use std::{fs, path::Path};

use abi_generator::{
    abi::{ty::TypeWidth, AbiBuilder},
    syntax::UnwrapFancy,
    TargetEnv,
};

fn add_file<'a>(build: &'a mut cc::Build, name: &'a str) -> &'a mut cc::Build {
    println!("cargo:rerun-if-changed={}", name);
    build.file(name)
}

fn build_libm() {
    println!("cargo:rerun-if-changed=libm/private.h");

    let mut build = cc::Build::new();

    build
        .compiler("clang")
        .flag("-ffreestanding")
        .flag("-nostdlib");

    add_file(&mut build, "libm/s_truncf.c");
    add_file(&mut build, "libm/s_ceilf.c");
    add_file(&mut build, "libm/s_floorf.c");
    add_file(&mut build, "libm/s_fabsf.c");
    add_file(&mut build, "libm/s_scalbnf.c");
    add_file(&mut build, "libm/s_copysignf.c");
    add_file(&mut build, "libm/e_powf.c");
    add_file(&mut build, "libm/e_sqrtf.c");
    add_file(&mut build, "libm/e_hypotf.c");
    add_file(&mut build, "libm/e_fmodf.c");
    add_file(&mut build, "libm/w_powf.c");
    add_file(&mut build, "libm/w_hypotf.c");
    add_file(&mut build, "libm/w_fmodf.c");

    build.compile("m");
}

fn generate_abi() {
    let output_dir = std::env::var("OUT_DIR").expect("$OUT_DIR not set");
    let generated_calls = Path::new(&output_dir).join("generated_calls.rs");

    let abi = AbiBuilder::from_string(
        yggdrasil_abi_def::ABI_FILE,
        TargetEnv {
            thin_pointer_width: TypeWidth::U64,
            fat_pointer_width: TypeWidth::U64,
        },
    )
    .unwrap_fancy("Could not parse/read ABI file");

    let calls = prettyplease::unparse(
        &abi.emit_file(false, true)
            .unwrap_fancy("Could not emit system calls"),
    );

    fs::write(generated_calls, calls).unwrap();
}

fn main() {
    build_libm();
    generate_abi();
}