--- a/rlgwebd.js	Fri Jun 15 16:23:57 2012 -0700
+++ b/rlgwebd.js	Mon Jun 18 13:43:51 2012 -0700
@@ -7,6 +7,7 @@
 var url = require('url');
 var path = require('path');
 var fs = require('fs');
+var events = require('events');
 var child_process = require('child_process');
 var daemon = require(path.join(localModules, "daemon"));
 
@@ -52,39 +53,46 @@
 /* Global state */
 var logins = {};
 var sessions = {};
+var clients = {};
 var allowlogin = true;
+var nextsession = 0;
 
-/* Constructor for TermSessions.  Note that it opens the terminal and 
- * adds itself to the sessions dict. It currently assumes the user has
- * been authenticated.
+/* Constructor.  A TermSession handles a pty and the game running on it.
+ *   game: (String) Name of the game to launch.
+ *   lkey: (String, key) The user's id, a key into logins.
+ *   dims: (Array [Number, Number]) Height and width of the pty.
+ *   handlers: (Object) Key-value pairs, event names and functions to
+ *           install to handle them.
+ *  Events:
+ *   "open": Emitted on startup.  Parameters: success (Boolean)
+ *   "data": Data generated by child. Parameters: buf (Buffer)
+ *   "exit": Child terminated. Parameters: exitcode, signal
  */
-/* TODO take a callback, or emit success/err events. */
-function TermSession(game, user, dims, lkey) {
-  /* First make sure starting the game will work. */
+function TermSession(game, lkey, dims, handlers) {
+  var ss = this;
+  /* Subclass EventEmitter to do the hard work. */
+  events.EventEmitter.call(this);
+  for (var evname in handlers)
+    this.on(evname, handlers[evname]);
+  /* Don't launch anything that's not a real game. */
   if (game in games) {
     this.game = games[game];
   }
   else {
-    // TODO: throw an exception instead
-    return null;
+    this.emit('open', false);
+    return;
   }
-  this.player = String(user);
-  this.key = lkey;
-  /* This order seems to best avoid race conditions... */
-  this.alive = false;
-  // A kludge until TermSession is rewritten to handle real watching.
-  this.sendq = false;
-  this.sessid = randkey(2);
-  while (this.sessid in sessions) {
-    this.sessid = randkey(2);
+  if (lkey in logins) {
+    this.key = lkey;
+    this.pname = logins[lkey].name;
+  }
+  else {
+    this.emit('open', false);
+    return;
   }
   /* Grab a spot in the sessions table. */
+  this.sessid = nextsession++;
   sessions[this.sessid] = this;
-  /* State for messaging. */
-  this.nsend = 0;
-  this.nrecv = 0;
-  this.msgQ = []
-  this.Qtimeout = null;
   /* Set up the sizes. */
   this.w = Math.floor(Number(dims[1]));
   if (!(this.w > 0 && this.w < 256))
@@ -98,22 +106,21 @@
     childenv[key] = process.env[key];
   }
   childenv["PTYHELPER"] = String(this.h) + "x" + String(this.w);
-  /* TODO handle tty-opening errors */
-  /* TODO make argument-finding into a method */
-  args = [this.game.path, "-n", user.toString()];
+  args = [this.game.path, "-n", this.pname];
   this.child = child_process.spawn("/bin/ptyhelper", args, {"env": childenv});
-  var ss = this;
-  this.alive = true;
-  this.data = [];
+  this.emit('open', true);
   /* Set up the lockfile and ttyrec */
   var ts = timestamp();
   var progressdir = "/dgldir/inprogress-" + this.game.uname;
-  this.lock = path.join(progressdir, this.player + ":node:" + ts + ".ttyrec");
+  this.lock = path.join(progressdir, this.pname + ":node:" + ts + ".ttyrec");
   var lmsg = this.child.pid.toString() + '\n' + this.w + '\n' + this.h + '\n'; 
   fs.writeFile(this.lock, lmsg, "utf8"); 
-  var ttyrec = path.join("/dgldir/ttyrec", this.player, this.game.uname, 
+  var ttyrec = path.join("/dgldir/ttyrec", this.pname, this.game.uname, 
