server.js

var url = require('url');
var nano = require('nano');
var couchdb = nano('https://myiriscouchserver.iriscouch.com');
var formidable = require('formidable');
var BufferedStream = require('bufferedstream');
var couchMapReduce = function (doc) {
    emit([doc.room, doc.when], doc);
};
couchdb.db.create('chat', function(err) {
    if (err && err.status_code !== 412) {
        throw err;
    }
    couchdb.db.create('users', function(err) {
        if (err && err.status_code !== 412) {
            throw err;
        }
        var designDoc = {
            language: "javascript",
            views: {
                by_room: {
                    map: couchMapReduce.toString()
                }
            }
        };
        var chatDB = couchdb.use('chat');
        (function insertOrUpdateDesignDoc() {
            chatDB.insert(designDoc, '_design/designdoc', function(err) {
                if (err) {
                    if (err.status_code === 409) {
                        chatDB.get('_design/designdoc', function(err, ddoc) {
                            if (err) { return console.error(err); }
                            designDoc._rev = ddoc._rev;
                            insertOrUpdateDesignDoc();
                        });
                        return;
                    } else {
                        return console.error(err);
                    }
                }
                startServer();
            });
        }());
    });
});
function startServer() {
    console.log('starting server');
    var chatDB = couchdb.use('chat');
    var userDB = couchdb.use('users');
    var httpd = require('http').createServer(handler);
    var io = require('socket.io').listen(httpd);
    var fs = require('fs');
    httpd.listen(4000);
    function handler(req, res) {
        var username;
        if (req.method === 'POST' && req.url.indexOf('/avatar') === 0) {
            var currentUserDocRev;
            console.log('got avatar');
            var bufferedRequest = new BufferedStream();
            bufferedRequest.headers = req.headers;
            bufferedRequest.pause();
            req.pipe(bufferedRequest);
// parse username
            console.log(url.parse(req.url).query);
            username = url.parse(req.url, true).query.username;
            userDB.insert({username: username}, username, function(err, user) {
                if (err) {
                    if (err.status_code === 409) {
                        userDB.get(username, function(err, user) {
                            if (err) {
                                console.error(err);
                                res.writeHead(500);
                                return res.end(JSON.stringify(err));
                            }
                            currentUserDocRev = user._rev;
                            bufferedRequest.resume();
                        });
                        return;
                    } else {
                        res.writeHead(500);
                        return res.end(JSON.stringify(err));
                    }
                }
                console.log('username inserted, rev = ', user.rev);
                currentUserDocRev = user.rev;
                console.log('currentUserDocRev:', currentUserDocRev);
                bufferedRequest.resume();
            });

            // handle avatar upload
            var form = new formidable.IncomingForm();
            form.encoding = 'utf8';
            form.parse(bufferedRequest);
            form.onPart = function(part) {
                if (part.name !== 'avatar') {
                    return;
                }
                var attachment = userDB.attachment.insert(
                    username, 'avatar', null, part.mime, {rev: currentUserDocRev});
                part.pipe(attachment);
                attachment.on('error', function(err) {
                    console.error(err);
                    res.writeHead(500);
                    return res.end(JSON.stringify(err));
                });
                attachment.on('end', function() {
                    res.end();
                });
            };
        } else if (req.url.indexOf('/avatar') === 0){
// serve the avatar
            username = url.parse(req.url, true).query.username;
            userDB.attachment.get(username, 'avatar').pipe(res);
        } else {
// serve the index page
            fs.readFile(__dirname + '/index.html',
                function(err, data) {
                    if (err) {
                        res.writeHead(500);
                        return res.end('Error loading index.html');
                    }
                    res.writeHead(200);
                    res.end(data);
                }
            );
        }
    }
    function sendBackLog(socket, room) {
        var getOptions = {
            start_key: JSON.stringify([room, 9999999999999]),
            end_key: JSON.stringify([room, 0]),
            limit: 10,
            descending: true
        };
        chatDB.get('_design/designdoc/_view/by_room', getOptions,
            function(err, results) {
                var messages = results.rows.reverse().map(function(res) {
                    return res.value;
                });
                socket.emit('backlog', messages);
            });
    }
    var chat = io.of('/chat');
    chat.on('connection', function (socket) {
        socket.on('clientMessage', function(content) {
            socket.get('username', function(err, username) {
                if (! username) {
                    username = socket.id;
                }
                socket.get('room', function(err, room) {
                    if (err) { throw err; }
                    var broadcast = socket.broadcast;
                    var message = content;
                    if (room) {
                        broadcast.to(room);
                    }
                    var messageDoc = {
                        when: Date.now(),
                        from: username,
                        room: room,
                        message: content
                    };
                    socket.emit('serverMessage', messageDoc);
                    chatDB.insert(messageDoc, function(err) {
                        if (err) { console.error(err); }
                    });
                    broadcast.emit('serverMessage', messageDoc);
                });
            });
        });
        socket.on('login', function(username) {
            socket.set('username', username, function(err) {
                if (err) { throw err; }
                var message = {
                    from: username,
                    message: 'Logged in',
                    when: Date.now()
                };
                socket.emit('serverMessage', message);
                socket.broadcast.emit('serverMessage', message);
                sendBackLog(socket, null);
            });
        });
        socket.on('disconnect', function() {
            socket.get('username', function(err, username) {
                if (! username) {
                    username = socket.id;
                }
                var message = {
                    from: username,
                    message: 'disconnected',
                    when: Date.now()
                };
                socket.broadcast.emit('serverMessage', message);
            });
        });
        socket.on('join', function(room) {
            socket.get('room', function(err, oldRoom) {
                if (err) { throw err; }
                socket.set('room', room, function(err) {
                    if (err) { throw err; }
                    socket.join(room);
                    if (oldRoom) {
                        socket.leave(oldRoom);
                    }
                    socket.get('username', function(err, username) {
                        if (! username) {
                            username = socket.id;
                        }
                        var message = {
                            from: username,
                            message: 'joined room ' + room + '. Fetching backlog...',
                            when: Date.now()
                        };
                        socket.emit('serverMessage', message);
                        socket.broadcast.to(room).emit('serverMessage', message);
                    });
                    sendBackLog(socket, room);
                });
            });
        });
        socket.emit('login');
    });
}