var client = {}
//client.clientId = undefined


client.init = function() {
    // this is required to so that the ui is able to communicate with the client through the API specified on the assignment sheet
    ui.setClient(client)

    // create Websocket object
    client.socket = new WebSocket('ws://' + document.location.hostname + ':' + config.server.wsport);

    // on open
    client.socket.onopen = function() {
        console.log('Connection established!');
    };

    // on close
    client.socket.onclose = function() {
        ui.fail('Lost connection to the server!');
    };

    // on error
    client.socket.onerror = function(event) {
        console.log('Error happened: ' + event.data);
    };

    // on message
    client.socket.onmessage = function(event) {
        var msg = JSON.parse(event.data);

        switch (msg.type) {
            case config.msgtype.CHANNEL_MSG:
                ui.addChannelMessage(msg.payload.src, msg.payload.channel, msg.payload.body);
                break;
            case config.msgtype.CHANNEL_SUB:
                ui.addChannelView(msg.payload.channel);
                break;
            case config.msgtype.CHANNEL_UNSUB:
                ui.removeChannelView(msg.payload.channel);
                break;
            case config.msgtype.CHANNEL_LIST:
                ui.updateChannelList(msg.payload.channel_list);
                break;
            case config.msgtype.QUEUE_PULL:
                getPullResponse(msg.payload);
                break;
            case config.msgtype.ERROR:
                ui.fail(msg.payload.error);
                break;
        }
    };
}
client.requestCreateChannel = function(target) {
    //logging to the console in a browser is in most cases not a good idea for production code
    //here it is just done for making debugging efforts slightly easier in the browser
    console.log('client.requestCreateChannel: ' + target)

    // for now, the following is invoked without considering any communication with the server
    // it is probably a bad idea to readily create a new tab in the UI at this time...
    // ... consider what happens if there are errors or if the server refuses to create this channel for some reason
    if (target.length != 0) {
        client.socket.send(createMsg(config.msgtype.CHANNEL_CREATE, createChannelPayload(target)));
    }
    else {
        ui.fail("No channel name entered")
    }
}

client.requestUnsubscribe = function(dst) {
    console.log('client.requestUnsubscribe: ' + dst)
    client.socket.send(createMsg(config.msgtype.CHANNEL_UNSUB, createChannelPayload(dst)));
}

client.requestSubscribe = function(dst) {
    console.log('client.requestSubscribe: ' + dst)
    client.socket.send(createMsg(config.msgtype.CHANNEL_SUB, createChannelPayload(dst)));
}

client.requestPublish = function(dst, msg) {
    console.log('client.requestPublish: ' + dst + ' ' + msg)
    var payload = createChannelPayload(dst);
    payload.body = msg;
    client.socket.send(createMsg(config.msgtype.CHANNEL_MSG, payload));
}

function createMsg(type, payload) {
    var msg = {};
    msg.type = type;
    msg.payload = payload;
    return JSON.stringify(msg);
}

client.requestPull = function(dst) {
  console.log('client.requestPull: ' + dst)
  client.socket.send(createMsg(config.msgtype.QUEUE_PULL, createQueuePayload(dst)));
}

client.requestPush = function (target, msg) {
    console.log('client.requestPushChannel: ' + target)
    if (target.length != 0) {
        var temp = createQueuePayload(target);
        temp.msg = msg;
        client.socket.send(createMsg(config.msgtype.QUEUE_PUSH,temp ));
    }
    else {
        ui.fail("No channel name entered")
    }
}


function getPullResponse(payload) {
  if(payload.error == 1)
  {
     console.log('There is nothing to pull');
  }
  else
  {
    console.log('Element pulled');
    //for futher use
    var msg = {};
    msg = payload.msg;
  }
}

function createChannelPayload(channel) {
    var payload = {};
    payload.channel = channel;
    return payload;
}

function createQueuePayload(dst) {
    var payload = {};
    payload.dst = dst;
    return payload;
}