//! The build's identity, for `spectra --version`: `SPECTRA_BUILD` when a release or
//! an install sets it (from `oxy describe` in this checkout), else the heads a Flow job is
//! building, else "local build".
fn main() {
    println!("cargo:rerun-if-env-changed=SPECTRA_BUILD");
    // The heads name the build only when SPECTRA_BUILD does not: a CI job that
    // sets it stays fresh from one state to the next (oxygenflow#52).
    if !std::env::var("SPECTRA_BUILD").is_ok_and(|b| !b.trim().is_empty()) {
        println!("cargo:rerun-if-env-changed=FLOW_HEADS");
    }
    let build = std::env::var("SPECTRA_BUILD")
        .ok()
        .map(|b| b.trim().to_string())
        .filter(|b| !b.is_empty())
        .or_else(|| {
            std::env::var("FLOW_HEADS")
                .ok()
                .and_then(|h| h.split('+').next().map(|x| format!("flow #{}", &x[..12.min(x.len())])))
                .filter(|b| b.len() > "flow #".len())
        })
        .unwrap_or_else(|| "local build".into());
    println!("cargo:rustc-env=SPECTRA_BUILD_ID={build}");
    println!("cargo:rustc-env=SPECTRA_VERSION_LONG={} ({build})", std::env::var("CARGO_PKG_VERSION").unwrap());
}