 'Content-Type': 'text/plain' });
      res.end('Not found');
      return;
    }
    const ext = path.extname(filePath).toLowerCase();
    res.writeHead(200, {
      'Content-Type': MIME[ext] || 'application/octet-stream',
      'Cache-Control': 'no-store',
    });
    res.end(data);
  });
});

const game = new Game();

let nextAllowedMsg = new WeakMap(); // conn -> timestamp budget

wsattach(server, '/ws', (conn) => {
  conn.onmessage = (str) => {
    let m;
    try { m = JSON.parse(str); } catch (_) { return; }
    if (!m || typeof m !== 'object') return;

    // simple flood guard: max ~40 msgs/sec
    const now = Date.now();
    const budget = nextAllowedMsg.get(conn) || now;
    if (now < budget - 1000) return; // way over -> drop
    nextAllowedMsg.set(conn, Math.max(budget + 25, now));

    const p = game.players.get(conn);
    switch (m.t) {
      case 'join': {
        const player = game.join(conn, String(m.name || '').slice(0, 16), m.sp);
        conn.send(JSON.stringify(game.welcomePayload(player)));
        break;
      }
      case 'in':
        if (p) game.onInput(p, m);
        break;
      case 'chat':
        if (p && p.alive !== undefined) game.onChat(p, m.msg);
        break;
      case 'dev':
        if (p) game.onDev(p, m);
        break;
      case 'devact':
        if (p) game.onDevAct(p, String(m.act || ''));
        break;
      case 'ping': conn.send('{"t":"pong"}'); break;
      case 'tp':
        if (p && (CHEATS || p.dev)) {
          p.x = Math.max(40, Math.min(7680 - 40, +m.x || p.x));
          p.y = Math.max(40, Math.min(7680 - 40, +m.y || p.y));
          if (typeof m.a === 'number') p.dir = m.a;
          p.vx = 0; p.vy = 0;
        }
        break;
      default:
        break;
    }
  };
  conn.onclose = () => game.leave(conn);
});

// heartbeat
setInterval(() => {
  for (const p of [...game.players.keys()]) {
    const c = p; // key is conn
    if (c.writable) c.ping();
  }
}, 25000);

// main loop with drift compensation
let last = Date.now();
setInterval(() => {
  const now = Date.now();
  let dt = (now - last) / 1000;
  last = now;
  dt = Math.min(dt, 0.25); // clamp big pauses
  try { game.tick(dt); } catch (e) { console.error('tick error', e); }
}, TICK_MS);

server.listen(PORT, () => {
  console.log(`[dino-isle] listening on http://localhost:${PORT}  (seed=${game.seed})`);
  console.log(`[dino-isle] open multiple browser tabs for multiplayer fun!`);
});