server.mjs

import fs from 'fs';
import path from 'path';

import express from 'express';
import bodyParser from 'body-parser';
import http from 'http';
import CRC32 from 'crc-32';

import WebSocket  from './server/websocket.mjs';
import Player     from './server/player.mjs';
import Room       from './server/room.mjs';
import MinifyRoom from './server/minify.mjs';

const app = express();
const server = http.Server(app);

const savedir = path.resolve() + '/save';
const sharedLinks = fs.existsSync(savedir + '/shares.json') ? JSON.parse(fs.readFileSync(savedir + '/shares.json')) : {};

fs.mkdirSync(savedir + '/assets', { recursive: true });
fs.mkdirSync(savedir + '/rooms',  { recursive: true });
fs.mkdirSync(savedir + '/states', { recursive: true });
fs.mkdirSync(savedir + '/links',  { recursive: true });
fs.mkdirSync(savedir + '/errors', { recursive: true });

function ensureRoomIsLoaded(id) {
  if(!id.match(/^[A-Za-z0-9_-]+$/))
    return false;
  if(!activeRooms.has(id)) {
    activeRooms.set(id, new Room(id, function() {
      activeRooms.delete(id);
    }));
  }
  return true;
}

async function downloadState(res, roomID, stateID, variantID) {
  try {
    if(ensureRoomIsLoaded(roomID)) {
      const d = await activeRooms.get(roomID).download(stateID, variantID);
      res.setHeader('Content-Type', d.type);
      res.setHeader('Content-Disposition', `attachment; filename="${d.name.replace(/[^A-Za-z0-9._-]/g, '_')}"`);
      res.send(d.content);
    }
  } catch(e) {
    console.log(new Date().toISOString(), `EXCEPTION in downloadState for ${roomID}.${stateID}.${variantID}: ${String(e)}`);
    res.sendStatus(500);
  }
}

function autosaveRooms() {
  setInterval(function() {
    for(const [ _, room ] of activeRooms)
      room.writeToFilesystem();
  }, 60*1000);
}

MinifyRoom().then(function(result) {
  app.use('/', express.static(path.resolve() + '/client'));
  app.use('/i', express.static(path.resolve() + '/assets'));
  app.use('/library', express.static(path.resolve() + '/library'));

  app.get('/assets/:name', function(req, res) {
    if(!req.params.name.match(/^[0-9_-]+$/))
      return;
    fs.readFile(savedir + '/assets/' + req.params.name, function(err, content) {
      if(!content) {
        res.sendStatus(404);
        console.log(new Date().toISOString(), 'WARNING: Could not load asset ' + req.params.name);
        return;
      }

      if(content[0] == 0xff)
        res.setHeader('Content-Type', 'image/jpeg');
      else if(content[0] == 0x89)
        res.setHeader('Content-Type', 'image/png');
      else if(content[0] == 0x3c)
        res.setHeader('Content-Type', 'image/svg+xml');
      else if(content[0] == 0x47)
        res.setHeader('Content-Type', 'image/gif');
      else if(content[0] == 0x52)
        res.setHeader('Content-Type', 'image/webp');
      else
        console.log(new Date().toISOString(), 'WARNING: Unknown file type of asset ' + req.params.name);

      res.send(content);
    });
  });

  app.post('/quit', function(req, res) {
    process.exit();
  });

  app.get('/', function(req, res) {
    res.redirect(Math.random().toString(36).substring(3, 7));
  });

  app.get('/dl/:room/:state/:variant', function(req, res) {
    downloadState(res, req.params.room, req.params.state, req.params.variant);
  });

  app.get('/dl/:room/:state', function(req, res) {
    downloadState(res, req.params.room, req.params.state);
  });

  app.get('/dl/:room', function(req, res) {
    downloadState(res, req.params.room);
  });

  app.get('/state/:room', function(req, res) {
    if(ensureRoomIsLoaded(req.params.room)) {
      res.setHeader('Content-Type', 'application/json');
      const state = {...activeRooms.get(req.params.room).state};
      delete state._meta;
      res.send(JSON.stringify(state, null, '  '));
    }
  });

  app.use(bodyParser.json({
    limit: '10mb'
  }));
  app.put('/state/:room', function(req, res) {
    if(typeof req.body == 'object') {
      if(ensureRoomIsLoaded(req.params.room)) {
        activeRooms.get(req.params.room).setState(req.body);
        res.send('OK');
      }
    } else {
      res.send('not a valid JSON object');
    }
  });

  app.get('/s/:link/:junk', function(req, res) {
    if(!sharedLinks[`/s/${req.params.link}`])
      return res.status(404);

    const tokens = sharedLinks[`/s/${req.params.link}`].split('/');
    downloadState(res, tokens[2], tokens[3]);
  });

  app.get('/share/:room/:state', function(req, res) {
    const target = `/dl/${req.params.room}/${req.params.state}`;
    for(const link in sharedLinks)
      if(sharedLinks[link] == target)
        return res.send(link);

    const newLink = `/s/${Math.random().toString(36).substring(3, 11)}`;
    sharedLinks[newLink] = target;
    fs.writeFileSync(savedir + '/shares.json', JSON.stringify(sharedLinks));
    res.send(newLink);
  });

  app.get('/:id', function(req, res) {
    if(!ensureRoomIsLoaded(req.params.id)) {
      res.send('Invalid characters in room ID.');
      return;
    }
    if(req.headers['accept-encoding'] && req.headers['accept-encoding'].match(/\bgzip\b/)) {
      res.setHeader('Content-Encoding', 'gzip');
      res.setHeader('Content-Type', 'text/html');
      res.send(result.gzipped);
    } else {
      res.send(result.min);
    }
  });

  app.use(bodyParser.raw({
    limit: '100mb'
  }));

  app.put('/asset', function(req, res) {
    const filename = `/assets/${CRC32.buf(req.body)}_${req.body.length}`;
    if(!fs.existsSync(path.resolve() + '/save' + filename))
      fs.writeFileSync(path.resolve() + '/save' + filename, req.body);
    res.send(filename);
  });

  server.listen(process.env.PORT || 8272, function() {
    console.log(new Date().toISOString(), 'Listening on ' + server.address().port);
  });
});

const activeRooms = new Map();
const ws = new WebSocket(server, function(connection, { playerName, roomID }) {
  if(ensureRoomIsLoaded(roomID))
    activeRooms.get(roomID).addPlayer(new Player(connection, playerName, activeRooms.get(roomID)));
});

autosaveRooms();

['exit', 'SIGINT', 'SIGUSR1', 'SIGUSR2', 'SIGTERM'].forEach((eventType) => {
  process.on(eventType, function() {
    for(const [ _, room ] of activeRooms)
      room.unload();
    if(eventType != 'exit')
      process.exit();
  });
});