use super::{Directory, File, fixture};
use dever::compiler::{build, project::Project};

#[test]
fn stream_aliases_continue_after_partial_reads_and_close_independently_of_file() {
    let directory = Directory::new();
    let path = directory.0.join("input");
    std::fs::write(&path, b"abcdef").unwrap();
    let file = File::open(path.to_str().unwrap()).unwrap();
    assert!(file.chunks(0, |value| value).is_err());
    let stream = file.chunks(2, |value| value).unwrap();
    let alias = stream.clone();
    assert_eq!(stream.next().unwrap().unwrap(), b"ab");
    assert_eq!(alias.next().unwrap().unwrap(), b"cd");
    alias.close();
    stream.close();
    assert!(stream.next().is_none());
    assert_eq!(file.read(2).unwrap().unwrap(), b"ef");
    let end = file.chunks(2, |value| value).unwrap();
    assert!(end.next().is_none());
    assert!(end.clone().next().is_none());
    file.close().unwrap();
    assert!(file.chunks(2, |value| value).is_err());
}

#[cfg(target_os = "linux")]
#[test]
fn terminal_stream_error_releases_source_before_returning_the_event() {
    let directory = Directory::new();
    let file = File::open(directory.0.to_str().unwrap()).unwrap();
    let stream = file.chunks(2, |value| value).unwrap();
    drop(file);
    let count = || {
        std::fs::read_dir("/proc/self/fd")
            .unwrap()
            .filter_map(Result::ok)
            .filter(|entry| std::fs::read_link(entry.path()).ok().as_ref() == Some(&directory.0))
            .count()
    };
    assert_eq!(count(), 1);
    assert!(stream.next().unwrap().is_err());
    assert_eq!(count(), 0);
    assert!(stream.next().is_none());
    assert!(stream.clone().next().is_none());
}

#[test]
fn native_stream_reduction_preserves_cursor_terminal_error_and_cleanup() {
    let directory = Directory::new();
    std::fs::write(directory.0.join("input"), b"abcdef").unwrap();
    let project = Project::load(&fixture().with_file_name("stream.dever")).unwrap();
    let program = project.check().unwrap();
    let binary = build::build(
        &program,
        &project.sources,
        "verify",
        &directory.0.join("verify"),
    )
    .unwrap();
    let output = std::process::Command::new(binary)
        .current_dir(&directory.0)
        .output()
        .unwrap();
    assert!(
        output.status.success(),
        "{}",
        String::from_utf8_lossy(&output.stderr)
    );
    assert_eq!(output.stdout, b"true\n");
}