// file: kb-app-demo-desktop/src/splash.rs
// version: 6

//! Splash-window payloads and startup sequencing helpers.

use tauri::Emitter; // rust-rules: trait-import
use tauri::Manager; // rust-rules: trait-import
use ts_rs::TS; // rust-rules: derive-import

/// Minimum splash duration before the main window is shown.
pub(crate) const SPLASH_MINIMUM_MS: u64 = 12100;
/// Splash fade duration.
pub(crate) const SPLASH_FADE_MS: u32 = 12000;
/// Delay after fade-out before destroying the splash window.
pub(crate) const SPLASH_CLOSE_WAIT_MS: u64 = 12100;

/// Command sent from Rust to the splash frontend.
#[derive(Clone, Debug, serde::Deserialize, serde::Serialize, TS)]
#[ts(
    export,
    export_to = "../frontend/ts/bindings/kb_app_demo_desktop/splash/SplashOrder.ts"
)]
pub(crate) struct SplashOrder {
    /// Command name.
    pub(crate) order: std::string::String,
    /// Optional message.
    pub(crate) msg: std::option::Option<std::string::String>,
    /// Optional status.
    pub(crate) status: std::option::Option<std::string::String>,
    /// Optional animation duration in milliseconds.
    pub(crate) duration_ms: std::option::Option<u32>,
}

/// Emits one splash command.
pub(crate) fn emit_splash_order(
    splash_window: &tauri::WebviewWindow,
    order: &str,
    msg: std::option::Option<&str>,
    status: std::option::Option<&str>,
    duration_ms: std::option::Option<u32>,
) {
    let payload = crate::SplashOrder {
        order: order.to_string(),
        msg: msg.map(std::string::ToString::to_string),
        status: status.map(std::string::ToString::to_string),
        duration_ms,
    };
    let emit_result = splash_window.emit("splash", payload);
    if let std::result::Result::Err(error) = emit_result {
        tracing::error!(target: crate::TRACING_TARGET, "cannot emit splash order '{order}': {error:?}");
    }
}

/// Runs the startup sequence after the splash frontend installed its listener.
pub(crate) async fn splash_frontend_ready(
    app: tauri::AppHandle,
    window: tauri::WebviewWindow,
    state: &crate::AppState,
) -> std::result::Result<(), std::string::String> {
    if window.label() != "splash" {
        return std::result::Result::Err(
            "splash readiness may only originate from splash".to_string(),
        );
    }
    if !state.begin_startup_sequence() {
        return std::result::Result::Ok(());
    }
    let main_window = match app.get_webview_window("main") {
        std::option::Option::Some(value) => value,
        std::option::Option::None => {
            return std::result::Result::Err("main window is missing".to_string());
        },
    };
    let started_at = tokio::time::Instant::now();
    crate::emit_splash_order(
        &window,
        "fadein",
        std::option::Option::None,
        std::option::Option::None,
        std::option::Option::Some(crate::SPLASH_FADE_MS),
    );
    crate::emit_splash_order(
        &window,
        "add_msg",
        std::option::Option::Some("Chargement de la configuration terminé."),
        std::option::Option::Some("success"),
        std::option::Option::None,
    );
    crate::emit_splash_order(
        &window,
        "add_log",
        std::option::Option::Some(
            format!("Profil actif : {}", state.active_profile().name).as_str(),
        ),
        std::option::Option::None,
        std::option::Option::None,
    );
    crate::emit_splash_order(
        &window,
        "add_msg",
        std::option::Option::Some(
            format!("Logging initialisé : {} routes actives.", state.logging_route_count())
                .as_str(),
        ),
        std::option::Option::Some("success"),
        std::option::Option::None,
    );
    crate::emit_splash_order(
        &window,
        "add_msg",
        std::option::Option::Some("Pool HTTP initialisé."),
        std::option::Option::Some("success"),
        std::option::Option::None,
    );
    crate::initialize_store_for_startup(state, &window).await;
    crate::emit_splash_order(
        &window,
        "add_msg",
        std::option::Option::Some("Initialisation terminée."),
        std::option::Option::Some("success"),
        std::option::Option::None,
    );
    wait_until_minimum(started_at, crate::SPLASH_MINIMUM_MS).await;
    crate::emit_splash_order(
        &window,
        "fadeout",
        std::option::Option::None,
        std::option::Option::None,
        std::option::Option::Some(crate::SPLASH_FADE_MS),
    );
    tokio::time::sleep(std::time::Duration::from_millis(crate::SPLASH_CLOSE_WAIT_MS)).await;
    if let std::result::Result::Err(error) = main_window.show() {
        return std::result::Result::Err(format!("cannot show main window: {error:?}"));
    }
    if let std::result::Result::Err(error) = main_window.set_focus() {
        return std::result::Result::Err(format!("cannot focus main window: {error:?}"));
    }
    if let std::result::Result::Err(error) = window.destroy() {
        return std::result::Result::Err(format!("cannot destroy splash window: {error:?}"));
    }
    return std::result::Result::Ok(());
}

/// Waits until the configured minimum splash duration has elapsed.
async fn wait_until_minimum(start: tokio::time::Instant, minimum_ms: u64) {
    let minimum = std::time::Duration::from_millis(minimum_ms);
    let elapsed = start.elapsed();
    if elapsed >= minimum {
        return;
    }
    tokio::time::sleep(minimum - elapsed).await;
}

#[cfg(test)]
mod tests {
    #[test]
    fn splash_order_serializes_duration_ms() {
        let order = crate::SplashOrder {
            order: "fadein".to_string(),
            msg: std::option::Option::None,
            status: std::option::Option::None,
            duration_ms: std::option::Option::Some(500),
        };
        let value_result = serde_json::to_value(order);
        let value = match value_result {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => panic!("cannot serialize splash order: {error}"),
        };
        assert_eq!(value["duration_ms"], serde_json::json!(500));
    }

    #[test]
    fn splash_timing_is_ordered() {
        assert_eq!(crate::SPLASH_MINIMUM_MS, 12100);
        assert_eq!(crate::SPLASH_FADE_MS, 12000);
        assert!(crate::SPLASH_CLOSE_WAIT_MS >= u64::from(crate::SPLASH_FADE_MS));
    }
}