# Preprocess Service

Reads unprocessed `raw_packets` from PostgreSQL and builds aircraft, flights, tracks, and track_points.

## What it does

1. Waits for PostgreSQL to be ready
2. Reads `fr24.processing_state` to find the last processed `raw_packet_id`
3. Fetches the next batch of unprocessed packets
4. For each packet: upserts `aircraft`, creates/reuses a `flight`, appends a `track_point`
5. Advances the cursor in `processing_state`
6. Touches `/tmp/preprocess-ready` for Docker healthcheck

Data is fake/test for this stage — real ADS-B decoding comes later.

## Dependencies

- `psycopg2-binary`

## Environment variables

| Variable | Default | Description |
|---|---|---|
| `POSTGRES_HOST` | required | DB host |
| `POSTGRES_PORT` | `5432` | DB port |
| `POSTGRES_DB` | required | DB name |
| `POSTGRES_USER` | required | DB user |
| `POSTGRES_PASSWORD` | required | DB password |
| `POLL_INTERVAL_SECONDS` | `5.0` | How often to poll for new packets |
| `BATCH_SIZE` | `20` | Packets per processing batch |

## Run locally

```bash
pip install -r requirements.txt
export POSTGRES_HOST=localhost POSTGRES_DB=fr24 POSTGRES_USER=fr24 POSTGRES_PASSWORD=change-me
python main.py
```

## Build & run via Docker

```bash
docker build -t fr24-preprocess .
docker run --env-file ../../compose/.env fr24-preprocess
```