dreamwell-runtime 1.0.0

// RuntimeApp — implements winit ApplicationHandler for the game loop.

use winit::application::ApplicationHandler;
use winit::event::WindowEvent;
use winit::event_loop::ActiveEventLoop;
use winit::window::WindowId;

use dreamwell_engine::game_object::PrimitiveKind;
use dreamwell_engine::TopologyLayer;
use dreamwell_fabric::packets::SyncPacket;

use crate::authority::{AuthorityClient, AuthorityEvent, LocalAuthority};
use crate::game_state::GameState;
use crate::input::InputState;
use crate::play::SimulationService;
use crate::renderer::SceneRenderer;
use crate::scene::Scene;
use crate::sync::stage::StagingBuffer;
use crate::time::FrameTimer;
use crate::window::WindowState;
use crate::{AuthorityMode, RuntimeConfig};
use dreamwell_fabric::decoder::{CausalEngineDecoder, DecoderInput};

// ── Chase Camera Constants ────────────────────────────────────────────
// Tuned for responsive third-person feel: camera tracks player with
// minimal perceived lag while avoiding mechanical snap.
//
// Reference: Unreal SpringArm defaults (lag speed 10, rotation lag speed 10).
// We use dt-scaled exponential lerp: alpha = 1 - e^(-rate * dt).
// At 60fps (dt=0.0167): rate=16 → alpha≈0.23 (4-frame 90% settle).

/// Minimum camera pitch (radians). -0.3 ≈ -17° allows looking slightly below horizon.
const MIN_PITCH: f32 = -0.3;
/// Maximum camera pitch (radians). 1.40 ≈ 80° near-overhead view.
const MAX_PITCH: f32 = 1.40;
/// Minimum camera distance from player (meters).
const MIN_CAMERA_DIST: f32 = 0.5;
/// Maximum camera distance from player (meters).
const MAX_CAMERA_DIST: f32 = 200.0;
/// Default camera distance from player (meters). 3.0m — tight third-person for 0.4m capsule.
const DEFAULT_CAMERA_DIST: f32 = 3.0;
/// Camera position smoothing rate. Higher = snappier. 16 ≈ 4-frame settle at 60fps.
const CAMERA_POSITION_LERP_RATE: f32 = 16.0;
/// Camera look-at smoothing rate. Slightly faster than position for crisp tracking.
const CAMERA_LOOKAT_LERP_RATE: f32 = 20.0;
/// Zoom smoothing rate.
const ZOOM_LERP_RATE: f32 = 14.0;
/// Over-shoulder horizontal offset (meters). Subtle — keeps character slightly left of center.
const SHOULDER_OFFSET: f32 = 0.3;
/// Look-at target height above player origin (meters). ~waist/chest height for particle centroid.
const LOOKAT_HEIGHT: f32 = 0.9;
/// Extra camera pull-back distance while sprinting (meters).
const SPRINT_PULL_BACK: f32 = 1.0;

/// Form-aware camera tuning profile.
/// Lerped between Cohere and Wave forms based on coherence parameter.
pub struct CameraProfile {
    pub boom_length: f32,
    pub yaw_lag: f32,
    pub fov: f32,
    pub shoulder_offset: f32,
    pub lookat_height: f32,
}

impl CameraProfile {
    /// Compact fibonacci particle — tighter camera.
    pub fn cohere() -> Self {
        Self {
            boom_length: 5.0,
            yaw_lag: 0.15,
            fov: 60.0,
            shoulder_offset: 0.4,
            lookat_height: 1.2,
        }
    }

    /// Broad wave fabric — wider camera.
    pub fn wave() -> Self {
        Self {
            boom_length: 7.0,
            yaw_lag: 0.25,
            fov: 65.0,
            shoulder_offset: 0.6,
            lookat_height: 1.0,
        }
    }

    /// Linearly interpolate between two profiles.
    pub fn lerp(a: &Self, b: &Self, t: f32) -> Self {
        let t = t.clamp(0.0, 1.0);
        Self {
            boom_length: a.boom_length + (b.boom_length - a.boom_length) * t,
            yaw_lag: a.yaw_lag + (b.yaw_lag - a.yaw_lag) * t,
            fov: a.fov + (b.fov - a.fov) * t,
            shoulder_offset: a.shoulder_offset + (b.shoulder_offset - a.shoulder_offset) * t,
            lookat_height: a.lookat_height + (b.lookat_height - a.lookat_height) * t,
        }
    }
}

/// Error type for runtime operations.
#[derive(Debug)]
pub enum RuntimeError {
    /// A scene or pack loading error.
    Load(String),
    /// Window or GPU initialization error.
    Init(String),
}

impl std::fmt::Display for RuntimeError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Load(msg) => write!(f, "load error: {msg}"),
            Self::Init(msg) => write!(f, "init error: {msg}"),
        }
    }
}

impl std::error::Error for RuntimeError {}

/// The runtime application, driven by winit's event loop.
pub struct RuntimeApp {
    config: RuntimeConfig,
    window_state: Option<WindowState>,
    renderer: Option<SceneRenderer>,
    scene: Scene,
    game_state: GameState,
    input: InputState,
    timer: FrameTimer,
    /// Authority backend (local or remote).
    authority: Box<dyn AuthorityClient>,
    /// Staging buffer for authority events awaiting tick-boundary application.
    staging: StagingBuffer,
    /// Per-frame sync packet drained from DreamFabric.
    sync_packet: SyncPacket,
    /// Mounted content pack JSON, stored for deferred scene loading.
    mounted_pack: Option<String>,
    /// Pre-allocated scratch buffer for authority events — reused every frame.
    /// Capacity is set at construction and never reallocated on the hot path.
    authority_events: Vec<AuthorityEvent>,
    /// SimulationService — CausalComputeKernel + SDK dispatch (gate-routed).
    /// Active when a tapestry lock file is loaded (Shapes and Dimensions demo).
    simulation: Option<SimulationService>,
    /// CausalEngineDecoder — formal GPU orchestration (encoder→bridge→decoder).
    decoder: Option<CausalEngineDecoder>,
    /// Chase camera orbit yaw in radians (accumulated from mouse drag).
    camera_orbit_yaw: f32,
    /// Chase camera orbit pitch in radians (clamped to [MIN_PITCH, MAX_PITCH]).
    camera_orbit_pitch: f32,
    /// Current camera distance from player (smoothed toward target).
    camera_distance: f32,
    /// Target camera distance — scroll sets this, actual distance lerps toward it.
    camera_target_distance: f32,
    /// Gilrs context for gamepad input (present only when `gamepad` feature is enabled).
    #[cfg(feature = "gamepad")]
    gilrs: gilrs::Gilrs,
    /// Audio system with OddioBackend (present only when `audio` feature is enabled).
    /// OddioBackend provides spatial 3D audio via oddio + cpal. Falls back to
    /// headless (no-op) mode when no audio device is available.
    #[cfg(feature = "audio")]
    audio: dreamwell_audio::AudioSystem<dreamwell_audio::OddioBackend>,
}