                ts + ".ttyrec");
   this.record = fs.createWriteStream(ttyrec, { mode: 0664 });
+  logins[lkey].sessions.push(this.sessid);
+  tslog("%s playing %s (index %d, pid %d)", this.pname, this.game.uname, 
+            this.sessid, this.child.pid);
   /* END setup */
   function ttyrec_chunk(buf) {
     var ts = new Date();
@@ -123,115 +130,180 @@
     chunk.writeUInt32LE(1000 * (ts.getTime() % 1000), 4);
     chunk.writeUInt32LE(buf.length, 8);
     buf.copy(chunk, 12);
-    ss.data.push(chunk);
     ss.record.write(chunk);
+    ss.emit('data', buf);
   }
   this.child.stdout.on("data", ttyrec_chunk);
   this.child.stderr.on("data", ttyrec_chunk);
+  this.write = function(data) {
+    this.child.stdin.write(data);
+  };
   this.child.on("exit", function (code, signal) {
-    ss.exitcode = (code != null ? code : 255);
-    ss.alive = false;
     fs.unlink(ss.lock);
-    /* Wait for all the data to get collected */
-    setTimeout(ss.cleanup, 1000);
+    ss.record.end();
+    ss.emit('exit', code, signal);
+    var id = ss.sessid;
+    delete sessions[id];
+    tslog("Session %s ended.", id);
   });
+  this.close = function () {
+    this.child.kill('SIGHUP');
+  };
+}
+TermSession.prototype = new events.EventEmitter();
+
+function Watcher(session) {
+  var ss = this; // that
+  this.session = session;
+  this.alive = true;
+  /* State for messaging. */
+  this.nsend = 0;
+  this.sendQ = [];
+  /* Get a place in the table. */
+  this.id = randkey(2);
+  while (this.id in clients) {
+    this.id = randkey(2);
+  }
+  clients[this.id] = this;
+  function dataH(buf) {
+    var reply = {};
+    reply.t = "d";
+    reply.n = ss.nsend++;
+    reply.d = buf.toString("hex");
+    ss.sendQ.push(reply);
+  }
+  function exitH(code, signal) {
+    ss.alive = false;
+    ss.sendQ.push({"t": "q"});
+  }
+  session.on('data', dataH);
+  session.on('exit', exitH);
+  this.read = function() {
+    /* Returns an array of all outstanding messages, empty if none. */
+    var temp = this.sendQ;
+    this.sendQ = [];
+    /* Clean up if finished. */
+    if (!this.alive) {
+      delete clients[this.id];
+    }
+    return temp;
+  };
+  this.quit = function() {
+    this.session.removeListener('data', dataH);
+    this.session.removeListener('exit', exitH);
+    delete clients[this.id];
+  };
+}
+
+function Player(gamename, lkey, dims, callback) {
+  var ss = this;
+  this.alive = false;
+  /* State for messaging. */
+  this.nsend = 0;
+  this.nrecv = 0;
+  this.sendQ = [];
+  this.recvQ = []
+  this.Qtimeout = null;
+  /* Get a place in the table. */
+  this.id = randkey(2);
+  while (this.id in clients) {
+    this.id = randkey(2);
+  }
+  clients[this.id] = this;
+
+  this.read = function() {
+    var temp = this.sendQ;
+    this.sendQ = [];
+    /* Clean up if finished. */
+    if (!this.alive) {
+      clearTimeout(this.Qtimeout);
+      delete clients[this.id];
+    }
+    return temp;
+  };
   this.write = function (data, n) {
     if (!this.alive || typeof (n) != "number") {
       return;
     }
-    //console.log("Got message " + n);
     var oindex = n - this.nrecv;
     if (oindex === 0) {
-      //console.log("Writing message " + n);
-      this.child.stdin.write(data);
+      this.session.write(data);
       this.nrecv++;
       var next;
-      while ((next = this.msgQ.shift()) !== undefined) {
-        //console.log("Writing message " + this.nrecv);
-        this.child.stdin.write(next);
+      while ((next = this.recvQ.shift()) !== undefined) {
+        this.session.write(next);
         this.nrecv++;
       }
-      if (this.msgQ.length == 0 && this.Qtimeout) {
+      if (this.recvQ.length == 0 && this.Qtimeout) {
