// file: crates/common/game-logging-lib/src/runtime.rs
// version: 2

/// Error returned when the process-global tracing subscriber cannot be configured.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct LoggingInitError;

impl std::fmt::Display for LoggingInitError {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        return formatter.write_str("the process-global tracing subscriber could not be configured");
    }
}

impl std::error::Error for LoggingInitError {}

/// Guard keeping platform tracing resources alive for the application lifetime.
pub struct LoggingWorkerGuard {
    #[cfg(not(target_os = "android"))]
    _worker_guard: tracing_appender::non_blocking::WorkerGuard,
}

/// Initializes process-global tracing for the current platform.
///
/// Native desktop/Tauri processes write formatted events to standard error.
/// Android processes write directly to logcat through the Android NDK logging API.
///
/// The returned guard must remain alive for as long as events may still be emitted.
pub fn init_console_tracing() -> std::result::Result<LoggingWorkerGuard, LoggingInitError> {
    #[cfg(target_os = "android")]
    {
        let layer = match tracing_android::layer("games.sasedev") {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(_) => return std::result::Result::Err(LoggingInitError),
        };
        let subscriber = tracing_subscriber::layer::SubscriberExt::with(tracing_subscriber::registry(), layer);
        if tracing::subscriber::set_global_default(subscriber).is_err() {
            return std::result::Result::Err(LoggingInitError);
        }
        return std::result::Result::Ok(LoggingWorkerGuard {});
    }
    #[cfg(not(target_os = "android"))]
    {
        let (writer, worker_guard) = tracing_appender::non_blocking(std::io::stderr());
        let subscriber = tracing_subscriber::fmt().with_target(true).with_writer(writer).finish();
        if tracing::subscriber::set_global_default(subscriber).is_err() {
            return std::result::Result::Err(LoggingInitError);
        }
        return std::result::Result::Ok(LoggingWorkerGuard { _worker_guard: worker_guard });
    }
}