//! Shared fixture copies and builds. A mutex protects cwd-init and the brush checkout.
use std::{
    path::{Path, PathBuf},
    process::{Command, ExitStatus},
    sync::{Mutex, OnceLock},
};
pub static BUILD: Mutex<()> = Mutex::new(());

pub fn copy_tree(source: &Path, destination: &Path) -> anyhow::Result<()> {
    std::fs::create_dir_all(destination)?;
    for entry in std::fs::read_dir(source)? {
        let entry = entry?;
        let target = destination.join(entry.file_name());
        if entry.file_type()?.is_dir() {
            copy_tree(&entry.path(), &target)?;
        } else {
            std::fs::copy(entry.path(), target)?;
        }
    }
    Ok(())
}

pub fn target_dir() -> PathBuf {
    std::env::var_os("CARGO_TARGET_DIR")
        .map(PathBuf::from)
        .unwrap_or_else(|| {
            Path::new(env!("CARGO_TARGET_TMPDIR"))
                .parent()
                .unwrap()
                .to_owned()
        })
}

pub fn cwd_init() {
    static INIT: OnceLock<()> = OnceLock::new();
    INIT.get_or_init(|| {
        let _guard = BUILD.lock().unwrap();
        let userland = Path::new(env!("CARGO_MANIFEST_DIR")).join("../userland");
        if !userland.join("cwd-init/init.o").is_file() {
            assert!(
                Command::new("nu")
                    .args(["--no-config-file", "cwd-init/build.nu"])
                    .current_dir(userland)
                    .status()
                    .unwrap()
                    .success()
            );
        }
    });
}

pub fn build_brush() -> std::io::Result<ExitStatus> {
    let _guard = BUILD.lock().unwrap();
    Command::new("nu")
        .args(["--no-config-file", "brush/build.nu"])
        .env("CARGO_TARGET_DIR", target_dir())
        .current_dir(Path::new(env!("CARGO_MANIFEST_DIR")).join("../userland"))
        .status()
}

pub fn build_git() -> &'static Path {
    static GIT: OnceLock<PathBuf> = OnceLock::new();
    GIT.get_or_init(|| {
        let userland = Path::new(env!("CARGO_MANIFEST_DIR")).join("../userland");
        let target = target_dir();
        cwd_init();
        assert!(
            Command::new("cargo")
                .args(["build", "--release", "-p", "git", "--manifest-path"])
                .arg(userland.join("Cargo.toml"))
                .args(["--target", "wasm32-wasip2", "--target-dir"])
                .arg(&target)
                .args(["-j", "2", "--locked"])
                .current_dir(&userland)
                .status()
                .unwrap()
                .success()
        );
        target
    })
}