# Truck Counting Bug Fix + Box Counts + Download Compression Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Fix truck-classed-as-sack counting bug, propagate sack vs box counts to results UI, compress downloads to max 250MB.

**Architecture:** (1) Filter truck class before counting and switch both pipelines to `MultiClassLineCounter` (defense in depth + box counts); fix dashboard hardcoded "sack" label. (2) Add box count fields to result dataclasses and UI. (3) Compress download on-the-fly via ffmpeg targeting 250MB.

**Tech Stack:** Python 3.10, Flask, OpenCV, ffmpeg subprocess, existing `MultiClassLineCounter`

**Spec:** Original repo reference: `/tmp/karung-counting-feedmill-semarang/predict.py` lines 1497-1500 (class filter), 1409 (`MultiClassLineCounter`)

## Global Constraints

- Python >= 3.10, NumPy < 2.0, Jetson Orin Nano
- All existing tests (71) must pass after each task
- Follow existing Flat Design system (teal/orange)
- Git remote: `git.proit.id/andrew/feedmill-recounter.git`

## File Structure

| Action | File | Responsibility |
|--------|------|----------------|
| Modify | `src/pipeline.py` | Class filter before counter, switch to MultiClassLineCounter, box counts in results |
| Modify | `src/job.py` | Box count fields in JobResult, pass from pipeline results |
| Modify | `src/dashboard.py` | Label from det.class_name not hardcoded "sack" |
| Modify | `templates/status.html` | Show sack vs box counts separately |
| Modify | `app.py` | Download route compresses via ffmpeg to 250MB |
| Modify | `tests/` | New tests for filter, box counts, compression |

---

### Task 1: Fix truck counting bug (pipeline + dashboard)

**Files:**
- Modify: `src/pipeline.py`
- Modify: `src/dashboard.py`
- Create/Modify: `tests/test_pipeline.py` (add filter tests)

**Root cause:**
1. `run_merged_pipeline` line 519: `counter.update([d for d in tracked if d.track_id is not None])` — no class filter, trucks counted
2. `dashboard.py` line 155: `label = "sack"` hardcoded
3. Both pipelines use `LineCrossCounter` which counts any class

**Changes:**

1. `src/pipeline.py` — import `MultiClassLineCounter` instead of / in addition to `LineCrossCounter`

2. `run_pipeline` (line 163): replace `LineCrossCounter(...)` with `MultiClassLineCounter(...)` (same args)

3. `run_merged_pipeline` (line 426): same replacement

4. `run_pipeline` line 248: `counter.update(tracked_sacks)` → filter first:
```python
counter.update([d for d in tracked_sacks if d.class_name in ("sack", "box")])
```

5. `run_merged_pipeline` line 519:
```python
countable = [d for d in tracked if d.track_id is not None and d.class_name in ("sack", "box")]
counter.update(countable)
```

6. `src/dashboard.py` `_draw_detections` line 155: `label = "sack"` → `label = det.class_name`

**Interfaces:**
- Consumes: `MultiClassLineCounter` from src/counting.py (exists, has `box_loading_count`, `box_unloading_count` properties)
- Produces: counter objects are now `MultiClassLineCounter` — same `.loading_count`/`.unloading_count` properties plus new `.box_loading_count`/`.box_unloading_count`

**Steps:**
- [ ] Write failing test: truck class detections not counted
- [ ] Run test to verify fail
- [ ] Apply 6 changes above
- [ ] Run full suite: `python -m pytest tests/ --tb=short`
- [ ] Commit: `fix: exclude truck class from counting, use MultiClassLineCounter, real class labels`

---

### Task 2: Box count propagation to results UI

**Files:**
- Modify: `src/pipeline.py` (PipelineResult, MergedPipelineResult, return statements)
- Modify: `src/job.py` (JobResult, both branches of _run_job)
- Modify: `templates/status.html`
- Modify: `static/app.js` (live stats if applicable)

**Changes:**

1. `PipelineResult` dataclass: add `box_loading_count: int = 0`, `box_unloading_count: int = 0`, property `box_net_count`

2. `MergedPipelineResult` dataclass: same fields

3. `run_pipeline` return (line ~323): add `box_loading_count=counter.box_loading_count, box_unloading_count=counter.box_unloading_count`

4. `run_merged_pipeline` return (line ~585): same

5. `JobResult` dataclass: add `box_loading_count: int = 0`, `box_unloading_count: int = 0`, `box_net_count: int = 0`

6. Both `JobResult` construction sites in `_run_job` (lines ~220 and ~264): pass box counts from result

7. `templates/status.html` results card: add box stats blocks:
```html
<div class="stat">
  <span class="stat-value">{{ r.box_loading_count }}</span>
  <span class="stat-label">Box In</span>
</div>
<div class="stat">
  <span class="stat-value">{{ r.box_unloading_count }}</span>
  <span class="stat-label">Box Out</span>
</div>
```
Keep existing Loading/Unloading as sack counts (rename labels to "Sack In"/"Sack Out" for clarity).

8. `/api/jobs/<job_id>` in app.py: include box counts in results JSON

**Interfaces:**
- Consumes: box counts from Task 1's MultiClassLineCounter
- Produces: `box_loading_count` etc. on JobResult — status.html and API consumers

**Steps:**
- [ ] Write failing test for box count propagation
- [ ] Run to verify fail
- [ ] Apply changes
- [ ] Run full suite
- [ ] Commit: `feat: propagate sack vs box counts to results and UI`

---

### Task 3: Download compression to max 250MB

**Files:**
- Modify: `app.py` (download route)
- Create: `tests/test_download_compress.py`

**Changes:**

1. Add helper `_compress_for_download(file_path, max_bytes=250*1024*1024) -> str | None`:
   - If file size <= max_bytes, return None (no compression)
   - Probe duration via ffprobe
   - Calculate target bitrate: `int((max_bytes * 8 * 0.92) / duration)` (8% safety margin, avoid container overhead overshoot)
   - ffmpeg: `ffmpeg -y -i input -c:v libx264 -b:v {bitrate} -c:a aac -b:a 64k output.mp4`
   - Output to `<job_dir>/<name>_compressed.mp4`
   - If compressed file exists, reuse it
   - Return compressed path or None

2. `download()` route: call helper, send compressed file if produced, else original

3. Handle ffmpeg missing: fall back to original file (no error)

**Steps:**
- [ ] Write failing tests (small file not compressed; helper signature)
- [ ] Run to verify fail
- [ ] Implement helper + route change
- [ ] Run full suite
- [ ] Commit: `feat: compress downloads to max 250MB via ffmpeg`