# AGENTS.md — bytetrack-counter

## Architecture

- **Edge AI counter**: RTSP camera → YOLO RKNN (NPU) → tracking → line-crossing → SQLite + JSON state → Flask dashboard.
- **2 counter scripts**, only 1 deployed:
  - `counter_live.py` — Jetson TensorRT artifact (CUDA, NOT used on RK3588).
  - **`counter_live_rknn_bytetrack.py`** — RK3588 with ByteTrack. **This is what systemd runs.** Reference for C++ port.
- `batch_store.py` — shared SQLite persistence + batch state machine.
- `counter_dashboard.py` — Flask dashboard on port 5000, same DB.
- `recounting_dashboard.py` — Flask recounting dashboard on port 5002, consumes live + recount APIs.
- `recounting_dashboard_upload.py` — Flask upload+recount dashboard on port 5003; uploads MP4 first, then launches `RECOUNT_CMD --source <mp4>`; START RECOUNT stays disabled until an upload completes.

## No build / test / lint

There is no build system, no test framework, no linter config, no typechecker.  
Do not try to run `pytest`, `ruff`, `mypy`, etc. — they don't exist here.

## How to run

```bash
# Copy env (required, .env is gitignored)
cp config.env.example .env

# Venv (must use system-site-packages for RKNN toolkit)
python3 -m venv --system-site-packages venv
source venv/bin/pip install -r requirements.txt

# Run counter (RK3588 only — needs rknn-toolkit-lite2 & RKNN model)
PYTHONNOUSERSITE=1 venv/bin/python counter_live_rknn_bytetrack.py

# Run dashboard
PYTHONNOUSERSITE=1 venv/bin/python counter_dashboard.py

# Run upload recounting dashboard
PYTHONNOUSERSITE=1 venv/bin/python recounting_dashboard_upload.py
```

## Key environment & install quirks

- **`PYTHONNOUSERSITE=1`** is mandatory when running from the venv — without it, system/user packages leak in.
- **`.env` is gitignored** — always copy from `config.env.example` first.
- **`numpy<2`** is required for `rknn-toolkit-lite2` compatibility.
- **Install path in service files is `/opt/bytetrack-counter`** (not the `/opt/jetson-counter` mentioned in README/DEPLOY). The `.env.example` also reflects `/opt/bytetrack-counter`.
- Service user is **`root`**, not `jetson` (despite README saying otherwise).
- Three systemd units: `bytetrack-counter.service`, `bytetrack-counter-dashboard.service`, and `bytetrack-recounting-upload-dashboard.service` (upload recounting dashboard, port 5003).
- `counter_live.py` (TensorRT) is Jetson-only and won't work on RK3588.
- **Reset flow**: `POST /api/reset` → deletes state JSON + touches `{SHM_DIR}/.reset`. `batch_store._check_reset_signal()` watches this marker and clears in-memory state on next crossing.
- **Upload filename contract**: uploads are expected as `batch_XX_YYYYMMDD_HHmmSS.mp4` (XX = batch number, timestamp = date). `recounting_dashboard_upload.py` parses both to query the live API's `/api/day-detail/<YYYY-MM-DD>` for the recorded count.
- **`RECOUNT_CMD`** in the upload dashboard is a template with a `{path}` placeholder, e.g. `bytetrack-counter config.env --source {path}`; the uploaded file path is `shlex.quote()`d before substitution.
- **Cross-dashboard header links**: `UPLOAD_DASHBOARD_URL` (live → upload dashboard, `counter_dashboard.py`) and `LIVE_DASHBOARD_URL` (upload → live dashboard, `recounting_dashboard_upload.py`); empty value hides the header link.

## Code conventions

- All config lives in `.env` (dotenv), read via `os.getenv()` at module top-level in each script.
- The 2 counter scripts share drawing/batch helpers. `counter_live_rknn_bytetrack.py` is the reference for C++ port.
- `batch_store.py` has its own threading (cutoff watcher, batch timeout timer) — thread safety is via a single `state_lock`.
- The dashboard re-creates DB tables on startup (`_ensure_db()`) independently from `batch_store.py`.
- No formal version tracking exists anywhere in this codebase.
- Dashboard template selectable via `DASHBOARD_TEMPLATE` env var — supports `dashboard.html`, `dashboard_lamborghini.html`, `dashboard_tesla.html`.