Update: Mutli Channel Support

RelayClient/MainPage.xaml

@@ -5,26 +5,60 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     Title="Relay Client">
 
-    <Grid RowDefinitions="Auto,*,Auto" Padding="12" RowSpacing="10">
+    <Grid RowDefinitions="Auto,*,Auto"
+          ColumnDefinitions="220,*"
+          Padding="12"
+          RowSpacing="10"
+          ColumnSpacing="10">
 
-        <Border Grid.Row="0" StrokeThickness="1" Padding="10">
+        <!-- Header -->
+        <Border Grid.Row="0"
+                Grid.ColumnSpan="2"
+                StrokeThickness="1"
+                Padding="10">
             <VerticalStackLayout Spacing="4">
                 <Label x:Name="UserLabel"
                        Text="Logged in as: Unknown"
                        FontAttributes="Bold"
                        FontSize="18" />
-                <Label Text="#general"
+                <Label x:Name="ChannelLabel"
+                       Text="No channel selected"
                        FontSize="14" />
             </VerticalStackLayout>
         </Border>
 
-        <Border Grid.Row="1" StrokeThickness="1" Padding="10">
+        <!-- Sidebar -->
-            <ScrollView x:Name="MessagesScrollView">
+        <Border Grid.Row="1"
-                <VerticalStackLayout x:Name="MessagesLayout" Spacing="8" />
+                Grid.Column="0"
+                StrokeThickness="1"
+                Padding="10">
+            <ScrollView>
+                <VerticalStackLayout Spacing="8">
+                    <Label Text="Channels"
+                           FontAttributes="Bold"
+                           FontSize="16" />
+                    <VerticalStackLayout x:Name="SidebarList"
+                                         Spacing="6" />
+                </VerticalStackLayout>
             </ScrollView>
         </Border>
 
-        <Grid Grid.Row="2" ColumnDefinitions="*,Auto" ColumnSpacing="10">
+        <!-- Messages -->
+        <Border Grid.Row="1"
+                Grid.Column="1"
+                StrokeThickness="1"
+                Padding="10">
+            <ScrollView x:Name="MessagesScrollView">
+                <VerticalStackLayout x:Name="MessagesLayout"
+                                     Spacing="8" />
+            </ScrollView>
+        </Border>
+
+        <!-- Input -->
+        <Grid Grid.Row="2"
+              Grid.Column="1"
+              ColumnDefinitions="*,Auto"
+              ColumnSpacing="10">
             <Entry x:Name="MessageEntry"
                    Grid.Column="0"
                    Placeholder="Type a message..."

RelayClient/MainPage.xaml.cs

@@ -8,8 +8,13 @@ namespace RelayClient;
 public partial class MainPage : ContentPage
 {
     private readonly string _username;
-    private readonly WebSocket wsc;
+    private readonly WebSocket _wsc;
     private string? _serverPublicKey;
+    private string? _currentChannelId;
+    private string? _currentChannelName;
+
+    private readonly Dictionary<string, List<ChatMessage>> _messagesByChannel = new();
+    private readonly List<ChannelItem> _channels = new();
 
     public MainPage(string username)
     {
@@ -25,15 +30,15 @@ public partial class MainPage : ContentPage
             KeyStorage.SavePublicKey(_username, keys.publicKey);
         }
 
-        wsc = new WebSocket("ws://localhost:1337/");
+        _wsc = new WebSocket("ws://localhost:1337/");
 
-        wsc.OnMessage += WscOnMessage;
+        _wsc.OnMessage += WscOnMessage;
-        wsc.Connect();
+        _wsc.Connect();
         
         var publicKey = KeyStorage.LoadPublicKey(_username);
-        wsc.Send($"REGISTER_KEY|{_username}|{publicKey}");
+        _wsc.Send($"REGISTER_KEY|{_username}|{publicKey}");
-        wsc.Send("GET_SERVER_KEY");
+        _wsc.Send("GET_SERVER_KEY");
-        wsc.Send($"GET_HISTORY|{_username}");
+        _wsc.Send("GET_CHANNELS");
     }
 
     private void SendButton_OnClicked(object? sender, EventArgs e)
@@ -63,6 +68,7 @@ public partial class MainPage : ContentPage
 
         var payload = new SocketEncryptedMessage
         {
+            ChannelId = _currentChannelId!,
             Type = "client_encrypted_chat",
             SenderUsername = _username,
             CipherText = encrypted.CipherText,
@@ -72,7 +78,7 @@ public partial class MainPage : ContentPage
         };
 
         var json = JsonSerializer.Serialize(payload);
-        wsc.Send(json);
+        _wsc.Send(json);
 
