//! DarkRoom Android entry point.
//!
//! The counterpart to `darkroom-desktop`'s `main`, with two differences that
//! come from the platform rather than from choice:
//!
//! * There are no command-line paths. Android's SAF hands out document URIs,
//!   not filesystem paths (ARCH §6.9), so the viewer opens with an empty
//!   browsing list and the library grid is the only way in.
//! * Logging goes to logcat. `env_logger` writes to stderr, which Android
//!   discards.

// `slint::android` exists only when compiling for Android, so the whole entry
// point is gated on the target rather than on a feature. Without this the
// crate is still a workspace member on the host, and `cargo test --workspace`
// fails to compile it — a build break that only ever appears off-device.
#[cfg(target_os = "android")]
/// TRACES: M-13 | M-14
/// Android application entry point, called by android-activity's glue.
#[no_mangle]
fn android_main(app: slint::android::AndroidApp) {
    android_logger::init_once(
        android_logger::Config::default()
            .with_max_level(log::LevelFilter::Info)
            .with_tag("DarkRoom"),
    );

    // Panics go to stderr, and Android discards stderr. Without this hook a
    // worker thread that panics is invisible: the process survives, the
    // channel it was writing to closes, and the UI reports only that
    // something "failed unexpectedly" with no way to find out what.
    std::panic::set_hook(Box::new(|info| {
        log::error!("panic: {info}");
    }));

    log::info!("DarkRoom v{}", env!("CARGO_PKG_VERSION"));

    // Before anything opens a store: Android has no $HOME and no XDG
    // directories, so the default guess resolves to a path the app cannot
    // write. Nothing failed loudly — the session list went to a doomed path, so
    // the account survived only as long as the process and backgrounding the app
    // lost the sign-in. `internal_data_path` is the app's private directory
    // (ARCH §6.9).
    match app.internal_data_path() {
        Some(dir) => {
            log::info!("data dir: {}", dir.display());
            dr_sync_nextcloud::session::set_data_dir(dir);
        }
        None => log::error!("no internal data path; settings will not persist"),
    }

    if let Err(e) = slint::android::init(app) {
        log::error!("Slint Android backend failed to initialise: {e}");
        return;
    }

    // Empty rather than the desktop's argv: see the module note above.
    //
    // Returning from `android_main` ends the process, so a failure here is
    // logged rather than propagated — there is no shell to show `Err` to.
    if let Err(e) = dr_ui::run(Vec::new()) {
        log::error!("DarkRoom exited with error: {e:#}");
    }
}