From 6ffeed84190bb33219540c149e0d9aa3a2ece86b Mon Sep 17 00:00:00 2001
From: cottongin <cottongin@users.noreply.github.com>
Date: Mon, 21 Sep 2026 11:57:08 -0400
Subject: [PATCH] fix: double-paste bug, show actual yt-dlp errors in UI

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 ...1_15-25-sdd-full-implementation-summary.md | 117 ++++++++++++++++++
 src/lib/components/UrlInput.svelte            |  43 ++++---
 src/lib/components/VideoPlayer.svelte         |   2 +-
 3 files changed, 146 insertions(+), 16 deletions(-)
 create mode 100644 chat-summaries/2026-09-21_15-25-sdd-full-implementation-summary.md

diff --git a/chat-summaries/2026-09-21_15-25-sdd-full-implementation-summary.md b/chat-summaries/2026-09-21_15-25-sdd-full-implementation-summary.md
new file mode 100644
index 0000000..18bbbb6
--- /dev/null
+++ b/chat-summaries/2026-09-21_15-25-sdd-full-implementation-summary.md
@@ -0,0 +1,117 @@
+# Video Clipper: Full SDD Implementation Summary
+
+**Date:** 2026-09-21  
+**Approach:** Subagent-Driven Development (12 tasks + final review)  
+**Total commits:** 23 (0bc1f1e → e4710b4)  
+**Test suite:** 31 Vitest + 28 Rust tests, all green  
+
+## Task Description
+
+Implemented the full MVP of a macOS GUI Video Clipper app (Tauri v2 + Svelte 5) across 12 tasks, each with an implementer subagent, task review, and fix rounds as needed. The app enables users to paste a YouTube URL, preview/scrub the video, mark clip regions, and export clips via ffmpeg.
+
+## Changes Made
+
+### Task 1: Project Scaffolding & App Shell
+- Tauri v2 + Svelte 5 project with Rust backend
+- Data models (`VideoMetadata`, `Clip`, `CookieSource`, `ExportConfig`, etc.)
+- Utility functions (`formatTime`, `parseTime`, `getClipColor`) with Vitest tests
+- App shell layout with 6 stub components
+- CSS theme with custom properties
+
+### Task 2: Dependency Manager & Setup Wizard
+- Rust `dependency_manager` service (ffmpeg, yt-dlp, JS runtime, PO token detection)
+- Tauri commands with Channel-based install progress streaming
+- SetupWizard Svelte component with auto-continue
+- **Fix round:** stderr threading for install output, cookie flags on PO token check
+
+### Task 3: Preferences Store
+- Svelte 5 rune store with `@tauri-apps/plugin-store` persistence
+- Output directory + cookie source preferences
+- PreferencesPanel component with gear toggle in toolbar
+- **Fix round:** guard saves against uninitialized store
+
+### Task 4: Video Resolver, URL Input & Video Player
+- Rust `video_resolver` service (yt-dlp JSON parsing, stream URL extraction)
+- `resolve_url` Tauri command with cookie support
+- `videoSession` store (reactive session state)
+- UrlInput (paste detection, resolve flow) + VideoPlayer (HTML5 `<video>`)
+- **Fix round:** validate empty stream_url, clear stale metadata on error
+
+### Task 5: Download Manager & Status Bar
+- Rust `download_manager` service with progress parsing
+- `start_download` command with Channel events
+- StatusBar showing download progress
+- Auto-download trigger after URL resolve
+- **Fix round:** redirect unused stdout to `Stdio::null()`
+
+### Task 6: Timeline Core
+- Canvas-based timeline with `TimelineState`, coordinate mapping
+- Playhead rendering, time ticks, placeholder lanes
+- Mouse scrubbing, cursor-anchored zoom (wheel)
+- 12 Vitest tests for pure functions
+
+### Task 7: Clip Management
+- `clips` store (Svelte 5 runes) with CRUD + in/out point marking
+- Canvas clip renderer with color-coded regions + drag handles
+- `hitTestClip` for mouse interaction
+- ClipList component (list, edit, select, delete)
+- 7 TDD tests for clip store
+
+### Task 8: Transport Controls & Keyboard Shortcuts
+- TransportControls component (play/pause, I/O, skip, frame step)
+- Global keyboard handler (Space, I, O, J/K/L shuttle, arrows, comma/period)
+- Shared `playback.ts` module for DRY transport logic
+
+### Task 9: Keyframe Index & Frame Navigation
+- Rust `keyframe_index` service (ffprobe parsing)
+- `extract_keyframes` Tauri command
+- Auto-fetch after download, wired to transport buttons (Shift+comma/period)
+
+### Task 10: Waveform Generation & Display
+- Rust `waveform_generator` service (ffmpeg audio peak extraction)
+- Canvas waveform renderer with zoom-aware peak drawing
+- Static placeholder while generating
+- **Fix round:** clear waveform data on new download
+
+### Task 11: Thumbnail Extraction & Display
+- Rust `thumbnail_extractor` service (ffmpeg frame extraction)
+- Adaptive density thumbnails on canvas timeline
+- Image caching with `convertFileSrc` (Tauri asset protocol)
+- **Fix round:** cache invalidation + temp directory cleanup
+
+### Task 12: Clip Export & Export Dialog
+- Rust `clip_exporter` service (lossless/precise, individual/merged)
+- ExportDialog component (cut mode, scope, directory, progress)
+- 6 Rust tests for ffmpeg command construction
+- **Fix round:** temp dir cleanup on merge failure
+
+### Final Review Fixes
+- Clear clips on new video load
+- WebM precise codec mapping (VP9/Opus)
+- Home path `~` expansion via `dirs` crate
+- computeZoom zero-range guard
+- Timeline viewport reset on media switch
+- Shuttle rate reset on new URL
+
+## Follow-Up Items
+
+These were identified in reviews as acceptable for MVP but should be addressed:
+
+1. **Per-frame JPGs → sprite sheets** — Thumbnails use individual files instead of tiled grids; performance concern for very long videos
+2. **Stream URL expiry handling** — No auto-re-resolve when streaming URL expires during preview
+3. **Auto-export on download complete** — Spec calls for this when user is waiting in export dialog
+4. **Merged export overlap trimming** — Overlapping clip ranges not trimmed before merge
+5. **Export Selected** — ClipList only has Export All, not Export Selected
+6. **Cmd+A select all clips** — Only preventDefault, no implementation
+7. **Analysis failure UX** — Silent console.error instead of "Failed to generate" placeholder
+8. **Zoom slider** — Only wheel zoom; no slider control
+9. **Status bar ETA/export progress** — Minimal status bar info
+10. **Dead `ExportEvent::Error` / `DownloadEvent::Error` variants** — Unused enum variants
+
+## Lessons Learned
+
+1. **Svelte 5 rune export limitation** — Can't export individual `$state` variables; must use a single `$state` object pattern (discovered in Task 3, applied throughout)
+2. **Pipe deadlock pattern** — Piping both stdout and stderr without reading both causes subprocess deadlock. Fixed in Tasks 2 and 5 with either dual-thread reading or `Stdio::null()`.
+3. **Stale state on session transitions** — Multiple tasks needed fixes for stale data (metadata, waveform, keyframes, clips) when loading a new URL. A centralized "new session" reset would prevent this pattern.
+4. **ffmpeg `aresample` semantics** — Sets sample rate (Hz), not output length; long videos produce large PCM buffers before bucketing.
+5. **SDD review loop value** — Per-task reviews caught real bugs (pipe deadlocks, stale state, missing cookie flags) that would have been expensive to debug later. The final whole-branch review caught cross-cutting issues (clip reset, codec mismatch) that per-task gates missed.
diff --git a/src/lib/components/UrlInput.svelte b/src/lib/components/UrlInput.svelte
index 9b4c3d3..9afc890 100644
--- a/src/lib/components/UrlInput.svelte
+++ b/src/lib/components/UrlInput.svelte
@@ -33,32 +33,40 @@
   function handlePaste(e: ClipboardEvent) {
     const text = e.clipboardData?.getData('text')?.trim();
     if (text && (text.startsWith('http://') || text.startsWith('https://'))) {
+      e.preventDefault();
       inputValue = text;
       setTimeout(handleSubmit, 50);
     }
   }
 </script>
 
