# continuum-proxy

Edge gateway daemon for the Continuum print farm platform. Runs on a Linux
SBC on-site, talks to printers over the LAN, and keeps a connection to the
cloud control plane (`continuum-backend`).

## This is a learning-stage boilerplate

This repo is deliberately minimal right now — real printer protocol clients
(Bambu MQTT+FTPS, PrusaLink REST, Klipper/Moonraker WebSocket) are **not**
implemented yet. Each vendor is a stub that just prints what it would do
(`src/printer/bambu.rs`, `prusa.rs`, `klipper.rs`). The idea is to learn
Rust's polymorphism pattern (trait + enum, since Rust has no class
inheritance) on something simple before adding real networking on top.

## Getting started

```bash
cp .env.example .env
cargo run                                  # the daemon: cloud uplink + go2rtc watchdog
cargo run --example printer_polymorphism   # standalone demo, no network/env needed
```

## Structure

```
src/
  main.rs      Runs the uplink and the go2rtc watchdog side by side
  config.rs    Loads settings from environment variables
  uplink/      WebSocket client to continuum-backend: connect, heartbeat, reconnect on drop
  printer/     Printer trait + PrinterBase + PrinterHandle enum + one stub per vendor
  go2rtc.rs    Restarts the go2rtc camera-restreaming process if it dies
examples/
  printer_polymorphism.rs   Runs all three printer stubs through one `connect()` call site
```

`src/printer/` is where the "inheritance" question lives — see that
module's doc comment for the trait+enum pattern this project uses instead
of class inheritance, and run the example above to see it work.

## What's not here yet (on purpose)

- Real MQTT/FTPS/HTTP/WebSocket printer clients — `src/printer/*.rs` has a
  `println!` where each of these will go.
- Local SQLite buffering for telemetry across connectivity gaps.
- LAN printer discovery (SSDP/mDNS).
- The mechanical plate-changer interface (serial/GPIO).

Add these back in one at a time as you get comfortable with the Rust
underneath them — each is its own small lesson (async I/O, a new crate's
API, error handling for a real protocol) rather than something to absorb
all at once.