ClaudeDo/docs/superpowers/plans/2026-06-04-prep-log-persistence.md

# Persist Daily-Prep Log Across Restarts — Plan

> **For agentic workers:** REQUIRED SUB-SKILL: superpowers:subagent-driven-development. Steps use `- [ ]`.

**Goal:** The prep log currently lives only in memory (`DetailsIslandViewModel.PrepLog`), so after an app restart the prep terminal is empty. Persist the last prep run's output to a file in the worker and load it into the prep terminal when opened.

**Root cause (confirmed):** `PrimeRunner.FireAsync` streams stdout lines via `_broadcaster.PrepLineAsync(line)` only — it writes no file and stores no record. `PrepLog` is an in-memory `ObservableCollection` populated only by live `PrepLine` events. Nothing persists → empty after restart.

**Approach:** Worker writes each streamed line to `<appdata>/logs/daily-prep.log` (truncated at run start = last run only) using the existing `LogWriter`. A new hub method `GetLastPrepLog()` returns the file (tail-capped, like `get_task_log`). The UI loads it into `PrepLog` when the prep view opens, but only when `PrepLog` is empty and no run is in progress.

**Tech:** ASP.NET Core SignalR, Avalonia + CommunityToolkit.Mvvm, xUnit.

## Build/test
```bash
dotnet build src/ClaudeDo.Worker/ClaudeDo.Worker.csproj -c Release
dotnet build src/ClaudeDo.App/ClaudeDo.App.csproj -c Release
dotnet test tests/ClaudeDo.Worker.Tests/ClaudeDo.Worker.Tests.csproj -c Release
dotnet test tests/ClaudeDo.Ui.Tests/ClaudeDo.Ui.Tests.csproj -c Release
```
GUI not headlessly verifiable — note it; human verifies visuals.

## Shared constant
The prep-log path must be identical in `PrimeRunner` (writer) and `WorkerHub` (reader). Define it once and reference from both:
`Path.Combine(ClaudeDo.Data.Paths.AppDataRoot(), "logs", "daily-prep.log")`.
Add a small static helper so both sides agree, e.g. in `src/ClaudeDo.Worker/Prime/DailyPrepPrompt.cs` (already the prep "home"):
```csharp
public static string LogPath() =>
    System.IO.Path.Combine(ClaudeDo.Data.Paths.AppDataRoot(), "logs", "daily-prep.log");
```

---

## Task 1: Worker — write the prep log + serve it

**Files:**
- Modify: `src/ClaudeDo.Worker/Prime/DailyPrepPrompt.cs` (add `LogPath()` helper)
- Modify: `src/ClaudeDo.Worker/Prime/PrimeRunner.cs`
- Modify: `src/ClaudeDo.Worker/Hub/WorkerHub.cs`
- Test: `tests/ClaudeDo.Worker.Tests/Prime/PrimeRunnerTests.cs`

- [ ] **Step 1: Add `DailyPrepPrompt.LogPath()`** (code above).

- [ ] **Step 2: Write the failing test.** Extend the existing streaming test (or add one) asserting that after `FireAsync` with emitted stdout lines, the file at `DailyPrepPrompt.LogPath()` contains those lines, and that a prior run's content is replaced (truncate-on-start). Since the path is the real app-data logs dir, the test should delete the file first and clean up after; assert exact line content.

```csharp
[Fact]
public async Task FireAsync_writes_last_run_to_prep_log_file()
{
    var path = DailyPrepPrompt.LogPath();
    if (File.Exists(path)) File.Delete(path);

    var claude = new FakeClaudeProcess(emitLines: new[] { "lineA", "lineB" }, exitCode: 0, result: "ok");
    var runner = NewRunner(claude, new RecordingPrimeBroadcaster());
    await runner.FireAsync(new PrimeScheduleDto(Guid.Empty, 0, TimeSpan.Zero, true, null, null), CancellationToken.None);

    var contents = await File.ReadAllTextAsync(path);
    Assert.Contains("lineA", contents);
    Assert.Contains("lineB", contents);

    // Truncation: a second run with different lines replaces the file.
    var claude2 = new FakeClaudeProcess(emitLines: new[] { "lineC" }, exitCode: 0, result: "ok");
    var runner2 = NewRunner(claude2, new RecordingPrimeBroadcaster());
    await runner2.FireAsync(new PrimeScheduleDto(Guid.Empty, 0, TimeSpan.Zero, true, null, null), CancellationToken.None);
    var after = await File.ReadAllTextAsync(path);
    Assert.DoesNotContain("lineA", after);
    Assert.Contains("lineC", after);
}
```

- [ ] **Step 3: Run — expect FAIL.**

- [ ] **Step 4: Write the file in `PrimeRunner.FireAsync`.** After the gate is acquired and before `RunAsync`: compute `var logPath = DailyPrepPrompt.LogPath();`, delete it if present (truncate → last run only), then create `await using var logWriter = new LogWriter(logPath);`. Change the stream callback to write AND broadcast:

```csharp
            var logPath = DailyPrepPrompt.LogPath();
            try { if (File.Exists(logPath)) File.Delete(logPath); } catch { /* best effort */ }
            await using var logWriter = new LogWriter(logPath);

            await _broadcaster.PrepStartedAsync();
            // ... build prompt/args/timeoutCts ...
            var result = await _claude.RunAsync(
                arguments: args, prompt: prompt, workingDirectory: cwd,
                onStdoutLine: async line =>
                {
                    await logWriter.WriteLineAsync(line);
                    await _broadcaster.PrepLineAsync(line);
                },
                ct: timeoutCts.Token);
```

Keep the existing `success`/`finally`/`PrepFinishedAsync`/gate logic. `using ClaudeDo.Worker.Runner;` is already present (LogWriter lives there). The `await using` LogWriter disposes (flushes) before the method returns.

