(function() {
    var messageChannel = 'MESSAGE_CHANNEL_GATE_GAME';
    var entityID;
    var gates;
    var racers;

    function sendMessage(message) {
        message.entityID = entityID;
        Messages.sendMessage(
            messageChannel,
            JSON.stringify(message)
        );
    }

    function onReceivedMessage(channel, message, senderID) {
        try {
            var data = JSON.parse(message);
        } catch (e) {
            print('Error parsing message: ' + message);
            return;
        }
        // print('data: ' + JSON.stringify(data));

        switch (data.type) {
            case 'INIT_GATE':
                gates.push(data.gateID);
                break;

            case 'REMOVE_GATE':
                var gateIndex = gates.indexOf(data.gateID);
                if (gateIndex > -1) {
                    gates.splice(gateIndex, 1);
                }
                break;

            case 'REMOVE_RACER':
                if (racers[data.avatarSessionUUID]) {
                    delete racers[data.avatarSessionUUID];
                    sendRenderMessage();
                }
                break;

            case 'PASS_THROUGH_GATE':
                print('RACERS ' + JSON.stringify(racers));
                print('GATES ' + gates.length + ' ' + JSON.stringify(gates));

                var racer = racers[data.avatarSessionUUID];
                if (!racer) {
                    racers[data.avatarSessionUUID] = racer = {
                        avatarDisplayName: data.avatarDisplayName || 'Anon',
                        isRacing: false
                    };
                }

                if (!racer.isRacing && data.gateID === gates[0]) {
                    racer.isRacing = true;
                    racer.startTime = Date.now();
                    racer.gatesPassed = 1;
                    racer.time = 'racing...';
                } else if (racer.gatesPassed < gates.length && gates[racer.gatesPassed] === data.gateID) {
                    racer.gatesPassed++;
                    sendMessage({
                        type: 'CHECKPOINT',
                        gateID: data.gateID
                    });
                } else if (racer.gatesPassed === gates.length && gates[0] === data.gateID) { // finish race by going into the starting ring again
                    racer.isRacing = false;
                    racer.time = ((Date.now() - racer.startTime) / 1000).toFixed(3) + ' sec';
                    if (!racer.bestTime || racer.time < racer.bestTime) {
                        racer.bestTime = racer.time;
                    }
                    sendMessage({
                        type: 'CHECKPOINT',
                        gateID: data.gateID
                    });
                } else {
                  return;
                }
                sendRenderMessage();
                break;
        }
    }

    function sendRenderMessage() {
        sendMessage({
            type: 'RENDER',
            racers: racers
        });
    }


    return {
        preload: function(id) {
            entityID = id;
            gates = [];
            racers = {};
            Messages.subscribe(messageChannel);
            Messages.messageReceived.connect(null, onReceivedMessage);
            print('Hello Scoreboard');
        },
        unload: function(id) {
            Messages.unsubscribe(messageChannel);
            Messages.messageReceived.disconnect(null, onReceivedMessage);
        },
    };
})