Split crate into shared logic library and binary crate (#52)

crates/shared/src/backpack/mod.rs

@@ -0,0 +1,61 @@
+mod backpack_ui;
+mod ui_head_state;
+
+use crate::{
+    cash::CashCollectEvent, global_observer, head_drop::HeadCollected, heads::HeadState,
+    heads_database::HeadsDatabase,
+};
+pub use backpack_ui::BackpackAction;
+use bevy::prelude::*;
+pub use ui_head_state::UiHeadState;
+
+#[derive(Resource, Default)]
+pub struct Backpack {
+    pub heads: Vec<HeadState>,
+}
+
+impl Backpack {
+    pub fn reloading(&self) -> bool {
+        for head in &self.heads {
+            if !head.has_ammo() {
+                return true;
+            }
+        }
+
+        false
+    }
+
+    pub fn contains(&self, head_id: usize) -> bool {
+        self.heads.iter().any(|head| head.head == head_id)
+    }
+
+    pub fn insert(&mut self, head_id: usize, heads_db: &HeadsDatabase) {
+        self.heads.push(HeadState::new(head_id, heads_db));
+    }
+}
+
+#[derive(Event)]
+pub struct BackbackSwapEvent(pub usize);
+
+pub fn plugin(app: &mut App) {
+    app.init_resource::<Backpack>();
+
+    app.add_plugins(backpack_ui::plugin);
+
+    global_observer!(app, on_head_collect);
+}
+
+fn on_head_collect(
+    trigger: Trigger<HeadCollected>,
+    mut cmds: Commands,
+    mut backpack: ResMut<Backpack>,
+    heads_db: Res<HeadsDatabase>,
+) {
+    let HeadCollected(head) = *trigger.event();
+
+    if backpack.contains(head) {
+        cmds.trigger(CashCollectEvent);
+    } else {
+        backpack.insert(head, heads_db.as_ref());
+    }
+}