         clearTimeout(this.Qtimeout);
         this.Qtimeout = null;
       }
     }
     else if (oindex > 0 && oindex <= 1024) {
-      tslog("Stashing message %d at %d", n, oindex - 1);
-      this.msgQ[oindex - 1] = data;
+      tslog("Client %s: Stashing message %d at %d", this.id,  n, oindex - 1);
+      this.recvQ[oindex - 1] = data;
       if (!this.Qtimeout) {
-        var nextn = this.nrecv + this.msgQ.length + 1;
+        var nextn = this.nrecv + this.recvQ.length + 1;
         this.Qtimeout = setTimeout(this.flushQ, 30000, this, nextn);
       }
     }
     /* Otherwise, discard it */
     return;
   };
-  this.flushQ = function (session, n) {
+  this.flushQ = function (client, n) {
     /* Callback for when an unreceived message times out.
      * n is the first empty space that will not be given up on. */
-    if (!session.alive)
+    if (!client.alive || client.nrecv >= n)
       return;
-    session.nrecv++;
+    client.nrecv++;
     var next;
     /* Clear the queue up to n */
-    while (session.nrecv < n) {
-      next = session.msgQ.shift();
+    while (client.nrecv < n) {
+      next = client.recvQ.shift();
       if (next !== undefined)
-        session.child.stdin.write(next);
-      session.nrecv++;
+        client.session.write(next);
+      client.nrecv++;
     }
     /* Clear out anything that's ready. */
-    while ((next = session.msgQ.shift()) !== undefined) {
-      session.child.stdin.write(next);
-      session.nrecv++;
+    while ((next = client.recvQ.shift()) !== undefined) {
+      client.session.write(next);
+      client.nrecv++;
     }
     /* Now set another timeout if necessary. */
-    if (session.msgQ.length != 0) {
-      var nextn = session.nrecv + session.msgQ.length + 1;
-      session.Qtimeout = setTimeout(session.flushQ, 30000, session, nextn);
+    if (client.recvQ.length != 0) {
+      var nextn = client.nrecv + client.recvQ.length + 1;
+      client.Qtimeout = setTimeout(client.flushQ, 30000, client, nextn);
     }
-    tslog("Flushing queue for session %s", session.sessid);
+    tslog("Flushing queue for player %s", player.id);
   };
-  this.read = function () {
-    if (this.data.length == 0)
-      return null;
-    var pos = 0;
-    var i = 0;
-    for (i = 0; i < this.data.length; i++)
-      pos += this.data[i].length - 12;
-    var nbuf = new Buffer(pos);
-    var tptr;
-    pos = 0;
-    while (this.data.length > 0) {
-      tptr = this.data.shift();
-      tptr.copy(nbuf, pos, 12);
-      pos += tptr.length - 12;
+  this.quit = function() {
+    if (this.alive)
+      this.session.close();
+  };
+  function openH(success) {
+    if (success) {
+      ss.alive = true;
     }
-    return nbuf;
-  };
-  this.close = function () {
-    if (this.alive)
-      this.child.kill('SIGHUP');
-  };
-  this.cleanup = function () {
-    /* Call this when the child is dead. */
-    if (ss.alive)
-      return;
-    ss.record.end();
-    /* Give the client a chance to read any leftover data. */
-    if (ss.data.length > 0 || !ss.sendq)
-      setTimeout(ss.remove, 8000);
-    else
-      ss.remove();
-  };
-  this.remove = function () {
-    var id = ss.sessid;
-    delete sessions[id];
-    tslog("Session %s removed.", id);
-  };
+    callback(ss, success);
+  }
+  function dataH(chunk) {
+    var reply = {};
+    reply.t = "d";
+    reply.n = ss.nsend++;
+    reply.d = chunk.toString("hex");
+    ss.sendQ.push(reply);
+  }
+  function exitH(code, signal) {
+    ss.alive = false;
+    ss.sendQ.push({"t": "q"});
+  }
+  var handlers = {'open': openH, 'data': dataH, 'exit': exitH};
+  this.session = new TermSession(gamename, lkey, dims, handlers);
 }
 
