use std::{env, process::Command};

fn main() {
    println!("cargo:rerun-if-changed=.git/HEAD");
    println!("cargo:rerun-if-changed=build.rs");

    let version = env::var("CARGO_PKG_VERSION").unwrap_or_else(|_| "development".to_string());
    let commit = git_output(&["rev-parse", "--short", "HEAD"]).unwrap_or_else(|| "unknown".into());
    let date =
        git_output(&["show", "-s", "--format=%cI", "HEAD"]).unwrap_or_else(|| "unknown".into());

    println!("cargo:rustc-env=CHANORA_RESOLVER_BUILD_VERSION={version}");
    println!("cargo:rustc-env=CHANORA_RESOLVER_BUILD_COMMIT={commit}");
    println!("cargo:rustc-env=CHANORA_RESOLVER_BUILD_DATE={date}");
}

fn git_output(args: &[&str]) -> Option<String> {
    let output = Command::new("git").args(args).output().ok()?;
    if !output.status.success() {
        return None;
    }

    let value = String::from_utf8(output.stdout).ok()?;
    Some(value.trim().to_owned())
}