private async Task sendString(Commands.ClientCommands cCom, string str)
{
using (MemoryStream ms = new MemoryStream())
{
//convert object to byte array
byte[] data;
if (str != "")
{
data = Encoding.Unicode.GetBytes(str);
} //get data from string slightly differently than for objects because of encoding
else
{
data = new byte[0];
}
//send command number
byte[] prep = BitConverter.GetBytes(Commands.getClientCommandUInt(cCom));
if (BitConverter.IsLittleEndian) //target computer might use different endian -> send and receive as big endian and if necessary, restore to little endian in client
{
Array.Reverse(prep);
}
await netS.WriteAsync(prep, 0, prep.Length); //write command (uint) to stream
//send data size
prep = BitConverter.GetBytes(data.Length);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(prep);
}
await netS.WriteAsync(prep, 0, prep.Length); //write length of data (int) to stream
//send object
await netS.WriteAsync(data, 0, data.Length); //write object to stream
}
}
private async Task receiveObject(Commands.ClientCommands cCom, int dataSize)
{
MemoryStream ms = new MemoryStream(await receiveData(dataSize));
BinaryFormatter bf = new BinaryFormatter();
ms.Position = 0;
receivedData = bf.Deserialize(ms);
//await saveClientCommand(cCom);
}
private async Task sendObject(Commands.ClientCommands cCom, object obj)
{
//see e.g.: https://stackoverflow.com/questions/2316397/sending-and-receiving-custom-objects-using-tcpclient-class-in-c-sharp
using (MemoryStream ms = new MemoryStream())
{
//convert object to byte array
byte[] data;
if (obj != null)
{
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ms, obj); //serialise object to memory stream first -> can provide size of data in byte
data = ms.ToArray(); //the object converted to a byte array
}
else
{
data = new byte[0];
}
//send command number
byte[] prep = BitConverter.GetBytes(Commands.getClientCommandUInt(cCom));
if (BitConverter.IsLittleEndian) //target computer might use different endian -> send and receive as big endian and if necessary, restore to little endian in client
{
Array.Reverse(prep);
}
await netS.WriteAsync(prep, 0, prep.Length); //write command (uint) to stream
//send data size
prep = BitConverter.GetBytes(data.Length);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(prep);
}
await netS.WriteAsync(prep, 0, prep.Length); //write length of data (int) to stream
//send object
await netS.WriteAsync(data, 0, data.Length); //write object to stream
}
}
private async Task sendCommand(Commands.ClientCommands cCom)
{
await sendObject(cCom, null);
}
private async Task receiveString(Commands.ClientCommands cCom, int dataSize)
{
receivedData = Encoding.Unicode.GetString(await receiveData(dataSize));
//await saveClientCommand(cCom);
}
//information processing, server-client communication
private async Task handleMessage(Commands.ClientCommands cCom, int dataSize)
{
Console.WriteLine("Handling message ({0})...", cCom);
switch (cCom)
{
case Commands.ClientCommands.RequestCompareVersionNumber:
Console.WriteLine("Comparing version number...");
await receiveString(cCom, dataSize);
Console.WriteLine("String received. {0} vs {1}", VersionNumber.get(), (string)receivedData);
if (VersionNumber.get() == (string)receivedData)
{
await sendCommand(Commands.ServerCommands.ValidVersionNumber); Console.WriteLine("Reply sent: valid.");
}
else
{
await sendCommand(Commands.ServerCommands.InvalidVersionNumber); Console.WriteLine("Reply sent: invalid.");
}
return;
case Commands.ClientCommands.SubmitUserName:
Console.Write("Checking submitted username... ");
await receiveString(cCom, dataSize);
username = "";
if (parentServer.getOnlineUsers().Contains((string)receivedData)) //the user going by this name is already logged in -> choose different name
{
await sendCommand(Commands.ServerCommands.UserAlreadyOnline); Console.WriteLine("Already online.");
}
else if (parentServer.getRegisteredUsers().Contains((string)receivedData)) //submitted name contained in the list of registered users?
{
await sendCommand(Commands.ServerCommands.UserNameFound); Console.WriteLine("Found.");
}
else
{
await sendCommand(Commands.ServerCommands.UserNameNotFound); Console.WriteLine("Not found.");
}
username = (string)receivedData;
Console.WriteLine("username set to {0}.", username);
return;
case Commands.ClientCommands.SubmitPassword_ExistingUser:
await receiveString(cCom, dataSize);
//Console.WriteLine("Checking password ({0} | {1})...", username, (string)receivedData);
if (parentServer.tryLogin(username, (string)receivedData))
{
await sendCommand(Commands.ServerCommands.LoginSuccessful);
await goOnline(); //sets online to true and updates all lbUser listboxes
parentServer.addSystemMessage($"{username} has come online.");
}
else
{
await sendCommand(Commands.ServerCommands.PasswordIncorrect); username = "";
}
break;
case Commands.ClientCommands.SubmitPassword_NewUser:
await receiveString(cCom, dataSize);
//Console.WriteLine("Creating new user ({0} | {1})...", username, (string)receivedData);
if (parentServer.tryRegister(username, (string)receivedData))
{
await sendCommand(Commands.ServerCommands.AccountCreatedSuccessfully);
await goOnline(); //sets online to true and updates all lbUser listboxes
parentServer.addSystemMessage($"{username} has created their account and is now online for the first time.");
}
else
{
await sendCommand(Commands.ServerCommands.ServerError); username = "";
}
break;
case Commands.ClientCommands.RequestOnlineUserList:
Console.WriteLine("Sending user list...");
await sendObject(Commands.ServerCommands.ReceiveList_String, parentServer.getOnlineUsers());
break;
case Commands.ClientCommands.RequestSendMessage:
Console.WriteLine("Sending message...");
await receiveObject(Commands.ClientCommands.RequestSendMessage, dataSize);
ChatMessage recMsg = (ChatMessage)receivedData;
if (await parentServer.sendMessage(recMsg))
{
await sendCommand(Commands.ServerCommands.MessageSent);
}
else
{
await sendCommand(Commands.ServerCommands.ServerError);
}
break;
default:
Console.WriteLine("Unhandled client command ({0}).", cCom);
break;
}
return;
}
