#!/usr/bin/env node

var http = require('http');
var https = require('https');
var net = require('net');
var url = require('url');
var path = require('path');
var fs = require('fs');
var events = require('events');
var child_process = require('child_process');
// Dependencies
var posix = require("posix");
var pty = require("pty.js");
var WebSocketServer = require("websocket").server;

/* Default options */
var rlgwebd_options = { 
  control_socket: "/var/run/rlgwebd.sock",
  http_port: 8080,
  https_port: 8081,
  chrootDir: "/var/dgl/",
  username: "rodney",
  static_root: "/var/www/"
};

/* Read configuration from a file */
var config_file = "/etc/rlgwebd.conf";
var config_lines = read_or_die(config_file, "Configuration file").toString().split('\n');

for (var i = 0; i < config_lines.length; i++) {
  if (config_lines[i].length > 0 && config_lines[i][0] != '#') {
    var config_fields = config_lines[i].split('=');
    if (config_fields.length < 2)
      continue;
    var option_name = config_fields[0].trim();
    // This can't handle values containing '=' or whitespace at the end
    var option_value = config_fields[1].trim();
    rlgwebd_options[option_name] = option_value;
  }
}

/* Should HTTPS be enabled? */
if ("domain_name" in rlgwebd_options && "keyfile" in rlgwebd_options &&
    "certfile" in rlgwebd_options)
  rlgwebd_options["use_https"] = true;

var clearbufs = [
  new Buffer([27, 91, 72, 27, 91, 50, 74]), // xterm: CSI H CSI 2J
  new Buffer([27, 91, 72, 27, 91, 74]) // screen: CSI H CSI J
];

/* Data on the games available. */
var games = {
  "rogue3": {
    "name": "Rogue V3",
    "uname": "rogue3",
    "suffix": ".r3sav",
    "path": "/usr/bin/rogue3"
  },
  "rogue4": {
    "name": "Rogue V4",
    "uname": "rogue4",
    "suffix": ".r4sav",
    "path": "/usr/bin/rogue4"
  },
  "rogue5": {
    "name": "Rogue V5",
    "uname": "rogue5",
    "suffix": ".r5sav",
    "path": "/usr/bin/rogue5"
  },
  "srogue": {
    "name": "Super-Rogue",
    "uname": "srogue",
    "suffix": ".srsav",
    "path": "/usr/bin/srogue"
  },
  "arogue5": {
    "name": "Advanced Rogue 5",
    "uname": "arogue5",
    "suffix": ".ar5sav",
    "path": "/usr/bin/arogue5"
  },
  "arogue7": {
    "name": "Advanced Rogue 7",
    "uname": "arogue7",
    "suffix": ".ar7sav",
    "path": "/usr/bin/arogue7"
  },
  "xrogue": {
    "name": "XRogue",
    "uname": "xrogue",
    "suffix": ".xrsav",
    "path": "/usr/bin/xrogue"
  }
};

/* Global state */
var logins = {};
var sessions = {};
var dglgames = {};
var allowlogin = true;
var gamemux = new events.EventEmitter();

/* A base class.  TermSession and DglSession inherit from it. */
function BaseGame() {
  /* Games subclass EventEmitter, though there are few listeners. */
  events.EventEmitter.call(this);
  /* Array of watching WebSockets. */
  this.watchers = [];
  /* replaybuf holds the output since the last screen clear, so watchers can
   * begin with a complete screen. replaylen is the number of bytes stored. */
  this.replaybuf = new Buffer(1024);
  this.replaylen = 0;
  /* Time of last activity. */
  this.lasttime = new Date();
}
BaseGame.prototype = new events.EventEmitter();

BaseGame.prototype.tag = function () {
  if (this.pname === undefined || this.gname === undefined)
    return "";
  return this.gname + "/" + this.pname;
};

BaseGame.prototype.framepush = function(chunk) {
  /* If this chunk resets the screen, discard what preceded it. */
  if (isclear(chunk)) {
    this.replaybuf = new Buffer(1024);
    this.replaylen = 0;
  }
  /* Make sure there's space. */
  while (this.replaybuf.length < chunk.length + this.replaylen) {
    var nbuf = new Buffer(this.replaybuf.length * 2);
    this.replaybuf.copy(nbuf, 0, 0, this.replaylen);
    this.replaybuf = nbuf;
    if (this.replaybuf.length > 65536) {
      tslog("Warning: %s frame buffer at %d bytes", this.tag(), 
              this.replaybuf.length);
    }
  }
  chunk.copy(this.replaybuf, this.replaylen);
  this.replaylen += chunk.length;
};