- [ ] **Step 5: Run — expect PASS.** Build the Worker.

- [ ] **Step 6: Add `WorkerHub.GetLastPrepLog()`** (no ctor change — reads the static path):

```csharp
public Task<string> GetLastPrepLog()
{
    var path = DailyPrepPrompt.LogPath();
    if (!File.Exists(path)) return Task.FromResult(string.Empty);

    const int maxBytes = 256 * 1024;
    var bytes = File.ReadAllBytes(path);
    var text = bytes.Length <= maxBytes
        ? System.Text.Encoding.UTF8.GetString(bytes)
        : System.Text.Encoding.UTF8.GetString(bytes, bytes.Length - maxBytes, maxBytes);
    return Task.FromResult(text);
}
```

Add `using ClaudeDo.Worker.Prime;` to `WorkerHub.cs` if not present.

- [ ] **Step 7: Build Worker; run the full Worker.Tests project.**

```bash
dotnet build src/ClaudeDo.Worker/ClaudeDo.Worker.csproj -c Release
dotnet test tests/ClaudeDo.Worker.Tests/ClaudeDo.Worker.Tests.csproj -c Release
```

- [ ] **Step 8: Commit** (stage only Task 1 files):
```bash
git commit -m "feat(daily-prep): persist last prep run to a log file and serve it via GetLastPrepLog"
```

---

## Task 2: UI — load the persisted prep log when opening

**Files:**
- Modify: `src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs`
- Modify: `src/ClaudeDo.Ui/Services/WorkerClient.cs`
- Modify: `src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs`
- Modify fakes: `tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs`, `tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs` (FakeWorkerClient)
- Test: `tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandPrepModeTests.cs`

- [ ] **Step 1: Declare on `IWorkerClient`:** `Task<string> GetLastPrepLogAsync();`

- [ ] **Step 2: Implement in `WorkerClient`:** `public Task<string> GetLastPrepLogAsync() => _hub.InvokeAsync<string>("GetLastPrepLog");` (match neighbouring call style; if there is a `TryInvokeAsync` helper for resilience, mirror `GetWeekReportAsync` and return `?? string.Empty`).

- [ ] **Step 3: Update fakes.** Add `public Task<string> GetLastPrepLogAsync() => Task.FromResult(string.Empty);` to both fakes. In `StubWorkerClient`, make it return a settable backing field, e.g. `public string LastPrepLog = ""; public Task<string> GetLastPrepLogAsync() => Task.FromResult(LastPrepLog);`.

- [ ] **Step 4: Write the failing test.**

```csharp
[Fact]
public async Task ShowPrep_loads_persisted_log_when_empty()
{
    var stub = new StubWorkerClient { LastPrepLog = "{\"type\":\"assistant\",\"text\":\"restored\"}" };
    var vm = NewDetailsVm(stub);

    vm.ShowPrep();
    await Task.Delay(50); // allow the async load to run; or expose the load task to await deterministically

    Assert.NotEmpty(vm.PrepLog);
}
```

Prefer determinism over `Task.Delay`: have `ShowPrep` start the load and expose the in-flight `Task` (e.g. a `LoadLastPrepLogAsync()` method the test can call/await directly), then assert. Use whichever the existing test style favors.

- [ ] **Step 5: Implement load in `DetailsIslandViewModel`.** Add a method and call it from `ShowPrep`:

```csharp
public void ShowPrep()
{
    Bind(null);
    IsNotesMode = false;
    IsPrepMode = true;
    _ = LoadLastPrepLogIfEmptyAsync();
}

private async Task LoadLastPrepLogIfEmptyAsync()
{
    if (_worker is null || IsPrepRunning || PrepLog.Count > 0) return;
    string text;
    try { text = await _worker.GetLastPrepLogAsync(); }
    catch { return; }
    if (IsPrepRunning || PrepLog.Count > 0) return; // a live run may have started meanwhile
    foreach (var line in text.Split('\n'))
    {
        var trimmed = line.TrimEnd('\r');
        if (trimmed.Length > 0) AppendStdoutLine(PrepLog, trimmed);
    }
}
```

This reuses the existing `AppendStdoutLine(PrepLog, line)` formatter path, so persisted NDJSON renders identically to the live stream. The guards ensure it never overwrites a live run (`PrepStarted` clears `PrepLog` and sets `IsPrepRunning`) or an already-loaded log.

- [ ] **Step 6: Build App + run UI tests.**

```bash
dotnet build src/ClaudeDo.App/ClaudeDo.App.csproj -c Release
dotnet test tests/ClaudeDo.Ui.Tests/ClaudeDo.Ui.Tests.csproj -c Release
dotnet test tests/ClaudeDo.Worker.Tests/ClaudeDo.Worker.Tests.csproj -c Release
```

- [ ] **Step 7: Manual smoke (human):** run a prep, restart the app, open the prep log on MyDay → the last run's output is shown.

- [ ] **Step 8: Commit** (stage only Task 2 files):
```bash
git commit -m "feat(daily-prep): load persisted prep log into the terminal on open"
```

## Notes / risks
- `PrimeRunner` writes via the same `LogWriter` pattern `TaskRunner` uses; concurrency behavior matches existing code (no new locking introduced).
- Path is shared via `DailyPrepPrompt.LogPath()` so writer and reader never diverge.
- Load is guarded (`PrepLog empty && !IsPrepRunning`) to avoid clobbering a live stream — the order of `ShowPrep`'s flag set vs. the async load matters; re-check the guard after the await.
- Last run only (file truncated each run); history is out of scope.