private async Task Receive(CancellationToken cancellationToken)
{
await Task.Run(() =>
{
using (var consumer = new ConsumerBuilder <Ignore, string>(config).Build())
{
Message message;
consumer.Subscribe("main");
while (!cancellationToken.IsCancellationRequested)
{
var consumeResult = consumer.Consume(cancellationToken);
var strMessage = consumeResult.Message.Value;
try
{
message = JsonConvert.DeserializeObject <Message>(consumeResult.Message.Value);
NewMessage?.BeginInvoke(message, null, null);
}
catch (Exception ex)
{
logger.Error(ex.Message);
}
}
consumer.Close();
}
});
}
/// <summary>
/// Send a message (data) to all server in the dictionnary (wsDict)
/// </summary>
/// <param name="data"></param>
/// <remarks>
/// It will close connection with server who didn't respond
/// </remarks>
public void Broadcast(string data)
{
var serverClose = new Dictionary <string, WebSocket>();
foreach (var item in MainViewModel.ServerList)
{
try
{
item.Value.Send(data);
}
catch (Exception)
{
NewMessage.BeginInvoke(this, new EventArgsMessage($"The server {item.Key} is closed."), null, null);
serverClose.Add(item.Key, item.Value);
}
}
foreach (var item in serverClose)
{
MainViewModel.ServerList.Remove(item);
var receivers = MainViewModel.ServerListUpdated?.GetInvocationList();
if (receivers != null)
{
foreach (EventHandler receiver in receivers)
{
receiver.BeginInvoke(this, EventArgs.Empty, null, null);
}
}
}
}
/// <summary>
/// Connect to a list of server
/// </summary>
/// <param name="servers"></param>
/// <see cref="Connect"/>
public void ConnectToAll(List <string> servers)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Connect to the others servers"), null, null);
// Connect to those servers
foreach (var address in servers)
{
Connect(address);
}
}
/// <summary>
/// Method used to connect to a server
/// It will :
/// - Create the "OnMessage" method to answer the server request
/// - Send the blockchain in local to the server (to check who have the good one)
/// - Ask for new server
/// </summary>
/// <param name="url">
/// The server address
/// </param>
/// <remarks>
/// It will create a connection only if the server is not the local one
/// and if the server is not already in the server list
/// </remarks>
public void Connect(string url)
{
// If we know the adress (url) or if it's our server address don't connect
if (MainViewModel.ServerList.ContainsKey(url) || url == ServerAddress)
{
return;
}
// Message for the console
NewMessage.BeginInvoke(this, new EventArgsMessage($"Begin Connection to {url}"), null, null);
// Create the webSocket from the url
var ws = new WebSocket(url);
ws.OnMessage += (sender, e) =>
{
var guid = Guid.NewGuid();
try
{
MainViewModel.WaitingForBlockchainAccess(guid);
#region BlockChain Received
if (e.Data.StartsWith(Constants.BLOCKCHAIN_IS_NOT_VALID))
{
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_IS_NOT_VALID), null, null);
var chainReceived = JsonConvert.DeserializeObject <KittyChain>(e.Data.Substring(Constants.BLOCKCHAIN_IS_NOT_VALID.Length));
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
else if (e.Data.StartsWith(Constants.BLOCKCHAIN_MISS_BLOCK))
{
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_MISS_BLOCK), null, null);
var chainReceived = JsonConvert.DeserializeObject <KittyChain>(e.Data.Substring(Constants.BLOCKCHAIN_MISS_BLOCK.Length));
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
else if (e.Data.StartsWith(Constants.BLOCKCHAIN_OVERWRITE))
{
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_OVERWRITE), null, null);
var chainReceived = JsonConvert.DeserializeObject <KittyChain>(e.Data.Substring(Constants.BLOCKCHAIN_OVERWRITE.Length));
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
else if (e.Data.StartsWith(Constants.NEED_BLOCKCHAIN))
{
ws.Send(Constants.BLOCKCHAIN + JsonConvert.SerializeObject(MainViewModel.BlockChain));
}
else if (e.Data.StartsWith(Constants.BLOCKCHAIN))
{
var chainReceived = JsonConvert.DeserializeObject <KittyChain>(e.Data.Substring(Constants.BLOCKCHAIN.Length));
if (!MainViewModel.BlockChain.IsValid() && chainReceived.IsValid())
{
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
}
#endregion
#region Server List Request Receive
// The request want our server list
else if (e.Data.StartsWith("ServerList"))
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Server list received"), null, null);
// Deserialize the server send in the request
