atomising item use: ItemEquipSystem{} and remove system tweak

src/inventory/equip_system.rs

@@ -0,0 +1,91 @@
+use super::{
+    gamelog, EquipmentChanged, Equippable, Equipped, InBackpack, MagicItem, MasterDungeonMap, Name, ObfuscatedName,
+    WantsToUseItem,
+};
+use crate::gui::{item_colour_u8, obfuscate_name};
+use specs::prelude::*;
+
+pub struct ItemEquipSystem {}
+
+impl<'a> System<'a> for ItemEquipSystem {
+    #[allow(clippy::type_complexity)]
+    type SystemData = (
+        ReadExpect<'a, Entity>,
+        Entities<'a>,
+        WriteStorage<'a, WantsToUseItem>,
+        ReadStorage<'a, Name>,
+        ReadStorage<'a, Equippable>,
+        WriteStorage<'a, Equipped>,
+        WriteStorage<'a, InBackpack>,
+        WriteStorage<'a, EquipmentChanged>,
+        ReadStorage<'a, MagicItem>,
+        ReadStorage<'a, ObfuscatedName>,
+        ReadExpect<'a, MasterDungeonMap>,
+    );
+
+    #[allow(clippy::cognitive_complexity)]
+    fn run(&mut self, data: Self::SystemData) {
+        let (
+            player_entity,
+            entities,
+            mut wants_to_use_item,
+            names,
+            equippable,
+            mut equipped,
+            mut backpack,
+            mut dirty,
+            magic_items,
+            obfuscated_names,
+            dm,
+        ) = data;
+        let mut remove: Vec<Entity> = Vec::new();
+        // For every item with a target, if the item is equippable, find the correct slot.
+        for (target, wants_to_use_item) in (&entities, &wants_to_use_item).join() {
+            if let Some(can_equip) = equippable.get(wants_to_use_item.item) {
+                let target_slot = can_equip.slot;
+                let mut logger = gamelog::Logger::new();
+
+                // Remove any items target has in item's slot
+                let mut to_unequip: Vec<Entity> = Vec::new();
+                for (item_entity, already_equipped, _name) in (&entities, &equipped, &names).join() {
+                    if already_equipped.owner == target && already_equipped.slot == target_slot {
+                        to_unequip.push(item_entity);
+                    }
+                }
+                for item in to_unequip.iter() {
+                    equipped.remove(*item);
+                    backpack.insert(*item, InBackpack { owner: target }).expect("Unable to insert backpack");
+                    if target == *player_entity {
+                        logger = logger
+                            .append("You remove your")
+                            .append_n(obfuscate_name(*item, &names, &magic_items, &obfuscated_names, &dm, None).0)
+                            .colour(item_colour_u8(*item, &names, &magic_items, &dm))
+                            .period();
+                    }
+                }
+
+                // Wield the item
+                equipped
+                    .insert(wants_to_use_item.item, Equipped { owner: target, slot: target_slot })
+                    .expect("Unable to insert equipped component");
+                backpack.remove(wants_to_use_item.item);
+                if target == *player_entity {
+                    logger = logger
+                        .append("You equip the")
+                        .append_n(
+                            obfuscate_name(wants_to_use_item.item, &names, &magic_items, &obfuscated_names, &dm, None)
+                                .0,
+                        )
+                        .colour(item_colour_u8(wants_to_use_item.item, &names, &magic_items, &dm))
+                        .period();
+                    logger.log();
+                }
+                remove.push(target);
+            }
+        }
+        remove.iter().for_each(|e| {
+            dirty.insert(*e, EquipmentChanged {}).expect("Unabble to insert EquipmentChanged");
+            wants_to_use_item.remove(*e).expect("Unable to remove *e");
+        })
+    }
+}