//! P5-41 / P5-35 — Register an AppUserModelID (AUMID) so the WinRT rich toasts in
//! `toast.rs` actually work on Windows.
//!
//! `ToastNotificationManager::CreateToastNotifierWithId` (and the ambient
//! `CreateToastNotifier`) require the process to run under an AUMID that maps to a
//! Start-Menu shortcut carrying `System.AppUserModel.ID`. An unpackaged Win32 app
//! (our NSIS build) has none by default, so `Show()` errored and the rich toast
//! (reply box + click-to-open-room) silently fell back to the plain plugin toast.
//!
//! Two pieces: (1) `set_process_aumid` advertises the AUMID for this process —
//! called at the very top of `run()` so it precedes the main window's taskbar
//! button (which otherwise groups under a mismatched implicit AUMID and shows a
//! second taskbar icon); (2) `ensure_app_user_model_id` installs/refreshes a
//! Start-Menu `.lnk` (same name → overwrites the installer's, no duplicate)
//! carrying the AUMID, reusing the `IShellLinkW` + `IPropertyStore` + `PROPVARIANT`
//! pattern proven in `jumplist.rs`. Best-effort: any failure is logged and
//! swallowed (the toast just keeps falling back, as before — never crash boot).
//!
//! Non-Windows: a no-op.

use tauri::AppHandle;

/// The AUMID this process advertises and that the Start-Menu shortcut carries.
/// `toast.rs` binds the toast notifier to it via `CreateToastNotifierWithId`.
///
/// This MUST equal the AUMID Tauri's NSIS installer stamps on its Desktop /
/// Start-Menu shortcuts (`System.AppUserModel.ID` = the bundle `identifier`),
/// otherwise the running window and a pinned shortcut group under different
/// identities and Windows shows two taskbar icons.
pub const APP_USER_MODEL_ID: &str = "org.lotusguild.lotus-chat";

/// Advertise this process's AUMID. MUST run before the main window is built so
/// the window's taskbar button groups under the same AUMID as the pinned
/// installer shortcut. Plain shell32 export — no COM init required, so this is
/// deliberately separate from the `.lnk` install (which needs its own STA COM).
#[cfg(target_os = "windows")]
pub fn set_process_aumid() {
    use windows::core::HSTRING;
    use windows::Win32::UI::Shell::SetCurrentProcessExplicitAppUserModelID;
    if let Err(e) =
        unsafe { SetCurrentProcessExplicitAppUserModelID(&HSTRING::from(APP_USER_MODEL_ID)) }
    {
        eprintln!("aumid: SetCurrentProcessExplicitAppUserModelID failed: {e}");
    }
}

#[cfg(not(target_os = "windows"))]
pub fn set_process_aumid() {}

#[cfg(target_os = "windows")]
pub fn ensure_app_user_model_id(_app: &AppHandle) {
    use std::os::windows::ffi::OsStrExt;
    use windows::core::{Interface, PCWSTR};
    // PKEY_AppUserModel_ID lives in EnhancedStorage (same module as jumplist's
    // PKEY_Title), NOT PropertiesSystem — use the ready-made constant rather than
    // hand-rolling the PROPERTYKEY.
    use windows::Win32::Storage::EnhancedStorage::PKEY_AppUserModel_ID;
    use windows::Win32::System::Com::{
        CoCreateInstance, CoInitializeEx, CoUninitialize, IPersistFile,
        StructuredStorage::PROPVARIANT, CLSCTX_INPROC_SERVER, COINIT_APARTMENTTHREADED,
    };
    use windows::Win32::UI::Shell::{
        PropertiesSystem::IPropertyStore, IShellLinkW, ShellLink,
    };

    // The process AUMID is advertised earlier (see `set_process_aumid`, called at
    // the top of `run()` before the window is built). Here we only install/refresh
    // the Start-Menu shortcut carrying the AUMID so Action Center attributes toasts
    // to "Lotus Chat". Path via %APPDATA% (avoids the SHGetKnownFolderPath free-mem
    // dance); dir already exists for installed apps.
    let appdata = match std::env::var_os("APPDATA") {
        Some(v) => v,
        None => return,
    };
    let mut lnk = std::path::PathBuf::from(appdata);
    lnk.push(r"Microsoft\Windows\Start Menu\Programs");
    let _ = std::fs::create_dir_all(&lnk);
    lnk.push("Lotus Chat.lnk");

    let exe = match std::env::current_exe() {
        Ok(p) => p,
        Err(_) => return,
    };
    let exe_wide: Vec<u16> = exe
        .as_os_str()
        .encode_wide()
        .chain(std::iter::once(0))
        .collect();
    let lnk_wide: Vec<u16> = lnk
        .as_os_str()
        .encode_wide()
        .chain(std::iter::once(0))
        .collect();

    // STA apartment for the shell link objects, mirroring jumplist.rs. All COM
    // interfaces are dropped before CoUninitialize.
    let hr = unsafe { CoInitializeEx(None, COINIT_APARTMENTTHREADED) };
    let result = (|| -> windows::core::Result<()> {
        unsafe {
            let link: IShellLinkW = CoCreateInstance(&ShellLink, None, CLSCTX_INPROC_SERVER)?;
            link.SetPath(PCWSTR(exe_wide.as_ptr()))?;
            link.SetIconLocation(PCWSTR(exe_wide.as_ptr()), 0)?;

            // Stamp the AUMID onto the link's property store (VT_LPWSTR, exactly
            // like PKEY_Title in jumplist.rs).
            let store: IPropertyStore = link.cast()?;
            let value = PROPVARIANT::from(APP_USER_MODEL_ID);
            store.SetValue(&PKEY_AppUserModel_ID, &value)?;
            store.Commit()?;

            // Persist the .lnk to the Start-Menu Programs folder.
            let persist: IPersistFile = link.cast()?;
            persist.Save(PCWSTR(lnk_wide.as_ptr()), true)?;
            Ok(())
        }
    })();

    if hr.is_ok() {
        unsafe { CoUninitialize() };
    }
    if let Err(e) = result {
        eprintln!("aumid: failed to install Start-Menu shortcut: {e}");
    }
}

#[cfg(not(target_os = "windows"))]
pub fn ensure_app_user_model_id(_app: &AppHandle) {}