         Console.WriteLine($"[{_username}] sent encrypted message.");
 
@@ -100,6 +106,38 @@ public partial class MainPage : ContentPage
 
             var type = typeElement.GetString();
 
+            if (type == "channel_list")
+            {
+                var channelList = JsonSerializer.Deserialize<SocketChannelList>(e.Data);
+                if (channelList is null)
+                    return;
+
+                _channels.Clear();
+                _channels.AddRange(channelList.Channels.OrderBy(c => c.CreatedAt));
+
+                var defaultChannel = _channels
+                                         .Where(c => c.Name.Equals("welcome", StringComparison.OrdinalIgnoreCase))
+                                         .OrderBy(c => c.CreatedAt)
+                                         .FirstOrDefault()
+                                     ?? _channels.OrderBy(c => c.CreatedAt).FirstOrDefault();
+
+                if (defaultChannel is not null)
+                {
+                    _currentChannelId = defaultChannel.ChannelId;
+                    _currentChannelName = defaultChannel.Name;
+
+                    MainThread.BeginInvokeOnMainThread(() =>
+                    {
+                        ChannelLabel.Text = $"#{_currentChannelName}";
+                        RenderChannelList();
+                    });
+
+                    _wsc.Send($"GET_HISTORY|{_username}|{_currentChannelId}");
+                }
+
+                return;
+            }
+
             if (type == "server_public_key")
             {
                 var serverKeyMessage = JsonSerializer.Deserialize<ServerPublicKeyMessage>(e.Data);
@@ -146,7 +184,80 @@ public partial class MainPage : ContentPage
                 Timestamp = DateTime.Now
             };
 
-            MainThread.BeginInvokeOnMainThread(async () =>
+            if (!_messagesByChannel.ContainsKey(payload.ChannelId))
+            {
+                _messagesByChannel[payload.ChannelId] = [];
+            }
+
+            _messagesByChannel[payload.ChannelId].Add(message);
+
+            if (payload.ChannelId == _currentChannelId)
+            {
+                MainThread.BeginInvokeOnMainThread(() =>
+                {
+                    RenderSingleMessage(message);
+                });
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[{_username}] failed to process websocket message: {ex.Message}");
+        }
+    }
+
+    protected override void OnDisappearing()
+    {
+        _wsc.OnMessage -= WscOnMessage;
+        _wsc.Close();
+        base.OnDisappearing();
+    }
+    
+    private void RenderChannelList()
+    {
+        SidebarList.Children.Clear();
+
+        foreach (var channel in _channels.OrderBy(c => c.CreatedAt))
+        {
+            var button = new Button
+            {
+                Text = $"#{channel.Name}"
+            };
+
+            button.Clicked += (_, _) =>
+            {
+                _currentChannelId = channel.ChannelId;
+                _currentChannelName = channel.Name;
+
+                ChannelLabel.Text = $"#{_currentChannelName}";
+                RenderCurrentChannelMessages();
+
+                if (!_messagesByChannel.ContainsKey(channel.ChannelId))
+                {
+                    _wsc.Send($"GET_HISTORY|{_username}|{channel.ChannelId}");
+                }
+            };
+
+            SidebarList.Children.Add(button);
+        }
+    }
+    
+    private void RenderCurrentChannelMessages()
+    {
+        MessagesLayout.Children.Clear();
+
+        if (_currentChannelId is null)
+            return;
+
+        if (!_messagesByChannel.TryGetValue(_currentChannelId, out var messages))
+            return;
+
+        foreach (var message in messages.OrderBy(m => m.Timestamp))
+        {
+            RenderSingleMessage(message);
+        }
+    }
+        
+    private async void RenderSingleMessage(ChatMessage message)
     {
         bool isOwnMessage = message.SenderUsername == _username;
 
@@ -165,40 +276,14 @@ public partial class MainPage : ContentPage
                 Spacing = 2,
                 Children =
                 {
-                            new Label
+                    new Label { Text = message.SenderUsername, FontAttributes = FontAttributes.Bold, FontSize = 12 },
-                            {
+                    new Label { Text = message.Text, FontSize = 14 },
-                                Text = message.SenderUsername,
+                    new Label { Text = message.Timestamp.ToString("h:mm tt"), FontSize = 10 }
-                                FontAttributes = FontAttributes.Bold,
-                                FontSize = 12
-                            },
-                            new Label
-                            {
-                                Text = message.Text,
-                                FontSize = 14
-                            },
-                            new Label
-                            {
-                                Text = message.Timestamp.ToString("h:mm tt"),
-                                FontSize = 10
-                            }
                 }
             }
         };
 
