Add Inventory system with Inventory, InventorySlot, and StatModifierItem classes; update character attributes to include level and experience

Assets/Scripts/Inventory/Inventory.cs

@@ -0,0 +1,66 @@
+using System.Collections.Generic;
+using Sirenix.Serialization;
+using UnityEngine;
+
+namespace Inventory
+{
+    public class Inventory : MonoBehaviour
+    {
+        [OdinSerialize, SerializeField] private List<InventorySlot> weaponSlots = new();
+        [OdinSerialize, SerializeField] private List<InventorySlot> itemSlots = new();
+        
+        public IReadOnlyList<InventorySlot> WeaponSlots => weaponSlots.AsReadOnly();
+        public IReadOnlyList<InventorySlot> ItemSlots => itemSlots.AsReadOnly();
+        
+        public void AddWeapon(WeaponItem weaponItem)
+        {
+            foreach (var slot in weaponSlots)
+            {
+                if (slot.item == weaponItem) return;
+            }
+            
+            weaponSlots.Add(new InventorySlot { item = weaponItem, quantity = 1 });
+        }
+        
+        public void AddItem(ScriptableObject item)
+        {
+            foreach (var slot in itemSlots)
+            {
+                if (slot.item != item) continue;
+                
+                slot.quantity++;
+                return;
+            }
+            
+            itemSlots.Add(new InventorySlot { item = item, quantity = 1 });
+        }
+        
+        public void RemoveWeapon(WeaponItem weaponItem)
+        {
+            for (var i = 0; i < weaponSlots.Count; i++)
+            {
+                if (weaponSlots[i].item != weaponItem) continue;
+                
+                if (--weaponSlots[i].quantity <= 0)
+                {
+                    weaponSlots.RemoveAt(i);
+                }
+                return;
+            }
+        }
+        
+        public void RemoveItem(ScriptableObject item)
+        {
+            for (var i = 0; i < itemSlots.Count; i++)
+            {
+                if (itemSlots[i].item != item) continue;
+                
+                if (--itemSlots[i].quantity <= 0)
+                {
+                    itemSlots.RemoveAt(i);
+                }
+                return;
+            }
+        }
+    }
+}