/// <summary>
/// Das Handling von P2PPaketen.
/// </summary>
/// <param name="package"></param>
/// <returns></returns>
public static P2PPackage ResolveP2P(P2PPackage package)
{
if (ServerConfig.CheckPackageID(package.GetPackageID()))
{
try
{
List <P2PPackage> returnList;
switch (package.P2Prequest)
{
case P2PRequest.NewServer:
//0. Falls ich ihn noch nicht als Nachbarn habe.
if (!ServerConfig.neighbours.Exists(x => x.ToString() == package.GetSource()))
{
//1. Anzahl Verbindungen (s. neighbours)
if (package.anzConn == P2PPackage.AnzConnInit || package.anzConn > ServerConfig.neighbours.Count)
{ //Wenn das Paket noch nicht angefasst wurde, oder wir ein mind. genausogutes Angebot haben geht es als Antwort zurück.
package.anzConn = ServerConfig.neighbours.Count;
package.lastIP = ServerConfig.host.ToString();
}
else if (package.anzConn == ServerConfig.neighbours.Count)
{
package.lastIP = ServerConfig.host.ToString();
}
}
//2. Test on TTL
if (package.DecrementTTL() == 0)
{
package.P2PAnswer = P2PAnswer.Timeout;
break;
}
//3. Forking to other servers via flooding
returnList = Forward();
//Comparing answers
foreach (P2PPackage p in returnList)
{
if (p.P2PAnswer == P2PAnswer.Error)
{
package.ErrorMsg = GenerateErrorString();
/*package.Exception = p.Exception;*/
}
else if (package.anzConn >= p.anzConn)
{
package.anzConn = p.anzConn;
package.lastIP = p.lastIP;
}
}
break;
case P2PRequest.RegisterServer:
//1. Nimm Server in neighbours auf. (Falls noch nicht existent)
if (!ServerConfig.neighbours.Exists(x => x.ToString() == package.GetSource()))
{
ServerConfig.neighbours.Add(IPAddress.Parse(package.GetSource()));
package.P2PAnswer = P2PAnswer.Success;
}
else
{
package.P2PAnswer = P2PAnswer.Visited;
}
break;
case P2PRequest.NewUser:
//0. Existiert der User?
if (ServerLogic.database.UserExist(package.GetUsername()))
{
package.P2PAnswer = P2PAnswer.UserExistent;
break;
}
//1. Anzahl User
int anzUser = ServerLogic.database.GetUserCount();
if (package.anzUser == P2PPackage.AnzUserInit || package.anzUser > anzUser)
{ // siehe case NewServer
package.anzUser = anzUser;
package.lastIP = ServerConfig.host.ToString();
}
else if (package.anzUser == anzUser)
{
package.lastIP = ServerConfig.host.ToString();
}
//2. Test on TTL ???? -> Nein! Nicht vereinbar mit nur einem User im gesamten Netz.
/*if (package.DecrementTTL() == 0)
* {
* package.P2PAnswer = P2PAnswer.Timeout;
* break;
* }*/
//3. Forking to other servers via flooding
returnList = Forward();
//Comparing answers
foreach (P2PPackage p in returnList)
{
if (p.P2PAnswer == P2PAnswer.Error)
{
package.ErrorMsg = p.ErrorMsg;
/*package.Exception = p.Exception;*/
package.P2PAnswer = P2PAnswer.Error;
return(package);
}
else if (package.anzUser >= p.anzUser)
{
package.anzUser = p.anzUser;
package.lastIP = p.lastIP;
}
}
package.P2PAnswer = P2PAnswer.Success;
break;
/*
* case P2PRequest.RegisterUser:
* //Client should connect directly to register.
* break;
*/
case P2PRequest.Login:
//1. Check Datenbank nach user
if (!ServerLogic.database.UserExist(package.GetUsername())) //2. Wenn nicht gefunden => weiterleiten
{
returnList = Forward();
//Falls nur ein return => Success
if (returnList.Count == 1)
{
package.P2PAnswer = returnList.First().P2PAnswer;
package.lastIP = returnList.First().lastIP;
}
else if (returnList.Count > 1)
{
foreach (P2PPackage p in returnList)
{
if (p.P2PAnswer == P2PAnswer.Success)
{
package.lastIP = p.lastIP;
}
}
}
else
{
package.P2PAnswer = P2PAnswer.Failure; //Error?
}
}
else
{
package.lastIP = ServerConfig.host.ToString();
package.P2PAnswer = P2PAnswer.Success;
}
break;
case P2PRequest.Invite:
//1. Check Datenbank nach user
if (!ServerLogic.database.UserExist(package.GetUsername())) //2. Wenn nicht gefunden => weiterleiten
{
returnList = Forward();
foreach (P2PPackage p in returnList)
{
if (p.P2PAnswer == P2PAnswer.Success)
{
package.P2PAnswer = p.P2PAnswer;
package.lastIP = p.lastIP;
}
}
}
else
{
ServerLogic.database.SaveInvites(package.GetUsername(), package.GetInvite());
package.lastIP = ServerConfig.host.ToString();
package.P2PAnswer = P2PAnswer.Success;
}
break;
default:
break;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
package.P2PAnswer = P2PAnswer.Error;
package.ErrorMsg = GenerateErrorString(ex);
/*package.Exception = ex;*/
//throw;
}
}
else
{
package.P2PAnswer = P2PAnswer.Visited; //Node wurde bereits angefragt, keine Aktion nötig
}
return(package);
List <P2PPackage> Forward()
{
Package sendPackage = new Package(package);
Package recievePackage;
List <P2PPackage> returnList = new List <P2PPackage>();
foreach (IPAddress iPAddress in ServerConfig.neighbours)
{
recievePackage = ServerLogic.Send(sendPackage, iPAddress);
if (recievePackage != null)
{
if (recievePackage != null && recievePackage.p2p.P2PAnswer == P2PAnswer.Success)
{
return new List <P2PPackage>()
{
recievePackage.p2p
}
}
;
returnList.Add(recievePackage.p2p);
}
}
return(returnList);
}
}