Mobile performance: paginated history loading

PolyPilot.Tests/TestStubs.cs

@@ -59,6 +59,7 @@ internal class StubWsBridgeClient : IWsBridgeClient
     public List<SessionSummary> Sessions { get; set; } = new();
     public string? ActiveSessionName { get; set; }
     public System.Collections.Concurrent.ConcurrentDictionary<string, List<ChatMessage>> SessionHistories { get; } = new();
+    public System.Collections.Concurrent.ConcurrentDictionary<string, bool> SessionHistoryHasMore { get; } = new();
     public List<PersistedSessionSummary> PersistedSessions { get; set; } = new();
     public string? GitHubAvatarUrl { get; set; }
     public string? GitHubLogin { get; set; }
@@ -87,7 +88,7 @@ public Task RequestSessionsAsync(CancellationToken ct = default)
         RequestSessionsCallCount++;
         return Task.CompletedTask;
     }
-    public Task RequestHistoryAsync(string sessionName, CancellationToken ct = default) => Task.CompletedTask;
+    public Task RequestHistoryAsync(string sessionName, int? limit = null, CancellationToken ct = default) => Task.CompletedTask;
     public Task SendMessageAsync(string sessionName, string message, CancellationToken ct = default) => Task.CompletedTask;
     public Task CreateSessionAsync(string name, string? model = null, string? workingDirectory = null, CancellationToken ct = default) => Task.CompletedTask;
     public string? LastSwitchedSession { get; private set; }

PolyPilot/Components/ExpandedSessionView.razor

@@ -105,11 +105,27 @@
 
     <div class="messages expanded-messages">
         @{ var expandedMessages = GetWindowedMessages(); }
-        @if (Session.History.Count > expandedMessages.Count)
+        @if (IsLoadingHistory)
         {
-            <button class="load-more-btn" @onclick="LoadMore">
-                ⬆️ Load more (@(Session.History.Count - expandedMessages.Count) remaining)
-            </button>
+            <div class="loading-history-indicator">
+                <div class="loading-history-spinner"></div>
+                <span>Loading conversation…</span>
+            </div>
+        }
+        else
+        {
+            @if (HasMoreRemoteHistory)
+            {
+                <button class="load-more-btn" @onclick="LoadFullHistory">
+                    ⬆️ Load rest of conversation
+                </button>
+            }
+            else if (Session.History.Count > expandedMessages.Count)
+            {
+                <button class="load-more-btn" @onclick="LoadMore">
+                    ⬆️ Load more (@(Session.History.Count - expandedMessages.Count) remaining)
+                </button>
+            }
         }
         <ChatMessageList Messages="expandedMessages"
                          StreamingContent="@StreamingContent"
@@ -267,6 +283,8 @@
     [Parameter] public string? UserAvatarUrl { get; set; }
     [Parameter] public ChatLayout Layout { get; set; } = ChatLayout.Default;
     [Parameter] public ChatStyle Style { get; set; } = ChatStyle.Normal;
+    [Parameter] public bool IsLoadingHistory { get; set; }
+    [Parameter] public bool HasMoreRemoteHistory { get; set; }
     [Parameter] public int FontSize { get; set; } = 20;
     [Parameter] public int MessageWindowSize { get; set; } = 25;
     [Parameter] public bool FiestaActive { get; set; }
@@ -285,6 +303,7 @@
 
     [Parameter] public EventCallback<int> OnFontSizeChange { get; set; }
     [Parameter] public EventCallback<string> OnLoadMore { get; set; }
+    [Parameter] public EventCallback<string> OnLoadFullHistory { get; set; }
     [Parameter] public EventCallback<(string SessionName, FiestaStartRequest Request)> OnStartFiesta { get; set; }
     [Parameter] public EventCallback<string> OnStopFiesta { get; set; }
     [Parameter] public EventCallback OnStopReflection { get; set; }
@@ -302,6 +321,7 @@
     }
 
     private void LoadMore() => OnLoadMore.InvokeAsync(Session.Name);
+    private void LoadFullHistory() => OnLoadFullHistory.InvokeAsync(Session.Name);
 