fn create_authority(mode: AuthorityMode) -> Box<dyn AuthorityClient> {
    match mode {
        AuthorityMode::Local => Box::new(LocalAuthority::new()),
        #[cfg(feature = "multiplayer")]
        AuthorityMode::Remote => Box::new(crate::authority::RemoteAuthority::new()),
        #[cfg(not(feature = "multiplayer"))]
        AuthorityMode::Remote => {
            log::warn!("Remote authority requested but multiplayer feature not enabled, falling back to local");
            Box::new(LocalAuthority::new())
        }
    }
}

impl RuntimeApp {
    /// Create a new runtime application.
    ///
    /// Returns `Err` if authority backend creation fails for the requested mode.
    pub fn new(config: RuntimeConfig) -> Result<Self, RuntimeError> {
        let authority = create_authority(config.authority_mode);
        Ok(Self {
            config,
            window_state: None,
            renderer: None,
            scene: Scene::default(),
            game_state: GameState::default(),
            input: InputState::default(),
            timer: FrameTimer::new(),
            authority,
            staging: StagingBuffer::new(),
            sync_packet: SyncPacket::new(),
            mounted_pack: None,
            // Pre-allocate with a reasonable capacity. Reallocates only if
            // more than 64 authority events arrive in a single frame (rare).
            authority_events: Vec::with_capacity(64),
            simulation: None,
            decoder: None,
            camera_orbit_yaw: 0.0,
            camera_orbit_pitch: 0.35, // ~20 degrees above horizon (natural third-person)
            camera_distance: 6.0,
            camera_target_distance: 6.0,
            #[cfg(feature = "gamepad")]
            gilrs: gilrs::Gilrs::new().unwrap_or_else(|e| {
                log::warn!("gamepad_init_failed:{e} — gamepad input disabled");
                // gilrs::Gilrs::new() returns a Result; the error variant also
                // contains a valid (empty) Gilrs instance.
                e.into()
            }),
            #[cfg(feature = "audio")]
            audio: {
                match dreamwell_audio::OddioBackend::new() {
                    Ok(backend) => dreamwell_audio::AudioSystem::new(backend),
                    Err(e) => {
                        log::warn!("audio_init_failed:{e} — falling back to headless");
                        dreamwell_audio::AudioSystem::new(dreamwell_audio::OddioBackend::headless())
                    }
                }
            },
        })
    }

    /// Mount a content pack from JSON. The pack data is stored and available
    /// for subsequent `load_scene` calls to reference.
    ///
    /// This does not immediately alter the running scene; it stages the pack
    /// for deferred loading via `load_scene`.
    pub fn mount_pack(&mut self, pack_json: &str) -> Result<(), String> {
        // Validate that the JSON is at least well-formed.
        if pack_json.is_empty() {
            return Err("mount_pack:empty pack JSON".into());
        }
        // Store the pack for later scene loading.
        self.mounted_pack = Some(pack_json.to_string());
        log::info!("Pack mounted ({} bytes)", pack_json.len());
        Ok(())
    }

    /// Load a scene by name. If a content pack has been mounted, the scene
    /// definition is resolved from the pack. Otherwise, falls back to the
    /// built-in demo scene.
    ///
    /// This is a structural stub that resets the scene and seeds objects.
    /// Full pack-driven scene deserialization is planned for a future release.
    pub fn load_scene(&mut self, scene_name: &str) -> Result<(), String> {
        if scene_name.is_empty() {
            return Err("load_scene:empty scene name".into());
        }
        // Reset scene state.
        self.scene = Scene::default();
        self.game_state = GameState::default();

        if let Some(ref pack_json) = self.mounted_pack {
            match dreamwell_engine::waymark::loader::PackLoader::load_pack_config(pack_json) {
                Ok(pack) => {
                    let loaded = dreamwell_engine::waymark::loader::load_pack_to_scene(&pack);
                    self.scene.game_objects = loaded.objects;
                    log::info!(
                        "Loaded scene '{}' from pack: {} objects",
                        scene_name,
                        self.scene.game_objects.len()
                    );
                    return Ok(());
                }
                Err(e) => {
                    log::warn!("Pack parse failed, falling back to demo: {}", e);
                }
            }
        }

        self.seed_demo_scene();
        log::info!("Scene '{}' loaded (demo fallback)", scene_name);
        Ok(())
    }

    /// Switch authority mode at runtime. Replaces the authority backend and
    /// clears staged events.
    ///
    /// Note: switching from Remote to Local while connected will drop the
    /// remote connection. Switching to Remote requires the `multiplayer`
    /// feature to be enabled; otherwise it falls back to Local with a warning.
    pub fn set_authority_mode(&mut self, mode: AuthorityMode) {
        if mode == self.config.authority_mode {
            return;
        }
        log::info!(
            "Switching authority mode: {:?} -> {:?}",
            self.config.authority_mode,
            mode
        );
        self.authority = create_authority(mode);
        self.staging = StagingBuffer::new();
        self.config.authority_mode = mode;
    }

