use std::env;
use std::path::PathBuf;

fn main() {
    // this doesn't make _much_ difference really, since this is our only Rust source file
    // but it seems it's probably better than not having it
    // what we really want is to tell Rust to only regenerate the header file if the Rust code actually compiles
    // but we don't have that flexibility
    // and it's an issue because cbindgen tries to be fault-tolerant in some ways that don't even seem to make sense
    //
    // e.g. mis-spell "Option" as "Option" and you get
    // void print_optional(Optio<const int8_t*> x);
    // instead of
    // void print_optional(const int8_t *x);
    // and that's only an issue because in HLS TH dependent-file watching gives up after an error
    // i.e. once the containing splice has thrown an exception once, the containing file needs a manual edit to kick it
    // and that's really not helped by Rust Analyzer mostly only showing diagnostics on save
    // P.S. strings to stdout?! what a terrible API
    // don't get me started in the discoverability of actually then using the terminal for debugging:
    // println!("cargo::warning={:?}", env::var("OUT_DIR"));
    println!("cargo::rerun-if-changed=lib.rs");
    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let profile = env::var("PROFILE").unwrap();
    cbindgen::Builder::new()
        .with_crate(&crate_dir)
        .with_language(cbindgen::Language::C)
        .with_style(cbindgen::Style::Tag)
        .generate()
        .expect("Unable to generate bindings")
        .write_to_file(
            PathBuf::from(&crate_dir)
                .join("target")
                .join(&profile)
                .join("garnet_rs.h"),
        );
}