     private static string PrettifyModel(string modelId)
     {

PolyPilot/Components/ExpandedSessionView.razor.css

@@ -293,6 +293,30 @@
     color: var(--text-primary);
 }
 
+/* Loading history indicator (remote mode) */
+.loading-history-indicator {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 0.75rem;
+    padding: 2rem;
+    flex: 1;
+    color: var(--text-secondary);
+    font-size: var(--type-callout, 0.85rem);
+}
+
+.loading-history-spinner {
+    width: 24px;
+    height: 24px;
+    border: 2.5px solid var(--hover-bg);
+    border-top-color: var(--accent-primary);
+    border-radius: 50%;
+    animation: spin 0.8s linear infinite;
+}
+
+@keyframes spin { to { transform: rotate(360deg); } }
+
 /* Error bar (expanded) */
 .expanded-card .error-bar {
     display: flex;

PolyPilot/Components/Pages/Dashboard.razor

@@ -115,6 +115,8 @@
                               @key="session.Name">
                 <ExpandedSessionView Session="session"
                                      IsCompleted="@completedSessions.Contains(session.Name)"
+                                     IsLoadingHistory="@(CopilotService.IsRemoteMode && session.MessageCount > 0 && session.History.Count == 0)"
+                                     HasMoreRemoteHistory="@CopilotService.HasMoreRemoteHistory(session.Name)"
                                      StreamingContent="@(streamingBySession.TryGetValue(session.Name, out var s2) ? s2 : "")"
                                      ActivityText="@(activityBySession.TryGetValue(session.Name, out var a2) ? a2 : "")"
                                      CurrentToolName="@(currentToolBySession.TryGetValue(session.Name, out var t2) ? t2 : "")"
@@ -145,6 +147,7 @@
                                      OnSetModel="(model) => SetExpandedModel(session, model)"
                                      OnFontSizeChange="HandleFontSizeChange"
                                      OnLoadMore="LoadMoreExpandedMessages"
+                                     OnLoadFullHistory="LoadFullRemoteHistory"
                                      OnStartFiesta="StartFiestaForSession"
                                      OnStopFiesta="StopFiestaForSession"
                                      OnStopReflection="() => StopReflectionForSession(session.Name)" />
@@ -2595,6 +2598,11 @@
         expandedMessageCounts[sessionName] = current + 25;
     }
 
+    private async Task LoadFullRemoteHistory(string sessionName)
+    {
+        await CopilotService.LoadFullRemoteHistoryAsync(sessionName);
+    }
+
     // === Model, plan mode, font, token helpers ===
 
     private static readonly string[] _fallbackModels = new[]

PolyPilot/Models/BridgeMessages.cs

@@ -146,6 +146,10 @@ public class SessionHistoryPayload
 {
     public string SessionName { get; set; } = "";
     public List<ChatMessage> Messages { get; set; } = new();
+    /// <summary>Total message count on the server (may be more than Messages.Count when limited).</summary>
+    public int TotalCount { get; set; }
+    /// <summary>True when the server has older messages not included in this response.</summary>
+    public bool HasMore { get; set; }
 }
 
 public class ContentDeltaPayload
@@ -225,6 +229,10 @@ public class ErrorPayload
 public class GetHistoryPayload
 {
     public string SessionName { get; set; } = "";
+    /// <summary>
+    /// Max messages to return (most recent). Null = all messages.
+    /// </summary>
+    public int? Limit { get; set; }
 }
 
 public class SendMessagePayload

PolyPilot/Services/CopilotService.Bridge.cs

@@ -333,7 +333,7 @@ private void SyncRemoteSessions()
             {
                 foreach (var name in sessionsNeedingHistory)
                 {
-                    try { await _bridgeClient.RequestHistoryAsync(name); }
+                    try { await _bridgeClient.RequestHistoryAsync(name, limit: 10); }
                     catch { }
                 }
             });
@@ -353,6 +353,21 @@ private void SyncRemoteSessions()
     private AgentSessionInfo? GetRemoteSession(string name) =>
         _sessions.TryGetValue(name, out var state) ? state.Info : null;
 
