plushie-renderer-lib 0.7.0

//! Application struct and core utility methods.
//!
//! Defines the [`App`] struct (the iced daemon's state) and the methods
//! that the rest of the renderer uses to query window titles, themes,
//! scale factors, and emit subscription events.

use std::sync::Arc;

use iced::{Task, Theme, keyboard, window};

use plushie_widget_sdk::protocol::OutgoingEvent;
use plushie_widget_sdk::registry::WidgetRegistry;
use plushie_widget_sdk::runtime::{Message, ThemeChrome};

use crate::constants::*;
use crate::effects::EffectHandler;
use crate::emitter::{CoalesceKey, EventEmitter};
use crate::emitters::SinkMutex;
use crate::window_map;

/// Validate and clamp a scale factor. Returns 1.0 for invalid values
/// (zero, negative, NaN, infinity).
pub fn validate_scale_factor(sf: f32) -> f32 {
    if sf <= 0.0 || !sf.is_finite() {
        log::warn!("invalid scale_factor {sf}, using 1.0");
        1.0
    } else {
        sf
    }
}

// ---------------------------------------------------------------------------
// App state
// ---------------------------------------------------------------------------

/// The iced daemon application. Owns the rendering engine, window
/// state, widget registry, and all runtime state needed to translate
/// between the wire protocol and iced's update/view cycle.
pub struct App {
    pub core: plushie_renderer_engine::Core,
    pub theme: Theme,
    pub theme_chrome: ThemeChrome,
    /// Widget ops and effects return iced Tasks, but `apply()` doesn't
    /// return them. They accumulate here and are drained via `Task::batch`
    /// in `update()` after `apply()` returns.
    pub pending_tasks: Vec<Task<Message>>,
    /// Bidirectional plushie ID <-> iced window ID mapping with per-window state.
    pub windows: window_map::WindowMap,
    /// In-memory image handles for use by Image widgets and canvas draw.
    pub image_registry: plushie_widget_sdk::image_registry::ImageRegistry,
    /// Current system theme, tracked via ThemeChanged subscription.
    pub system_theme: Theme,
    /// True when the app-level theme is "system" (follow OS preference).
    pub theme_follows_system: bool,
    /// Global scale factor multiplier (1.0 = follow OS DPI).
    pub scale_factor: f32,
    /// Unified widget registry. All widget types are dispatched through
    /// this registry.
    pub registry: WidgetRegistry,
    /// Epoch for animation_frame timestamp calculation.
    pub animation_epoch: Option<iced::time::Instant>,
    /// Rate-limited event emitter with coalescing.
    pub emitter: EventEmitter,
    /// Platform-specific effect handler injected at construction.
    /// Native and WASM crates each provide their own [`EffectHandler`]
    /// implementation.
    pub effect_handler: Box<dyn EffectHandler>,
    /// Renderer-side animation manager. Tracks transitions, springs,
    /// and exit ghosts. Advances on frame ticks and writes interpolated
    /// values to SharedState.interpolated_props.
    pub transition_manager: plushie_widget_sdk::animation::TransitionManager,
    /// Current keyboard modifier state, updated on every ModifiersChanged
    /// event. Included on all outgoing pointer events.
    pub current_modifiers: keyboard::Modifiers,
    /// Wire protocol codec. Used for encoding stub acks and scripting
    /// responses. Stored here so these paths don't need the global.
    pub codec: plushie_renderer_engine::Codec,
}

impl App {
    pub fn new(
        registry: WidgetRegistry,
        effect_handler: Box<dyn EffectHandler>,
        sink: Arc<SinkMutex>,
    ) -> Self {
        Self {
            core: plushie_renderer_engine::Core::new(),
            theme: DEFAULT_THEME,
            theme_chrome: ThemeChrome::default(),
            pending_tasks: Vec::new(),
            windows: window_map::WindowMap::new(),
            image_registry: plushie_widget_sdk::image_registry::ImageRegistry::new(),
            system_theme: DEFAULT_THEME,
            theme_follows_system: false,
            scale_factor: 1.0,
            registry,
            animation_epoch: None,
            emitter: EventEmitter::new(sink),
            effect_handler,
            transition_manager: plushie_widget_sdk::animation::TransitionManager::new(),
            current_modifiers: keyboard::Modifiers::default(),
            codec: plushie_renderer_engine::Codec::MsgPack,
        }
    }

