sickn33/antigravity-awesome-skills/robius-state-management

use serde::{Serialize, Deserialize};
use std::collections::HashMap;
use matrix_sdk::ruma::{OwnedRoomId, RoomId, UserId, OwnedUserId};
 
/// App-wide state that is stored persistently across multiple app runs
/// and shared/updated across various parts of the app.
#[derive(Clone, Default, Debug, Serialize, Deserialize)]
pub struct AppState {
    /// The currently-selected room
    pub selected_room: Option<SelectedRoom>,
 
    /// Saved UI layout state for main view
    pub saved_layout_state: SavedLayoutState,
 
    /// Per-item saved states (e.g., per-space dock layouts)
    pub saved_state_per_item: HashMap<OwnedRoomId, SavedLayoutState>,
 
    /// Whether a user is currently logged in
    #[serde(skip)]  // Don't persist login state
    pub logged_in: bool,
}
 
/// Represents a currently selected item
#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum SelectedRoom {
    JoinedRoom { room_name_id: RoomNameId },
    InvitedRoom { room_name_id: RoomNameId },
    Space { space_name_id: RoomNameId },
}
 
impl SelectedRoom {
    pub fn room_id(&self) -> &OwnedRoomId {
        match self {
            Self::JoinedRoom { room_name_id } => room_name_id.room_id(),
            Self::InvitedRoom { room_name_id } => room_name_id.room_id(),
            Self::Space { space_name_id } => space_name_id.room_id(),
        }
    }
 
    /// Upgrade from invited to joined state
    pub fn upgrade_invite_to_joined(&mut self, room_id: &RoomId) -> bool {
        match self {
            Self::InvitedRoom { room_name_id } if room_name_id.room_id() == room_id => {
                let name = room_name_id.clone();
                *self = Self::JoinedRoom { room_name_id: name };
                true
            }
            _ => false,
        }
    }
}
 
// Equality based on room_id only
impl PartialEq for SelectedRoom {
    fn eq(&self, other: &Self) -> bool {
        self.room_id() == other.room_id()
    }
}
impl Eq for SelectedRoom {}

/// A snapshot of UI layout state for restoration
#[derive(Clone, Default, Debug, Serialize, Deserialize)]
pub struct SavedLayoutState {
    /// All items contained in the layout, keyed by ID
    pub layout_items: HashMap<LiveIdSerde, LayoutItemSerde>,
 
    /// Items currently open, keyed by ID
    pub open_items: HashMap<LiveIdSerde, SelectedRoom>,
 
    /// Order items were opened (chronological)
    pub item_order: Vec<SelectedRoom>,
 
    /// Currently selected item when state was saved
    pub selected_item: Option<SelectedRoom>,
}
 
/// Serializable wrapper for LiveId
#[derive(Clone, Debug, Hash, Eq, PartialEq, Serialize, Deserialize)]
pub struct LiveIdSerde(pub u64);
 
impl From<LiveId> for LiveIdSerde {
    fn from(id: LiveId) -> Self {
        Self(id.0)
    }
}
 
impl From<LiveIdSerde> for LiveId {
    fn from(s: LiveIdSerde) -> Self {
        LiveId(s.0)
    }
}

impl AppMain for App {
    fn handle_event(&mut self, cx: &mut Cx, event: &Event) {
        // Forward to MatchEvent
        self.match_event(cx, event);
 
        // Create Scope with AppState data
        let scope = &mut Scope::with_data(&mut self.app_state);
 
        // Pass to widget tree - all children can access AppState
        self.ui.handle_event(cx, event, scope);
    }
}

impl Widget for RoomScreen {
    fn handle_event(&mut self, cx: &mut Cx, event: &Event, scope: &mut Scope) {
        // Access AppState from scope
        if let Some(app_state) = scope.data.get::<AppState>() {
            if let Some(selected) = &app_state.selected_room {
                self.update_for_room(cx, selected);
            }
        }
 
        self.view.handle_event(cx, event, scope);
    }
}

impl Widget for RoomsList {
    fn handle_event(&mut self, cx: &mut Cx, event: &Event, scope: &mut Scope) {
        // Mutable access to AppState
        if let Some(app_state) = scope.data.get_mut::<AppState>() {
            if self.selection_changed {
                app_state.selected_room = self.get_selected();
            }
        }
    }
}

use std::path::{Path, PathBuf};
use std::sync::OnceLock;
 
const LATEST_APP_STATE_FILE_NAME: &str = "latest_app_state.json";
const WINDOW_GEOM_STATE_FILE_NAME: &str = "window_geom_state.json";
 