    /// Load scene from tapestry.lock if available, else seed demo primitives.
    /// When a lock file is present, initializes the full CausalComputeKernel
    /// simulation with gate-routed SDK dispatch per THE_BRAIDED_PATH.
    fn seed_demo_scene(&mut self) {
        // Try loading from tapestry.lock (Shapes and Dimensions or any authored scene).
        if let Some(ref lock_path) = self.config.lock_file {
            if let Ok(json) = std::fs::read_to_string(lock_path) {
                if let Ok(lock) = dreamwell_sdk::tapestry::TapestryLock::from_json(&json) {
                    log::info!("Loading scene from tapestry.lock: {} objects", lock.object_count);
                    self.load_scene_from_lock(&lock);
                    return;
                }
            }
            log::warn!("Failed to load lock file '{}', falling back to demo", lock_path);
        }

        // Fallback: canonical 3D template (player particle + ground + skybox).
        // Uses the same template as CLI `dream up init` and Editor New Project.
        let tmpl = dreamwell_sdk::templates::default_3d_scene();

        // Set active layer to Point (9) BEFORE anything else — template objects live on layer 9.
        // This must happen unconditionally so the observer matches the scene content.
        self.game_state.active_layer = TopologyLayer::Point;

        let scene = &mut self.scene.game_objects;
        for obj in &tmpl.objects {
            let kind = match obj.name.as_str() {
                "Ground" => Some(PrimitiveKind::Plane),
                _ => None,
            };
            let id = if let Some(k) = kind {
                scene.spawn_primitive(obj.name.clone(), k)
            } else {
                scene.spawn(obj.name.clone())
            };
            if let Ok(id) = id {
                if let Some(go) = scene.find_mut(id) {
                    go.transform.position = obj.position;
                    go.transform.scale = obj.scale;
                    go.property_tags = obj.tags.clone();
                    // Transfer material preset from template.
                    if let Some(ref mat) = obj.material {
                        go.property_tags.push(format!("material={mat}"));
                    }
                }
            }
        }

        // Template lights will be added to the renderer's DreamFabric after it's created.
        // Store them for deferred application in the resumed() handler.
        // (GpuScene adds a default directional sun if no lights are explicitly set.)

        log::info!(
            "Demo scene seeded from template '{}': {} objects, {} lights",
            tmpl.name,
            scene.len(),
            tmpl.lights.len(),
        );

        // Initialize SimulationService from template scene.
        let spawn_pos = tmpl
            .objects
            .iter()
            .find(|o| o.tags.iter().any(|t| t == "isInputReceiver"))
            .map(|o| o.position)
            .unwrap_or([0.0, 0.5, 0.0]);

        let mut go_scene = dreamwell_engine::game_object::GameObjectScene::new(tmpl.name.clone());
        for obj in &tmpl.objects {
            let kind = match obj.name.as_str() {
                "Ground" => Some(PrimitiveKind::Plane),
                _ => None,
            };
            let id = if let Some(k) = kind {
                go_scene.spawn_primitive(obj.name.clone(), k)
            } else {
                go_scene.spawn(obj.name.clone())
            };
            if let Ok(id) = id {
                if let Some(go) = go_scene.find_mut(id) {
                    go.transform.position = obj.position;
                    go.transform.scale = obj.scale;
                    go.property_tags = obj.tags.clone();
                }
            }
        }

        let particle_count = dreamwell_metaphors::DEFAULT_PARTICLE_COUNT;
        let mut sim = SimulationService::new(&tmpl.name, crate::play::SimulationMode::Published);
        if let Err(e) = sim.initialize(go_scene, spawn_pos, particle_count) {
            log::error!("Simulation init failed: {e}");
            // Layer is already set to Point — scene will still render even without simulation
        } else {
            self.simulation = Some(sim);
            self.decoder = Some(dreamwell_fabric::decoder::CausalEngineDecoder::new());
        }
        self.game_state.player_position = glam::Vec3::from_array(spawn_pos);

        // Position chase camera behind and above the player.
        // 0.30 rad ≈ 17° elevation — standard third-person overhead angle.
        self.camera_orbit_pitch = 0.30;
        self.camera_distance = DEFAULT_CAMERA_DIST;
        self.camera_target_distance = DEFAULT_CAMERA_DIST;
        let pitch = self.camera_orbit_pitch;
        let yaw = self.camera_orbit_yaw;
        let horiz = pitch.cos() * self.camera_distance;
        let height = pitch.sin() * self.camera_distance;
        let cam_offset = glam::Vec3::new(
            -yaw.cos() * horiz + yaw.sin() * SHOULDER_OFFSET,
            height,
            -yaw.sin() * horiz - yaw.cos() * SHOULDER_OFFSET,
        );
        let player = glam::Vec3::from_array(spawn_pos);
        self.scene.camera.position = player + cam_offset;
        self.scene.camera.center = glam::Vec3::new(spawn_pos[0], spawn_pos[1] + LOOKAT_HEIGHT, spawn_pos[2]);
        self.scene.camera.update_view_matrix();
    }

    /// Load a full scene from TapestryLock and initialize SimulationService.
    /// Follows THE_BRAIDED_PATH: tapestry.lock → Loom::weave → WovenScene
    /// → CausalComputeKernel + DreamGate + SDK Decoherence on layer 9.
    fn load_scene_from_lock(&mut self, lock: &dreamwell_sdk::tapestry::TapestryLock) {
        use dreamwell_engine::loom;

        // Reconstruct GameObjectScene from lock objects.
        let mut scene = dreamwell_engine::game_object::GameObjectScene::new(lock.scene_name.clone());
        for obj in &lock.objects {
            // Determine primitive kind from tags/name for mesh geometry.
            let primitive = Self::infer_primitive_kind(&obj.tags, &obj.name);
            let id = if let Some(kind) = primitive {
                scene.spawn_primitive(obj.name.clone(), kind)
            } else {
                scene.spawn(obj.name.clone())
            };
            if let Ok(id) = id {
                if let Some(go) = scene.find_mut(id) {
                    go.transform.position = obj.position;
                    go.transform.rotation = obj.rotation;
                    go.transform.scale = obj.scale;
                    go.visible = obj.visible;
                    go.parent_id = obj.parent_id;
                    go.property_tags = obj.tags.clone();
                    // Parse topology layer from tags.
                    for tag in &obj.tags {
                        if let Some(rest) = tag.strip_prefix("isTopologyLayer") {
                            if let Ok(layer) = rest.parse::<u8>() {
                                go.topology_layer = layer.min(9);
                            }
                        }
                    }
                }
            }
        }