+/* Some functions which check whether a player is currently playing or 
+ * has a saved game.  Maybe someday they will provide information on 
+ * the game. */
 function checkprogress(user, game, callback, args) {
   var progressdir = "/dgldir/inprogress-" + game.uname;
   fs.readdir(progressdir, function(err, files) {
@@ -359,11 +431,9 @@
 function reaper() {
   var now = new Date();
   function reapcheck(session) {
-    if (!session.alive)
-      return;
     fs.fstat(session.record.fd, function (err, stats) {
       if (!err && now - stats.mtime > playtimeout) {
-        tslog("Reaping %s", session.sessid);
+        tslog("Reaping session %s", session.sessid);
         /* Dissociate it with its login name. */
         var sn = logins[session.key].sessions.indexOf(session.sessid);
         if (sn >= 0) {
@@ -403,7 +473,7 @@
       if (expired.length > 0) {
         logins[lkey].ts = new Date(now);
         for (var j = 0; j < expired.length; j++) {
-          targarray.splice(targarray.indexOf(expired[j], 1));
+          targarray.splice(targarray.indexOf(expired[j]), 1);
         }
       }
     }
@@ -412,15 +482,15 @@
 
 function login(req, res, formdata) {
   if (!allowlogin) {
-    sendError(res, 6, null);
+    sendError(res, 6, null, false);
     return;
   }
   if (!("name" in formdata)) {
-    sendError(res, 2, "Username not given.");
+    sendError(res, 2, "Username not given.", false);
     return;
   }
   else if (!("pw" in formdata)) {
-    sendError(res, 2, "Password not given.");
+    sendError(res, 2, "Password not given.", false);
     return;
   }
   var username = String(formdata["name"]);
@@ -478,6 +548,7 @@
   }
   var username = logins[lkey].name;
   var gname = formdata["game"];
+  // If dims are not given or invalid, the constructor will handle it.
   var dims = [formdata["h"], formdata["w"]];
   if (!(gname in games)) {
     sendError(res, 2, "No such game: " + gname);
@@ -492,23 +563,41 @@
       return;
     }
     // Game starting has been approved.
-    var nsession = new TermSession(gname, username, dims, lkey);
-    if (nsession) {
-      res.writeHead(200, {'Content-Type': 'application/json'});
-      var reply = {"t": "l", "id": nsession.sessid, "w": nsession.w, "h": 
-                   nsession.h};
-      res.write(JSON.stringify(reply));
-      res.end();
-      tslog("%s playing %s (key %s, pid %d)", username, gname, 
-                  nsession.sessid, nsession.child.pid);
-      logins[lkey].sessions.push(nsession.sessid);
-    }
-    else {
-      sendError(res, 5, "Failed to open TTY");
-      tslog("Unable to allocate TTY for %s", gname);
-    }
+    var respondlaunch = function(nclient, success) {
+      if (success) {
+        res.writeHead(200, {'Content-Type': 'application/json'});
+        var reply = {"t": "s", "id": nclient.id, "w": nclient.w, "h": 
+                     nclient.h};
+        res.write(JSON.stringify(reply));
+        res.end();
+      }
+      else {
+        sendError(res, 5, "Failed to open TTY");
+        tslog("Unable to allocate TTY for %s", gname);
+      }
+    };
+    new Player(gname, lkey, dims, respondlaunch);
+  };
+  checkprogress(username, games[gname], launch, []);
+}
+
+function watch(req, res, formdata) {
+  if (!("n" in formdata)) {
+    sendError(res, 2, "Game number not given");
+    return;
   }
-  checkprogress(username, games[gname], launch, []);
+  var gamenumber = Number(formdata["n"]);
+  if (!(gamenumber in sessions)) {
+    sendError(res, 7);
+    return;
+  }
+  var session = sessions[gamenumber];
+  var watch = new Watcher(session);
+  var reply = {"t": "w", "id": watch.id, "w": session.w, "h": session.h};
+  res.writeHead(200, {'Content-Type': 'application/json'});
+  res.write(JSON.stringify(reply));
+  res.end();
+  tslog("Game %d is being watched (key %s)", gamenumber, watch.id);
 }
 
 /* Sets things up for a new user, like dgamelaunch's commands[register] */
@@ -574,27 +663,27 @@
   return;
 }
 
-function endgame(term, res) {
-  if (!term.alive) {
-    sendError(res, 7, null);
+/* Ends the game, obviously.  Less obviously, stops watching the game if
+ * the client is a Watcher instead of a Player. */
+function endgame(client, res) {
+  if (!client.alive) {
+    sendError(res, 7, null, true);
     return;
   }
-  term.close();
-  var resheaders = {'Content-Type': 'application/json'};
-  res.writeHead(200, resheaders);
-  res.write(JSON.stringify({"t": "q"}));
-  res.end();
-  term.sendq = true;
+  client.quit();
+  // Give things some time to happen.
+  if (client instanceof Player)
+    setTimeout(readFeed, 200, client, res);
   return;
 }
 
-function findTermSession(formdata) {
+function findClient(formdata, playersOnly) {
   if (typeof(formdata) != "object")
     return null;
   if ("id" in formdata) {
-    var sessid = formdata["id"];
-    if (sessid in sessions) {
-      return sessions[sessid];
+    var id = formdata["id"];
+    if (id in clients && (!playersOnly || clients[id] instanceof Player)) {
+      return clients[id];
     }
   }
   return null;
@@ -648,47 +737,29 @@
   return;
 }
 