// The Substring cut "GetServers"
var servers = JsonConvert.DeserializeObject <List <string> >(e.Data.Substring(10));
ConnectToAll(servers);
}
#endregion
// Unknow request
else
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Unknown message"), null, null);
}
}
catch (Exception ex)
{
NewMessage.BeginInvoke(this, new EventArgsMessage(ex.Message), null, null);
}
finally
{
MainViewModel.BlockChainWaitingList.Remove(guid);
var receivers = MainViewModel.BlockChainUpdated?.GetInvocationList();
if (receivers != null)
{
foreach (EventHandler receiver in receivers)
{
receiver.BeginInvoke(this, EventArgs.Empty, null, null);
}
}
}
};
ws.Connect();
var receiversServerList = MainViewModel.ServerListUpdated?.GetInvocationList();
if (receiversServerList != null)
{
foreach (EventHandler receiver in receiversServerList)
{
receiver.BeginInvoke(this, EventArgs.Empty, null, null);
}
}
ws.Send(Constants.BLOCKCHAIN + JsonConvert.SerializeObject(MainViewModel.BlockChain));
ws.Send(Constants.GET_SERVERS + JsonConvert.SerializeObject(new List <string>(GetServers())
{
ServerAddress
}));
MainViewModel.ServerList.Add(url, ws);
}
/// <summary>
/// Method called when the server receive a message
/// </summary>
/// <param name="e"></param>
protected override void OnMessage(MessageEventArgs e)
{
var guid = Guid.NewGuid();
try
{
MainViewModel.WaitingForBlockchainAccess(guid);
#region BlockChain Receive
// The request send the entire blockchain
if (e.Data.StartsWith(Constants.BLOCKCHAIN))
{
// Deserialize the blockchain received
// The Substring cut "BlockChain" or "BlockChainOverwrite"
var chainReceived = JsonConvert.DeserializeObject <KittyChain>(e.Data.Substring(e.Data.StartsWith("BlockChainOverwrite") ? 19 : 10));
NewMessage.BeginInvoke(this, new EventArgsMessage("Check blockchain"), null, null);
/* If chain received and local is not valid
* OR
* If same blockchain received and local
* OR
* If same chain and same pending transfers list
* => Do nothing
*/
if (MainViewModel.BlockChain.Equals(chainReceived))
{
MainViewModel.BlockChainWaitingList.Remove(guid);
return;
}
var localIsValid = MainViewModel.BlockChain.IsValid();
var receivedIsValid = chainReceived.IsValid();
if (!localIsValid &&
!receivedIsValid)
{
MainViewModel.BlockChain.InitializeChain();
}
// If chain received is not valid but local is
// => Send that the received blockchain is not valid
if (!receivedIsValid && localIsValid)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Blockchain receive not valid but local is"), null, null);
Send(Constants.BLOCKCHAIN_IS_NOT_VALID + JsonConvert.SerializeObject(MainViewModel.BlockChain));
}
// If chain received is valid but local is not
// Copy the received blockchain
if (receivedIsValid && !localIsValid)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Blockchain receive is valid and local is not"), null, null);
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
// If the received chain is bigger than local
// => Copy the received blockchain
else if (chainReceived.Chain.Count > MainViewModel.BlockChain.Chain.Count)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Blockchain is bigger than local"), null, null);
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
// If the received chain is lower than local
// => Send the local blockchain
else if (chainReceived.Chain.Count < MainViewModel.BlockChain.Chain.Count)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Blockchain receive lower than local"), null, null);
Send(Constants.BLOCKCHAIN_MISS_BLOCK + JsonConvert.SerializeObject(MainViewModel.BlockChain));
}
// If the chain are equals but the pending transfer list are different
// => Get the pending transfer not in local and send the list of transfer
else if (chainReceived.Chain.SequenceEqual(MainViewModel.BlockChain.Chain) &&
!chainReceived.PendingTransfers.SequenceEqual(MainViewModel.BlockChain.PendingTransfers))
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Chain equals but different pending transfers/nWaiting for transfer message"), null, null);
}
else
{
// If the sender force to overwrite the local
if (e.Data.StartsWith(Constants.BLOCKCHAIN_OVERWRITE))
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Overwrite BlockChain from sender"), null, null);
MainViewModel.BlockChain = chainReceived;
NewMessage.BeginInvoke(this, new EventArgsMessage(Constants.BLOCKCHAIN_UPDATED), null, null);
}
// Send a overwrite force to the sender
else