        // Hydrate tags from template if lock has empty tag arrays.
        Self::hydrate_tags_from_template(&mut scene);

        // Weave through Loom for validation + physics body extraction.
        let woven = match loom::weave(scene, loom::RenderConfig::default()) {
            Ok(w) => w,
            Err(errs) => {
                log::error!("Loom validation failed: {:?}", errs);
                return;
            }
        };

        // Find spawn position (isInputReceiver tag).
        let spawn_pos = woven
            .scene
            .objects
            .iter()
            .find(|o| o.property_tags.iter().any(|t| t == "isInputReceiver"))
            .map(|o| o.transform.position)
            .unwrap_or([0.0, 0.5, 0.0]);

        // Initialize SimulationService with full gate-routed SDK dispatch.
        let mut sim = SimulationService::new(&woven.scene.name, crate::play::SimulationMode::Published);

        // Collect decoherence fields from scene tags.
        sim.decoherence_fields = Self::collect_decoherence_fields(&woven);

        // Set active layer BEFORE simulation init — scene content lives on layer 9.
        self.game_state.active_layer = TopologyLayer::Point;

        // Initialize kernel at spawn point on topology layer 9 (Point).
        // sim.initialize() sets sim.scene internally from the woven scene.
        let particle_count = dreamwell_metaphors::DEFAULT_PARTICLE_COUNT;
        if let Err(e) = sim.initialize(woven.scene, spawn_pos, particle_count) {
            log::error!("Simulation init failed: {e}");
            return;
        }
        self.game_state.player_position = glam::Vec3::from_array(spawn_pos);

        // Store the woven scene as the renderable scene.
        self.scene.game_objects = sim.scene.clone();

        // Initialize chase camera from kernel facing direction.
        let init_yaw = sim
            .encoder
            .as_ref()
            .map(|e| e.kernel().facing_yaw)
            .or_else(|| sim.kernel.as_ref().map(|k| k.facing_yaw));
        if let Some(yaw) = init_yaw {
            self.camera_orbit_yaw = yaw;
        }
        self.camera_orbit_pitch = 0.35; // ~20 degrees above horizon
        self.camera_distance = DEFAULT_CAMERA_DIST;
        self.camera_target_distance = DEFAULT_CAMERA_DIST;

        // Position camera behind and above the spawn point, looking forward.
        let yaw = self.camera_orbit_yaw;
        let pitch = self.camera_orbit_pitch;
        let horiz = pitch.cos() * self.camera_distance;
        let height = pitch.sin() * self.camera_distance;
        let cam_offset = glam::Vec3::new(
            -yaw.cos() * horiz + yaw.sin() * SHOULDER_OFFSET,
            height,
            -yaw.sin() * horiz - yaw.cos() * SHOULDER_OFFSET,
        );
        self.scene.camera.position = glam::Vec3::from_array(spawn_pos) + cam_offset;
        self.scene.camera.center = glam::Vec3::new(spawn_pos[0], spawn_pos[1] + LOOKAT_HEIGHT, spawn_pos[2]);
        self.scene.camera.update_view_matrix();

        // Diagnostic: count mesh bindings for debugging visibility issues.
        let mesh_count = self
            .scene
            .game_objects
            .objects
            .iter()
            .filter(|o| matches!(o.mesh, dreamwell_engine::game_object::MeshBinding::Primitive { .. }))
            .count();
        let visible_mesh_count = self
            .scene
            .game_objects
            .objects
            .iter()
            .filter(|o| matches!(o.mesh, dreamwell_engine::game_object::MeshBinding::Primitive { .. }) && o.visible)
            .count();
        for obj in &self.scene.game_objects.objects {
            log::debug!(
                "  obj '{}': mesh={:?}, visible={}, pos=[{:.1},{:.1},{:.1}]",
                obj.name,
                obj.mesh,
                obj.visible,
                obj.transform.position[0],
                obj.transform.position[1],
                obj.transform.position[2],
            );
        }
        log::info!(
            "Tapestry scene loaded: {} objects ({} meshes, {} visible), spawn at [{:.1}, {:.1}, {:.1}], layer 9 (Point)",
            self.scene.game_objects.len(),
            mesh_count, visible_mesh_count,
            spawn_pos[0], spawn_pos[1], spawn_pos[2],
        );

        self.simulation = Some(sim);
        self.decoder = Some(CausalEngineDecoder::new());
    }

    /// Convert CPU InterferenceKernels to GPU-uploadable GpuParticleKernel array.
    /// Maps 10 Complex pairs × 3 axes to flat 60-float per-particle kernel.
    fn convert_interference_kernels(
        kernels: &dreamwell_quantum::InterferenceKernels,
        particle_count: u32,
    ) -> Vec<dreamwell_gpu::dreamlet_catalog::GpuParticleKernel> {
        let n = (particle_count as usize).min(kernels.kernels.len());
        let mut gpu_kernels = Vec::with_capacity(n);
        for p in 0..n {
            let mut flat = [0.0f32; 60];
            for pair in 0..10 {
                for axis in 0..3 {
                    let c = kernels.kernels[p][pair][axis];
                    flat[pair * 6 + axis * 2] = c.re;
                    flat[pair * 6 + axis * 2 + 1] = c.im;
                }
            }
            gpu_kernels.push(dreamwell_gpu::dreamlet_catalog::GpuParticleKernel {
                kernels: flat,
                _pad: [0.0; 4],
            });
        }
        gpu_kernels
    }

