build.rs

#[cfg(feature = "generate")]
use std::{env, ffi::OsStr, fs, io::prelude::*, path::Path};
#[cfg(feature = "generate")]
use protobuf_codegen::{Codegen,Customize};
#[cfg(feature = "generate")]
use protoc_bin_vendored::protoc_bin_path;

#[cfg(feature = "generate")]
fn proto_modules(proto_dir: &Path) -> Vec<String> {
	fs::read_dir(proto_dir)
		.expect("Could not read protobuf directory")
		.filter_map(|entry| {
			let path = entry.ok()?.path();
			if path.is_file() && path.extension() == Some(OsStr::new("proto")) {
				path.file_stem().and_then(|n| n.to_os_string().into_string().ok())
			} else {
				None
			}
		})
		.collect()
}

#[cfg(feature = "generate")]
fn main() {
	let in_dir = "./s2client-proto/s2clientprotocol";
	let out_dir = &env::var("OUT_DIR").unwrap();

	// Read list of all input protobuf files
	let input_mods = proto_modules(Path::new(in_dir));
	let input_files: Vec<String> = input_mods
		.iter()
		.map(|s| format!("{}/{}.proto", in_dir, s))
		.collect();

	// Compile protocol buffers
	Codegen::new()
		.out_dir(out_dir)
		.protoc_path(&protoc_bin_path().unwrap())
		.include("./s2client-proto/")
		.inputs(input_files)
		.run_from_script();

	println!("protobufs were generated successfully");

	// Generate the lib.rs source code
	let mut buffer = fs::File::create(format!("{}/{}", out_dir, "lib.rs")).unwrap();
	buffer
		.write_all(
			input_mods
				.iter()
				.map(|s| format!("pub mod {};", s))
				.collect::<Vec<_>>()
				.join("\n")
				.as_bytes(),
		)
		.unwrap();

	// Copy generated *.rs files to "src"
	fs::read_dir(out_dir).unwrap().for_each(|f| {
		let f = f.unwrap();
		fs::copy(f.path(), format!("src/{}", f.file_name().to_str().unwrap())).unwrap();
	});
}

#[cfg(not(feature = "generate"))]
fn main() {
	println!("using pre-generated *.rs files in 'src/'");
}