shine-cli 2.1.1

use anyhow::{Result, bail};

/// Detect the current OS identifier using `std::env::consts::OS` and, on Linux,
/// the `ID=` field from `/etc/os-release`.
pub async fn detect_os_id() -> Result<String> {
    let os_release = tokio::fs::read_to_string("/etc/os-release").await.ok();
    detect_os_id_from(std::env::consts::OS, os_release.as_deref())
}

fn detect_os_id_from(os: &str, os_release: Option<&str>) -> Result<String> {
    match os {
        "macos" => Ok("macos".to_string()),
        "windows" => Ok("windows".to_string()),
        "linux" => {
            if let Some(content) = os_release {
                for line in content.lines() {
                    if let Some(id) = line.strip_prefix("ID=") {
                        return Ok(id.trim_matches('"').to_lowercase());
                    }
                }
            }
            bail!(
                "Could not detect Linux distribution. \
                 Expected ID= in /etc/os-release. Supported: ubuntu"
            )
        }
        other => bail!(
            "Unsupported platform '{}'. Supported targets: ubuntu (Linux), macos, windows",
            other
        ),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn detects_macos() {
        let result = detect_os_id_from("macos", None).unwrap();
        assert_eq!(result, "macos");
    }

    #[test]
    fn detects_windows() {
        let result = detect_os_id_from("windows", None).unwrap();
        assert_eq!(result, "windows");
    }

    #[test]
    fn detects_ubuntu_from_os_release() {
        let os_release = "PRETTY_NAME=\"Ubuntu 22.04\"\nID=ubuntu\nVERSION_ID=\"22.04\"\n";
        let result = detect_os_id_from("linux", Some(os_release)).unwrap();
        assert_eq!(result, "ubuntu");
    }

    #[test]
    fn detects_quoted_id() {
        let os_release = "ID=\"ubuntu\"\n";
        let result = detect_os_id_from("linux", Some(os_release)).unwrap();
        assert_eq!(result, "ubuntu");
    }

    #[test]
    fn lowercases_id() {
        let os_release = "ID=Debian\n";
        let result = detect_os_id_from("linux", Some(os_release)).unwrap();
        assert_eq!(result, "debian");
    }

    #[test]
    fn errors_on_linux_without_os_release() {
        let err = detect_os_id_from("linux", None).unwrap_err();
        assert!(err.to_string().contains("os-release"));
    }

    #[test]
    fn errors_on_unsupported_platform() {
        let err = detect_os_id_from("freebsd", None).unwrap_err();
        assert!(err.to_string().contains("freebsd"));
    }
}