    /// Extract quantum DecoherenceFields from woven scene objects.
    fn collect_decoherence_fields(
        woven: &dreamwell_engine::loom::WovenScene,
    ) -> Vec<dreamwell_quantum::DecoherenceField> {
        use dreamwell_engine::input::parse_decoherence_tag;
        use dreamwell_engine::input::wave::{DecoherenceTagValue, WaveForm};

        fn to_quantum_form(f: WaveForm) -> dreamwell_quantum::WaveForm {
            match f {
                WaveForm::Particle => dreamwell_quantum::WaveForm::Particle,
                WaveForm::Humanoid => dreamwell_quantum::WaveForm::Humanoid,
                WaveForm::Vehicle => dreamwell_quantum::WaveForm::Vehicle,
                WaveForm::Fluid => dreamwell_quantum::WaveForm::Fluid,
            }
        }

        let mut fields = Vec::new();
        for obj in &woven.scene.objects {
            let is_zone = obj.property_tags.iter().any(|t| t == "isDecoherenceZone");
            if !is_zone {
                continue;
            }

            let mut target_form = WaveForm::Humanoid;
            let mut gamma = 2.0f32;
            let mut clip = String::new();
            for tag in &obj.property_tags {
                if let Some(val) = parse_decoherence_tag(tag) {
                    match val {
                        DecoherenceTagValue::Form(form, animation) => {
                            target_form = form;
                            clip = animation;
                        }
                        DecoherenceTagValue::Gamma(rate) => {
                            gamma = rate;
                        }
                    }
                }
            }

            let radius = obj
                .property_tags
                .iter()
                .find_map(|t| t.strip_prefix("decohere.radius=").and_then(|v| v.parse::<f32>().ok()))
                .unwrap_or(10.0);

            fields.push(dreamwell_quantum::DecoherenceField {
                position: obj.transform.position,
                radius,
                target_form: to_quantum_form(target_form),
                gamma,
                animation_clip: clip,
                source_tag: "isDecoherenceZone".into(),
            });
        }
        fields
    }

    #[cfg(feature = "bundled-skybox")]
    fn default_skybox_bytes() -> &'static [u8] {
        include_bytes!("../assets/skyboxes/textures/basic_skybox.jpeg")
    }

    #[cfg(not(feature = "bundled-skybox"))]
    fn default_skybox_bytes() -> &'static [u8] {
        &[]
    }

    /// Infer PrimitiveKind from object tags and name.
    /// Returns None for objects that shouldn't have geometry (skybox, player, zone markers).
    fn infer_primitive_kind(tags: &[String], name: &str) -> Option<PrimitiveKind> {
        let has_tag = |t: &str| tags.iter().any(|s| s == t);
        // Skybox, player avatar, and zone markers have no mesh geometry.
        if has_tag("isSkybox") || has_tag("isInputReceiver") || has_tag("isPlayer") {
            return None;
        }
        // Zone topology markers (no position/scale) are invisible.
        if name.starts_with("Zone ") {
            return None;
        }
        // Ground/floor → Plane (rendered as a flat slab via cube with thin Y scale)
        if has_tag("isGround") {
            return Some(PrimitiveKind::Cube);
        }
        // Walls → Cube
        if has_tag("isWall") || has_tag("isCollider") {
            return Some(PrimitiveKind::Cube);
        }
        // POI/Fractal → Sphere
        if has_tag("poi") || has_tag("isInteractable") || has_tag("isFractal") {
            return Some(PrimitiveKind::Sphere);
        }
        // Default: Cube for any remaining visible object
        if !tags.is_empty() {
            return Some(PrimitiveKind::Cube);
        }
        None
    }

    /// Hydrate tags from template when lock file has empty tags arrays.
    /// Also assigns MeshBinding::Primitive based on hydrated tags, since
    /// objects from stale locks have MeshBinding::None.
    fn hydrate_tags_from_template(scene: &mut dreamwell_engine::game_object::GameObjectScene) {
        if scene.objects.iter().any(|o| !o.property_tags.is_empty()) {
            // Tags already present — still ensure mesh bindings are assigned.
            for obj in &mut scene.objects {
                if matches!(obj.mesh, dreamwell_engine::game_object::MeshBinding::None) {
                    if let Some(kind) = Self::infer_primitive_kind(&obj.property_tags, &obj.name) {
                        obj.mesh = dreamwell_engine::game_object::MeshBinding::Primitive {
                            kind,
                            color: [0.7, 0.7, 0.7, 1.0],
                        };
                    }
                }
            }
            return;
        }
        let tmpl = dreamwell_sdk::templates::shapes_and_dimensions();
        for obj in &mut scene.objects {
            if let Some(tmpl_obj) = tmpl.objects.iter().find(|t| t.name == obj.name) {
                obj.property_tags = tmpl_obj.tags.clone();
                for tag in &obj.property_tags {
                    if let Some(rest) = tag.strip_prefix("isTopologyLayer") {
                        if let Ok(layer) = rest.parse::<u8>() {
                            obj.topology_layer = layer.min(9);
                        }
                    }
                }
                // Assign mesh binding from hydrated tags.
                if matches!(obj.mesh, dreamwell_engine::game_object::MeshBinding::None) {
                    if let Some(kind) = Self::infer_primitive_kind(&obj.property_tags, &obj.name) {
                        obj.mesh = dreamwell_engine::game_object::MeshBinding::Primitive {
                            kind,
                            color: [0.7, 0.7, 0.7, 1.0],
                        };
                    }
                }
            }
        }
        log::info!("Tag hydration: applied template tags to stale lock");
    }
}

impl ApplicationHandler for RuntimeApp {
    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
        if self.window_state.is_some() {
            return;
        }

        let window_state = WindowState::new(event_loop, &self.config.title, self.config.width, self.config.height);
        let renderer = SceneRenderer::with_msaa(&window_state, self.config.msaa_samples);
        self.window_state = Some(window_state);
        self.renderer = Some(renderer);

        // Validate GPU shaders via naga IR (no GPU device needed).
        let naga_report = dreamwell_naga::validate_startup();
        if naga_report.is_ok() {
            log::info!(
                "Naga: {}/{} shaders OK",
                naga_report.passed,
                naga_report.shader_results.len()
            );
        } else {
            log::warn!("Naga validation warnings:\n{}", naga_report.summary());
        }

