// SonicForge DAW — desktop shell: spawn/terminate daw_engine.exe sidecar.
use tauri::Manager;
use tauri_plugin_shell::process::CommandChild;
use tauri_plugin_shell::ShellExt;
use std::sync::Mutex;

struct EngineProcess(Mutex<Option<CommandChild>>);

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    tauri::Builder::default()
        .plugin(tauri_plugin_shell::init())
        .plugin(tauri_plugin_dialog::init())
        .setup(|app| {
            // 1. Spawn daw_engine (PyInstaller ONEDIR bundle — khong giai nen
            // moi lan chay nhu onefile, khoi dong nhanh). Bundle qua Tauri
            // resources: resource_dir()/daw_engine/daw_engine(.exe)
            let res_dir = app
                .path()
                .resource_dir()
                .expect("resource dir not found");
            let engine_dir = res_dir.join("daw_engine");
            let engine_exe = if cfg!(windows) {
                engine_dir.join("daw_engine.exe")
            } else {
                engine_dir.join("daw_engine")
            };
            let (_rx, child) = app
                .shell()
                .command(engine_exe)
                .env("SF_PARENT_PID", std::process::id().to_string())
                .spawn()
                .expect("Failed to spawn daw_engine (onedir resource) — run build_windows.ps1 first");

            app.manage(EngineProcess(Mutex::new(Some(child))));
            println!("Python Background Engine started (localhost:8000, auto-fallback 8000-8010)");
            Ok(())
        })
        .on_window_event(|window, event| {
            // 2. Terminate sidecar khi DAW window dong — tranh orphan process
            if let tauri::WindowEvent::Destroyed = event {
                // Lay child ra khoi lock, guard drop ngay tai day (trach E0597)
                let child = window
                    .state::<EngineProcess>()
                    .0
                    .lock()
                    .ok()
                    .and_then(|mut lock| lock.take());
                if let Some(child) = child {
                    let _ = child.kill();
                    println!("daw_engine sidecar terminated.");
                }
            }
        })
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}