         MessagesLayout.Children.Add(bubble);
         await MessagesScrollView.ScrollToAsync(MessagesLayout, ScrollToPosition.End, true);
-            });
-        }
-        catch (Exception ex)
-        {
-            Console.WriteLine($"[{_username}] failed to process websocket message: {ex.Message}");
-        }
-    }
-
-    protected override void OnDisappearing()
-    {
-        wsc.OnMessage -= WscOnMessage;
-        wsc.Close();
-        base.OnDisappearing();
     }
 }

RelayClient/Models/ChannelItem.cs

@@ -0,0 +1,8 @@
+namespace RelayClient.Models;
+
+public class ChannelItem
+{
+    public required string ChannelId { get; set; }
+    public required string Name { get; set; }
+    public required DateTime CreatedAt { get; set; }
+}

RelayClient/Models/SocketChannelList.cs

@@ -0,0 +1,7 @@
+namespace RelayClient.Models;
+
+public class SocketChannelList
+{
+    public required string Type { get; set; }
+    public required List<ChannelItem> Channels { get; set; }
+}

RelayClient/Models/SocketEncryptedMessage.cs

@@ -5,6 +5,7 @@ public class SocketEncryptedMessage
     public required string Type { get; set; }
     public required string SenderUsername { get; set; }
     public string? RecipientUsername { get; set; }
+    public required string ChannelId { get; set; }
     public required string CipherText { get; set; }
     public required string Nonce { get; set; }
     public required string Tag { get; set; }

RelayServer/Models/SocketChannelInfo.cs

@@ -0,0 +1,8 @@
+namespace RelayServer.Models;
+
+public class SocketChannelInfo
+{
+    public required string ChannelId { get; set; }
+    public required string Name { get; set; }
+    public required DateTime CreatedAt { get; set; }
+}

RelayServer/Models/SocketChannelList.cs

@@ -0,0 +1,7 @@
+namespace RelayServer.Models;
+
+public class SocketChannelList
+{
+    public required string Type { get; set; }
+    public required List<SocketChannelInfo> Channels { get; set; }
+}

RelayServer/Models/SocketEncryptedMessage.cs

@@ -4,7 +4,8 @@ public class SocketEncryptedMessage
 {
     public required string Type { get; set; }
     public required string SenderUsername { get; set; }
-    public required string RecipientUsername { get; set; }
+    public string? RecipientUsername { get; set; }
+    public required string ChannelId { get; set; }
     public required string CipherText { get; set; }
     public required string Nonce { get; set; }
     public required string Tag { get; set; }

RelayServer/Program.cs

@@ -75,18 +75,29 @@ var channel = await db.Create("channels", new Channels
     CreatedAt = DateTime.UtcNow
 });
 
-var channel2 = await db.Create("files", new Channels
+var channel2 = await db.Create("channels", new Channels
 {
     Name = "files",
     CreatedAt = DateTime.UtcNow.Subtract(new TimeSpan(0, 4, 0, 0))
 });
 
+var channel3 = await db.Create("channels", new Channels
+{
+    Name = "welcome",
+    CreatedAt = DateTime.UtcNow.Subtract(new TimeSpan(1, 4, 4, 4))
+});
 
+Console.WriteLine($"Channel created: {ToJsonString(channel)}");
 Console.WriteLine($"Channel created: {ToJsonString(channel2)}");
+Console.WriteLine($"Channel created: {ToJsonString(channel3)}");
 
 var channelId = GetRecordId(channel.Id);
+var channelId2 = GetRecordId(channel2.Id);
+var channelId3 = GetRecordId(channel3.Id);
+
 Console.WriteLine($"Resolved channelId: {channelId}");
-ChatTest.DefaultChannelId = channelId;
+Console.WriteLine($"Resolved channelId: {channelId2}");
+Console.WriteLine($"Resolved channelId: {channelId3}");
 
 var keyBase64 = cryptoService.GenerateKey();
 var serverKeys = E2EeHelper.GenerateRsaKeyPair();

RelayServer/Services/ChatTest.cs

@@ -12,7 +12,6 @@ public class ChatTest : WebSocketBehavior
     public static string? ServerPrivateKey { get; set; }
     public static string? ChannelDbKey { get; set; }
     public static SurrealDb.Net.SurrealDbClient? Db { get; set; }
-    public static string? DefaultChannelId { get; set; }
 
     protected override void OnMessage(MessageEventArgs e)
     {
@@ -31,6 +30,12 @@ public class ChatTest : WebSocketBehavior
             return;
         }
 
+        if (msg == "GET_CHANNELS")
+        {
+            HandleGetChannels();
+            return;
+        }
+
         if (msg.StartsWith("GET_HISTORY|"))
         {
             HandleGetHistory(msg);
@@ -76,6 +81,35 @@ public class ChatTest : WebSocketBehavior
         Send($"SERVER:REGISTERED_KEY:{username}");
     }
 