        // Seed demo scene and upload to GPU.
        self.seed_demo_scene();
        if let (Some(ws), Some(r)) = (&self.window_state, &mut self.renderer) {
            // Set projection matrix from actual window dimensions.
            let aspect = ws.surface_config.width as f32 / ws.surface_config.height.max(1) as f32;
            self.scene.camera.update_projection(aspect, 60.0);

            r.fabric.upload_scene(&ws.device, &self.scene.game_objects);

            // Add template directional sun — required for PBR lighting.
            // Without this, Cook-Torrance BRDF receives zero light and outputs black.
            {
                let sun_dir = glam::Vec3::new(0.3, -1.0, 0.4).normalize();
                r.fabric.gpu_scene_mut().scene_lights.add_directional(
                    dreamwell_engine::lighting::DirectionalLightDesc {
                        direction: sun_dir.to_array(),
                        color: [1.0, 0.98, 0.92],
                        intensity_lux: 2.0,
                    },
                );
            }

            // Load skybox environment map.
            let skybox_bytes = Self::default_skybox_bytes();
            if !skybox_bytes.is_empty() {
                if r.fabric.load_skybox_image(&ws.device, &ws.queue, skybox_bytes) {
                    log::info!("Skybox loaded ({} bytes)", skybox_bytes.len());
                } else {
                    log::warn!("Skybox decode failed");
                }
            }

            // If simulation is active (tapestry.lock loaded), initialize particle dreamlets
            // for the wave controller avatar. 256 particles on golden spiral, uploaded to
            // DreamFabric for GPU particle physics compute (THE_BRAIDED_PATH Phase G).
            if let Some(ref sim) = self.simulation {
                if !sim.particle_offsets.is_empty() {
                    let spawn_pos = sim
                        .encoder
                        .as_ref()
                        .map(|e| e.kernel().position)
                        .or_else(|| sim.kernel.as_ref().map(|k| k.position))
                        .unwrap_or([0.0, 0.5, 0.0]);
                    let dreamlets = dreamwell_gpu::dreamlet_catalog::generate_particle(
                        spawn_pos,
                        sim.particle_offsets.len() as u32,
                        0.8,
                        [0.4, 0.6, 1.0, 0.85],
                        &sim.particle_offsets,
                    );
                    r.fabric.ensure_dreamlet_catalog_ready(&ws.device, &ws.queue);
                    r.fabric.init_particle_physics(&ws.device);
                    r.fabric.upload_dreamlets(&ws.queue, &dreamlets);
                    r.fabric.mark_particle_uploaded();

                    // Initialize quantum bridge (CPU→GPU density matrix upload).
                    let particle_count = dreamlets.len() as u32;
                    r.fabric.init_quantum_bridge(&ws.device, particle_count);

                    // Upload per-particle interference kernels from quantum state (once).
                    let quantum_kernels = sim
                        .encoder
                        .as_ref()
                        .map(|e| &e.kernel().quantum.kernels)
                        .or_else(|| sim.kernel.as_ref().map(|k| &k.quantum.kernels));
                    if let Some(kernels) = quantum_kernels {
                        let gpu_kernels = Self::convert_interference_kernels(kernels, particle_count);
                        r.fabric.upload_interference_kernels(&ws.queue, &gpu_kernels);
                    }

                    log::info!(
                        "Particle dreamlets uploaded: {} particles, quantum bridge active",
                        dreamlets.len()
                    );
                }
            }

            // Warm up pipeline cache synchronously before first frame.
            let mut warmup = dreamwell_fabric::WarmupPhase::standard_entries();
            warmup.complete_all(&ws.device, r.fabric.pipeline_cache_mut());
            r.fabric.init_post_process_pipelines(&ws.device);
            log::info!("Tapestry warmed: {} pipelines compiled", warmup.total());
        }

        // Configure render mode. PbrDefault auto-enables HDR (Rgba16Float) framebuffer.
        // Particles render to HDR, then tonemap composites to swapchain surface.
        // Without tonemap enabled, HDR content is never presented — particles invisible.
        if let (Some(_ws), Some(r)) = (&self.window_state, &mut self.renderer) {
            r.set_scene_dream_mode(dreamwell_engine::material::SceneDreamMode::PbrDefault);
            // for_pbr() enables bloom + ACES tonemap — ensures HDR→surface compositing.
            r.set_post_process_config(dreamwell_gpu::post::PostProcessConfig::for_pbr());
            log::info!("Render mode: PbrDefault, post-processing: bloom + ACES tonemap");
        }

