build.rs

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

fn main() {
    let commit = get_commit();
    let commit_date = get_commit_date();
    println!(
        "cargo:rustc-env=AUDIOSERVE_LONG_VERSION={}",
        get_long_version(&commit, &commit_date)
    );
    println!("cargo:rustc-env=AUDIOSERVE_COMMIT={}", commit);
    println!(
        "cargo:rustc-env=AUDIOSERVE_COMMIT_WITH_DATE={} ({})",
        commit, commit_date
    );
    println!("cargo:rustc-env=AUDIOSERVE_FEATURES={}", get_features());
}

fn get_long_version(commit: &str, commit_date: &str) -> String {
    let ver = env::var("CARGO_PKG_VERSION").expect("cargo version is missing");
    format!("{} #{} ({})", ver, commit, commit_date)
}

const FEATURE_PREFIX: &str = "CARGO_FEATURE_";

fn get_features() -> String {
    env::vars()
        .filter_map(|(v, _)| v.strip_prefix(FEATURE_PREFIX).map(|s| s.to_string()))
        .map(|f| f.to_ascii_lowercase().replace('_', "-"))
        .collect::<Vec<_>>()
        .join(", ")
}

fn get_commit() -> String {
    Command::new("git")
        .args(["rev-parse", "HEAD"])
        .output()
        .map(|mut o| {
            o.stdout.truncate(7);
            String::from_utf8(o.stdout).expect("git output must be utf-8")
        })
        .unwrap_or_else(|e| {
            eprintln!("Error running git: {}", e);
            "?".to_string()
        })
}

fn get_commit_date() -> String {
    Command::new("git")
        .args([
            "log",
            "-1",
            "--format=%cd",
            "--date=format:%d.%m.%Y %H:%M:%S",
            "HEAD",
        ])
        .output()
        .map(|mut o| {
            // trim trailing newline
            while o.stdout.last() == Some(&b'\n') || o.stdout.last() == Some(&b'\r') {
                o.stdout.pop();
            }
            String::from_utf8(o.stdout).expect("git output must be utf-8")
        })
        .unwrap_or_else(|e| {
            eprintln!("Error running git: {}", e);
            "?".to_string()
        })
}