/// Get user-specific persistent state directory
fn persistent_state_dir(user_id: &UserId) -> PathBuf {
    app_data_dir()
        .join("users")
        .join(user_id.as_str().as_bytes().iter().map(|b| format!("{b:02x}")).collect::<String>())
}
 
/// Get app-wide data directory
fn app_data_dir() -> &'static Path {
    // Platform-specific app data location
    static APP_DATA_DIR: OnceLock<PathBuf> = OnceLock::new();
    APP_DATA_DIR.get_or_init(|| {
        dirs::data_dir()
            .expect("Platform app-data directory is required")
            .join("myapp")
    })
}

use std::io::Write;
 
pub fn save_app_state(
    app_state: AppState,
    user_id: OwnedUserId,
) -> anyhow::Result<()> {
    let directory = persistent_state_dir(&user_id);
    std::fs::create_dir_all(&directory)?;
    // Requires the application to add the tempfile crate. Same-filesystem atomic replace.
    let mut temporary = tempfile::NamedTempFile::new_in(&directory)?;
    serde_json::to_writer(temporary.as_file_mut(), &app_state)?;
    temporary.as_file_mut().flush()?;
    temporary.as_file().sync_all()?;
    temporary.persist(directory.join(LATEST_APP_STATE_FILE_NAME))?;
    log!("Successfully saved app state to persistent storage.");
    Ok(())
}
 
/// Save window geometry state (user-agnostic)
pub fn save_window_state(window_ref: WindowRef, cx: &Cx) -> anyhow::Result<()> {
    let inner_size = window_ref.get_inner_size(cx);
    let position = window_ref.get_position(cx);
    let window_geom = WindowGeomState {
        inner_size: (inner_size.x, inner_size.y),
        position: (position.x, position.y),
        is_fullscreen: window_ref.is_fullscreen(cx),
    };
    std::fs::create_dir_all(app_data_dir())?;
    let mut temporary = tempfile::NamedTempFile::new_in(app_data_dir())?;
    serde_json::to_writer(temporary.as_file_mut(), &window_geom)?;
    temporary.as_file_mut().flush()?;
    temporary.as_file().sync_all()?;
    temporary.persist(app_data_dir().join(WINDOW_GEOM_STATE_FILE_NAME))?;
    Ok(())
}

/// Load app state with graceful fallback
pub async fn load_app_state(user_id: &UserId) -> anyhow::Result<AppState> {
    let state_path = persistent_state_dir(user_id).join(LATEST_APP_STATE_FILE_NAME);
 
    // Read file
    let file_bytes = match tokio::fs::read(&state_path).await {
        Ok(fb) => fb,
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
            log!("No saved app state found, using default.");
            return Ok(AppState::default());
        }
        Err(e) => return Err(e.into()),
    };
 
    // Deserialize with fallback
    match serde_json::from_slice(&file_bytes) {
        Ok(app_state) => {
            log!("Successfully loaded app state.");
            Ok(app_state)
        }
        Err(e) => {
            error!("Failed to deserialize: {e}. May be incompatible format.");
 
            // Backup old file
            let backup_path = state_path.with_extension("json.bak");
            if let Err(backup_err) = tokio::fs::rename(&state_path, &backup_path).await {
                return Err(backup_err.into()); // Never overwrite the only unreadable copy.
            } else {
                log!("Old state backed up to: {:?}", backup_path);
            }
 
            log!("Using default app state.");
            Ok(AppState::default())
        }
    }
}
 
/// Load window geometry (synchronous, on UI thread)
pub fn load_window_state(window_ref: WindowRef, cx: &mut Cx) -> anyhow::Result<()> {
    let file = match std::fs::File::open(app_data_dir().join(WINDOW_GEOM_STATE_FILE_NAME)) {
        Ok(file) => file,
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(()),
        Err(e) => return Err(e.into()),
    };
 
    let window_geom: WindowGeomState = serde_json::from_reader(file)?;
    log!("Restoring window geometry: {window_geom:?}");
 
    window_ref.configure_window(
        cx,
        dvec2(window_geom.inner_size.0, window_geom.inner_size.1),
        dvec2(window_geom.position.0, window_geom.position.1),
        window_geom.is_fullscreen,
        "MyApp".to_string(),
    );
    Ok(())
}

impl MatchEvent for App {
    fn handle_startup(&mut self, cx: &mut Cx) {
        // Load window geometry (sync, on UI thread)
        if let Err(e) = persistence::load_window_state(
            self.ui.window(ids!(main_window)), cx
        ) {
            error!("Failed to load window state: {}", e);
        }