        log::info!("Runtime initialized");
    }

    fn window_event(&mut self, event_loop: &ActiveEventLoop, _window_id: WindowId, event: WindowEvent) {
        match event {
            WindowEvent::CloseRequested => {
                event_loop.exit();
            }
            WindowEvent::Resized(size) => {
                if let Some(ws) = &mut self.window_state {
                    ws.resize(size.width, size.height);
                    if let Some(r) = &mut self.renderer {
                        r.resize(size.width, size.height, &ws.device);
                    }
                }
            }
            WindowEvent::KeyboardInput { event, .. } => {
                self.input.handle_keyboard(&event);
                if let winit::keyboard::PhysicalKey::Code(code) = event.physical_key {
                    use winit::event::ElementState;
                    use winit::keyboard::KeyCode;
                    match (code, event.state) {
                        // TAB: cycle active metaphor profile (Wave → Fibonacci → Stream → Wave).
                        (KeyCode::Tab, ElementState::Pressed) => {
                            if let Some(ref mut sim) = self.simulation {
                                let name = sim.cycle_metaphor();
                                log::info!("Metaphor: {name}");
                            }
                        }
                        // Q: Cohere form (fibonacci, coherent particles)
                        (KeyCode::KeyQ, ElementState::Pressed) => {
                            if let Some(ref mut sim) = self.simulation {
                                sim.set_coherence_target(1.0);
                            }
                        }
                        // E: Wave form (sinusoidal, decoherent particles)
                        (KeyCode::KeyE, ElementState::Pressed) => {
                            if let Some(ref mut sim) = self.simulation {
                                sim.set_coherence_target(0.0);
                            }
                        }
                        // Ctrl: Gather mode (hold)
                        (KeyCode::ControlLeft | KeyCode::ControlRight, ElementState::Pressed) => {
                            if let Some(ref mut sim) = self.simulation {
                                sim.set_gather(true);
                            }
                        }
                        (KeyCode::ControlLeft | KeyCode::ControlRight, ElementState::Released) => {
                            if let Some(ref mut sim) = self.simulation {
                                sim.set_gather(false);
                            }
                        }
                        _ => {}
                    }
                }
            }
            WindowEvent::MouseInput { state, button, .. } => {
                self.input.handle_mouse_button(button, state);
                // Primary mouse button: emit strength
                if button == winit::event::MouseButton::Left {
                    if let Some(ref mut sim) = self.simulation {
                        match state {
                            winit::event::ElementState::Pressed => sim.set_emit_strength(1.0),
                            winit::event::ElementState::Released => sim.set_emit_strength(0.0),
                        }
                    }
                }
            }
            WindowEvent::CursorMoved { position, .. } => {
                self.input.handle_cursor_move(position.x as f32, position.y as f32);
            }
            WindowEvent::MouseWheel { delta, .. } => {
                self.input.handle_scroll(&delta);
            }
            WindowEvent::RedrawRequested => {
                self.timer.tick();

                // Phase 1: PollInput — collect window/input events.
                // When simulation is active, WASD drives the kernel (not camera pan).
                // Camera follows the player via chase-cam in Phase 5a.
                if self.simulation.is_none() {
                    self.input
                        .apply_to_camera(&mut self.scene.camera, self.timer.delta_time());
                } else {
                    // Only apply mouse look (scroll zoom, drag rotation) — not WASD pan.
                    self.input
                        .apply_mouse_to_camera(&mut self.scene.camera, self.timer.delta_time());
                }

                // Phase 1b: Gamepad input (feature-gated, no-op when disabled).
                #[cfg(feature = "gamepad")]
                self.input.handle_gamepad(&mut self.gilrs, &mut self.scene.camera);

                // Phase 2: PollAuthority — non-blocking check for authority events
                self.authority_events.clear();
                self.authority.poll_events(&mut self.authority_events);

                // Phase 3: StageAuthorityEvents — buffer events for atomic application.
                // Explicit reborrow to satisfy the borrow checker: staging and
                // authority_events are disjoint fields but accessed through `self`.
                {
                    let staging = &mut self.staging;
                    let events = &mut self.authority_events;
                    staging.extend(events.drain(..));
                }

                // Phase 4: ApplyAuthorityEvents — apply staged events at tick boundary
                for event in self.staging.drain() {
                    match event {
                        AuthorityEvent::Ack { .. } => { /* intent acknowledged */ }
                        AuthorityEvent::Reject { seq, reason } => {
                            log::debug!("Authority rejected intent {seq}: {reason}");
                        }
                        AuthorityEvent::CanonEvent { tick, event_type, .. } => {
                            log::trace!("Canon event at tick {tick}: {event_type}");
                        }
                        AuthorityEvent::SnapshotChunk { .. } => { /* snapshot processing */ }
                    }
                }

                // Phase 5: UpdateMirror — update client mirror from applied events
                self.game_state.update(self.timer.delta_time());

                // Phase 5a: CausalComputeKernel tick (THE_BRAIDED_PATH phases B-E).
                // Single canonical input path: FabricInput.build_frame() → InputPacket::from_frame().
                // Binding-aware: rebinding WASD works. Gamepad overlays via synthetic key presses.
                if let Some(ref mut sim) = self.simulation {
                    let dt_secs = self.timer.delta_time();

                    // Gamepad → synthetic key presses into FabricInput (before build_frame).
                    #[cfg(feature = "gamepad")]
                    {
                        use dreamwell_engine::input::VirtualKey;
                        const DEADZONE: f32 = 0.2;
                        use gilrs::Axis;
                        if let Some((_id, gamepad)) = self.gilrs.gamepads().next() {
                            let lx = gamepad.value(Axis::LeftStickX);
                            let ly = gamepad.value(Axis::LeftStickY);
                            if ly > DEADZONE {
                                self.input.fabric.key_down(VirtualKey::W);
                            }
                            if ly < -DEADZONE {
                                self.input.fabric.key_down(VirtualKey::S);
                            }
                            if lx < -DEADZONE {
                                self.input.fabric.key_down(VirtualKey::A);
                            }
                            if lx > DEADZONE {
                                self.input.fabric.key_down(VirtualKey::D);
                            }
                            if gamepad.is_pressed(gilrs::Button::South) {
                                self.input.fabric.key_down(VirtualKey::Space);
                            }
                            if gamepad.is_pressed(gilrs::Button::LeftTrigger2) {
                                self.input.fabric.key_down(VirtualKey::ShiftLeft);
                            }
                        }
                    }

                    // Consume orbit input BEFORE building InputPacket so camera_yaw is current.
                    self.camera_orbit_yaw += self.input.orbit_dx;
                    self.camera_orbit_pitch =
                        (self.camera_orbit_pitch + self.input.orbit_dy).clamp(MIN_PITCH, MAX_PITCH);
                    self.camera_target_distance =
                        (self.camera_target_distance - self.input.scroll_delta).clamp(MIN_CAMERA_DIST, MAX_CAMERA_DIST);

                    // Build binding-aware InputFrame → InputPacket (single canonical path).
                    // coherence_current is the smoothly-lerped value (lerped inside sim.tick
                    // last frame). This gives the encoder a gradual transition, not a hard snap.
                    let frame = self.input.fabric.build_frame();
                    let packet = dreamwell_engine::input::InputPacket::from_frame(
                        &frame,
                        self.camera_orbit_yaw,
                        dt_secs,
                        sim.elapsed_time as f64,
                        sim.tick + 1,
                        sim.encoder.as_ref().map(|e| e.kernel().grounded).unwrap_or(true),
                        sim.coherence_current,
                        sim.gather_active,
                        sim.emit_strength,
                    );

