/// <summary>
/// Gets the current callback channel and adds it to the collection of all channels.
/// </summary>
/// <returns></returns>
public ChannelWrapper RegisterClient(Message message)
{
var manager = new NewsfeedManager();
string username;
if (manager.TryGetCurrentUsername(message, out username))
{
ChannelWrapper wrapper;
//If the user is logged and resfresh the page, a new channel will be opened and the old should be removed
if (this.clients.TryGetValue(username, out wrapper))
{
this.clients.Remove(username);
}
var client = OperationContext.Current.GetCallbackChannel<INewsfeedServiceCallback>();
wrapper = new ChannelWrapper(username, client);
wrapper.Closed += Connection_Closed;
wrapper.Faulted += Connection_Closed;
var usersRepository = new Domain.UserRepository();
wrapper.User = usersRepository.Get(username);
this.clients.Add(username, wrapper);
return wrapper;
}
return null;
}
private void BroadcastMessage(Model.Message message)
{
//Prevent modifying the collection when someone is sending message
lock (NewsfeedService.clientsLock)
{
var manager = new NewsfeedManager();
foreach (var client in ClientsManager.Instance.Clients)
{
try
{
//get only usernames from the BsonDosument collection
var blockedUsernames = client.Value.User.BlockedUsers.Select(u => u.GetElement("Username").Value.AsString);
if (blockedUsernames.Contains(message.Username))
{
continue;
}
client.Value.Callback.Send(manager.CreateMessage(message));
}
catch
{
}
}
ClientsManager.Instance.ClearFailed();
}
}
private void SendOlderMessagesToClient(IEnumerable<Domain.Message> messages, NewsfeedManager manager)
{
foreach (var m in messages)
{
var uiMessage = manager.MapDomainMessageToClient(m);
uiMessage.Action = ServiceAction.ShowMore.ToString();
this.currentClient.Callback.Send(manager.CreateMessage(uiMessage));
}
}
public void Recieve(Message message)
{
var manager = new NewsfeedManager();
string username;
if (!manager.TryGetCurrentUsername(message, out username) || !manager.ValidateSameOrigin(message))
{
//If the sender is not logged user or the message comes from different domain do nothing
return;
}
if (!message.IsEmpty) //New message is recieved
{
var content = manager.GetMessage(message);
var action = (ServiceAction)Enum.Parse(typeof(ServiceAction), content.Action);
switch (action)
{
case ServiceAction.ShowMore:
var messagesRepo = new Domain.MessageRepository();
var messages = messagesRepo.GetLatestMessages(content.DisplayedMessages, 20, this.currentClient.User.BlockedUsers);
this.SendOlderMessagesToClient(messages, manager);
break;
case ServiceAction.NewMessage:
manager.SaveMessage(content, this.currentClient.User);
this.BroadcastMessage(content);
break;
case ServiceAction.LikeMessage:
manager.LikeMessage(content);
this.BroadcastMessage(content);
this.SendLikeNotification(content, username);
break;
case ServiceAction.BlockUser:
manager.BlockUser(this.currentClient.User, content);
break;
default:
break;
}
}
else //New connection has been created and this is her opening message
{
ClientsManager.Instance.ClearFailed();
//Associate the opened channel with the logged user
this.currentClient = ClientsManager.Instance.RegisterClient(message);
var messagesRepo = new Domain.MessageRepository();
var messages = messagesRepo.GetLatestMessages(0, 20, this.currentClient.User.BlockedUsers);
this.SendOlderMessagesToClient(messages, manager);
var hello = new Model.Message()
{
Action = ServiceAction.Notification.ToString(),
Text = "Welcome to the newsfeed!",
SentDate = DateTime.Now
};
this.currentClient.Callback.Send(manager.CreateMessage(hello));
}
}
private void SendLikeNotification(Model.Message content, string username)
{
var notification = new Model.Message()
{
Action = ServiceAction.Notification.ToString(),
Text = String.Format("{0} liked your message: {1}", username, content.Text),
SentDate = DateTime.Now
};
var manager = new NewsfeedManager();
var notificationMessage = manager.CreateMessage(notification);
ChannelWrapper client;
if (ClientsManager.Instance.Clients.TryGetValue(content.Username, out client))
{
//TODO: save the notifcation in the database so the user can recieve it later when he is logged;
client.Callback.Send(notificationMessage);
}
}
