starbase_utils 0.12.10

use std::env;
use std::fs;
use std::path::PathBuf;
use std::sync::OnceLock;

fn has_env_var(key: &str) -> bool {
    match env::var(key) {
        Ok(var) => !var.is_empty(),
        Err(_) => false,
    }
}

fn has_proc_config(path: &str, value: &str) -> bool {
    match fs::read_to_string(path) {
        Ok(contents) => contents.to_lowercase().contains(value),
        Err(_) => false,
    }
}

/// Return true if we're in a CI environment.
pub fn is_ci() -> bool {
    static CI_CACHE: OnceLock<bool> = OnceLock::new();

    *CI_CACHE.get_or_init(|| has_env_var("CI"))
}

/// Return true if we're in a Docker container.
pub fn is_docker() -> bool {
    static DOCKER_CACHE: OnceLock<bool> = OnceLock::new();

    *DOCKER_CACHE.get_or_init(|| {
        if PathBuf::from("/.dockerenv").exists() {
            return true;
        }

        has_proc_config("/proc/self/cgroup", "docker")
    })
}

/// Return true if we're in WSL (Windows Subsystem for Linux).
pub fn is_wsl() -> bool {
    static WSL_CACHE: OnceLock<bool> = OnceLock::new();

    *WSL_CACHE.get_or_init(|| {
        if env::consts::OS != "linux" || is_docker() {
            return false;
        }

        if has_proc_config("/proc/sys/kernel/osrelease", "microsoft") {
            return true;
        }

        has_proc_config("/proc/version", "microsoft")
    })
}

/// Return true if we're in a test environment, based on `STARBASE_TEST`.
pub fn is_test() -> bool {
    static TEST_CACHE: OnceLock<bool> = OnceLock::new();

    *TEST_CACHE.get_or_init(|| has_env_var("STARBASE_TEST"))
}

/// Return the `PATH` environment variable as a list of [`PathBuf`]s.
#[inline]
pub fn paths() -> Vec<PathBuf> {
    let Some(path) = env::var_os("PATH") else {
        return vec![];
    };

    env::split_paths(&path).collect::<Vec<_>>()
}

/// Return an environment variable as a boolean value. If the value is a `1`, `true`,
/// `yes`, `on`, or `enable`, return true, otherwise return false for all other cases.
#[inline]
pub fn bool_var(key: &str) -> bool {
    match env::var(key) {
        Ok(value) => {
            let value = value.to_lowercase();

            value == "1" || value == "true" || value == "yes" || value == "on" || value == "enable"
        }
        Err(_) => false,
    }
}

/// Return an environment variable with a path-like value, that will be converted
/// to an absolute [`PathBuf`]. If the path is relative, it will be prefixed with
/// the current working directory.
#[inline]
pub fn path_var(key: &str) -> Option<PathBuf> {
    match env::var(key) {
        Ok(value) => {
            if value.is_empty() {
                return None;
            }

            let path = PathBuf::from(value);

            Some(if path.is_absolute() {
                path
            } else {
                env::current_dir()
                    .expect("Unable to get working directory!")
                    .join(path)
            })
        }
        Err(_) => None,
    }
}

/// Return the "home" or "root" path for a vendor-specific environment variable,
/// like `CARGO_HOME`. If the path is relative, it will be prefixed with the current
/// working directory. If the variable is not defined, the fallback function will
/// be called with the home directory.
#[inline]
pub fn vendor_home_var<F: FnOnce(PathBuf) -> PathBuf>(key: &str, fallback: F) -> PathBuf {
    match path_var(key) {
        Some(path) => path,
        None => fallback(dirs::home_dir().expect("Unable to get home directory!")),
    }
}