                    // Smooth zoom: lerp actual distance toward target for buttery scroll feel.
                    let zoom_t = 1.0 - (-ZOOM_LERP_RATE * dt_secs).exp();
                    self.camera_distance += (self.camera_target_distance - self.camera_distance) * zoom_t;

                    if sim.frame == 0 {
                        log::info!(
                            "Sim pre-tick: input_enabled={} readiness={:?} encoder={} movement=[{:.2},{:.2}]",
                            sim.input_enabled(),
                            sim.readiness,
                            sim.encoder.is_some(),
                            packet.movement[0],
                            packet.movement[1],
                        );
                    }
                    if let Some(result) = sim.tick(&packet) {
                        if sim.frame <= 3 || sim.frame % 600 == 0 {
                            log::info!(
                                "Sim tick #{}: pos=[{:.2},{:.2},{:.2}] mode={} bridge={}",
                                sim.frame,
                                result.position[0],
                                result.position[1],
                                result.position[2],
                                result.locomotion_mode,
                                sim.last_bridge_packet.is_some(),
                            );
                        }
                        // Sync kernel result back to game state for GPU upload.
                        self.game_state.player_position = glam::Vec3::from_array(result.position);
                        if result.layer_changed {
                            if let Some(layer) = TopologyLayer::from_u8(result.topology_layer) {
                                self.game_state.active_layer = layer;
                            }
                        }
                        // Sync scene from simulation (mutations applied by DreamGate).
                        self.scene.game_objects = sim.scene.clone();

                        // POI interaction + collision dispatch.
                        sim.tick_collisions();
                        sim.tick_poi_interactions();

                        // Chase camera: third-person over-shoulder follow.
                        // Sprint pull-back: widen the view slightly while sprinting.
                        let sprint_extra = if packet.sprint { SPRINT_PULL_BACK } else { 0.0 };
                        let effective_dist = self.camera_distance + sprint_extra;

                        // Use encoder kernel if available, else fall back to direct kernel.
                        let kernel_pos = sim
                            .encoder
                            .as_ref()
                            .map(|e| e.kernel().position)
                            .or_else(|| sim.kernel.as_ref().map(|k| k.position));
                        if let Some(kpos) = kernel_pos {
                            let pos = glam::Vec3::from_array(kpos);
                            let yaw = self.camera_orbit_yaw;
                            let pitch = self.camera_orbit_pitch;

                            // Spherical offset: pitch controls elevation, yaw controls azimuth.
                            // cos(pitch) = horizontal distance factor, sin(pitch) = height factor.
                            let horiz = pitch.cos() * effective_dist;
                            let height = pitch.sin() * effective_dist;
                            let offset = glam::Vec3::new(
                                -yaw.cos() * horiz + yaw.sin() * SHOULDER_OFFSET,
                                height,
                                -yaw.sin() * horiz - yaw.cos() * SHOULDER_OFFSET,
                            );
                            let target_cam_pos = pos + offset;
                            // Exponential smoothing: alpha = 1 - e^(-rate * dt).
                            // Frame-rate independent — identical behavior at 30/60/144fps.
                            let pos_t = 1.0 - (-CAMERA_POSITION_LERP_RATE * dt_secs).exp();
                            let look_t = 1.0 - (-CAMERA_LOOKAT_LERP_RATE * dt_secs).exp();
                            self.scene.camera.position = self.scene.camera.position.lerp(target_cam_pos, pos_t);
                            self.scene.camera.center = self
                                .scene
                                .camera
                                .center
                                .lerp(pos + glam::Vec3::Y * LOOKAT_HEIGHT, look_t);
                            // Recompute view matrix from updated position/center.
                            // Without this, shaders use the stale default VP matrix.
                            self.scene.camera.update_view_matrix();
                        }

                        // Bridge packet is produced inside sim.tick() and consumed in Phase 5c.
                    }
                }

                // Phase 5b: Audio tick — mixer update, not render pass (feature-gated).
                #[cfg(feature = "audio")]
                {
                    let _ = &self.audio;
                }

                // Phase 5c: Consume pre-bridged packet from SimulationService.
                // The bridge was already called in sim.tick(), so we just consume the packet.
                let mut decoder_handled = false;
                if let (Some(ref mut sim), Some(ref mut decoder), Some(r)) =
                    (&mut self.simulation, &mut self.decoder, &mut self.renderer)
                {
                    if let Some(ref packet) = sim.last_bridge_packet {
                        let input = DecoderInput::from_bridge_packet(packet);
                        decoder.submit(&mut r.fabric, &input);
                        decoder_handled = true;
                    }
                }

                // Phase 6: UpdatePresentation — rebuild render-facing interpolated state
                // (currently handled by game_state.update above)

                // Phase 7: AssembleFrame — prepare observer context + render packet
                let dt = self.timer.delta_time();
                let player_pos = self.game_state.player_position();
                let active_layer = self.game_state.active_layer();

                // Phase 7: AssembleFrame — observer context from game state.
                // The bridge packet (Phase 5c) is the sole source of GPU state.
                // No fallback path — if the bridge didn't produce a packet, GPU uses last-frame state.
                let _ = decoder_handled;

                // Phase 8: Render — submit DreamFabric frame
                if let (Some(ws), Some(r)) = (&self.window_state, &mut self.renderer) {
                    r.render(ws, &self.scene, dt, player_pos, active_layer);
                }

                // Phase 9: DrainSync — drain sync packet and enqueue outgoing work
                if let Some(r) = &mut self.renderer {
                    self.sync_packet.clear();
                    r.fabric.drain_sync(&mut self.sync_packet);
                    if !self.sync_packet.intents.is_empty() {
                        self.authority.submit_intents(&self.sync_packet.intents);
                    }
                }

                // End-of-frame input cleanup
                self.input.end_frame();

                // Request next frame
                if let Some(ws) = &self.window_state {
                    ws.window.request_redraw();
                }
            }
            _ => {}
        }
    }
}