//! 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());

}