-<div class="url-input">
-  <input
-    type="text"
-    placeholder="Paste a video URL and press Enter…"
-    bind:value={inputValue}
-    onkeydown={handleKeydown}
-    onpaste={handlePaste}
-    disabled={session.status === 'resolving'}
-  />
-  {#if session.status === 'resolving'}
-    <span class="spinner">⏳</span>
-  {/if}
+<div class="url-input-wrapper">
+  <div class="url-input">
+    <input
+      type="text"
+      placeholder="Paste a video URL and press Enter…"
+      bind:value={inputValue}
+      onkeydown={handleKeydown}
+      onpaste={handlePaste}
+      disabled={session.status === 'resolving'}
+    />
+    {#if session.status === 'resolving'}
+      <span class="spinner">⏳</span>
+    {/if}
+  </div>
   {#if session.error}
-    <span class="error" title={session.error}>⚠</span>
+    <div class="error-bar" title={session.error}>⚠ {session.error}</div>
   {/if}
 </div>
 
 <style>
-  .url-input {
+  .url-input-wrapper {
     flex: 1;
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+  }
+  .url-input {
     display: flex;
     align-items: center;
     gap: 8px;
@@ -69,8 +77,13 @@
   .spinner {
     animation: pulse 1s ease-in-out infinite;
   }
-  .error {
+  .error-bar {
     color: var(--danger);
+    font-size: 12px;
+    line-height: 1.3;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
     cursor: help;
   }
   @keyframes pulse {
diff --git a/src/lib/components/VideoPlayer.svelte b/src/lib/components/VideoPlayer.svelte
index 968f741..c444a27 100644
--- a/src/lib/components/VideoPlayer.svelte
+++ b/src/lib/components/VideoPlayer.svelte
@@ -61,7 +61,7 @@
   {:else if session.status === 'resolving'}
     <div class="placeholder">Loading video…</div>
   {:else if session.status === 'error'}
-    <div class="placeholder error">Failed to load video. Check the URL and try again.</div>
+    <div class="placeholder error">{session.error ?? 'Failed to load video.'}</div>
   {:else}
     <div class="placeholder">Paste a URL above to load a video</div>
   {/if}