var http    = require('http'),
    router  = require('choreographer').router(),
    redis   = require('redis-node'),
    io      = require('socket.io'),
    fs      = require('fs'),
    config  = require('./conf');

http.ServerResponse.prototype.serveFile = function(file, type) {
    var res = this;
    type = type || 'text/html';
    fs.readFile('./public/' + file, function(err, data) {
        if(err) {
            res.writeHead(500);
            res.end("Couldn't serve " + file + ". Error: " + err);
        } else {
            res.writeHead(200, {
                'Content-Type': type,
                'Content-Length': data.length
            });
            res.end(data);
        }
    });
};

router.get('/', function(req, res) {
    res.serveFile('index.html');
}).get('/style.css', function(req, res) {
    res.serveFile('style.css', 'text/css');
}).get('/client.js', function(req, res) {
    res.serveFile('client.js', 'text/javascript');
});

var server = http.createServer(router);
server.listen(config.port);
var socket = io.listen(server);

socket.on('connection', function(client) {
    var redis_client = redis.createClient();
    var redis_subscriber;
    var channel = null;
    var nick = null;
    client.on('message', function(data) {
        var packet = JSON.parse(data);
        switch(packet.cmd)
        {
        case 'join':
            channel = packet.channel.replace(/[^A-Za-z0-9_\-']/,'');
            nick = packet.nick;
            redis_client.incr('channels:' + channel);
            redis_client.sadd('channels', channel);
            redis_client.publish(channel, JSON.stringify({
                ev: 'join',
                from: nick,
                time: Math.round(new Date().getTime() / 1000),
                msg: packet.msg
            }));
            redis_subscriber = redis.createClient();
            redis_subscriber.subscribeTo(channel, function(channel, msg) {
                client.send(msg);
            });
            client.send(JSON.stringify({ev:'welcome'}));
            break;
        case 'part':
            doPart();
            break;
        case 'list':
            redis_client.smembers('channels', function(err, status) {
                client.send(JSON.stringify({
                    ev: 'list',
                    channels: status
                }));
            });
            break;
        case 'msg':
            if(channel == null)
                break;
            redis_client.publish(channel, JSON.stringify({
                ev: 'msg',
                from: nick,
                time: Math.round(new Date().getTime() / 1000),
                msg: packet.msg
            }));
            break;
        }
    });
    function doPart() {
        if(channel != null) {
            console.log(nick + " parted " + channel)
            redis_client.decr('channels:' + channel);
            redis_client.publish(channel, JSON.stringify({
                ev: 'part',
                from: nick,
                time: Math.round(new Date().getTime() / 1000)
            }));
        }
        if(redis_subscriber != null) {
            redis_subscriber.unsubscribe(channel);
            redis_subscriber.close();
            redis_subscriber = null;
        }
    }
    client.on('disconnect', function() {
        doPart();
        redis_client.close();
    });
});