+    /// <summary>
+    /// Whether the server has more history for this session than what's been loaded.
+    /// </summary>
+    public bool HasMoreRemoteHistory(string sessionName) =>
+        IsRemoteMode && _bridgeClient.SessionHistoryHasMore.TryGetValue(sessionName, out var hasMore) && hasMore;
+
+    /// <summary>
+    /// Request the full (unlimited) history for a session from the remote server.
+    /// </summary>
+    public async Task LoadFullRemoteHistoryAsync(string sessionName)
+    {
+        if (!IsRemoteMode) return;
+        await _bridgeClient.RequestHistoryAsync(sessionName, limit: null);
+    }
+
     // --- Remote repo operations ---
 
     public async Task<(string RepoId, string RepoName)?> AddRepoRemoteAsync(string url, Action<string>? onProgress = null, CancellationToken ct = default)

PolyPilot/Services/IWsBridgeClient.cs

@@ -12,6 +12,7 @@ public interface IWsBridgeClient
     List<SessionSummary> Sessions { get; }
     string? ActiveSessionName { get; }
     System.Collections.Concurrent.ConcurrentDictionary<string, List<ChatMessage>> SessionHistories { get; }
+    System.Collections.Concurrent.ConcurrentDictionary<string, bool> SessionHistoryHasMore { get; }
     List<PersistedSessionSummary> PersistedSessions { get; }
     string? GitHubAvatarUrl { get; }
     string? GitHubLogin { get; }
@@ -37,7 +38,7 @@ public interface IWsBridgeClient
     Task ConnectAsync(string wsUrl, string? authToken = null, CancellationToken ct = default);
     void Stop();
     Task RequestSessionsAsync(CancellationToken ct = default);
-    Task RequestHistoryAsync(string sessionName, CancellationToken ct = default);
+    Task RequestHistoryAsync(string sessionName, int? limit = null, CancellationToken ct = default);
     Task SendMessageAsync(string sessionName, string message, CancellationToken ct = default);
     Task CreateSessionAsync(string name, string? model = null, string? workingDirectory = null, CancellationToken ct = default);
     Task SwitchSessionAsync(string name, CancellationToken ct = default);

PolyPilot/Services/WsBridgeClient.cs

@@ -26,6 +26,7 @@ public class WsBridgeClient : IWsBridgeClient, IDisposable
     public List<SessionSummary> Sessions { get; private set; } = new();
     public string? ActiveSessionName { get; private set; }
     public ConcurrentDictionary<string, List<ChatMessage>> SessionHistories { get; } = new();
+    public ConcurrentDictionary<string, bool> SessionHistoryHasMore { get; } = new();
     public List<PersistedSessionSummary> PersistedSessions { get; private set; } = new();
     public string? GitHubAvatarUrl { get; private set; }
     public string? GitHubLogin { get; private set; }
@@ -168,9 +169,9 @@ public void Stop()
     public async Task RequestSessionsAsync(CancellationToken ct = default) =>
         await SendAsync(new BridgeMessage { Type = BridgeMessageTypes.GetSessions }, ct);
 
-    public async Task RequestHistoryAsync(string sessionName, CancellationToken ct = default) =>
+    public async Task RequestHistoryAsync(string sessionName, int? limit = null, CancellationToken ct = default) =>
         await SendAsync(BridgeMessage.Create(BridgeMessageTypes.GetHistory,
-            new GetHistoryPayload { SessionName = sessionName }), ct);
+            new GetHistoryPayload { SessionName = sessionName, Limit = limit }), ct);
 
     public async Task SendMessageAsync(string sessionName, string message, CancellationToken ct = default) =>
         await SendAsync(BridgeMessage.Create(BridgeMessageTypes.SendMessage,
@@ -460,7 +461,8 @@ private void HandleServerMessage(string json)
                 if (history != null)
                 {
                     SessionHistories[history.SessionName] = history.Messages;
-                    Console.WriteLine($"[WsBridgeClient] Got history for '{history.SessionName}': {history.Messages.Count} messages");
+                    SessionHistoryHasMore[history.SessionName] = history.HasMore;
+                    Console.WriteLine($"[WsBridgeClient] Got history for '{history.SessionName}': {history.Messages.Count} messages (total={history.TotalCount}, hasMore={history.HasMore})");
                     OnStateChanged?.Invoke();
                 }
                 break;

