use std::env;
use std::path::PathBuf;
use bindgen::CargoCallbacks;
use gobuild::BuildMode;
use std::path::Path;

fn main() {
    // Find compiler: if /usr/local/go/bin/go exists, use that
    // otherwise, rely on PATH
    let compiler;
    if Path::new("/usr/local/go/bin/go").exists() {
        println!("Using /usr/local/go/bin/go");
        compiler = "/usr/local/go/bin/go";
    } else {
        compiler = "go";
    }

    gobuild::Build::new().compiler(compiler).buildmode(BuildMode::CArchive).file("main.go").compile("nebulaffi");

    println!("Go compile success");

    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());

    println!("cargo:rustc-link-search={}", out_path.display());
    println!("cargo:rustc-link-lib=dylib=nebulaffi");
    println!("cargo:rerun-if-changed=go.mod");
    println!("cargo:rerun-if-changed=go.sum");
    println!("cargo:rerun-if-changed=main.go");

    println!("Generating bindings");

    let bindings = bindgen::Builder::default()
        .header(out_path.join("libnebulaffi.h").display().to_string())
        .parse_callbacks(Box::new(CargoCallbacks))
        .generate()
        .expect("Error generating CFFI bindings");


    bindings
        .write_to_file(out_path.join("bindings.rs"))
        .expect("Couldn't write bindings!");
}