    /// Set the wire protocol codec. Called during startup after
    /// codec negotiation. Defaults to MsgPack.
    pub fn set_codec(&mut self, codec: plushie_renderer_engine::Codec) {
        self.codec = codec;
    }

    pub fn title_for_window(&self, iced_id: window::Id) -> String {
        if let Some(window_id) = self.windows.get_window_id(&iced_id)
            && let Some(node) = self.core.tree.find_window(window_id)
            && let Some(title) = node.props.get_str("title")
        {
            return title.chars().filter(|c| !c.is_control()).collect();
        }
        DEFAULT_WINDOW_TITLE.to_string()
    }

    pub fn theme_for_window(&self, iced_id: window::Id) -> Theme {
        self.theme_ref_for_window(iced_id).clone()
    }

    pub fn theme_ref_for_window(&self, iced_id: window::Id) -> &Theme {
        if let Some(window_id) = self.windows.get_window_id(&iced_id)
            && self.windows.theme_follows_system(window_id)
        {
            return &self.system_theme;
        }
        if let Some(window_id) = self.windows.get_window_id(&iced_id)
            && let Some(cached) = self.windows.cached_theme(window_id)
        {
            return cached;
        }
        if self.theme_follows_system {
            &self.system_theme
        } else {
            &self.theme
        }
    }

    pub fn theme_chrome_for_window(&self, iced_id: window::Id) -> ThemeChrome {
        if let Some(window_id) = self.windows.get_window_id(&iced_id)
            && self.windows.theme_follows_system(window_id)
        {
            return ThemeChrome::default();
        }
        if let Some(window_id) = self.windows.get_window_id(&iced_id)
            && let Some(chrome) = self.windows.cached_theme_chrome(window_id)
        {
            return chrome;
        }
        if self.theme_follows_system {
            ThemeChrome::default()
        } else {
            self.theme_chrome
        }
    }

    pub fn scale_factor_for_window(&self, iced_id: window::Id) -> f32 {
        let window_id = self.windows.get_window_id(&iced_id);

        // Per-window override from WindowState (set via window open/update ops).
        if let Some(sf) = window_id.and_then(|jid| self.windows.scale_factor(jid)) {
            return validate_scale_factor(sf);
        }

        // Fall back to the tree node's scale_factor prop.
        let sf = window_id
            .and_then(|jid| self.core.tree.find_window(jid))
            .and_then(|node| node.props.get_f32("scale_factor"))
            .unwrap_or(self.scale_factor);
        validate_scale_factor(sf)
    }

    /// Emit a subscription event to all matching entries (specific kind +
    /// catch-all SUB_EVENT), filtered by window_id. The event_fn is called
    /// once per matching entry with the entry's tag.
    ///
    /// `event_fn` receives the tag as `&str`; the OutgoingEvent constructor
    /// allocates the owned tag internally via `impl Into<String>`. Earlier
    /// versions cloned the tag at the call site before passing it in.
    pub fn emit_subscription(
        &self,
        key: &str,
        captured: bool,
        event_fn: impl Fn(&str) -> OutgoingEvent,
    ) -> Task<Message> {
        self.emit_subscription_for_window(key, None, captured, event_fn)
    }

    /// Emit a subscription event scoped to a specific window.
    pub fn emit_subscription_for_window(
        &self,
        key: &str,
        window_id: Option<&str>,
        captured: bool,
        event_fn: impl Fn(&str) -> OutgoingEvent,
    ) -> Task<Message> {
        let entries = self
            .core
            .matching_entries_with_catchall(key, SUB_EVENT, window_id);
        // Fast paths for the common 0- and 1-entry cases avoid
        // allocating a `Vec` and a `Task::batch` per event.
        match entries.len() {
            0 => Task::none(),
            1 => {
                let entry = &entries[0];
                self.emitter
                    .emit_direct(event_fn(entry.tag.as_str()).with_captured(captured))
            }
            _ => {
                let tasks: Vec<_> = entries
                    .into_iter()
                    .map(|entry| {
                        self.emitter
                            .emit_direct(event_fn(entry.tag.as_str()).with_captured(captured))
                    })
                    .collect();
                Task::batch(tasks)
            }
        }
    }

    pub fn lookup_widget_event_rate(&self, widget_id: &str) -> Option<u32> {
        let node = self.core.tree.find_by_id(widget_id)?;
        node.props
            .get("event_rate")
            .and_then(|v| v.as_u64())
            .map(|v| v as u32)
    }

    /// True when the widget at `widget_id` is declared disabled and is
    /// of a type that participates in functional disabled interception.
    ///
    /// iced's native `Status::Disabled` is style-only: events still reach
    /// `update()` from widgets the user considers disabled. This helper
    /// lets the dispatcher swallow events for input-family widgets so
    /// `disabled: true` blocks interaction as every host SDK documents.
    ///
    /// Widget types in scope: `text_input`, `text_editor`, `combo_box`,
    /// `pick_list`. Extending coverage to other widgets (e.g. slider)
    /// is a future step once their behaviour is audited.
    pub fn is_widget_disabled_for_interception(&self, widget_id: &str) -> bool {
        let Some(node) = self.core.tree.find_by_id(widget_id) else {
            return false;
        };
        if !matches!(
            node.type_name.as_str(),
            "text_input" | "text_editor" | "combo_box" | "pick_list"
        ) {
            return false;
        }
        node.props
            .get("disabled")
            .and_then(|v| v.as_bool())
            .unwrap_or(false)
    }