{
NewMessage.BeginInvoke(this, new EventArgsMessage("BlockChain receive is same size than actual but different information"), null, null);
Send(Constants.BLOCKCHAIN_OVERWRITE + JsonConvert.SerializeObject(MainViewModel.BlockChain));
}
}
}
else if (e.Data.StartsWith(Constants.NEED_BLOCKCHAIN))
{
Send(Constants.BLOCKCHAIN + JsonConvert.SerializeObject(MainViewModel.BlockChain));
}
#endregion
#region Block Receive
else if (e.Data.StartsWith(Constants.BLOCK))
{
// Deserialize the block
// The Substring cut "Block"
var newBlock = JsonConvert.DeserializeObject <Block>(e.Data.Substring(5));
NewMessage.BeginInvoke(this, new EventArgsMessage("New Block received"), null, null);
if (!MainViewModel.BlockChain.IsValid() ||
newBlock.PreviousHash != MainViewModel.BlockChain.LastBlock.Hash ||
newBlock.Index != MainViewModel.BlockChain.LastBlock.Index + 1)
{
Send(Constants.NEED_BLOCKCHAIN);
}
else
{
MainViewModel.BlockChain.Chain.Add(newBlock);
foreach (var tr in newBlock.Transfers)
{
MainViewModel.BlockChain.PendingTransfers.Remove(tr);
}
if (newBlock.Index % Constants.NUMBER_OF_BLOCKS_TO_CHECK_DIFFICULTY == 0)
{
NewMessage.BeginInvoke(this, new EventArgsMessage(MainViewModel.BlockChain.CheckDifficulty()), null, null);
}
}
}
#endregion
#region Transfer Receive
// The request send a new transfer
else if (e.Data.StartsWith(Constants.TRANSFER))
{
// Deserialize the transfer
// The Substring cut "Transfer"
var newTransfer = JsonConvert.DeserializeObject <Transfer>(e.Data.Substring(8));
NewMessage.BeginInvoke(this, new EventArgsMessage("New transfer received"), null, null);
var chain = MainViewModel.BlockChain.Chain.ToArray();
var transactions = MainViewModel.BlockChain.PendingTransfers.ToArray();
// If we already have it (in pending transfer or already validated) or it's not a valid transfer don't add it
if (transactions.Any(t => t.Equals(newTransfer)) ||
chain.Any(b => b.Transfers.Any(t => t.Equals(newTransfer))) ||
!newTransfer.IsValid() ||
newTransfer.Amount <= 0 ||
newTransfer.Biscuit < 0 ||
MainViewModel.BlockChain.GetBalance(newTransfer.FromAddress, chain, transactions) < newTransfer.Amount + newTransfer.Biscuit)
{
NewMessage.BeginInvoke(this, new EventArgsMessage("New Transfer not valid or already in local"), null, null);
}
else
{
// If already is Ok add it to our pending transfer list
MainViewModel.BlockChain.PendingTransfers.Add(newTransfer);
NewMessage.BeginInvoke(this, new EventArgsMessage("New transfer added from server"), null, null);
}
}
// The request send a list of transfer
else if (e.Data.StartsWith(Constants.TRANSFERS))
{
// Deserialize the transfer
// The Substring cut "Transfer"
var newTransfers = JsonConvert.DeserializeObject <List <Transfer> >(e.Data.Substring(9));
NewMessage.BeginInvoke(this, new EventArgsMessage("New list of transfer received"), null, null);
foreach (var newTransfer in newTransfers)
{
// If we already have it or it's not a valid transfer don't add it
if (MainViewModel.BlockChain.PendingTransfers.Any(t => t.Equals(newTransfer)) ||
MainViewModel.BlockChain.Chain.Any(b => b.Transfers.Any(t => t.Equals(newTransfer))) ||
!newTransfer.IsValid())
{
NewMessage.BeginInvoke(this, new EventArgsMessage("New Transfer not valid or already in local"), null, null);
}
else
{
// If already is Ok add it to our pending transfer list
MainViewModel.BlockChain.PendingTransfers.Add(newTransfer);
NewMessage.BeginInvoke(this, new EventArgsMessage("New transfer added from server"), null, null);
}
}
}
#endregion
#region GetServers Receive
else if (e.Data.StartsWith(Constants.GET_SERVERS))
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Get Servers request received"), null, null);
var listWs = JsonConvert.DeserializeObject <List <string> >(e.Data.Substring(10));
ServerUpdate.BeginInvoke(this, new EventArgsObject(listWs), null, null);
if (MainViewModel.ServerList.Any())
{
Send("ServerList" + JsonConvert.SerializeObject(MainViewModel.ServerList.Select(x => x.Key)));
}
}
#endregion
else
{
NewMessage.BeginInvoke(this, new EventArgsMessage("Unknown message"), null, null);
}
}
catch (Exception ex)
{
NewMessage.BeginInvoke(this, new EventArgsMessage(ex.Message), null, null);
}
finally
{
MainViewModel.BlockChainWaitingList.Remove(guid);
var receivers = MainViewModel.BlockChainUpdated?.GetInvocationList();
if (receivers != null)
{
foreach (EventHandler receiver in receivers)
{
receiver.BeginInvoke(this, EventArgs.Empty, null, null);
}
}
}
}
