use std::env;
use std::process::Command;

fn main() {
    if let Ok(val) = env::var("DOCS_RS") {
        if val.parse::<u32>() == Ok(1) {
            return;
        }
    }

    // This is a workaround to the current nightly toolchain (2024-06-27 which started with
    // toolchain 2024-05-05) build issue
    // Essentially if cbindgen is running, a wrong argument ends up forwarded to the cuda backend
    // "make" command during macro expansions for TFHE-rs C API, crashing make for make < 4.4 and
    // thus crashing the build
    // On the other hand, this speeds up C API build greatly given we don't have macro expansions
    // in the CUDA backend so this skips the second compilation of TFHE-rs for macro inspection by
    // cbindgen
    if std::env::var("_CBINDGEN_IS_RUNNING").is_ok() {
        return;
    }

    println!("Build tfhe-cuda-backend");
    println!("cargo::rerun-if-changed=cuda/include");
    println!("cargo::rerun-if-changed=cuda/src");
    println!("cargo::rerun-if-changed=cuda/tests_and_benchmarks");
    println!("cargo::rerun-if-changed=cuda/CMakeLists.txt");
    println!("cargo::rerun-if-changed=src");
    if env::consts::OS == "linux" {
        let output = Command::new("./get_os_name.sh").output().unwrap();
        let distribution = String::from_utf8(output.stdout).unwrap();
        if distribution != "Ubuntu\n" {
            println!(
                "cargo:warning=This Linux distribution is not officially supported. \
                Only Ubuntu is supported by tfhe-cuda-backend at this time. Build may fail\n"
            );
        }
        let dest = cmake::build("cuda");
        println!("cargo:rustc-link-search=native={}", dest.display());
        println!("cargo:rustc-link-lib=static=tfhe_cuda_backend");

        // Try to find the cuda libs with pkg-config, default to the path used by the nvidia runfile
        if pkg_config::Config::new()
            .atleast_version("10")
            .probe("cuda")
            .is_err()
        {
            println!("cargo:rustc-link-search=native=/usr/local/cuda/lib64");
        }
        println!("cargo:rustc-link-lib=gomp");
        println!("cargo:rustc-link-lib=cudart");
        println!("cargo:rustc-link-search=native=/usr/lib/x86_64-linux-gnu/");
        println!("cargo:rustc-link-lib=stdc++");
    } else {
        panic!(
            "Error: platform not supported, tfhe-cuda-backend not built (only Linux is supported)"
        );
    }
}