    /// Coalesce a subscription event for all matching entries.
    pub fn coalesce_subscription(
        &mut self,
        key: &str,
        captured: bool,
        event_fn: impl Fn(&str) -> OutgoingEvent,
    ) -> Task<Message> {
        coalesce_subscription_into(&self.core, &mut self.emitter, key, None, captured, event_fn)
    }

    /// Coalesce a subscription event scoped to a specific window.
    /// Each matching entry gets its own coalesce buffer (keyed by tag)
    /// so rate limiting is isolated per subscription entry.
    pub fn coalesce_subscription_for_window(
        &mut self,
        key: &str,
        window_id: Option<&str>,
        captured: bool,
        event_fn: impl Fn(&str) -> OutgoingEvent,
    ) -> Task<Message> {
        coalesce_subscription_into(
            &self.core,
            &mut self.emitter,
            key,
            window_id,
            captured,
            event_fn,
        )
    }

    /// Route a [`Message`] to every widget with an active subscription
    /// for `kind` (optionally scoped to `window_id`) and emit the
    /// resulting outgoing events.
    ///
    /// Fast path: returns [`Task::none`] when no widget cares about
    /// `kind`, so handlers can call this unconditionally without
    /// cloning message payloads in the common case.
    pub fn dispatch_widget_subscription(
        &mut self,
        kind: &str,
        window_id: Option<&str>,
        msg: &Message,
    ) -> Task<Message> {
        dispatch_widget_subscription_into(
            &mut self.registry,
            &mut self.emitter,
            kind,
            window_id,
            msg,
        )
    }
}

/// Free-function form of [`App::dispatch_widget_subscription`] for
/// the same split-borrow reason as [`coalesce_subscription_into`]:
/// callers can hold a `&str` borrowed from `App.windows` while
/// passing `&mut App.emitter` and `&mut App.registry` separately.
pub(crate) fn dispatch_widget_subscription_into(
    registry: &mut WidgetRegistry,
    emitter: &mut EventEmitter,
    kind: &str,
    window_id: Option<&str>,
    msg: &Message,
) -> Task<Message> {
    if !registry.has_widget_subscription(kind) {
        return Task::none();
    }
    let events = registry.dispatch_widget_subscription(kind, window_id, msg);
    if events.is_empty() {
        return Task::none();
    }
    let tasks: Vec<_> = events
        .into_iter()
        .map(|event| emitter.emit_immediate(event))
        .collect();
    Task::batch(tasks)
}

/// Free-function form of [`App::coalesce_subscription_for_window`] so
/// callers can hold a `&str` borrowed from `App.windows` while
/// passing `&mut App.emitter` and `&App.core` separately. Going
/// through the `&mut self` method form would force the borrow
/// checker to take a whole-self mutable borrow, which conflicts
/// with the live `&str` into windows.
pub(crate) fn coalesce_subscription_into(
    core: &plushie_renderer_engine::Core,
    emitter: &mut EventEmitter,
    key: &str,
    window_id: Option<&str>,
    captured: bool,
    event_fn: impl Fn(&str) -> OutgoingEvent,
) -> Task<Message> {
    let entries = core.matching_entries_with_catchall(key, SUB_EVENT, window_id);
    // Fast paths for the common 0- and 1-entry cases avoid
    // allocating a `Vec` and a `Task::batch` per high-frequency
    // event (cursor move, scroll, etc.).
    //
    // The closure receives `&str`; the event constructor allocates
    // the owned tag internally via `impl Into<String>`. Earlier
    // versions cloned the tag at the call site before passing it in.
    match entries.len() {
        0 => Task::none(),
        1 => {
            let entry = &entries[0];
            let event = event_fn(entry.tag.as_str()).with_captured(captured);
            emitter.coalesce(CoalesceKey::Subscription(entry.tag.clone()), event)
        }
        _ => {
            let tasks: Vec<_> = entries
                .into_iter()
                .map(|entry| {
                    let event = event_fn(entry.tag.as_str()).with_captured(captured);
                    emitter.coalesce(CoalesceKey::Subscription(entry.tag.clone()), event)
                })
                .collect();
            Task::batch(tasks)
        }
    }
}