PolyPilot/Services/WsBridgeServer.cs

@@ -306,13 +306,13 @@ await SendToClientAsync(clientId, ws,
             }
             await SendPersistedToClient(clientId, ws, ct);
 
-            // Send history for all active sessions so mobile has full state on connect
+            // Send recent history for all active sessions (limited to reduce initial payload)
             if (_copilot != null)
             {
                 foreach (var session in _copilot.GetAllSessions())
                 {
                     if (session.History.Count > 0)
-                        await SendSessionHistoryToClient(clientId, ws, session.Name, ct);
+                        await SendSessionHistoryToClient(clientId, ws, session.Name, 10, ct);
                 }
             }
 
@@ -371,7 +371,7 @@ await SendToClientAsync(clientId, ws,
                 case BridgeMessageTypes.GetHistory:
                     var histReq = msg.GetPayload<GetHistoryPayload>();
                     if (histReq != null)
-                        await SendSessionHistoryToClient(clientId, ws, histReq.SessionName, ct);
+                        await SendSessionHistoryToClient(clientId, ws, histReq.SessionName, histReq.Limit, ct);
                     break;
 
                 case BridgeMessageTypes.SendMessage:
@@ -415,7 +415,7 @@ await SendToClientAsync(clientId, ws,
                     {
                         _copilot.SetActiveSession(switchReq.SessionName);
                         BroadcastSessionsList();
-                        await SendSessionHistoryToClient(clientId, ws, switchReq.SessionName, ct);
+                        await SendSessionHistoryToClient(clientId, ws, switchReq.SessionName, 10, ct);
                     }
                     break;
 
@@ -748,15 +748,32 @@ private async Task SendPersistedToClient(string clientId, WebSocket ws, Cancella
         await SendToClientAsync(clientId, ws, msg, ct);
     }
 
-    private async Task SendSessionHistoryToClient(string clientId, WebSocket ws, string sessionName, CancellationToken ct)
+    private async Task SendSessionHistoryToClient(string clientId, WebSocket ws, string sessionName, int? limit, CancellationToken ct)
     {
         if (_copilot == null) return;
 
         var session = _copilot.GetSession(sessionName);
         if (session == null) return;
 
+        var allMessages = session.History;
+        var totalCount = allMessages.Count;
+
+        // Apply limit — take the most recent N messages
+        List<ChatMessage> messagesToSend;
+        bool hasMore;
+        if (limit.HasValue && limit.Value < totalCount)
+        {
+            messagesToSend = allMessages.Skip(totalCount - limit.Value).ToList();
+            hasMore = true;
+        }
+        else
+        {
+            messagesToSend = allMessages.ToList();
+            hasMore = false;
+        }
+
         // Populate ImageDataUri for Image messages so mobile can render them
-        foreach (var m in session.History)
+        foreach (var m in messagesToSend)
         {
             if (m.MessageType == ChatMessageType.Image && string.IsNullOrEmpty(m.ImageDataUri) && !string.IsNullOrEmpty(m.ImagePath))
             {
@@ -775,7 +792,9 @@ private async Task SendSessionHistoryToClient(string clientId, WebSocket ws, str
         var payload = new SessionHistoryPayload
         {
             SessionName = sessionName,
-            Messages = session.History.ToList()
+            Messages = messagesToSend,
+            TotalCount = totalCount,
+            HasMore = hasMore
         };
         var msg = BridgeMessage.Create(BridgeMessageTypes.SessionHistory, payload);
         await SendToClientAsync(clientId, ws, msg, ct);