use std::{
    env,
    path::{Path, PathBuf},
};

fn find_package(name: &str) -> Vec<PathBuf> {
    let vcpkg_root = std::env::var("VCPKG_ROOT").unwrap();
    let mut path: PathBuf = vcpkg_root.into();
    let target_os = std::env::var("CARGO_CFG_TARGET_OS").unwrap();
    let mut target_arch = std::env::var("CARGO_CFG_TARGET_ARCH").unwrap();
    if target_arch == "x86_64" {
        target_arch = "x64".to_owned();
    } else if target_arch == "aarch64" {
        target_arch = "arm64".to_owned();
    } else {
        target_arch = "arm".to_owned();
    }
    let target = if target_os == "macos" {
        "x64-osx".to_owned()
    } else if target_os == "windows" {
        "x64-windows-static".to_owned()
    } else if target_os == "android" {
        format!("{}-android-static", target_arch)
    } else {
        "x64-linux".to_owned()
    };
    println!("cargo:info={}", target);
    path.push("installed");
    path.push(target);
    println!(
        "{}",
        format!("cargo:rustc-link-lib={}", name.trim_start_matches("lib"))
    );
    println!(
        "{}",
        format!(
            "cargo:rustc-link-search={}",
            path.join("lib").to_str().unwrap()
        )
    );
    let include = path.join("include");
    println!("{}", format!("cargo:include={}", include.to_str().unwrap()));
    vec![include]
}

fn generate_bindings(ffi_header: &Path, include_paths: &[PathBuf], ffi_rs: &Path) {
    #[derive(Debug)]
    struct ParseCallbacks;
    impl bindgen::callbacks::ParseCallbacks for ParseCallbacks {
        fn int_macro(&self, name: &str, _value: i64) -> Option<bindgen::callbacks::IntKind> {
            if name.starts_with("OPUS") {
                Some(bindgen::callbacks::IntKind::Int)
            } else {
                None
            }
        }
    }
    let mut b = bindgen::Builder::default()
        .header(ffi_header.to_str().unwrap())
        .parse_callbacks(Box::new(ParseCallbacks))
        .generate_comments(false);

    for dir in include_paths {
        b = b.clang_arg(format!("-I{}", dir.display()));
    }

    b.generate().unwrap().write_to_file(ffi_rs).unwrap();
}

fn gen_opus() {
    let includes = find_package("opus");
    let src_dir = env::var_os("CARGO_MANIFEST_DIR").unwrap();
    let src_dir = Path::new(&src_dir);
    let out_dir = env::var_os("OUT_DIR").unwrap();
    let out_dir = Path::new(&out_dir);

    let ffi_header = src_dir.join("opus_ffi.h");
    println!("rerun-if-changed={}", ffi_header.display());
    for dir in &includes {
        println!("rerun-if-changed={}", dir.display());
    }

    let ffi_rs = out_dir.join("opus_ffi.rs");
    generate_bindings(&ffi_header, &includes, &ffi_rs);
}

fn main() {
    gen_opus()
}