# The Nexrs dev journal

## Task 1: Getting the machine's local IP address

This proved to be harder than I suspected, and naturally with my luck, not very
portable. I opted for a Linux-exclusive solution: A combination of `ifconfig`
and `grep`. Rust has a nice set of tools for building and executing commands on
the local machine. `grep` appears to be having issues, however, so we're gonna
execute `ifconfig` and do the string searching/parsing in Rust itself.

Well hot damn. Took us a day and a half but we finally got it working. Rust's
explicit types are sometimes extremely brutal when my strongest languages are
Python and Javascript. We have a function that, through a dirty, ugly method,
finds the machine's local IP(v4) address. With that, we'll naively scan other IPs in
our range for other Nexrs servers. Easy and bad! Let's go!

## Task 2: Scanning for other servers

The idea behind this one is straightforward. Hold the first 3 octets of the IP
address constant, and step the last one up one. Attempt to connect on our port.
If we connect, send a heartbeat (`0xFF`). If we received a return heartbeat
(`0xFE`), add this machine to our list of servers.

This SHOULD be straightforward, but this is Rust and me we're talking about,
so...

Good news! It actually was straightforward. The `attempt_heartbeat()` function simply looks for a server listening on port 1738. If it succeeds, it prints out a confirmation. If it fails, prints out a failure message. E.z.

We'll expand this to do some additional checking:

* We'll keep sending unicode literals. It's easy.
* Confirm that a proper message is received (`"hbc"`)
* Later, do some encryption (via TLS, maybe?)

For now, we'll work on listening and responding. Then we can finally get a small network going!

## Task 3: Listen, and listen good.

Now we set about on the other half of communication: Listening. We're going to explore the `TcpListener` API, and use pattern matching to handle any of the various input messages we might receive.