From e5622087dc1966076e515f46d21c1a1841551e3d Mon Sep 17 00:00:00 2001
From: Orion Kindel <cakekindel@gmail.com>
Date: Tue, 4 Apr 2023 18:11:29 -0700
Subject: [PATCH] docs: update readme

---
 README.md | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++----
 build.sbt | 11 --------
 2 files changed, 79 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 102c5ca..0d1df2d 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,82 @@
-## sbt project compiled with Scala 3
+## toad-java
 
-### Usage
+This repo contains the Java & Scala APIs for the [toad](https://github.com/toad-lib/toad) CoAP network runtime.
 
-This is a normal sbt project. You can compile code with `sbt compile`, run it with `sbt run`, and `sbt console` will start a Scala 3 REPL.
+### Developing
+#### Developing - Clone
+```sh
+> git clone git@github.com:toad-lib/toad-java toad-java
+> cd toad-java
+```
 
-For more information on the sbt-dotty plugin, see the
-[scala3-example-project](https://github.com/scala/scala3-example-project/blob/main/README.md).
+#### Developing - Tooling
+##### Developing - Tooling - System
+If on a minimal os (ex. bare debian image) install if not present:
+- a C compiler, examples:
+   - [debian `apt install gcc`](https://packages.debian.org/stable/devel/gcc)
+   - [macos `brew install gcc`](https://formulae.brew.sh/formula/gcc)
+   - [macos - xcode commandline tools](https://developer.apple.com/xcode/resources/)
+- openssl, examples:
+   - [debian `apt install libssl-dev`](https://packages.debian.org/stable/devel/gcc)
+   - [macos `brew install openssl`](https://formulae.brew.sh/formula/gcc)
+- (debian only) `apt install pkg-config`
+
+##### Developing - Tooling - asdf
+this repo is configured to use asdf for managing versions of rust, the JVM, and coursier
+used by this project.
+
+To use it follow the [asdf installation guide](https://asdf-vm.com/guide/getting-started.html#official-download)
+then run the following in bash or zsh in the directory you cloned the repo to:
+
+```sh
+> asdf install
+> asdf plugin add java     # skip if you have system install of JDK version 20
+> asdf plugin add rust     # skip if you have system install of Rust
+> asdf plugin add coursier # skip if you have system install of coursier
+```
+
+##### Developing - Tooling - Manual
+- install [openjdk](https://jdk.java.net/20/) _or equivalent_ version 20 or higher
+  - after installing, ensure that `$JAVA_HOME` correctly refers to JDK 20 (`java -version` should output `openjdk version "20" 202x-xx-xx`)
+- install [coursier](https://get-coursier.io/docs/cli-install)
+- install [rust](https://rustup.rs)
+
+##### Developing - Tooling - sbt
+After following the above steps, add coursier-installed binaries to your PATH, ex with:
+```sh
+> echo 'export PATH=$PATH:/root/.local/share/coursier/bin' >> ~/.zshrc
+```
+
+Then install `sbt`
+```sh
+> coursier install sbt
+```
+
+#### Developing - Rust
+There is a non-trivial amount of nasty glue code necessary to support the interop between
+`toad` (a rust library) and `toad-java` (a java project).
+
+There is a published library [`toad-jni`](https://github.com/toad-lib/toad/tree/main/toad-jni) which contains
+general abstractions that are useful for this project and may be useful to others.
+This includes things like _"high-level rust struct for `java.util.ArrayList`
+doing nice things like implementing [`Iterator`](https://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html)."_
+
+Separately is a rust project in this repository, `./toad-java-glue-rs/`.
+This is *not* a published crate and is instead source code for a
+shared library specifically to implement native java methods in this java project.
+
+Development tips specific to the glue lib can be found in `./toad-java-glue-rs/README.md`.
+
+#### Developing - Build
+the sbt command `compile` (`sbt compile` or `compile` in the `sbt` shell)
+is the only required build step for this project.
+
+`sbt compile` can be broken into the following steps:
+ 1. run `javac` to generate C headers for java files with `native` function requirements
+ 1. dump the headers into `./toad-java-glue-rs/target/debug/`
+    - _(dual purpose; a native interface available to manually cross-check against the hard rust implementation, as well as providing an interface to the built library artifact)_
+ 1. run `cargo build` within `./toad-java-glue-rs/`
+ 1. build java & scala sources to `./target/`
+
+### Tests
+todo
diff --git a/build.sbt b/build.sbt
index 6b08025..a44aa33 100644
--- a/build.sbt
+++ b/build.sbt
@@ -32,17 +32,6 @@ lazy val root = project
       "glue.target" -> (baseDirectory.value / "toad-java-glue-rs" / "target" / "debug").toString,
       "java.classTarget" -> (baseDirectory.value / "target" / "scala-3.2.2" / "classes").toString
     ),
-    // Test / compile / javacOptions ++= Seq("--enable-preview", "--release", "20", "-Xlint:preview"),
-    // Test / run / javaOptions ++= Seq(
-    //   "-Djava.library.path=" + path.value("glue.target"),
-    //   "--enable-preview"
-    // ),
-    // Compile / doc / javacOptions ++= Seq("--enable-preview", "--release", "20", "-Xlint:preview"),
-    // Compile / compile / javacOptions ++= Seq("--enable-preview", "--release", "20", "-Xlint:preview"),
-    // Compile / run / javaOptions ++= Seq(
-    //   "-Djava.library.path=" + path.value("glue.target"),
-    //   "--enable-preview"
-    // ),
     ejectHeaders := {
       val files =
         FileTreeView.default.iterator(glob.value("java.sources")).foldLeft("") {