/* Adds a watcher. */
BaseGame.prototype.attach = function (wsReq) {
  var conn = wsReq.accept(null, wsReq.origin);
  conn.sendUTF(JSON.stringify({
          "t": "w", "w": this.w, "h": this.h, "p": this.pname, "g": this.gname
  }));
  conn.sendUTF(JSON.stringify({"t": "d",
      "d": this.replaybuf.toString("hex", 0, this.replaylen)}));
  conn.on('close', this.detach.bind(this, conn));
  this.watchers.push(conn);
};

BaseGame.prototype.detach = function (socket) {
  var n = this.watchers.indexOf(socket);
  if (n >= 0) {
    this.watchers.splice(n, 1);
    tslog("A WebSocket watcher has left game %s", this.tag());
  }
};

/* Constructor.  A TermSession handles a pty and the game running on it.
 *   gname: (String) Name of the game to launch.
 *   pname: (String) The player's name.
 *   wsReq: (WebSocketRequest) The request from the client.
 *
 *  Events:
 *   "data": Data generated by child. Parameters: buf (Buffer)
 *   "exit": Child terminated. Parameters: none
 */
function TermSession(gname, pname, wsReq) {
  BaseGame.call(this);
  /* Don't launch anything that's not a real game. */
  if (gname in games) {
    this.game = games[gname];
    this.gname = gname;
  }
  else {
    this.failed = true;
    wsReq.reject(404, errorcodes[2], "No such game");
    tslog("Game %s is not available", game);
    return;
  }
  this.pname = pname;
  /* Set up the sizes. */
  this.w = Math.floor(Number(wsReq.resourceURL.query.w));
  if (!(this.w > 0 && this.w < 256))
    this.w = 80;
  this.h = Math.floor(Number(wsReq.resourceURL.query.h));
  if (!(this.h > 0 && this.h < 256))
    this.h = 24;
  /* Environment. */
  var childenv = {};
  for (var key in process.env) {
    childenv[key] = process.env[key];
  }
  var args = ["-n", this.pname];
  var spawnopts = {"env": childenv, "cwd": "/", "rows": this.h, "cols": this.w,
                   "name": "xterm-256color"};
  this.term = pty.spawn(this.game.path, args, spawnopts);
  tslog("%s playing %s (pid %d)", this.pname, this.gname, this.term.pid);
  this.failed = false;
  sessions[this.gname + "/" + this.pname] = this;
  gamemux.emit('begin', this.gname, this.pname, 'rlg');
  /* Set up the lockfile and ttyrec */
  var ts = timestamp(this.lasttime);
  var progressdir = path.join("/dgldir/inprogress", this.gname);
  this.lock = path.join(progressdir, this.pname + ":node:" + ts + ".ttyrec");
  var lmsg = this.term.pid.toString() + '\n' + this.h + '\n' + this.w + '\n'; 
  fs.writeFile(this.lock, lmsg, "utf8"); 
  var ttyrec = path.join("/dgldir/ttyrec", this.pname, this.gname, 
               ts + ".ttyrec");
  this.record = fs.createWriteStream(ttyrec, { mode: 0664 });
  /* The player's WebSocket and its handlers. */
  this.playerconn = wsReq.accept(null, wsReq.origin);
  this.playerconn.on('message', this.input_msg.bind(this));
  this.playerconn.on('close', this.close.bind(this));
  /* Send initial data. */
  this.playerconn.sendUTF(JSON.stringify({"t": "s", "w": this.w, "h": this.h, 
               "p": this.pname, "g": this.gname}));
  /* Begin the ttyrec with some metadata, like dgamelaunch does. */
  var descstr = "\x1b[2J\x1b[1;1H\r\n";
  descstr += "Player: " + this.pname + "\r\nGame: " + this.game.name + "\r\n";
  descstr += "Server: Roguelike Gallery - rlgallery.org\r\n";
  descstr += "Filename: " + ts + ".ttyrec\r\n";
  descstr += "Time: (" + Math.floor(this.lasttime.getTime() / 1000) + ") ";
  descstr += this.lasttime.toUTCString().slice(0, -4) + "\r\n";
  descstr += "Size: " + this.w + "x" + this.h + "\r\n\x1b[2J";
  this.write_ttyrec(descstr);
  this.term.on("data", this.write_ttyrec.bind(this));
  this.term.on("exit", this.destroy.bind(this));
}
TermSession.prototype = new BaseGame();

