From 1788f33c2f82b8a013524adc5bb8cd0a54f8bf42 Mon Sep 17 00:00:00 2001
From: ti_mo <timo.niemann@campus.tu-berlin.de>
Date: Sat, 21 Feb 2026 23:38:28 +0100
Subject: [PATCH] Connection is established correctly now - need to improve
 content handling

---
 DirectoryScanReceiver/Program.cs | 134 ++++++++++++++++++++++---------
 1 file changed, 97 insertions(+), 37 deletions(-)

diff --git a/DirectoryScanReceiver/Program.cs b/DirectoryScanReceiver/Program.cs
index 142b9ef..0aebdc9 100644
--- a/DirectoryScanReceiver/Program.cs
+++ b/DirectoryScanReceiver/Program.cs
@@ -1,51 +1,75 @@
 using System.Net;
+using System.Net.NetworkInformation;
 using System.Net.Sockets;
+using System.Text;
 
 namespace DirectoryScanReceiver;
 
+struct Data
+{
+    public string Name;
+    public int Length;
+    public string Content;
+
+    public override string ToString() => $"Name: {Name}\nLength: {Length}";
+}
+
 static class DataExtractor
 {
-    public static string? ExtractHeader(byte[] data)
-    {
-        int idx = Array.IndexOf(data, (byte)'\n');
-        return Encoding.UTF8.GetString(data[..idx]);
-    }
+    public static Data Data;
 
-    public static byte[] ExtractContent(byte[] data)
+    public static void LoadAndParseData(string data)
     {
-        return data[Array.IndexOf(data, (byte)'\n')..];
+        Data = new Data();
+        if (data.Length == 0) return;
+
+        var s = data.Split('|').ToList();
+        if(s.Count < 3) return;
+
+        Data.Name = s[0];
+
+        try { Data.Length = int.Parse(s[1]); }
+        catch (Exception ex) { Console.WriteLine(ex.Message); }
+
+        var sb = new StringBuilder();
+        foreach (var sub in s[2..]) sb.Append(sub);
+        var content = sb.ToString();
+
+        var length = Math.Min(content.Length, Data.Length);
+        Data.Content = content[..length];
     }
 }
 
 static class DataHandler
 {
-    const string OutputDir = "./output";
+    public const string OutputDir = "./output";
 
-    public static void Parse(byte[] data)
+    public static void Parse(string data)
     {
         if (data.Length == 0) return;
 
-        var header = DataExtractor.ExtractHeader(data);
-        var content = DataExtractor.ExtractContent(data);
+        DataExtractor.LoadAndParseData(data);
+        var parsed = DataExtractor.Data;
+        Console.WriteLine(parsed);
 
-        if (header is null || content is null) return;
+        if (parsed.Name.Length == 0 || parsed.Length == 0 || parsed.Content.Length == 0) return;
 
-        var fi = new FileInfo(header);
-        var dir = Path.GetDirectoryName(header) ?? OutputDir;
+        var newPath = Path.Combine(OutputDir, parsed.Name);
+        var fi = new FileInfo(newPath);
+        var dir = Path.GetDirectoryName(newPath) ?? OutputDir;
         var di = new DirectoryInfo(dir);
 
         if (!di.Exists) di.Create();
         if (fi.Exists) return;
 
-        Console.WriteLine($"Writing File: {header}");
-        fi.Create().WriteAsync(new ReadOnlyMemory<byte>(content));
+        Console.WriteLine($"Writing File: {newPath}");
+        fi.Create().Write(Encoding.UTF8.GetBytes(parsed.Content));
     }
 }
 
-class Server
+internal class Server
 {
-    private TcpListener _listener;
-    private NetworkStream _stream;
+    private readonly TcpListener _listener;
 
     public Server(int port)
     {
@@ -53,9 +77,18 @@ class Server
         _listener.Start();
     }
 
+    public static TcpState GetState(TcpClient tcpClient)
+    {
+        var foo = IPGlobalProperties.GetIPGlobalProperties()
+            .GetActiveTcpConnections()
+            .SingleOrDefault(x => x.LocalEndPoint.Equals(tcpClient.Client.LocalEndPoint));
+        return foo is not null ? foo.State : TcpState.Unknown;
+    }
+
+
     public void Receiver()
     {
-        // var bytes = new byte[134217728]; // 128 MB
+        if(Directory.Exists(DataHandler.OutputDir)) Directory.Delete(DataHandler.OutputDir, true);
 
         while (true)
         {
@@ -65,40 +98,67 @@ class Server
             var stream = peer.GetStream();
 
             Console.WriteLine($"Connected to Peer: {peer.Client.RemoteEndPoint}");
-            while (peer.Connected)
+            while (GetState(peer) == TcpState.Established)
             {
-                var availableBytes = peer.Available;
-                if(availableBytes <= 0) continue;
+                var buffer = "";
 
-                var bytes = new byte[availableBytes];
                 try
                 {
-                    var recvCount = stream.Read(bytes);
-                    if(recvCount <= 0) continue;
-                }
-                catch (Exception ex)
-                {
-                    Console.WriteLine(ex.Message);
-                }
+                    var start = DateTime.Now;
+                    while (!buffer.EndsWith("\r\n\r\n"))
+                    {
+                        if (DateTime.Now.Subtract(start).TotalMilliseconds >= 10000)
+                        {
+                            Console.WriteLine("Receive Timeout!");
+                            break;
+                        }
 
-                Console.WriteLine("Received:\n" + BitConverter.ToString(bytes));
-                DataHandler.Parse(bytes);
+                        var availableBytes = peer.Available;
+                        while (availableBytes > 0)
+                        {
+                            var recvBytes = new byte[availableBytes];
+                            var recvCount = stream.Read(recvBytes);
+                            if(recvCount <= 0) continue;
+
+                            // TODO: for is to heavy
+                            for (var i = 0; i < recvCount; i++) buffer += (char)recvBytes[i];
+                            availableBytes -= recvCount;
+                        }
+                    }
+                }
+                catch (Exception ex) { Console.WriteLine(ex.Message); }
+
+                if(buffer.Length == 0) continue;
+
+                foreach (var b in buffer.Split("\r\n\r\n"))
+                {
+                    Console.WriteLine($"Received {b.Length} bytes");
+                    DataHandler.Parse(b);
+                }
             }
             Console.WriteLine("Disconnected from Peer!");
         }
     }
 }
 
-public class Program
+public static class Program
 {
     public static void Main()
     {
+        var server = new Server(7156);
+        Console.WriteLine("Started Server!");
         while (true)
         {
-            var server = new Server(7156);
-            Console.WriteLine("Started Server!");
             Console.WriteLine("Waiting for data!");
-            server.Receiver();
+            try
+            {
+                server.Receiver();
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine("Receiver crashed!");
+                Console.WriteLine(ex.Message);
+            }
         }
     }
 }
\ No newline at end of file