extern crate compiletest_rs as compiletest;

use std::path::{PathBuf, Path};
use std::io::Write;

fn compile_fail(sysroot: &str) {
    let flags = format!("--sysroot {} -Dwarnings", sysroot);
    for_all_targets(sysroot, |target| {
        let mut config = compiletest::default_config();
        config.host_rustcflags = Some(flags.clone());
        config.mode = "compile-fail".parse().expect("Invalid mode");
        config.run_lib_path = Path::new(sysroot).join("lib").join("rustlib").join(&target).join("lib");
        config.rustc_path = "target/debug/miri".into();
        config.src_base = PathBuf::from("tests/compile-fail".to_string());
        config.target = target.to_owned();
        config.target_rustcflags = Some(flags.clone());
        compiletest::run_tests(&config);
    });
}

fn run_pass() {
    let mut config = compiletest::default_config();
    config.mode = "run-pass".parse().expect("Invalid mode");
    config.src_base = PathBuf::from("tests/run-pass".to_string());
    config.target_rustcflags = Some("-Dwarnings".to_string());
    config.host_rustcflags = Some("-Dwarnings".to_string());
    compiletest::run_tests(&config);
}

fn miri_pass(path: &str, target: &str) {
    let mut config = compiletest::default_config();
    config.mode = "mir-opt".parse().expect("Invalid mode");
    config.src_base = PathBuf::from(path);
    config.target = target.to_owned();
    config.rustc_path = PathBuf::from("target/debug/miri");
    compiletest::run_tests(&config);
}

fn for_all_targets<F: FnMut(String)>(sysroot: &str, mut f: F) {
    for target in std::fs::read_dir(format!("{}/lib/rustlib/", sysroot)).unwrap() {
        let target = target.unwrap();
        if !target.metadata().unwrap().is_dir() {
            continue;
        }
        let target = target.file_name().into_string().unwrap();
        match &*target {
            "etc" | "src" => continue,
            _ => {},
        }
        let stderr = std::io::stderr();
        writeln!(stderr.lock(), "running tests for target {}", target).unwrap();
        f(target);
    }
}

#[test]
fn compile_test() {
    // Taken from https://github.com/Manishearth/rust-clippy/pull/911.
    let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));
    let toolchain = option_env!("RUSTUP_TOOLCHAIN").or(option_env!("MULTIRUST_TOOLCHAIN"));
    let sysroot = match (home, toolchain) {
        (Some(home), Some(toolchain)) => format!("{}/toolchains/{}", home, toolchain),
        _ => option_env!("RUST_SYSROOT")
            .expect("need to specify RUST_SYSROOT env var or use rustup or multirust")
            .to_owned(),
    };
    run_pass();
    for_all_targets(&sysroot, |target| {
        miri_pass("tests/run-pass", &target);
        if let Ok(path) = std::env::var("MIRI_RUSTC_TEST") {
            miri_pass(&path, &target);
        }
    });
    compile_fail(&sysroot);
}