/* Currently this also sends to the player and any watchers. */
TermSession.prototype.write_ttyrec = function (datastr) {
  this.lasttime = new Date();
  var buf = new Buffer(datastr);
  var chunk = new Buffer(buf.length + 12);
  /* TTYREC headers */
  chunk.writeUInt32LE(Math.floor(this.lasttime.getTime() / 1000), 0);
  chunk.writeUInt32LE(1000 * (this.lasttime.getTime() % 1000), 4);
  chunk.writeUInt32LE(buf.length, 8);
  buf.copy(chunk, 12);
  this.record.write(chunk);
  this.framepush(buf);
  /* Send to the player. */
  var msg = JSON.stringify({"t": "d", "d": buf.toString("hex")});
  this.playerconn.sendUTF(msg);
  /* Send to any watchers. */
  for (var i = 0; i < this.watchers.length; i++) {
    if (this.watchers[i].connected)
      this.watchers[i].sendUTF(msg);
  }
  this.emit('data', buf);
};

/* For writing to the subprocess's stdin. */
TermSession.prototype.write = function (data) {
  this.term.write(data);
};

TermSession.prototype.input_msg = function (message) {
  var parsedMsg = getMsgWS(message);
  if (parsedMsg.t == 'q') {
    this.close();
  }
  else if (parsedMsg.t == 'd') {
    var hexstr = parsedMsg.d.replace(/[^0-9a-f]/gi, "");
    if (hexstr.length % 2 != 0) {
      hexstr = hexstr.slice(0, -1);
    }
    var keybuf = new Buffer(hexstr, "hex");
    this.write(keybuf);
  }
};

/* Teardown. */
TermSession.prototype.close = function () {
  if (this.tag() in sessions)
    this.term.kill('SIGHUP');
};

TermSession.prototype.destroy = function () {
  var tag = this.tag();
  fs.unlink(this.lock);
  this.record.end();
  var watchsocks = this.watchers;
  this.watchers = [];
  for (var i = 0; i < watchsocks.length; i++) {
    if (watchsocks[i].connected)
      watchsocks[i].close();
  }
  if (this.playerconn.connected) {
    this.playerconn.sendUTF(JSON.stringify({"t": "q"}));
    this.playerconn.close();
  }
  this.emit('exit');
  gamemux.emit('end', this.gname, this.pname);
  delete sessions[tag];
  tslog("Game %s ended.", tag);
  /* Was that the last game? */
  if (!allowlogin && Object.keys(sessions).length == 0) {
    shutdown();
  }
};

function DglSession(filename) {
  BaseGame.call(this);
  var pathcoms = filename.split('/');
  this.gname = pathcoms[pathcoms.length - 2];
  if (!(this.gname in games)) {
    this.emit('open', false);
    return;
  }
  var basename = pathcoms[pathcoms.length - 1];
  var firstsep = basename.indexOf(':');
  this.pname = basename.slice(0, firstsep);
  var fname = basename.slice(firstsep + 1);
  this.ttyrec = path.join("/dgldir/ttyrec", this.pname, this.gname, fname);
  /* Flag to prevent multiple handlers from reading simultaneously and
   * getting into a race. */
  this.reading = false;
  this.rpos = 0;
  fs.readFile(filename, {encoding: "utf8"}, (function (err, data) {
    if (err) {
      this.emit('open', false);
      return;
    }
    var lines = data.split('\n');
    this.h = Number(lines[1]);
    this.w = Number(lines[2]);
    fs.open(this.ttyrec, "r", (function (err, fd) {
      if (err) {
        this.emit('open', false);
      }
      else {
        this.fd = fd;
        this.emit('open', true);
        tslog("DGL %s: open", this.tag());
        gamemux.emit('begin', this.gname, this.pname, 'dgl');
        this.startchunk();
        this.recwatcher = fs.watch(this.ttyrec, this.notifier.bind(this));
      }
    }).bind(this));
  }).bind(this));
}
DglSession.prototype = new BaseGame();

/* 3 functions to get data from the ttyrec file. */
DglSession.prototype.startchunk = function () {
  if (this.reading)
    return;
  this.reading = true;
  var header = new Buffer(12);
  fs.read(this.fd, header, 0, 12, this.rpos, this.datachunk.bind(this));
};

DglSession.prototype.datachunk = function (err, n, buf) {
  /* Stop recursion if end of file has been reached. */
  if (err || n < 12) {
    if (!err && n > 0) {
      tslog("DGL %s: expected 12-byte header, got %d", this.tag(), n);