//! Build script generating the header for the `servicepoint` C library.
//!
//! When the environment variable `SERVICEPOINT_HEADER_OUT` is set, the header is copied there from
//! the out directory. This can be used to use the build script as a command line tool from other
//! build tools.

use std::{env, fs::copy};

fn main() {
    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    println!("cargo::rerun-if-changed={crate_dir}");

    let config = cbindgen::Config::from_file(crate_dir.clone() + "/cbindgen.toml").unwrap();

    let output_dir = env::var("OUT_DIR").unwrap();
    let header_file = output_dir.clone() + "/servicepoint.h";

    if let Ok(bindings) = cbindgen::generate_with_config(crate_dir, config) {
        bindings.write_to_file(&header_file);

        println!("cargo:include={output_dir}");

        println!("cargo::rerun-if-env-changed=SERVICEPOINT_HEADER_OUT");
        if let Ok(header_out) = env::var("SERVICEPOINT_HEADER_OUT") {
            let header_copy = header_out + "/servicepoint.h";
            println!("cargo:warning=Copying header to {header_copy}");
            copy(header_file, &header_copy).unwrap();
            println!("cargo::rerun-if-changed={header_copy}");
        }
    } else {
        eprintln!("cargo:warning=Servicepoint header could not be generated");
    }
}