1 files changed, 82 insertions, 0 deletions
diff --git a/src/preload/mod.rs b/src/preload/mod.rs
new file mode 100644
index 0000000..b90db38
--- /dev/null
+++ b/src/preload/mod.rs
@@ -0,0 +1,82 @@
+use crate::cache::DirworldCache;
+use crate::{
+    components::DirworldEntity,
+    resources::{DirworldCodecs, DirworldObservers, EntryType},
+    utils::extract_entity_payload,
+    Extensions,
+};
+use bevy::prelude::*;
+use std::{collections::HashMap, path::PathBuf};
+
+mod systems;
+
+mod resources;
+pub use resources::*;
+
+mod events;
+pub use events::DirworldPreload;
+
+pub(crate) struct DirworldPreloadPlugin;
+
+impl Plugin for DirworldPreloadPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            PostUpdate,
+            systems::handle_preload.run_if(in_state(PreloadState::Loading)),
+        )
+        .add_systems(OnEnter(PreloadState::Done), systems::handle_spawn)
+        .init_resource::<RoomAssets>()
+        .init_state::<PreloadState>();
+    }
+}
+
+/// State of asset preloading
+#[derive(States, Debug, Clone, PartialEq, Eq, Hash, Default)]
+pub enum PreloadState {
+    /// Indicates assets are in the process of loading
+    #[default]
+    Loading,
+    /// Indicates all room assets are finished loading, i.e. all assets are loaded with
+    /// dependencies
+    Done,
+}
+
+/// Initiates loading of an asset
+// TODO: Make into a command extension
+pub fn load_entity(
+    entry: &PathBuf,
+    cache: &mut DirworldCache,
+    codecs: &DirworldCodecs,
+    observers: &DirworldObservers,
+    commands: &mut Commands,
+    preload_state: &mut NextState<PreloadState>,
+    room_assets: &mut RoomAssets,
+) {
+    let (mut payload, data) = extract_entity_payload(&entry, &codecs);
+    payload = payload.map(|p| cache.get_entity_cache(&entry).unwrap_or(p));
+    let entry_type = if entry.is_dir() {
+        EntryType::Folder
+    } else {
+        EntryType::File(entry.extensions())
+    };
+    let transform = payload
+        .as_ref()
+        .map(|payload| payload.transform.clone())
+        .unwrap_or_default();
+    let entity = commands
+        .spawn((
+            *transform,
+            Visibility::Inherited,
+            DirworldEntity {
+                path: entry.clone(),
+                payload,
+            },
+        ))
+        .id();
+    if let Some(observer) = observers.get(&entry_type) {
+        preload_state.set(PreloadState::Loading);
+        room_assets.insert(entry.clone(), HashMap::default());
+        commands.trigger_targets(DirworldPreload { entity, data }, observer.clone());
+        info!("Triggered preload for {entry:?}");
+    }
+}