inventory finishes

src/inventory_system.rs

@@ -1,4 +1,7 @@
-use super::{gamelog::GameLog, CombatStats, InBackpack, Name, Position, Potion, WantsToDrinkPotion, WantsToPickupItem};
+use super::{
+    gamelog::GameLog, CombatStats, InBackpack, Name, Position, Potion, WantsToDrinkPotion, WantsToDropItem,
+    WantsToPickupItem,
+};
 use specs::prelude::*;
 
 pub struct ItemCollectionSystem {}
@@ -66,3 +69,41 @@ impl<'a> System<'a> for PotionUseSystem {
         wants_drink.clear();
     }
 }
+
+pub struct ItemDropSystem {}
+
+impl<'a> System<'a> for ItemDropSystem {
+    #[allow(clippy::type_complexity)]
+    type SystemData = (
+        ReadExpect<'a, Entity>,
+        WriteExpect<'a, GameLog>,
+        Entities<'a>,
+        WriteStorage<'a, WantsToDropItem>,
+        ReadStorage<'a, Name>,
+        WriteStorage<'a, Position>,
+        WriteStorage<'a, InBackpack>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (player_entity, mut gamelog, entities, mut wants_drop, names, mut positions, mut backpack) = data;
+
+        for (entity, to_drop) in (&entities, &wants_drop).join() {
+            let mut dropper_pos: Position = Position { x: 0, y: 0 };
+            {
+                let dropped_pos = positions.get(entity).unwrap();
+                dropper_pos.x = dropped_pos.x;
+                dropper_pos.y = dropped_pos.y;
+            }
+            positions
+                .insert(to_drop.item, Position { x: dropper_pos.x, y: dropper_pos.y })
+                .expect("Failed to insert position.");
+            backpack.remove(to_drop.item);
+
+            if entity == *player_entity {
+                gamelog.entries.push(format!("You drop the {}.", names.get(to_drop.item).unwrap().name));
+            }
+        }
+
+        wants_drop.clear();
+    }
+}