use std::{
    env,
    fs::File,
    path::{Path, PathBuf},
};
use tar::Archive;

fn main() {
    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());

    let bindings = bindgen::Builder::default()
        .header("c_api.h")
        .rustfmt_bindings(true)
        .generate()
        .expect("Unable to generate bindings.");

    bindings
        .write_to_file(out_dir.join("bindings.rs"))
        .expect("Couldn't write bindings.");

    extract_libraries(&out_dir);

    println!("cargo:rustc-link-search={}/libs", out_dir.display());
    println!("cargo:rustc-link-lib=dylib=catboostmodel");
}

fn extract_libraries(out_dir: &Path) -> Result<(), Box<dyn std::error::Error>> {
    let out_dir = out_dir.join("libs");
    std::fs::create_dir(&out_dir)?;

    let libs_path = format!("{}/libs.tar", env!("CARGO_MANIFEST_DIR"));
    let libs = File::open(libs_path)?;
    let libs = zstd::Decoder::new(libs)?;

    let mut archive = Archive::new(libs);

    for file in archive.entries()? {
        let mut file = file?;
        let out_file = out_dir.join(file.path()?);
        file.unpack(out_file)?;
    }

    Ok(())
}