use std::process::Command;

fn main() {
    const MIN_VERSION: (u32, u32, u32) = (1, 75, 0);

    let rustc = std::env::var("RUSTC").unwrap_or_else(|_| "rustc".into());
    let output = Command::new(&rustc)
        .arg("--version")
        .output()
        .expect("failed to invoke rustc");

    let version_line = String::from_utf8_lossy(&output.stdout);
    let version_str = version_line.split_whitespace().nth(1).unwrap_or("0.0.0");
    let sanitized = version_str.split('-').next().unwrap_or(version_str);

    let mut parts = sanitized
        .split('.')
        .map(|part| part.parse::<u32>().unwrap_or(0));
    let current = (
        parts.next().unwrap_or(0),
        parts.next().unwrap_or(0),
        parts.next().unwrap_or(0),
    );

    if current < MIN_VERSION {
        panic!(
            "owlen requires rustc {}.{}.{} or newer (found {version_line})",
            MIN_VERSION.0, MIN_VERSION.1, MIN_VERSION.2
        );
    }
}