+    private void HandleGetChannels()
+    {
+        if (Db is null)
+        {
+            Console.WriteLine("Db is not initialized.");
+            return;
+        }
+
+        var channels = Task.Run(async () => await Db.Select<Channels>("channels"))
+            .GetAwaiter()
+            .GetResult()
+            .OrderBy(c => c.CreatedAt)
+            .Select(c => new SocketChannelInfo
+            {
+                ChannelId = GetRecordId(c.Id),
+                Name = c.Name,
+                CreatedAt = c.CreatedAt
+            })
+            .ToList();
+
+        var payload = new SocketChannelList
+        {
+            Type = "channel_list",
+            Channels = channels
+        };
+
+        Send(JsonSerializer.Serialize(payload));
+    }
+    
     private void HandleGetServerKey()
     {
         if (string.IsNullOrWhiteSpace(ServerPublicKey))
@@ -113,8 +147,7 @@ public class ChatTest : WebSocketBehavior
         if (ClientKeyService is null ||
             Db is null ||
             string.IsNullOrWhiteSpace(ServerPrivateKey) ||
-            string.IsNullOrWhiteSpace(ChannelDbKey) ||
+            string.IsNullOrWhiteSpace(ChannelDbKey))
-            string.IsNullOrWhiteSpace(DefaultChannelId))
         {
             Console.WriteLine("Server crypto/database dependencies are not initialized.");
             return;
@@ -150,7 +183,7 @@ public class ChatTest : WebSocketBehavior
             var savedMessage = Task.Run(async () =>
                 await Db.Create("channel_messages", new ChannelMessages
                 {
-                    ChannelId = DefaultChannelId,
+                    ChannelId = clientPayload.ChannelId,
                     SenderUserId = $"users:{clientPayload.SenderUsername.ToLower()}",
                     CipherText = dbEncrypted.cipherText,
                     Nonce = dbEncrypted.nonce,
@@ -182,6 +215,7 @@ public class ChatTest : WebSocketBehavior
                 Type = "encrypted_chat",
                 SenderUsername = clientPayload.SenderUsername,
                 RecipientUsername = client.Username,
+                ChannelId = clientPayload.ChannelId,
                 CipherText = encrypted.CipherText,
                 Nonce = encrypted.Nonce,
                 Tag = encrypted.Tag,
@@ -194,20 +228,20 @@ public class ChatTest : WebSocketBehavior
 
     private void HandleGetHistory(string msg)
     {
-        var parts = msg.Split('|', 2);
+        var parts = msg.Split('|', 3);
 
-        if (parts.Length < 2)
+        if (parts.Length < 3)
         {
             Console.WriteLine("Invalid GET_HISTORY payload.");
             return;
         }
 
         var username = parts[1];
+        var channelId = parts[2];
 
         if (ClientKeyService is null ||
             Db is null ||
-            string.IsNullOrWhiteSpace(ChannelDbKey) ||
+            string.IsNullOrWhiteSpace(ChannelDbKey))
-            string.IsNullOrWhiteSpace(DefaultChannelId))
         {
             Console.WriteLine("History dependencies are not initialized.");
             return;
@@ -228,7 +262,7 @@ public class ChatTest : WebSocketBehavior
             .GetResult();
 
         var channelMessages = allMessages
-            .Where(m => m.ChannelId == DefaultChannelId)
+            .Where(m => m.ChannelId == channelId)
             .OrderBy(m => m.CreatedAt)
             .ToList();
 
@@ -262,6 +296,7 @@ public class ChatTest : WebSocketBehavior
                 Type = "encrypted_chat",
                 SenderUsername = ExtractUsernameFromUserId(dbMessage.SenderUserId),
                 RecipientUsername = username,
+                ChannelId = channelId,
                 CipherText = encrypted.CipherText,
                 Nonce = encrypted.Nonce,
                 Tag = encrypted.Tag,
@@ -271,4 +306,21 @@ public class ChatTest : WebSocketBehavior
             Send(JsonSerializer.Serialize(outbound));
         }
     }
+    
+    private static string GetRecordId(object? id)
+    {
+        if (id is null)
+            return string.Empty;
+
+        var json = JsonSerializer.Serialize(id);
+
+        using var doc = JsonDocument.Parse(json);
+
+        var root = doc.RootElement;
+
+        var recordId = root.GetProperty("Id").GetString() ?? string.Empty;
+        var table = root.GetProperty("Table").GetString() ?? string.Empty;
+
+        return $"{table}:{recordId}";
+    }
 }