/// one true function for returning the conduwuit version with the necessary
/// CONDUWUIT_VERSION_EXTRA env variables used if specified
///
/// Set the environment variable `CONDUWUIT_VERSION_EXTRA` to any UTF-8 string
/// to include it in parenthesis after the SemVer version. A common value are
/// git commit hashes.
use std::sync::OnceLock;

static BRANDING: &str = "Conduwuit";
static SEMANTIC: &str = env!("CARGO_PKG_VERSION");

static VERSION: OnceLock<String> = OnceLock::new();
static USER_AGENT: OnceLock<String> = OnceLock::new();

#[inline]
#[must_use]
pub fn name() -> &'static str { BRANDING }

#[inline]
pub fn version() -> &'static str { VERSION.get_or_init(init_version) }

#[inline]
pub fn user_agent() -> &'static str { USER_AGENT.get_or_init(init_user_agent) }

fn init_user_agent() -> String { format!("{}/{}", name(), version()) }

fn init_version() -> String {
	option_env!("CONDUWUIT_VERSION_EXTRA")
		.or(option_env!("CONDUIT_VERSION_EXTRA"))
		.map_or(SEMANTIC.to_owned(), |extra| format!("{BRANDING} ({extra})"))
}