-function readFeed(res, term) {
-  if (term) {
-    var reply = {};
-    var result = term.read();
-    if (result == null) {
-      if (term.alive)
-        reply.t = "n";
-      else {
-        if (allowlogin) {
-          reply.t = "q";
-          term.sendq = true;
-        }
-        else {
-          sendError(res, 6, null);
-          return;
-        }
-      }
-    }
-    else {
-      reply.t = "d";
-      reply.n = term.nsend++;
-      reply.d = result.toString("hex");
-    }
-    res.writeHead(200, { "Content-Type": "application/json" });
-    res.write(JSON.stringify(reply));
-    res.end();
+function readFeed(client, res) {
+  if (!client) {
+    sendError(res, 7, null, true);
+    return;
   }
-  else {
-    sendError(res, 7, null);
+  var msgs = client.read();
+  if (!allowlogin && !msgs.length) {
+    sendError(res, 6, null, true);
+    return;
   }
+  res.writeHead(200, { "Content-Type": "application/json" });
+  res.write(JSON.stringify(msgs));
+  res.end();
 }
 
 function statusmsg(req, res) {
   var reply = {"s": allowlogin, "g": []};
   for (var sessid in sessions) {
-    if (sessions[sessid].alive) {
-      var gamedesc = {};
-      gamedesc["p"] = sessions[sessid].player;
-      gamedesc["g"] = sessions[sessid].game.name;
-      reply["g"].push(gamedesc);
-    }
+    var gamedesc = {};
+    gamedesc["n"] = sessid;
+    gamedesc["p"] = sessions[sessid].pname;
+    gamedesc["g"] = sessions[sessid].game.name;
+    reply["g"].push(gamedesc);
   }
   res.writeHead(200, { "Content-Type": "application/json" });
   if (req.method != 'HEAD')
@@ -723,7 +794,7 @@
         "Login failed", "Already playing", "Game launch failed",
         "Server shutting down", "Game not in progress" ];
 
-function sendError(res, ecode, msg) {
+function sendError(res, ecode, msg, box) {
   res.writeHead(200, { "Content-Type": "application/json" });
   var edict = {"t": "E"};
   if (!(ecode < errorcodes.length && ecode > 0))
@@ -732,10 +803,14 @@
   edict["s"] = errorcodes[ecode];
   if (msg)
     edict["s"] += ": " + msg;
-  res.write(JSON.stringify(edict));
+  if (box)
+    res.write(JSON.stringify([edict]));
+  else
+    res.write(JSON.stringify(edict));
   res.end();
 }
 
+// TODO new-objects done to here
 function webHandler(req, res) {
   /* default headers for the response */
   var resheaders = {'Content-Type': 'text/html'};
@@ -753,30 +828,33 @@
   function respond() {
     formdata = getMsg(reqbody);
     var target = url.parse(req.url).pathname;
-    var cterm = findTermSession(formdata);
     /* First figure out if the client is POSTing to a command interface. */
     if (req.method == 'POST') {
       if (target == '/feed') {
-        if (!cterm) {
-          sendError(res, 7, null);
+        var client = findClient(formdata, false);
+        if (!client) {
+          sendError(res, 7, null, true);
           return;
         }
         if (formdata.t == "q") {
           /* The client wants to terminate the process. */
-          endgame(cterm, res);
+          endgame(client, res);
         }
         else if (formdata.t == "d" && typeof(formdata.d) == "string") {
+          if (!(client instanceof Player)) {
+            sendError(res, 7, "Watching", true);
+            return;
+          }
           /* process the keys */
           hexstr = formdata.d.replace(/[^0-9a-f]/gi, "");
           if (hexstr.length % 2 != 0) {
-            sendError(res, 2, "incomplete byte");
+            sendError(res, 2, "incomplete byte", true);
             return;
           }
           keybuf = new Buffer(hexstr, "hex");
-          /* TODO OoO correction */
-          cterm.write(keybuf, formdata.n);
+          client.write(keybuf, formdata.n);
         }
-        readFeed(res, cterm);
+        readFeed(client, res);
       }
       else if (target == "/login") {
         login(req, res, formdata);
@@ -787,6 +865,9 @@
       else if (target == "/play") {
         startgame(req, res, formdata);
       }
+      else if (target == "/watch") {
+        watch(req, res, formdata);
+      }
       else {
         res.writeHead(405, resheaders);
         res.end();
@@ -797,13 +878,10 @@
         if (req.method == 'HEAD') {
           res.writeHead(200, {"Content-Type": "application/json"});
           res.end();
-          return;
         }
-        if (!cterm) {
-          sendError(res, 7, null);
-          return;
-        }
-        readFeed(res, cterm);
+        else
+          sendError(res, 7, null, true);
+        return;
       }
       else if (target == '/status') {
         statusmsg(req, res);
@@ -841,14 +919,13 @@
     for (var sessid in sessions) {
       sessions[sessid].close();
     }
-    setTimeout(shutdown, 10000);
+    setTimeout(shutdown, 2000);
   }