#![allow(dead_code)]
// Shared across test targets; each uses only part of this module.
use std::fs;
use std::io::{Read, Write};
use std::process::{Child, Command, Output, Stdio};
use std::time::{Duration, Instant};

pub fn spawn(source: &str) -> (tempfile::TempDir, Child) {
    let dir = tempfile::tempdir().unwrap();
    let path = dir.path().join("main.js");
    fs::write(&path, source).unwrap();
    let child = Command::new(env!("CARGO_BIN_EXE_avril"))
        .arg("run")
        .arg(path)
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .spawn()
        .unwrap();
    (dir, child)
}

fn capture(mut pipe: impl Read + Send + 'static) -> std::thread::JoinHandle<Vec<u8>> {
    std::thread::spawn(move || {
        let mut bytes = Vec::new();
        pipe.read_to_end(&mut bytes).unwrap();
        bytes
    })
}

pub fn wait(mut child: Child) -> Output {
    let stdout = child.stdout.take().map(capture);
    let stderr = child.stderr.take().map(capture);
    let deadline = Instant::now() + Duration::from_secs(5);
    let status = loop {
        if let Some(status) = child.try_wait().unwrap() {
            break status;
        }
        if Instant::now() >= deadline {
            child.kill().unwrap();
            child.wait().unwrap();
            panic!("Runtime did not exit within five seconds");
        }
        std::thread::sleep(Duration::from_millis(10));
    };
    Output {
        status,
        stdout: stdout
            .map(|thread| thread.join().unwrap())
            .unwrap_or_default(),
        stderr: stderr
            .map(|thread| thread.join().unwrap())
            .unwrap_or_default(),
    }
}

pub fn run(source: &str, input: &[u8]) -> Output {
    let (_dir, mut child) = spawn(source);
    let mut stdin = child.stdin.take().unwrap();
    let input = input.to_vec();
    let writer = std::thread::spawn(move || stdin.write_all(&input));
    let output = wait(child);
    writer.join().unwrap().unwrap();
    assert!(
        output.status.success(),
        "{}",
        String::from_utf8_lossy(&output.stderr)
    );
    output
}